Bioinspired and biointegrated materials as frontiers nanomaterials VI

Resume : Design, formation smart nanomaterials as a biocompatible, responded at cells signals and their biointerfaces can be сreate by bioinspired engineering what this 20 September Session presentations demonstrate.. Creative innovative nanomaterials functions for Bio -, Nano -medicine applications have been studied.

Resume : Advances of bioelectronics towards high-resolution communication and long-term implantation are reaching limitations of traditional materials such as metals and silicone. An ideal electronic material integrating softness, biofunction and low impedance is desired to meet the required biocompatibility, and electrical trade-offs for interfacing with cells/tissues. Toward this aim, we developed a series of biomimetic conducting polymer from zwitterionic and cell-targeted ethylenedioxythiophenes (EDOTs), which specifically interact with cells on a protein-resistance background. The predominant presence of zwitterionic side-groups on surface prevent enzyme and cell binding, allowing the polymers to functionalize in aqueous buffer for an extended period of time and preventing nonspecific interaction. The cell-targeted peptides, proteins or polymer chains on surface ensure specific interaction with desired cells. The further introduction of stimuli-responsive bio-conjugation linkage or polymer chains allows a stimuli-responsive cell capture and release, which could be used to build noninvasively removed bioelectronic devices or cell-detachable sensors. The most recent achievement is to construct a 3D specific recognition network for the biomimetic PEDOT, which could make electrode interact specifically with more neurons, and communicate more efficiently with nerve tissues. Combining the molecular design features, all these materials demonstrated an intimate, stable and efficient electrical interfacing with targeted cells. It is ensured by the integration of nonspecific-binding resistance, specific (static, dynamic or 3D) interaction and low-impedance communication. [1] H.-A. Lin, B. Zhu, Y.-w. Wu, J. Sekine, A. Nakao, S.-C. Luo, Y. Yamashita, H.-h. Yu submitted. [2] B. Zhu, S.-C. Luo, H. Zhao, H.-A. Lin, J. Sekine, A. Nakao, C. Chen, Y. Yamashita, H.-h. Yu Nat. Commun. 2014, 5:4523. [3] H.-A. Lin, S.-C. Luo, B. Zhu, Y. Yamashita, H.-h. Yu Adv. Funct. Mater. 2013, 23, 3212.

Resume : Biodegradable and biocompatible elastomers (bioelastomers) could resemble the mechanical properties of extracellular matrix and soft tissues, thus, are very useful for many biomedical applications. Despite the significant advances, tunable bioelastomers with easy processing, facile biofunctionalization, and withstand mechanically dynamic environment has remained elusive. Here, we reported new dynamic hydrogen-bond crosslinked PSeD-U bioelastomers possessing aforementioned features by grafting 2-ureido-4[1H]-pyrimidinones (UPy) units with strong self-complementary quadruple hydrogen bonds to poly(sebacoyl diglyceride) (PSeD),[1] a refined version of a widely used bioelastomer poly(glycerol sebacate) (PGS). PSeD-U polymers exhibited strong mechanical strength than their counterparts of chemically crosslinked PSeD, and tunable elasticity by simply varying the content of UPy units. In addition to good biocompatibility and biodegradability as PSeD, PSeD-U showed fast self-healing (within 30 min) at mild conditions (60 oC) and could be readily processing at moderate temperature (100 oC) or using solvent casting at room temperature. Furthermore, the free hydroxyl groups of PSeD-U enabled facile functionalization.

Resume : Controllable drug release and effective intracellular accumulation highlighted by anisotropic biodegradable PLGE nanoparticles Jun-Bing Fan Laboratory of Bio-inspired Smart Interface Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190 (P. R. China); Email: fjb2012@mail.ipc.ac.cn The continuing interest in colloidal polymer nanoparticles, poses questions toward their special properties, such as shape or surface chemistry, which would eventually lead to special applications in healthcare fields. Theoretical calculation and fundamental research indicate that colloidal nanoparticles with anisotropic shape or surface chemistry have superiorities over spherical particles. Here, taking the morphology and biocompatibility of polymer particles into consideration, a series of anisotropic amphiphilic biocompatible and biodegradable PLGE nanoparticles with tuneable length/width aspect ratio (AR) can be synthesized from spherical PLGE nanoparticles by a simple film stretching/compressing method. The anisotropic morphologies include ellipsoids, rods, spherical and elliptical disks. The morphology of the synthesized anisotropic nanoparticles was stable enough when they were treated at body temperature. The drug release, endocytosis and intracellular accumulation test of anisotropic PLGE nanoparticles show significantly enhanced properties in comparison with spherical nanoparticles, indicating they are good candidates for drug delivery.

Resume : Circulating tumor cells (CTCs) have become an emerging ?biomarker? for monitoring cancer metastasis and prognosis. Although there are existing technologies available for isolating/counting CTCs, the most common of which using immunomagnetic beads, they are limited by their low capture efficiencies and low specificities. By introducing a three-dimensional (3D) nanostructured substrate ? specifically, a silicon-nanowire (SiNW) array coated with anti-EpCAM ? we can capture CTCs with much higher efficiency and specificity. The conventional methods of isolating CTCs depend on biomolecular recognitions, such as antigen-antibody interaction. Unlikely, we here proposed that nanoscaled local topographic interactions besides biomolecular recognitions inspired by natural immuno-recognizing system. This cooperative effect of physical and chemical issues between CTCs and substrate leads to increased binding of CTCs, which significantly enhance capture efficiency. Recently, we have also developed a 3D cell capture/release system triggered by aptamer enzyme, electrical potential and Temperature, which is effective and of ?free damage" to capture and release cancer cells. The bio-inspired interfaces of cell capture and release open up a light to rare-cell based diagnostics, such as CTCs, fetal cells, stem cell and so on. References [1] Huang, C.; Yang, G.; Ha, Q.; Meng, J.; Wang, S. T.* Adv. Mater. 2015, 27, 310-313. [2].Liu, X.; Wang, S. T.* Chem. Soc. Rev. 2014, 43, 2385-2401 [3] Liu, H.; Li, Y.; Sun, K.; Fan, J.; Zhang, P.; Meng, J.; Wang, S. T.*; Jiang, L. J. Am. Chem. Soc. 2013, 135, 7603-7609

Resume : Near-infrared (NIR) laser-induced photothermal ablation therapy (PAT) has attracted increasing interest as a minimally invasive and potentially more effective technology for the treatment of cancers, and its prerequisite is to obtain biocompatible and efficient NIR photothermal nanoagents. To address this problem, we have used hydrophilic polymer as surface ligands to prepare several semiconductor nanoagents, including CuS superstructures[1], W18O49 nanowires[2] and CsxWO3 nanorods[3]. Their aqueous dispersions exhibit intense absorbance in NIR region and excellent photothermal conversion performances. Importantly, if we inject aqueous dispersion into the tumor in mice, cancer cells in vivo can be efficiently ablated under the irradiation of 980 nm laser with a safe power density of (0.51-0.72 W/cm2) for ~10 min. Recently, by combing semiconductor nanoagents and thermosensitive polymer nanogels, we design and construct smart nanocapsules (G-CuS-DOX[4]) that can be switched by NIR-laser. The nanocapsules exhibit the controllable and efficient photothermal/chemotherapy effect compared with single PAT or chemotherapy effect for the tumor. Therefore, these inorganic-organic nanocomposites have great potential in NIR-PAT of tumor. [1] Tian, Q. W.; Tang, M. H.; Sun, Y. G.; Zou, R. J.; Chen, Z. G.; Zhu, M. F.; Yang, S. P.; Wang, J. L.; Wang, J. H.; Hu, J. Q. Adv. Mater. 2011, 23: 3542-3547. [2] (a) Chen, Z. G.; Wang, Q.; Wang, H. L.; Zhang, L. S.; Song, G. S.; Song, L. L.; Hu, J. Q.; Wang, H. Z.; Liu, J. S.; Zhu, M. F.; Zhao, D. Y. Adv. Mater. 2013, 25: 2095-2100; (b) Xu, W.; Tian, Q.; Chen, Z.; Xia, M.; Macharia, D. K.; Sun, B.; Tian, L.; Wang, Y.; Zhu, M. J. Mater. Chem. B 2014, 2: 5594 - 5601. [3] Xu, W.; Meng, Z.; Yu, N.; Chen, Z.; Sun, B.; Jiang, X.; Zhu, M. RSC Adv. 2015, 5: 7074-7082. [4] Meng, Z.; Wei, F.; Wang, R.; Xia, M.; Chen, Z.; Wang, H.; Zhu, M. Adv. Mater. 2016, 28: 245-253.

Resume : Here we present a novel fabrication approach for producing three-dimensional (3D) conducting polymer-based bioelectronic interfaces (BEIs) that can be integrated on electronic devices for rare circulating tumor cell (CTC) isolation, detection, and collection via an electrically triggered cell released from chips. Based on the chemical oxidative polymerization of carboxylic acid?modified 3,4-ethylenedioxythiophene and modified poly(dimethylsiloxane) (PDMS) transfer printing technology, the high-aspect-ratio structures of poly(3,4-ethylenedioxythiophene) (PEDOT)-based "nanorod" arrays can be fabricated on indium tin oxide (ITO) electrodes when using the Si "microrod" arrays as masters. Furthermore, we integrated the biotinylated poly-(L)-lysine-graft-poly-ethylene-glycol (PLL-g-PEG-biotin) coating with 3D PEDOT-based BEIs for dynamic control of the capture/release performance of CTCs on chips; this combination exhibited an optimal cell-capture yield cells of ~ 45000 cells cm?2 from EpCAM-positive MCF7 while maintaining resistance from the adhesion of EpCAM-negative Hela cells at a density of ~4000 cells cm?2. By taking advantage of electrochemical doping/dedoping properties of PEDOT materials, the captured CTCs can be triggered to electrically release through the desorption phenomena of PLL-g-PEG-biotin. More than 90% of the captured cells can be released while maintaining very high cell viability. Therefore, it is conceivable that use of a 3D PEDOT-based BEI platform will meet the requirements for the development of downstream characterization of CTCs, as well as the next generation of bioelectronics for biomedical applications.

Resume : Now it is a well-known fact that 3D cell culture systems are better representation of in-vivo situation as compare to traditional 2D systems. Therefore, modern life science demands for new generation of cell cultivation systems replicating the 3D architecture not only on arbitrary bulk scale but also until precise microfluidic and cellular level. Using modern methods in microsystem technology in combination with latest advancement in stimuli responsive bio inspired surfaces, is promoting the development of a promising toolbox for modeling biological systems. The core problem to solve using this toolbox is the design of 3D artificial cellular environments, both in fluidic systems and on solid substrates. The construction of 3D cell cultures on substrates involves various fabrication techniques which use different polymers and biopolymers processed by micromachining, stimuli responsive bio inspired surfaces, photopolymerization, and organ printing methods. These methods together have the potential to create an artificial system with the complete hierarchical, geometrical, and functional organization found in an actual biological system [1]. Starting from our work concerning 3D cultivation as a first step towards more biological modelling of cellular environments [2] we performed different studies concerning the use of such systems as pharmacological test platforms [3], the different genetic behavior of the cells in 2D and 3D [4], different structuring techniques [5, 6] towards the integration of different organ like systems on one chip [7]. In this contribution we will explain our approach to gain complex cellular structures while using chemical and mechanical modification of thin polymer foils. We invented folding and stacking of this pre manufactured cell sheet layers, which makes the formation of complex cellular and fluidic entities like in real tissue possible[8]. Our approach to develop photo responsive biocompatible surfaces is an added advantage to fine tune the surface properties until submicron [9]. We will discuss the different methods of designing complex cellular structures such as liver lobe. Open questions of co-cultivation different cell types, structuring Disse space like areas and the methods thereof will be analyzed and conclusions are given. [1] A. Schober, U. Fernekorn, S. Singh, G. Schlingloff, M. Gebinoga, J. Hampl, A. Williamson, ?Biotechnical multi-scale engineering mimicking the biological world ?, Eng. Life Sci. 2013, 13, 352?367;[2] A. Schober, C. Augspurger, G. Schlingloff, M. Gebinoga, M. Worgull, M. Schneider, C. Hildmann, U. Fernekorn, F. Weise, J. Hampl, L. Silveira, I. Cimalla, B. Lübbers, ?Microfluidics and Biosensors as Tools for NanoBioSystems research with applications in the Life Science?, Materials Science and Engineering: B 169 (2010), 174-181;[3] U. Fernekorn, J. Hampl, F. Weise, C. Augspurger, C. Hildmann, M. Klett, A. Läffert, M. Gebinoga, K.F. Weibezahn, G. Schlingloff, M. Worgull, M. Schneider, A. Schober, Microbioreactor design for 3-D cell cultivation to create a pharmacological screening system; Eng. Life Sci. 2011, 11, No. 2, 133-139;[4] Fernekorn U., Hampl, J., Augsburger C., Hildmann Ch., Weise F., Klett M., Läffert A., Gebinoga M., Williamson A, Schober A., In vitro cultivation of biopsy derived primary hepatocytes leads to a more metabolic genotype in perfused 3D scaffolds than static 3D cell culture, RSC Adv., 2013, 3, 16558-16568;[5] M. Gebinoga, J. Katzmann, U. Fernekorn, J. Hampl, F.Weise, M. Klett, A. Läffert, T. Klar, A. Schober, ?Multiphoton structuring of native polymers: A case study for structuring natural proteins?, Eng. Life Sci. 2013, 13,, Issue 4, pages 368?375;[6] J. Tobola, Schober et al. ?Thermoforming techniques for manufacturing porous scaffolds for application in 3D cell cultivation? Materials Science and Engineering: C, 2015, 49, 509-516;[7] Williamson A., Singh S., Fernekorn U., Schober A., The future of the patient-specific Body-on-a-chip, Lab Chip, 2013, 13, 3471-3480 [8] A. Schober, J. Hampl et al. ?Formkörper zur Nachbildung einer Struktur eines biologischen Gewebes und Verfahren zu dessen Herstellung" DE 10 2014 112 660.2 [9] S. Singh, Schober et al Spatiotemporal Photopatterning on Polycarbonate Surface through Visible Light Responsive Polymer Bound DASA Compounds, 2015, 4, 1273-1277.

Resume : Adipose- derived stem cells (ADSCs) are a recently-discovered type of mesenchymal stem cells (MSCs). MSCs are widely used for differentiation to tissues and cells such as blood cells, bone and muscle. Up until recently, the most common type of MSCs for clinical application were Bone Marrow-derived MSCs (BM-MSCs). Although BM-MSCs and ADSCs are similar in nature, ADSCs possess the superior capability of being easier to harvest: In the case of BM-MSCs, the procedure is more invasive and requires penetration of the hipbone. On the other hand, ADSCs can be obtained in a safer way and larger amounts, by using subcutaneous fat tissue. This makes them far more applicable in cases where invasive surgery is not an option, such as on infants and young children. ADSCs are able to differentiate into a range of cell types, such as bone, chondrocytes and neurons. Due to their accessibility, ADSCs are a particularly attractive solution for the correction of congenital defects, such as craniofacial defects using autologous grafts. Autologous grafts are the Holy Grail of tissue engineering and regenerative medicine, as they are mitigating the risk of rejection, because they are derived from the patients own body. In the past, the interaction between human Neural Stem Cells (hNSCs) and nanodiamonds (NDs) has been widely investigated. NDs possess great biocompatibility properties and they have been shown to interact particularly well with hNSCs. Early in vitro results have also shown compatibility with ADSCs. In proof-of-concept experiments, Oxygen-terminated NDs have been shown to function as a more efficient environment for the proliferation and differentiation of ADSCs than other types of ND-based microenvironments, creating optimal conditions for the development of a range of tissues potentially both in vitro and in vivo.

Resume : Organic electronics has a remarkable potential for the development of electronic products that are non-toxic, environmentally friendly, and biodegradable. A desirable solution for the fabrication of such devices involves the selection of natural origin materials, or alternatively of synthetic derivatives of natural origin materials that have been proved to be biodegradable and/or biocompatible. We continued our investigations on biomolecules for organic electronics applications by careful investigating naturally-extracted resins, waxes and gums. We analyzed the processibility, film forming characteristics, surface morphology, resistance to degradation and dielectric properties of various grades of natural Shellac as well as other resins as for example copal, amber, elemi, guggul, damar, sandarac, pine, mastic, rosin, frankincense, and myrrh, to name a few. Various naturally occurring waxes as beeswax, carnauba and paraffin, as well as naturally occurring gums were part of our investigation for both substrate and dielectric layers of organic electronic devices. We also investigated aqueous Shellac (Norelac) obtained from our partner and distributor in Germany. Flexible films of Shellac were cast and their flexibility exploited for substrates in the fabrication of organic electronic devices. We demonstrate that flexibility is preserved even when exposed up to 30 minutes to temperature approaching 200 deg. C. Such substrates are ideal for the fabrication of electronics that require post-fabrication heat treatment of the active layers in order to increase their performance (e.g. metal oxides semiconductors, bulk-heterojunction solar cells, etc). We have demonstrated fully-biodegradable devices featuring natural substrate and dielectric Shellac and naturally occurring semiconducting layers (Indigo, Tyrian Purple) and showed that the success of implementing these novel class of ?green? technologies to field effect transistors could be successfully extended to organic photovoltaic field.

Resume : Bones have been shown to exhibit piezoelectric properties, responding to electrical stimulation and generating electrical potential upon mechanical deformation. Thus, significant research has been devoted to study the effects of electrical stimulation on bone tissue engineering. However, in bone regeneration applications, only few studies have focused on the use of electroactive 3D biodegradable scaffolds and the effects on stem cells compatibility. We describe a method to combine the bone regeneration capabilities of 3D-printed macroporous medical grade polycaprolactone (PCL) scaffolds with the electrical and electrochemical capabilities of the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT). We report on a protocol we developed for scaffolds functionalization with PEDOT, using vapor-phase polymerization, resulting in a conformal conducting layer surrounding scaffolds features. Scaffolds? porosity as well as mechanical stability, important for in vivo bone regeneration applications, are retained. Human fetal mesenchymal stem cells proliferation is assessed on the functionalized scaffolds, showing the cytocompatibility of the polymeric coating. These preliminary results pave the way to further studies on the combined effects of electrical and topographical cues in bone tissue regeneration applications Acknowledgements: This research has been funded by Knut and Alice Wallenberg foundation and the Nanyang Technological University Internal Funding.

Resume : Successful bioelectronics should rely on an active material that is biocompatible and interfaces intimately with cells. We report on biocompatible hydrogen-bonded semiconductor nanostructured crystals for cellular photostimulation. The biomimetic hierarchical crystals show impressive affinity for cellular coupling and efficient stimulation. The close interface between the nanostructured crystals and cells was elucidated using electron microscopy. Light irradiation was found to elicit a reversible electrophysiological response, measured using patch-clamp microelectrochemistry, only in cells that grow in contact with the nanostructured crystals. The mechanism of action was studied by investigating the effects of photoexcitation on specific ion channels. In total, three different types of ion channels and two types of cells were studied. We discuss the interplay between capacitive, faradaic, and thermal effects on cellular electrophysiology. Over the presented materials would be a potent candidate for cellular photostimulation, which is highly relevant to the new generation of wireless retinal implants.

Resume : G-quadruplexes are unique secondary DNA structures that have been proposed to play a regulatory role in cell biology [1] and are possible targets for anti-cancer drugs [2]. G-quadruplexes can also be utilized as a biocompatible structure in DNA nanotechnology, where DNA is used for building functional bottom-up synthetic nanostructures [3]. Here we employed single-molecule FRET microscopy to investigate the folding and underlying conformational dynamics of G-quadruplexes formed by the human telomeric sequence. Our experiments allowed detecting several folded states that are populated in the course of G-quadruplex folding. Combining single-molecule data with molecular dynamics simulations enabled obtaining a structural description of the experimentally observed folded states. Our work thus provides a comprehensive thermodynamic and kinetic description of the folding of G-quadruplexes that proceeds through a complex multi-route pathway, involving several intermediate conformational states. (1) Rhodes, D.; Lipps, H. J. Nucleic Acids Res. 2015, 43, 8627. (2) Balasubramanian, S.; Hurley, L. H.; Neidle, S. Nat Rev Drug Discov 2011, 10, 261. (3) Y. Krishnan and F. C. Simmel, Angew. Chem. Int. Ed. 2011, 50, 3124.

Resume : We present the growth of hybrid organic-inorganic thin-films with nano-scale Turing pattern textures. The films contain a bi-continuous network of the inorganic (ZnO) and organic (Rhodamine B), that mimics biological structures like brain coral, and many animal skin color patterns. This biomimicry is a direct result of the reaction-diffusion growth mechanism that governs the film morphology. This mechanism, mathematically described by Alan Turing, produces many of the biological patterns found in nature. We present a mathematical model that corresponds to the measured diffusion and catalytic reaction parameters of the two species system, adapted to the three dimensional film growth. The computational model and the experimentally grown films show strikingly similar morphology, with the key input parameter of Rhodamine B concentration having a deterministic variation on the resulting morphology. By varying the concentration across a critical threshold, we can produce films with Rhodamine B spots on a background of ZnO, ZnO spots on a background of Rhodamine B, and an inter-connected labyrinth pattern. Such films may prove useful for nano-scale filters, or for solar cells grown from solution in a low-energy fabrication similar to the growth of seashells.

Resume : Neural stem cells (NSCs) have great potential for inducing repair in damaged areas of the nervous system. NSCs have the ability to self-renew, but also are able to differentiate into neurons, oligodendrocytes and astrocytes, which are the main cells in the central nervous system (CNS). Understanding the differentiation into these cell lineages is critical for regenerative therapy treatment of diseases such as Parkinson?s and Alzheimer?s, as detailed knowledge of how these specific cells are affected by disease is vital(1) In order to utilise the potential of stem cells in the field of regenerative medicine, it is essential that we are able to isolate the cells from their natural setting, propagate the cells in culture, and introduce the cells to a foreign environment(2). Given the outstanding biocompatibility of nanodiamonds (NDs) towards neuronal cells(3), nanocrystalline diamond (NCD) towards hNSCs(4) and their excellent ability to promote neuronal cell adhesion and outgrowth, the proliferation and differentiation of human NSCs (hNSCs) and their relationship with functionalised ND coatings has been investigated. Firstly, the interaction of hNSCs with varying surface functionalised NDs is investigated; with Oxygen-terminated functionalised surfaces favouring the proliferation of hNSC, compared to those with a Hydrogen-terminated surface. Quantitative cell count data of the hNSCs has been determined on the varying functionalised NDs as well as glass and tissue culture polystyrene (TCPS), along with a contact angle investigation. Secondly ND surfaces of different functionalisation (H/O) are shown to influence the differentiation and proliferation of hNSCs in varying ways. hNSCs fate has been investigated via inducing and spontaneously differentiating the cells on varying nanodiamond substrates. 1. Lindvall O, Kokaia Z. Stem cells for the treatment of neurological disorders. Nature. Nature Publishing Group; 2006 Jun 29;441(7097):1094?6. 2. Scadden DT. The stem-cell niche as an entity of action. Nature. 2006 Jun 29;441(7097):1075?9. 3. Thalhammer A, Edgington RJ, Cingolani LA, Schoepfer R, Jackman RB. The use of nanodiamond monolayer coatings to promote the formation of functional neuronal networks. Biomaterials. 2010 Mar;31(8):2097?104. 4. Taylor AC, Vagaska B, Edgington R, Hebert C, Ferretti P, Bergonzo P, et al. Biocompatibility of nanostructured boron doped diamond for the attachment and proliferation of human neural stem cells. J Neural Eng. IOP Publishing; 2015 Dec 1;12(6):066016.

Resume : Films consisting of pristine- and nitrogen-doped multi-walled carbon nanotubes (further denoted as MWCNTs and N-MWCNTs, respectively) were fabricated by means of chemical vapor deposition technique and modified with gold nanoparticles (AuNPs) [1,2]. The scanning electron microscopic findings reveal that on surface of MWCNTs and N-MWCNTs films, AuNPs of different diameters are formed. The electrochemical responses of modified MWCNTs and N-MWCNTs films, further denoted as MWCNTs/AuNPs and N-MWCNTs/AuNPs, were initially investigated towards ferrocyanide/ferricyanide, [Fe(CN)6]3-/4- standard redox system in aqueous potassium chloride solutions. Within the two different types of films studied, N-MWCNTs/AuNPs reveals improved limit of detection towards [Fe(CN)6]3-/4- due probably to incorporated into nanotubes nitrogen that enhances its electrocatalytic activity [3,4]. Nevertheless, the findings demonstrate that the electrochemical response of both MWCNTs-based films noticeably enhances upon deposition of AuNPs onto their surface. Namely, the limit of detection of MWCNTs/AuNPs and N-MWCNTs/AuNPs towards [Fe(CN)6]3-/4- appears to be ~40% and ~20% smaller, respectively, compared to that of unmodified films. The results indicate that modifying the surface of MWCNTs-based films with AuNPs is crucial in improving their sensitivity. The AuNPs-modified MWCNTs-based films were successfully applied for the simultaneous analysis of ascorbic acid, uric acid, and dopamine. The obtained results exhibit that the nitrogen-doped MWCNTs-based films possess good performance for electrochemical oxidation of these biomolecules. [1] N.G. Tsierkezos, U. Ritter, J. Solid State Electrochem. 2010, 14, 1101. [2] N.G. Tsierkezos, U. Ritter, J. Nanosci. Lett. 2012, 2, 25 [3] P. Szroeder, N.G. Tsierkezos, P. Scharff, U. Ritter, Carbon 2010, 48, 4489. [4] N.G. Tsierkezos, U. Ritter, Chemical Sensors 2013, 3, 8

Resume : Plant-based polysaccharides such as cellulose and its derivatives are receiving increasing interest for a large variety of applications because they represent an environmentally friendly alternative to plastics. Many of them are commonly used in diverse industrial applications, such as food additives and for biomedical devices due to their non-toxic and water-soluble nature. Here, by a simple two-step procedure, large photonic strain sensors using a bio-compatible cellulose derivative are fabricated. A transient colour shift of the sensors is explained by deformation of cholesteric domains in agreement with our theoretical model. The extremely simple fabrication method is suitable for both miniaturisation and large-sale manufacture, taking advantage of inexpensive and sustainable materials.

Resume : Organic Electrochemical Transistors (OECTs) have been proposed as low cost chemical sensors for the detection of several analytes thanks to their remarkable features such as signal amplification, the use of an easy and cheap readout electronics, low supply voltage (usually < 1 V), low power operation (< 100 ?W), bio-compatibly, and, moreover, they can be easily miniaturized and adapted to non-flat or/and flexible devices. An OECT is composed by a stripe of conductive polymer that works as a channel, and by another electrode, usually a metal, that works as a gate. When the device is dipped in an electrolyte solution, the current flowing in the channel can be modulated through the gate voltage because it promotes electrochemical reactions that change the charge carrier concentration in the polymer and, consequently, its conductivity. Redox compounds can act on such processes by varying the doping degree of the conductive polymer, thereby changing the current density inside the channel. This contribution describes the development of sensors based on an OECT made only by poly(ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) as conductive material. The sensor was optimized by studying its response to different redox compounds of biological interest such as ascorbic acid, dopamine, adrenaline and uric acid. The bio-molecules react with PEDOT:PSS by extracting charge carriers from the transistor channel, and consequently an increase of analyte concentration leads to a decrease of the absolute value of the drain current. This variation results linear dependent on the logarithm of the bio-molecule concentration. The limit of detection is 10-8 M, much lower than the ones reported for common amperometric sensors. Such results demonstrate the potentiality of all-PEDOT OECTs as platform for developing chemical sensors for the detection of redox-active molecules. The main drawback of the device is presently the lack of selectivity which hinders its widespread use in real applications. To overcome this problem we have worked in two directions: on one side optimizing the OECT parameters as a function of the kinetics of reaction of the different analytes and, on the other side, introducing on the polymer chain functional groups able to selectively interact with the target analyte. The ?click chemistry? approach was exploited to link ferrocene to PEDOT chain. The procedure is easy and requires only two steps consisting of the electrodeposition of PEDOT-N3 followed by copper-catalyzed azide?alkyne cycloaddition of ethynylferrocene [1] E. Scavetta, R. Mazzoni, F. Mariani, R. G. Margutta, A. Bonfiglio, M. Demelas,S. Fiorilli, M. Marzocchi and B. Fraboni ?Dopamine amperometric detection at a ferrocene clicked PEDOT:PSS coated electrode? J.Mater.Chem B 2, 2861 (2014) [2] I. Gualandi, M. Marzocchi,E. Scavetta, M. Calienni, A. Bonfiglio, B. Fraboni: ?A simple all-PEDOT:PSS electrochemical transistor for ascorbic acid sensing? J. Materials Chemistry B 3, 6753-6762 (2015)

Resume : This contribution describes development of selective chemosensor with electrochemically deposited molecularly imprinted polymer (MIP) as recognition unit for determination of cystatin C. The cystatin C is a small, elliptical peptide composed of 120 amino acids belonging to the class II of cystatins. It is continuously synthesized in all cells of living organisms and then secreted to body fluids.1,2 It has been demonstrated that cystatin C is a very convenient biomarker for monitoring of kidneys functioning.3 It is almost completely destroyed in kidneys, therefore its elevated level in blood indicates their malfunctioning. Moreover, concentration of cystatin C in blood does not depend on sex, age, race or diet. Up to date, methods for determination of this biomarker are based on antigen-antibody interactions, which suffer from lack of stability and costly preparation of antibodies with sufficient purity. Therefore, from practical point of view, it would be interesting to devise a small, portable and selective chemosensor allowing for of cystatin C level in body fluids. To this end, a polymer imprinted with cystatin C has been deposited on the surface of the electrode by using electrochemically initiated radical polymerization. Deposition of polymer has been confirmed by differential pulse voltammetry (DPV) with use of redox probe, as well as IR spectroscopy. Morphology of the deposited film has been studied using AFM and formation of thin polymer film has been confirmed. Subsequently, DPV and capacitive impedimetry has been used to assess sensor performance. Bibliography: 1. V. Le?ai?, J. Med. Biochem., 29 (2010), 288. 2. E. Gorodkiewicz et al., Folia Histochem. Cytobiol., 50 (2012), 130. 3. G. Filler et al., Clin. Biochem., 38 (2005), 1.

Resume : Nature?s most vivid colours rely on the ability to produce complex and hierarchical photonic structures with lattice constants on the order of the wavelength of visible radiation. [1]. A recurring strategy design found both in the animal and plant kingdoms for producing such effects is the helicoidal architecture [2,3]. In such structures, a series of individual nano-fibers (made of natural polymers as cellulose and chitin) are arranged parallel to each other in stacked planes. When distance between such planes is comparable to the wavelength of light, a strong polarised, colour selective response can be obtained. These helicoidal multilayers are generally structured on the micro-scale and macroscopic scale, giving rise to hierarchical structures with a complex optical response. Mimicking natural architectures with natural polymers enables us to fabricate novel photonic structures using low cost materials in ambient conditions [4-5]. Importantly, it also allows us to understand the biological processes at work during the growth of these structures in nature. In this talk the route for the fabrication of complex bio-mimetic polymer-based photonic structures will be presented and the optical properties of artificial structures will be analysed and compared with the natural ones. 1. Kinoshita, S. et al. (2008). Physics of structural colors. Rep. Prog. Phys. 71(7), 076401. 2. Vignolini, S. et al. (2012). Pointillist structural color in Pollia fruit PNAS 109, 15712-15716. 3. Wilts, B. D, et al. (2014). Natural Helicoidal Structures: Morphology, Self-assembly and Optical Properties. Materials Today: Proceedings, 1, 177?185. 4. Dumanli A. et. al (2014) Digital Color in Cellulose Nanocrystal Films, ACS Appl. Mater. Interfaces ACS Appl. Mater. Interfaces 6, 12302 5. Dumanli A. et. al(2014) Controlled bio-inspired self-assembly of cellulose-based chiral reflectors, Adv. Opt. Mat. 2, 646

Resume : DNA can be used as a building block to create DNA structures and devices with sizes ranging from a few to several hundreds of nanometers [1]. Owing to their phenomenal addressability, these DNA nanostructures are attractive platforms for organizing matter at the molecular level for creating photonic devices. They provide indeed high flexibility for positioning fluorescent molecules and controlling fluorescent outputs. We present here our investigations of controlled fluorescence outputs using a DNA origami box and DNA-based logical operations [2] and through the controlled switching of polymer conformations on a DNA origami platform [3]. [1] Y. Krishnan and F. C. Simmel, Angew. Chem. Int. Ed. 50: 3124-3156, 2011. [2] R. M. Zadegan, M. D. E. Jepsen, L. L. Hildebrandt, V. Birkedal, J. Kjems, Small 11: 1811?1817, 2015 [3] A. Krissanaprasit, M. Madsen, J. Knudsen, D. Gudnason, W. Surareungchai, V. Birkedal, K. V. Gothelf, ACS Nano 10: 2243?2250, 2016.

Resume : In mid of 1990s, the Light-Emitting Electrochemical Cells (LECs) came out as an alternative device concept to OLEDs1. The simple device architecture with a single organic layer and silver (Ag) cathode makes it advantageous for printing processes2. Today, one of the important arguments in the organic electronics field is to replace the synthetic polymers with biopolymers for biodegradable, biocompatible electronics3-4. This is comforted by the present scientific policy related to the humanity problem of creation of sustainability and minimizing the environmental pollution by reducing the electronic-waste5. In this work, DNA and the DNA-lipid complex (DNA-CTMA) were tested as Solid Polymer Electrolytes (SPEs) from aqueous and organic solvent media. Different salts were engaged as additional ionic source and the ionic conductivity for different ratios was investigated. The blend of SPEs and commercially available water-soluble blue emitter or organo-soluble yellow emitter was deposited between two electrodes to form the active layer. The luminance-voltage-current density characteristics and lifetime were investigated. The maximum luminance was recorded 2000 cd/m2 and 7 cd/m2 for yellow and blue BioLECs, respectively, with the turn on voltages of 3.5-10 V. The ionic conductivity of SPEs was obtained at the range of 10-6 S/cm at RT using impedance spectroscopy. Additionally, morphology of the blend films and electrochemical stability window of SPEs were explored. References [1] Q. B. Pei, G. Yu, C. Zhang, Y. Yang, A. J. Heeger, Science 269, 1086-1088 (1995). [2] G. Hernandez?Sosa, S. Tekoglu, S. Stolz, R. Eckstein, C. Teusch, J. Trapp, U. Lemmer, M. Hamburger, N. Mechau, Adv. Mat. 26, 3235-3240 (2014). [3] B. Singh and N. S. Sariciftci, Proc. OEC 1-4, (2006). [4] M. Irimia-Vladu, Chem. Soc. Rev. 43, 588-610 (2014). [5] I. Rau, J. G. Grote, F. Kajzar and A. Pawlicka, C. R. Physique 13, 853-864 (2012).

Resume : Non-centrosymmetric chiral, coiled and spiral configurations, revealed by Louis Pasteur in biological world, are abundant in nature and spanning from basic elementary bio-molecular scaffolds amino acids and proteins to biological structures, such as plants, animal and human tissues. Low symmetry structural conformation being universal intrinsic property of biological systems, permits observation of fundamental physical phenomena of ferroelectricity and related effects described by tensors of the odd rank. These ferroelectric effects include piezoelectric, pyroelectric, nonlinear optical and linear electrooptical effects. Biological units such as proteins and peptides have the intrinsic property to self-assemble into elongated natural biological nanostructures such as protein fibers and amyloid fibrils. These biological tubular nanostructures are the inspiration for the development of a new class of man-made nanomaterials, peptide nanostructures composed of chemically synthesized peptide biomolecules, which can self-organized into various nanostructures such as peptide nanotubes, nanofibers, micro- and nanospheres, hydrogels, etc. These supramolecular bioinspired nanomaterials mimic biological structures, inherit their self-assembly mechanism and fundamental physical properties including ferroelectric ones. Ferroelectric properties, such as electrical spontaneous polarization, piezoelectric and nonlinear optical effect (second harmonic generation) have been recently revealed in ultrashort bioinspired diphenylalanine (FF), dileucine (LL) nanotubes and tri-phenylalanine (FFF) nanobelts and nanospheres [?1,?2]. In this lecture, I will present basic physics of ferroelectric effects, structure and symmetry of bioinspired peptide nanostructures, which could be considered as supramolecular ferroelectrics. The main stress is done on nonlinear optical properties (second harmonic generation - SHG) revealed in these bio-inspired peptide nanostructures. I will discuss the orientation molecular ordering of peptides nanostructures that affects second-order nonlinear optical response, resulting in observed efficient optical frequency conversion. New effect of linear and nonlinear optical waveguiding, which was recently found in peptide nanostructures will be also presented [?3]. These findings permit to propose a new direction in both bio-ferroelectricity and bio-nanotechnology. It is based on observed physical properties of environmentally clean bio-inspired peptide structures. A new generation of bioinspired nonlinear optical nanomaterials and optical waveguides (POW) can be widely applied in nanophotonics and biomedicine for diagnostics and therapy.

Resume : The colour of certain butterfly wings is determined by two components: pigments (chemical origin) and physical coloration based on the photonic crystal structures found in the wing scales [1]. This structural coloration is modulated by the periodicity and characteristic dimensions of the structure and also by the refractive index of the building materials. Small changes in the refractive index generate a variation perceptible with optical spectrometry. This property was used in determination of the gas / vapour surrounding the butterfly wing by reflected light colour measurements [2]. Earlier we showed on Lycaenid butterfly wings [3] two methods for the evaluation of colour change: principal component analysis and colour space representation based on the visual system of these species [4]. It was pointed out that the mechanism of the gas sensing is capillary condensation of vapours in the structure [5]. Present work is focused on the comparison of wing scales of different butterfly species as their various nanoarchitectures react differently for different gas types and external temperature. The signal diversity in combination with proper data processing methods is used for enhancing selective vapour sensing. [1] L. P. Biró, J. P. Vigneron, Laser Photon. Rev. 2011, 5, 27 [2] R. A. Potyrailo et al. Nat. Photonics 2007, 1, 123?128 [3] Zs. Bálint et al. JRS Interface 73 (2012) 1745 [4] G. Piszter et al. Opt Exp 22 (2014) 22649 [5] K. Kertész et al. Appl. Surf. Sci. 2013, 281, 49?53

Resume : Organic material based devices cannot compete with their inorganic counterparts, e.g. silicon-based devices, in terms of performance output and stability. The merits of organic materials lie more in their structural flexibility, i.e., the possibility to introduce new functionalities upon targeted structural modification of the molecular building block. Especially the implementation of stereogenic centers allowing for optical activity, such as circular dichroism (CD), enables polarization sensitive absorption of light as an intrinsic property predominant for chiral organic materials. In this context, the substitution pattern of 1,3-bis(N,N-substituted-2,6-dihydroxy-anilino) squaraines is modified with natural chiral functional groups such as a prolinol derivative. These natural compounds are available in their enantiomerically pure forms making costly separation of racemic product mixtures obsolete. Strong circular dichroism is measured in spin-casted thin films proving homo-chiral aggregation. Blended with a fullerene acceptor, these squaraines perform as light harvesting compound in a photodiode. The strong circular dichroism of the photoactive layer can enable a photocurrent readout sensitive to the circular polarization state of the incident light.

Resume : One of the main goals of solar energy conversion technology is to mimic natural photosynthesis. Most of the attention has been focused on dye sensitized solar cells (DSSCs), where a dye, like in the photosynthetic process, captures the sunlight and produces an electron injection to a metal oxide conduction band, generating charge separation. In recent years, a number of studies have analyzed and optimized the dyes properties, neglecting the role of the peptide matrix, through which the electron transfer (ET) process takes place in natural photosynthesis. In this interdisciplinary work novel biomimetic materials have been immobilized on TiO2 surfaces for application in solar energy conversion technology. The systems used are short peptides, doubly functionalized with groups able to bind the surface and with chromophores able to convert light into electronic current. [1-3] The peptides investigated are designed to attain helical structures, because they are formed by strongly folding inducer residues. We demonstrate that the peptides generate compact and stable monolayers on surface, which inhibit the direct contact of the dye and the electrolyte with titania. Furthermore the peptide spacers maintain the dyes quite distant from each other and from the surface, minimizing excited state interactions. This design increases the cell photon-to-current conversion efficiency, with respect to the value obtained when the dye is simply layered on the TiO2 surface, suggesting that helical peptides can be considered very promising materials to be used in DSSC technology. Preliminary results obtained with the peptide-based DSSCs will be showed [4]. REFERENCES. [1] Gatto E., Stella L., Baldini C., Venanzi M., Toniolo C., Formaggio F. Superlattices Microstruct. 46, 34?39 (2009). [2] Gatto E, Caruso M., Porchetta A., Formaggio F., Toniolo C., Crisma M. & Venanzi M. J. Pept. Sci. 17, 124?131 ( 2011). [3] Gatto E., Porchetta A., Scarselli M., De Crescenzi M., Formaggio F., Toniolo C. & Venanzi M. Langmuir 28, 2817?2826 (2012). [4] Gatto E., Quatela A., Caruso M., Tagliaferro R., De Zotti M., Formaggio F., Toniolo C., Di Carlo A., Venanzi M. ChemPhysChem 15, 64-68 (2014).

Resume : Search on solar energy harvesting has been particularly attractive in the last decades as the global energy demand is supposed to increase in the next future. Sunlight can provide more than enough energy to meet our needs, in theory. In practice, the development of synthetic systems capable of energy harvesting is a very challenging task. Indeed, the sky over the researchers is sometime covered with clouds and the sunny days often disappears behind the horizon. Design inspired by the Nature is obviously the ideal protocol. Supramolecular assemblies of complexes containing chromophores and redox-active centers represent a concrete bio-inspired strategy for photocatalysis and light-harvesting. In the last few years, we focused our efforts on the developing of efficient strategies for interfacing the photo-active complexes with electrodes. Introduction of the active chromophores at the metal or oxide surfaces is typically obtained by synthesizing complexes in solution and, subsequently, adsorbing them at the surface through a suitable head group. At variance, our approach involves the formation of the active polypyridine-metal complex directly at the surface.[1] In particular, we demonstrated the feasibility of such approach on polypyridine-transition metal complexes on metal [2] and oxide [3] substrates, prepared by direct reaction on self assembled containing a terpyridine ligand. These systems have been characterized by means of optical (Fluorescence, Ultrafast spectroscopy, etc.) and surface science techniques (ToF-SIMS, XPS, AFM, etc.) and compared with those obtained on similar systems prepared by more conventional methods, such as the anchoring of a pre-synthesized complex at the surface. The electrical properties, properly measured at the nanoscale, indicate these systems as candidates both for fundamental studies of charge transport, and for practical application in molecular and/or organic electronics.[4] REFERENCES. [1] Auditore, A., Tuccitto, N., Marzanni, G., Quici, S., Puntoriero, F., Campagna, S., Licciardello, A. Chemical Communications, 9, 2494-2495, (2003). [2] Tuccitto, N., Delfanti, I., Torrisi, V., Scandola, F., Chiorboli, C., Stepanenko, V., Würthner, F., Licciardello, A. Physical Chemistry Chemical Physics, 11 , 4033-4038, (2009). [3] Spampinato, V., Tuccitto, N., Quici, S., Calabrese, V., Marletta, G., Torrisi, A., Licciardello, A. Langmuir, 26 , 8400-8406, (2010). [4] Tuccitto, N., Ferri, V., Cavazzini, M., Quici, S., Zhavnerko, G., Licciardello, A., Rampi, M.A. Nature Materials, 8, 41-46, (2009).

Resume : 2016 MRS Fall meeting Symposium B: Bioinspired and bio integrated materials as frontiers VI Wettability gradient-induced alignment of peptide nanotubes as templates for biosensing applications Sawsan Almohammed,a,b Sarah Olabisi Oladapo,a Kate Ryan,a,b Andrei L. Kholkin,c James H. Ricea and Brian J. Rodrigueza,b aSchool of Physics, University College Dublin, Belfield, Dublin 4, Ireland bConway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland cDepartment of Physics & CICECO-Aveiro Institute of Materials, 3810-193 Aveiro, Portugal and Institute of Natural Sciences, Ural Federal University, 620000 Ekaterinburg, Russia Self-assembled diphenylalanine (FF) peptide nanotubes (PNTs) have attracted significant attention due to their well-ordered supramolecular structure and wide range of functional capabilities that may enable potential nanobiotechnology applications. However, self-assembled PNTs are generally inhomogenous at the macroscale, which has limited their potential use. Reproducibly controlling the assembly and alignment of PNTs is therefore critical to enable the widespread use of PNTs, e.g., in sensing applications. In this study, a surface patterning technique based on UV/ozone exposure through a shadow mask is used to align PNTs. Exposed regions become hydrophilic, leading to directed spreading of the FF solution and alignment of the PNTs that improves as the difference in wettability between adjacent regions increases, suggestion that the difference in wettability between region leads to a chemical force, which drives the alignment process. Alignment is further found to depend on the concentration and temperature-dependent diameter of the PNTs formed and the size of the hydroplic area. The degree of alignment is quantified as a function of FF concentration (4, 2 and 0.5 mg/ml) and the opening size of the mask (0.9, 0.5, and 0.3 cm) using FFT and FWHM analysis. It is found that for high concentration FF (4 and 2 mg/ml) the alignment is best for larger opening size, whereas for low concentration FF (0.5 mg/ml) the best for the smallest (0.3 cm) opening size. Finally, aligned PNT decorated with silver nanoparticles are used as templates to sense an analyte molecule (TMPyP) using surface enhanced Raman spectroscopy. The Ag NPs stabilised the PNTs during the application of the analyte and plasmonically enhanced the Raman signal. Using aligned PNTs as template for SERS-active materials may provide route to improving the reproducibility of the SERS signal by tailoring the density and location of the materials.

Resume : An optically transparent poly(3,4-ethylenedioxythiophene) (PEDOT) based organic electronic devices have been developed to investigate the behavior of human mesenchymal stem cell (hMSC) and to sense and to capture circulating tumor cells. We first conducted a control experiment on electrical cell-substrate impedance sensing (ECIS) device by culturing the hMSC on the chip. According to our result, the impedance increased reflected the hMSC proliferation, attachment and motility during the first 16 hours of cell culture. In order to control the differentiation of human mesenchymal stem cell (hMSC) on chip, we also developed all-solution-processed multifunctional organic devices, comprising reduced graphene oxide (rGO) and dexamethasone 21-phosphate disodium salt (DEX) drug loaded poly(3,4-ethylenedioxythiophene) (PEDOT) microelectrode arrays on indium tin oxide glass, that can be used to manipulate differentiation. In our devices, the rGO micropatterns were used as the adhesive coating to attract the adhesion of hMSC cells whereas PLL-g-PEG coated PEDOT electrodes served as the anti-adhesive coating where no hMSC cells can attach. In addition, the PEDOT electrodes also work as drug releasing components where control DEX release from PEDOT matrix can be achieved via cyclic potential stimulation (CPS). To capture the circulating tumor cells, we fabricated 3D PEDOT-based micro/nanorod array, which can be further surface-grafted with capture agents for directed specific recognition to study the cell–substrate interactions on bioelectronics interfaces (BEIs). This BEI platform features the advantageous characteristics: (1) diverse dimensional structures (tunable from the microscale to the nanoscale), (2) varied surface chemical properties (tunable from nonspecific to specific), (3) high electrical conductivity, and (4) reversible chemical redox switching. Furthermore, through systematic studies of PEDOT systems, we explore the effects of both chemistry and topography on the circulating tumor cell (CTC)-capture performance. The 400 nm PEDOT pillars exhibited the optimal cell-capture efficiency; it could be used to isolate CTCs with minimal contamination from surrounding nontargeted cells (e.g., EpCAM-negative cells, white blood cells) and negligible disruption of the CTCs’ viability and functions. It is conceivable that PEDOT-based micro/nanorod array films function as a critical therapeutic intervention for monitoring tumor progression and metathesis, providing valuable insight into the use of electronics for tissue engineering and regenerative medicine.

Resume : Over the last decades vast efforts were devoted to understand and utilize the unique properties of transition metal dichalcogenide (TMDC) layered compounds. Such compounds have strong (covalent) bonds in the layer (a-b plane) and weak van der Waals forces along the c-axis which hold the layers together. Tenne et al., showed that, due to the high energy stored in the dangling bonds at the periphery of the nanoscopic sheets, the TMDC layered compounds are prone to form closed-cage nanostructures (NS). [1] Due to their unique properties and promising applications, the study of these NS is a rapidly growing field. Recently, it was learned that the semiconducting MS2 (M=Mo,W) NS, maintains the excitonic structure of the bulk together with a new plasmonic scattering resonance (which does not exist in the bulk). [2] The optical properties of such NS can be modified and controlled by verity of methods, including doping, size, aspect ratio etc. [3-5] Thus, in addition to current application as solid lubricants and host of intriguing medical applications and for biopolymer reinforcement [6], MS2 NS can be used for nano-optoelectronics. Here nano-imaging is used to study the properties of plasmonic and excitonic photo-induced response in an individual WS2 nanotube (NT) in the visible and IR region. Surface waves were detected and imaged with 2-5 nm resolution at 633 nm using a scattering-type scanning near-field optical microscope (s-SNOM) (Fig. 1). Interestingly, these waves were not observed at 1500 nm. These findings coincide with the assumption that WS2 NT plasmons occur mainly in the visible and near IR region. The standing wave appears with specific incident light polarization and is anticipated to be induced by interference between the tip-excited wave and its reflection from the NT. In addition, single particle spectroscopy microscopy (SPSM) was used in order to measure absorption and scattering of individual NTs over the spectral range of 420-720 nm. Here again, surface waves with specific incident light polarization were detected in the visible light range (Fig. 2). The s-SNOM or SPSM techniques provide a unique way to study the light-matter interactions in a single NS. Furthermore, the combination of these techniques and the unique properties of MS2 NS allow generation of exciton and/or plasmon resonances over a wide spectral range (400-2500nm). Since the optical modes in MS2 NS vary as a function of incident waves, polarization etc., they can be used for nanophotonic circuitry and as saturable absorbers. Moreover, the MS2 NS are not toxic and are optically active in the visible area, thus can be used for optical tracking during medical diagnostics, targeted drug delivery or medical diagnostics. _____ 1. Tenne, R., et al., “Polyhedral and cylindrical structures of WS2“, Nature, 1992. 360(6403); 2. Yadgarov. L., et al., “Plexciton in WS2 nanotubes”, In preparation 2016.; 3.Yadgarov, L., et al., “Dependence of the absorption and optical surface plasmon scattering of MoS2 nanoparticles on aspect ratio, size and media” ACS nano, 2014. 8(4). ; 4. Sun, Q.C., Yadgarov. L., et al., et al., “Observation of a Burstein–Moss shift in Re-doped MoS2 nanoparticles”, ACS nano, 2013. 7(4); 5. Yadgarov L., et al., “Controlled doping of MS2 (M= W, Mo) nanotubes and fullerene‐like nanoparticles, Angew. Chem. Int. Ed., 2012. (51); 6. Visic, B. and R. Tenne, 2015, Wiley-VCH Verlag; 7. Pardo, M, et al. "Low cytotoxicity of inorganic nanotubes and fullerene-like nanostructures in human bronchial epithelial cells: relation to inflammatory gene induction and antioxidant response." Environmental science & technology 48.6 (2014): 3457-3466.

Resume : Optical properties of biomolecules have been extensively investigated for many decades in order to find intrinsic optical biomarkers. Recently, intrinsic fluorescence has been found in a variety of bioinspired peptide nanostructures [1-3]. In this work we report on the aggregation properties of an amphiphilic peptide, the (Ala)10-(His)6, denoted in the following as A10H6, by AFM and fluorescence measurements. We found that this peptide is able to form amyloid-like fibrils above a critical aggregation concentration[4]. Interestingly, by fluorescence microscopy measurements we observed an intrinsic fluorescence of these supramolecular peptide nanostructures in the visible range. Steady state and time resolved fluorescence measurements have been performed in solution at different peptide concentrations and using different solvents, in order to correlate the measured fluorescence intensity to the aggregation process and to the morphology of the nanostructures obtained. The possibility to obtain intrinsic fluorescence from peptide nanostructures would pave the way to develop a new generation of bio-inspired optoelectronic nanomaterials for nanophotonic applications. REFERENCES. [1] Del Mercato L. L., Pompa P., Maruccio G., Della Torre A., Sabella S., Tamburro A. M., Cingolani R., Rinaldi R. PNAS 104, 18019-18024 (2007). [2] Chan F. T. S., Kaminski Schierie G. S., Kumita J. R., Bertoncini C. W., Dobson C. M., Kaminski C. F. Analyst 138, 2156-2162 (2013). [3] Handelman A., Kuritz N., Natan A., Rosenman G. Langmuir 32, 2847–2862 (2016). [4] Hamley I. W., Kirkham S., Dehsorkhi A., Castelletto V., Adamcik J., Mezzenga R., Ruokolainen J., Mazzuca C., Gatto E., Venanzi M., Placidi E., Bilalis P., Iatrou H. Biomacromolecules 15, 3412−3420 (2014).

Resume : Enzymatic proteins are highly efficient biocatalysts. It is desirable to recover the enzymes after a reaction in order to purify the chemical product and to enable enzyme reuse in large-scale processes. Immobilisation of enzymes on solid material supports simplifies recovery because the proteins are separated from the reactants in solution. Porous supports are commonly used due to their high surface area. Recent studies have shown that polyphenol coatings may be formed on diverse material surfaces under mild aqueous conditions. The coatings have been proposed as versatile and chemically reactive interfacial layers that can act as immobilisation agents of biomolecules. We present results on exploiting the coatings for enzyme immobilisation. Different approaches were tested, including the time of each procedure, polyphenol/enzyme concentrations and pH. Pyrogallol and tannic acid were used as precursors of the polyphenol coatings, and phosphatase and chymotrypsin were immobilised. Nanoporous anodic aluminium oxide (AAO) membranes were used as model supports due to their straight, close-packed cylindrical pores where the path of molecular diffusion is clearly defined. Physical adsorption on bare AAO was used as a control and the results were compared with immobilisation via the previously reported and popular polydopamine coating. The pH during immobilisation was found to be a key parameter influencing both enzyme activity and stability. Coating conditions that give relatively stable immobilised activity were found. Although physisorbed and polyphenol-immobilised phosphatase showed similar activities, higher immobilised activities for chymotrypsin were observed using the polyphenol coating method.

Resume : Advanced neuroprosthetics could substitute for damaged motor, sensory, or cognitive modalities, thereby recovering bodily functions, and thus more and more patients accept it as a routine clinical procedure. However, advances of these technologies towards high-resolution communication and long-term implantation are reaching limits imposed by electrical trade-off and biocompatibility of tradition electrode materials. Furthermore, these electronic devices, particularly for children, cannot outlive patients because of medical reasons, electronic failures, electrode failures, soft failures, or technique upgrade. In the end, a reimplantation becomes a necessary and routine procedure. To meet the requirements of electrical trade-off, biocompatibility and noninvasive reimplantation for advanced neuroprosthetics, we developed a dynamic electrode based on biomimetic PEDOT functionalized with electroswitches and zwitterions. The dynamic PEDOT electrode integrates low impedance, nonspecific binding resistance, and redox-responsive characteristics while couples with neurons stably and specifically. The combination of these features ensures a stable, efficient and intimate electrical communication with nerve cells, and promises a potential to diminish the immunogenic response due to the strong resistance to nonspecific interaction; more significantly, the integration of these features on one electrode detach differentiated cells on demand without damage to viability and neurite, which make it possible to remove implanted electrodes noninvasively for reimplantation. We consider it is the first example with optimized electrochemical and biological characteristics toward biocompatible and controllable electrical interfacing with neuron at low impedance.

Resume : Molecular design at the nanoscale enables tuning the properties of functional materials. We report on the use of two oppositely charged protein containers, derived from human heavy chain ferritin, as building blocks for a new type of material. Binary assemblies with crystalline order were obtained and were characterized by X-ray crystallography to high resolution. Moreover, the cavities of the engineered protein containers could be used for the size-constrained synthesis of metal oxide nanoparticles. By assembling oppositely charged protein containers with nanoparticle cargo, biohybrid structures with variable nanoparticle compositions could be obtained. Importantly, the assembly of these protein-nanoparticle composites in this way yields highly ordered binary nanoparticle superlattices as free-standing crystals, with up to a few hundred micrometers in size. Furthermore, the protein containers may act as a biocompatible scaffold structure while simultaneously allowing selective access to the nanoparticle core.

Resume : Neural stem cells (NSCs) are able to differentiate into neurons, emerging as important players in the regeneration of the injured or diseased central nervous system (CNS). Except from biochemical cues, the behavior of NSCs is affected by topographical cues such as the discontinuities and differences in roughness of the ECM molecules. We have investigated the effect of topological parameters such as pattern and size on the proliferation and differentiation of embryonic NSCs. Using laser precision 3D micro/nano-fabrication techniques on silicon (Si) substrates parallel oriented elliptical microcones (of high, medium and low roughness), microgrooves, and nanoripples were fabricated. We observed similar NSCs proliferation to control (glass) on the microgrooved Si substrate, whilst on the nanorippled substrate the NSCs showed reduced viability and proliferation. In addition, NSC proliferation was higher on microcones of low and intermediate roughness compared to high roughness, although overall it was lower compared to control. Interestingly, it is observed that NSCs become preferentially oriented parallel to the ellipsoidal structure of the medium and high roughness microcones. Moreover, when the differentiation of NSCs was induced, the dendrites of the derived neurons were longer on surfaces of low and intermediate roughness microcones. These observations provide a better understanding on the different roles of topographical cues on NSC behavior.

Resume : The fundamental and practical interest in intercalated compounds (IC) of crystalline layered solids has been stimulated by their remarkable mechanical, physical, chemical, and catalytic properties as well as a possibility to use them as precursors for the exfoliation to single atomic layers. The latter was demonstrated by preparing the monolayers of graphene oxide, some metal chalcogenides and oxides, and graphene cones. The intercalation chemistry of hexagonal boron nitride (h-BN), however, is much more challenging than that of graphite, despite h-BN and graphite are isoelectronic and have the same crystal structure with very close cell parameters. This difficulty results from the stronger interlayer interaction (due to the polar character of the B-N bonds and different interlayer registry in h-BN with eclipsing B and N atoms in the neighboring layers) and very different electronic structure. h-BN is a wide gap insulator, while graphite is a semimetal. The BN redox potential is ~ 2V more positive relative to graphite and its oxidative intercalation is much harder to achieve. Only a few ICs of h-BN have been reported. This work demonstrates a possibility of the non-oxidative h-BN intercalation with BrØnsted acids, such as H2SO4 and H3PO4. The h-BN- H2SO4 and h-BN- H3PO4 compounds have the interlayer distances of 6.9-7.4 A that implies the formation of the stage-1 ICs of h-BN. The structure and guest-host interactions have been studied by XRD, TEM, SEM, FTIR, XPS, thermal analysis and computational simulations. We assume that the acid molecules interact with the h-BN layers by formation of hydrogen bonds of the type B-N…H-OP(S)< (or even protonation of N atoms), and dative bonds of the type >P(S)=O:-->B-N.

Resume : Guided bone regeneration (GBR) is a well defined method to achieve bone regeneration, especially in the maxillofacial region. GBR treatment is based on the application of a barrier membrane to cover an osseous defect. The principle of GBR is based on the need that the membrane excludes non-osteogenic tissues from interfering with bone healing for efficient bone formation. To this end several biomaterials have been studies and developed. In this last years great attention has been put on graphene thanks to the enthusiastic results obtained on regenerative medicine. Its biocompatibility, and its ability to promote the adhesion, proliferation, and differentiation of various cells such as human Mesenchymal stem cells (hMSCs), human Neuronal Stem Cells (hNSCs), and induced Pluripotent stem cells (iPSCs) make this material indeed the perfect candidate for a great range of applications in tissue engineering and regenerative medicine. In the present work we have developed a natural based membrane enriched with silica nanoparticles covered by graphene for the in vitro reconstruction of a GBR like situation. Using tissue engineering strategies of our laboratory we have create a 3D in vitro situation strongly similar to a GBR:a membrane between a gingival like tissue on the upper site and a vascularised bone tissue on the bottom site. Biochemical, molecolar biology and morphological analyses confirm not only that the membrane was able to support the growth and development of two different tissues but that the presence of graphene strongly aids bone regeneration, reducing the time of stem cells commitment and showing in the mean time a well defined antibacterial activity.

Resume : In many blindness-causing diseases, photoreceptors degenerate whereas second order and projecting neurons are largely unaffected. Thus, one promising avenue to restore vision in affected patients is to develop artificial photoreceptors for retinal prosthetic devices. Organic semiconductors based artificial photoreceptors emerged as promising alternative for inorganic materials due to increased biocompatibility and the feasibility of direct optical stimulation. Nevertheless, the excitation pathway from the organic semiconductor to livings cells or tissue is largely unresolved. Therefore, we followed an electrophysiological patch clamp approach to conduct fundamental mechanistic studies on a model system, which consisted of murine neuroblastoma (N2A) cells grown on a textured small molecular organic semiconductor thin film under physiological conditions. We have chosen an anilino-squaraine dye, in particular 2,4-bis[4-(N,N-diisobutylamino)-2,6-dihydroxyphenyl]squaraine (SQIB), for the photoactive layer, which provided excellent biocompatibility and environmental stability. Patch clamp recordings showed that photoexcitation of the system with short light pulses stimulated fast capacitive transmembrane currents in the N2A cells. The electrical coupling between the artificial photoreceptor and the neuronal cells was fast and direct, but yet was only of passive nature. The required active response, i.e., opening of voltage-gated ion channels, could not be documented. Thus, additional excitation pathways need to be considered, such as photo-thermal effects, for elucidating the operation mechanism of organic artificial photoreceptors.

Resume : Superparamagnetic nanoparticles (SPMNPs) used for synergetic cancer therapy including magnetic fluid hyperthermia (MFH) guided with magnetic resonance imaging (MRI) techniques frequently face tradeoff between a high magnetization saturation and their biophysical properties such as good colloidal stability, high specific absorption rate (SAR) and most importantly biological compatibility. This necessitates the development of new nanomaterials as MFH and MRI, which are considered to be one of the most promising combined noninvasive treatment. To explore this potential applications, we synthesized Garphene oxide-SPMNPs (GO-SPMNPs) with methoxy-polyethylene glycol (PEG)-polethyleneamine micelle structure, and loaded Doxorubicin (DOX) with high loading capacity. The superparamagnetic GO-SPMNPs revealed a high saturation magnetization, colloidal stability, high SAR and excellent biocompatibility. A high SAR of 520 W/g was observed due to higher colloidal stability leading to an increased Brownian and Neel’s spin relaxation. Cell viability of micelle capped nanoparticles is up to 80% on different cell lines tested rigorously using different methods. Micelle structure provided excellent hemocompatibility to human red blood cells. Further, we found that DOX-loading resulted in cancer cell death comparable to free DOX, and that the combined effect of DOX and GO-SPMNPs induced hyperthermia enhanced cancer cell death in vitro. Additionally, improved MRI characteristics were also observed for the micelle formulation in aqueous. Taken together, GO-SPMNPs can serve as a promising candidate for effective multimodal cancer treatment i.e. combined chemotherapy–hyperthermia cancer treatment.

Resume : Multiscale nanoporous microspheres have attracted great interest in separation, catalysis, sensors, energy storage, tissues engineering and drug release, due to their excellent permeability, high surface area, low density and stable mechanical properties. Several popular techniques have been developed to produce porous structures in polymer matrices, such as gas foaming, salt leaching and phase separation, etc. However, these techniques in general need additional pore-forming agents to achieve porous structures of microspheres. It is still challenge to control the size of microspheres and pores independently when pore-forming agents are used. Here, we report a facile approach involving a synergy effect between the hydrophilic PEG and rapid solvent evaporation from amphiphilic triblock copolymer poly (lactideco-glycolide -b-ethylene glycol-b-lactide-co-glycolide) (PLGE), to prepare porous Evansblue-loaded microspheres. There are no other additional pore-forming agents are employed in our system. The microsphere’s size, surface geometries, pore sizes as well as drug encapsulation efficiencies can be well controlled by regulating the compositions of copolymer. Compared with the slow solvent evaporation at room temperature, the rapid solvent evaporation at boiling points can significantly improve the drug encapsulation efficiencies. Meanwhile, the drug burst behavior can be controlled effectively by varying the compositions and concentrations of copolymer.

Resume : Phosphorylated polymers are promising for bone regeneration because they may recapitulate the essence of phosphorylated bone extracellular matrix (ECM) to build an instructive environment for bone formation. However, most of the existing synthetic phosphorylated polymers are not fully biodegradable; thus, they are not ideal for tissue engineering. Here, we designed and synthesized a new phosphorylated polymer, poly(sebacoyl diglyceride) phosphate (PSeD-P), based on the biodegradable osteoconductive backbone PSeD. To our knowledge, PSeD-P is the first polymer to integrate the osteoinductive moiety β-glycerol phosphate (β-GP). PSeD-P shows good biodegradability and can be readily fabricated on 3D porous scaffolds. It has a porous structure with interconnected macropores (75-150 μm) and extensive micropores (several microns). PSeD-P promotes the adhesion, proliferation, and maturation of osteoblasts more effectively than poly(lactic-co-glycolic acid) (PLGA). Furthermore, PSeD-P induces a significantly higher expression of osteogenic biomarkers and ALP activity in mesenchymal stem cells (MSCs) compared to its non-phosphorylated precursor, PSeD. The level of improvement is comparable to free β-GP in culture medium. More importantly, without using β-GP, the typical mineralization promoter in osteogenic culture media, PSeD-P substantially induces mineralized ECM in MSCs, which is totally absent using PSeD under identical culture conditions. PSeD-P provides a new strategy to integrate bioactive phosphates via β-GP into biomaterial, and has promise for bone regeneration applications. In addition, the synthetic method is versatile; both the backbone and the side phosphate groups could be readily tailored to generate a family of phosphorylated polymers for a wide range of biomedical applications.

Resume : A hierarchical assembled ITO nanowire array with both horizontal and vertical nanowire branches was fabricated as a new three-dimensional fractal nanobiointerface for efficient cancer cell capture. Comparing with ITO nanowire array without branches, this fractal nanobiointerface exhibited much higher efficiency (89% vs 67%) and specificity in capturing cancer cells and took shorter time (35 vs 45 min) to reach the maximal capture efficiency. As indicated by the immunofluorescent and ESEM images, this enhancement can be attributed to the improvement of topographical interaction between cells and the substrate. The introduction of horizontal and vertical nanowire branches makes the substrate topographically match better with cell filopodia and provides more binding sites for cell capture. The live/dead cell staining and proliferation experiments confirm that this fractal nanobiointerface displays excellent cyto-compatibility with an over 96% cell viability after capture. These results provide new insights and may open up opportunities in designing and engineering new cell-material interfaces for advanced biomedical applications. [1] Feilong Zhang, Yan Jiang, Xueli Liu, Jingxin Meng, Pengchao Zhang, Hongliang Liu, Gao Yang, Guannan Li, Lei Jiang, Jinsong Hu, and Shutao Wang. Nano Lett., 2016, 16, 766-772.

Resume : Bone defects by tumor or infection causes severe complications in patients receiving orthopedic surgery due to the lack of proper implantable materials. For the last few decades calcium phosphate (CaP) compounds have been examined as potential bone repair materials. Many CaP compounds have been shown to be chemically similar to natural bone tissues and they possess both biocompatibility and bioactivity. Due to these properties, CaP compounds are in high demand by biomaterial scientists. Several previous studies have reported on the osteoconduction of these biomimetic CaP compounds. Methylcellulose (MC) is one of cellulose derivatives with a certain degree of substitution of methyl groups, and is known to undergo thermoreversible gelation in aqueous solution upon heating. The thermal transition of MC solution is closely associated with concentration, heating rate and degree of substitution. Furthermore, thermo-responsive hydrogelation is also affected by salt. A salt, such as NaCl, has a greater affinity for water than MC, resulting in the removal of water from the hydrated polymer and thus a lowering of its sol?gel transition temperature due to an enhancement of the hydrophobic association of MC molecular chains. The gelation temperature of MC solution significantly decreases with increasing of the salt concentration. In this study, CaP nanoparticles were synthesized in MC solution using CaP precursor salts. Also, the effect of CaP precursor salt on the gelation behavior of MC hydrogel was investigated.

Resume : In recent years, nanomaterials that mimic natural enzymes (nanozymes) have elicited huge interest in nanomedicine (Wei and Wang, Chemical Society Reviews, 2013). Our recent findings show that pure, biocompatible platinum nanoparticles (Pt NPs) of 5 and 20 nm of diameter are able to counteract molecular dysfunctions that cause accumulation of intracellular reactive oxygen species (ROS). After performing a systematic characterization of Pt NPs as biocompatible and antioxidant materials, we demonstrated, for the first time, that Pt nanozymes are capable to restore physiological ROS homeostasis in a real experimental model of a human cerebrovascular disease, namely Cerebral Cavernous Malformation (CCM). CCM is characterized by an increased level of intracellular ROS, and we found that Pt nanozymes can completely recover the cellular phenotype, similar to that of wild type cells. This is possible because of the strong and broad antioxidant nanozyme activity of Pt NPs, which are simultaneously endowed with strong catalase-, peroxidase-, and superoxide dismutase-like activities, with superior performance than natural enzymes and higher adaptability/resistance to changes in environmental conditions (Moglianetti et al., Nanoscale, 2016). These findings are important and of broad interest, and open up novel perspectives in nanomedicine for the development of multifunctional active nanocarriers integrating the function of high-performance antioxidant drugs, with strong potential for therapies of complex oxidative stress-related diseases.

Resume : A novel drug nanocarrier based on porous silicon coated with temperature responsive polymer was developed. The polymer was additionally modified with FITC to provide the nanocarrier visualization. The nanocarrier can preserve the loaded drug inside the pores below the critical temperature of the polymer. The encapsulation of the drug is highly dependent on the polymer amount, and the highest loading capacity is around 33% (w/w). Silicon core can be efficiently heated with infrared raidation while radiofrequency electromagnetic radiation is used to heat up the ambient medium of the nanoparticles. The temperature rise resulted in polymer chain collapse, pore opening and triggered drug release as the critical temperature was exceeded. The polymer coated nanoparticles reduced the cytotoxicity in comparison to uncoated nanoparticles and were nontoxic up to concentration of 1 mg/ml. During the in vitro evaluation, the radiofrequency triggered showed better results, because for efficient infrared heating, high concentration of nanoparticles is needed. Thus, for in vivo studies, only radiofrequency triggered release was used. It was found, that combined treatment of mice with doxorubicin loaded temperature responsive nanoparticles and radifrequency radiation significantly suppressed the tumor growth and prolonged the survival time.

Resume : We present a novel approach for bioinspired material design on prepatterned surfaces. Our method combines the advantages of nanosphere lithography (NSL) and enzyme mediated autodeposition (EMA). By NSL large areas of nanoparticle arrays can be obtained on a large variety of surfaces at low cost. Hexagonally arranged monolayers of polymer spheres are produced by convective self-assembly and act as shadow mask in a subsequent metal deposition process. In this work plasma induced shrinking of polymer spheres enables the formation of antidot structured Pt thin films on SiO2. Immobilization of the enzyme chymosin in freely accessible SiO2 areas of antidots allows to induce site-specific deposition of casein particles in the nanometer scale. Enzyme-catalyzed cleavage reactions can drastically change the solubility of dispersed biomolecules, such as casein. The EMA uses this for a controlled deposition of destabilized particles in close proximity to a surface. Key factor is the tethering of enzyme onto the surface, defining the area with enzymatic activity. Limitation of enzyme activity to this reaction zone induces controlled deposition only in this area and prevents uncontrolled protein precipitation. Size of the reaction zone can be tailored and is defined in this combined approach in all dimensions. Its lateral area is determined by NSL-formed antidots, its vertical range by enzyme coupling. Site-specific deposition of protein particles was verified by XPS and AFM measurements.

Resume : To learn more about neurological diseases such as stroke, Parkinson’s and dementia, it is of upmost importance that neuronal behaviour and electrical activity of 3D neural networks is understood. 2D microelectrode arrays (MEAs) are commonly used for neuronal stimulation and recording of electrical signals. Present electrophysiological techniques allow for extracellular recording of non–specific collections of neurons. 3D electrodes are highly desirable as they allows for a better electrode–neural interface, with a larger surface area and the ability to record from within the cell. Current optimisation of MEAs is ongoing, and devices, which are able to facilitate simultaneous recording and stimulation, are required. The electrical recording and stimulation of large populations of individual neurons which are location tracked is required. Boron–doped nanocrystalline diamond (BNCD) coated carbon nanotubes (CNTs) have shown to be an attractive choice of material for neural interfacing due to the low impedance, high capacitance and biocompatibility observed[1], [2]. Here at UCL, CNTs growth, which is performed in a DC plasma CVD process, is optimised in order to produce both patterns of vertically aligned and individual CNTs for intra–cellular recording application. Since combining individual BNCD coated CNT electrodes with 3D hydrogels is planned, controlled location and size of CNTs is desired. Therefore, we have developed recipes in which specific dimensions of CNTs can be grown. [1] G. Piret, C. Hebert, J. P. Mazellier, L. Rousseau, E. Scorsone, M. Cottance, G. Lissorgues, M. O. Heuschkel, S. Picaud, P. Bergonzo, and B. Yvert, “3D-nanostructured boron-doped diamond for microelectrode array neural interfacing,” Journal of Neuroscience Methods, vol. 53, pp. 173–183, Jun. 2015. [2] A. C. Taylor, B. Vagaska, R. Edgington, C. Hebert, P. Ferretti, P. Bergonzo, and R. B. Jackman, “Biocompatibility of nanostructured boron doped diamond for the attachment and proliferation of human neural stem cells,” J. Neural Eng., vol. 12, no. 6, p. 066016, Dec. 2015.

Resume : Water-soluble fullerene derivatives have a big potential for biomedical applications owing to their versatile biological properties including efficient antitumor action, antiviral, antibacterial and neuroprotective activities [1]. Friedel-Сrafts arylation of the chlorofullerene C60Cl6 with methyl esters of benzylmalonic and phenylacetic acids with the subsequent cleavage of the ester groups in C60Ar5Cl compounds was reported as a facile synthetic route to water-soluble fullerene derivatives exhibiting pronounced anti-HIV activity [2]. Here we report the synthesis and characterization of four novel highly water-soluble fullerene derivatives С60Ar5X, where Ar represents a residue of phenylsuccinic acid, while X = H, Cl, Me, Et. Replacement of Cl in С60Ar5X with H was achieved using Ph3P/H2O method reported by R. Taylor [3]. Compounds С60Ar5Me and С60Ar5Et were synthesized from the same chlorine-containing precursor С60Ar5Cl using novel C-C bond formation reaction. Acid-induced hydrolysis of the ester groups allowed us to prepare 4 novel water-soluble fullerene derivatives bearing 10 carboxylic groups in their molecular frameworks. Antiviral activity and toxicity of the prepared compounds will be discussed. [1] F. Cataldo, T. da Ros, Medicinal Chemistry and Pharmacological Potential of Fullerenes and Carbon Nanotubes, Springer, 2008 [2] O. A. Troshina et al., Org. Biomol. Chem., 2007, 5, 2783–2791 [3] P. B. Birkett et al., J. Chem. Soc., Perkin Tans., 2, 1997, 457

Resume : Protein imprinting is quite challenging, mainly because of their large size and conformation susceptibility to experimental conditions. In case of non-covalent imprinting, it is very difficult to estimate which and how many sites on surface of the protein template molecule are accessible for binding. To overcome this drawback, semi-covalent imprinting was introduced. We devised and fabricated conducting molecularly imprinted polymer (MIP) based on bis(2,2-bithien-5-yl)methane for human serum albumin (HSA) determination. Very high imprinting factor (IF > 20) proves that we obtained MIP with molecular cavities of well-defined structure and high affinity to HSA molecules. This MIP was deposited in a form of several thin films of different thickness (i.e., 500 nm, 15 nm) and structure (i.e., continuous or macroporous). These MIP films were deposited on proper gold substrates (e.g., an Au disk electrode, or a semi-transparent Au film coated glass slide). Devised that way recognizing units were integrated with different transduction platforms, including DPV, EIS, EG-FET, SPR, and transparency of a liquid crystal thin layer, thus allowing selective determination of the target protein even in the femtomolar concentration range.

Resume : The main aim of our research was to combine two kinds of anticancer therapy in a single multifunctional nanocapsules with desired optical and magnetic properties. We synthesized and analyse the upconverting NaYF4:Yb,Ln nanoparticles and the superparamagnetic Fe3O4 nanoparticles encapsulated in SiO2 shell. Upconversion is a process of a lower energy, near-infrared light (NIR), conversion to a higher energy (visible light). NIR light can penetrate deeper into the tissue than UV or VIS light. As a result of enhanced tissue penetration, the upconverting properties of NaYF4, doped by rare earth metal ions, are potentially useful for photodynamic therapy (PDT). We synthesized and optimized the NaYF4 doped by the Er-Yb and Tm-Yb pairs for the multi-coloured luminescence. The size of nanoparticles was about 20 nm. The nanoparticles were encapsulated in SiO2 shell with the thickness of about 3 nm. The NaYF4 nanoparticles, with and without the SiO2 shell, are non-toxic in HeLa cells cultures, as studied by MTT Assay. These nanoparticles were introduced into the cells and imaged by a confocal microscopy. We observed the nanoparticles inside the cells without any apparent autofluorescence of the biological molecules. Superparamagnetic iron oxide nanoparticles can be applied in hyperthermia therapy. The magnetic properties of the nanoparticles allow to increase of temperature of the biological samples by applying alternating magnetic field, thus causing cancer cells damages. We synthesized and optimized the 6 nm Fe3O4 nanoparticles . These nanoparticles were used in the hyperthermia measurements. Concentration dependent increase of the temperature, in alternating magnetic field, was observed. Acknowledgements The research was partially supported by the project „Development of the cluster center of biomedical engineering” implemented under Economy Operational Program (project no. UDA-POIG.05.01.00-00), the EU Research Project FP7-People-2012-IRSES-BRASINOEU (Grant Agreement Number: PIRSES-GA-2012-318916), the grants of PNSC 2013/11/B/NZ1/00089, NN UMO-2013/08/A/ST3/00297, DEC-2012/07/B/ST5/02080 and DEC-2014/15/D/ST5/02604. This work has been done in the NanoFun laboratories co-financed by the European Regional Development Fund within the Innovation Economy Operational Program, the Project No. POIG.02.02.00-00-025/09/. This research was also co-financed by the Swiss National Science Foundation through the Nano-Tera.ch Focused Project (NTF), ‘NanoUp’.

Resume : The work is aimed on the look-up of “green” energy sources. Changes in the mechanism and the selectivity of binding components from the enzyme mixture preparation of Natural Black Horseradish adsorbed on the kaolin and aerosil are proved by the sum of physical and chemical methods. The differences in the binding mechanisms of metal-containing sites of enzyme molecules based on the implementation of the spatial separation of enzyme fragments containing Fe, Ni, Cu and Zn metal ions are shown. The implementation of this division improves in 4 times the oxidation activity and stability of the immobilized preparation and creates conditions for the formation of regions capable for specific adsorption of charge. The spatially separated binding of enzyme fragments to inorganic carrier exhibits the stabilizing effect on the formation of the areas capable for charging and accumulating red-ox transformations. Electrochemical methods have shown the possibility for the formation of structures responsible for the accumulation of energy like supercapacitor in the immobilized enzyme systems.

Resume : This scientific work is devoted to synthesis of new biologically active folat-containing polyurethaneureas based on the macrodiisocyanate, diamines (1, 6-hexamethylenediamine, 4, 4’-diaminodiphenilmetan) and folic acid (FA). The film-type materials under the different molar ratio of diamine and folic acid were obtained. Properties of polymer film-type materials for medical application were investigated. It was shown, that polyurethaneureas containing folic acid possessed an enhanced durability to biodegradation in simulated body fluids. In order to study the dynamic release of the folic acid in vivo a novel spectrophotometer technique was used. It was shown that FA release period may be controlled by changing the molar ratio of diamine and immobilized FA. Due to medical-biological investigation was established that folat-containing polyurethaneureas were biologically active and biocompatible film-type materials that may be wide used for wounds and burns treatment.

Resume : Nanoparticles used for the biomedical applications are “up –converting” (UCNPs), meaning that they emit visible light when illuminated with λ = 980 nm infrared light. Excitation by infrared radiation, minimizes background emission and light scattering so UCNPs are promising optical contrast agents and have potential in medicine and biology for bio-medical imaging, biosensing, therapy and diagnostic. To improve the therapeutic potential of the up-converting nanoparticles it is important to understand basic mechanism of the NPs interactions with living cells, affecting the cellular uptake mechanism, the intracellular trafficking and cytotoxicity. Toxicity studies of the β-NaYF4:20%Yb3+,2%Er3+, 10%Gd3+ up-converting nanoparticles on the cell viability and proliferation was evaluated by several commercial assays: MTT, PrestoBlue and RealTime MT-Glo Cell Viability Assay. We found that the nanoparticles entered the cells and are relatively non-toxic to the selected cellular function. We investigated the cell ability to absorb the NPs, established the way of the cellular uptake and fate of the internalized material in in vitro studies on HeLa and HEK293 cells. The NPs may interact with the cellular membranes followed by internalization pathways through a process called endocytosis. Nanoparticles were found entrapped in the late endosomes and lysosomes upon entry, as determined by the colocalization studies under confocal microscopy and transmission electron microscopy (TEM). To study the endocytosis of NPs, we monitored the fate of 20 nm diameter NPs in HeLa and HEK293 cells incubated with specific inhibitors blocking different endocytosis mechanisms. We used chlorpromazine to inhibit the clathrin-mediated endocytosis and methyl-β-cyclodextrin (MβCD) to inhibit the caveolae-mediated endocytosis and also to inhibit a process of exocytosis, responsible for reduction of intracellular accumulation of nanoparticles. The presence and chemical content of the nanoparticles in the cytosol was confirmed by EDX. Pre-treatment of HeLa and HEK293 cells with the endocytic inhibitors (e.g., chlorpromazine, MβCD) showed that more than one mechanism is involved in the NPs uptake. The NPs are biocompatible, they reveiled no apparent cytotoxicity and exhibited a fast cellular uptake by various nondestructive endocytotic pathways. Acknowledgements: The research was partially supported by NN UMO-2013/08/A/ST3/00297, DEC-2012/07/B/ST5/02080, 2013/11/B/NZ1/00089 and DEC-2014/15/D/ST5/02604. This work has been done in the NanoFun laboratories co-financed by the European Regional Development Fund within the Innovation Economy Operational Program, the Project No. POIG.02.02.00-00-025/09/.

Resume : Magnetic Hyperthermia is one of the method of anti-cancer treatment using magnetic nanoparticles. In the process, magnetic particles are injected locally into cancer tissues that can be heated up to the required temperature of about 43 °C in the external alternating magnetic field. Magnetic nanoparticles were synthesized by single-step high-temperature decomposition of tris(acetylacetonato) iron(III) in the presence 1,2-hexadecanediol. The solvent used was phenyl ether containing surfactant (oleylamine) and oleic acid. The reaction was carried out in inert atmosphere in the temperature about 300 °C. Transmission electronic microscopy shows that the nanoparticles had a spherical shape and were dispersed uniformly. The size of the Fe3O4-NP ranged about 5,5 nm ± 1.8 nm. XRD pattern of the nanoparticles indicates that the samples are single phase with the inverted cubic spinel structure of Fe3O4. Magnetic properties of synthesized by us nanoparticles were examined by SQUID. The measurements confirm that our nanoparticles are superparamagnetic. To test the potential feasibility for hyperthermia application, the predetermined amount of MNPs suspended in organic solution were put into a test vessel situated within the magnetic heating coil. To ensure stable conditions, independent of changes in ambient temperature, test vessel was in a vacuum insulated Dewar container. We measured time-dependence of heating temperature of the magnetic fluid samples with particles concentration varying from 10 to 50 mg/ml exposing an alternating magnetic field having a frequency of 292 kHz and 413 kHz, and its field strength of 16 kA/m. After about 25-30 minutes of heating, the temperature of the samples comes to saturation when the energy loss to the surrounding medium equals to the energy generated by the alternating magnetic field. It is clear that the saturation temperature and rising temperature rate strongly depend on the concentration of particles in the liquid. The specific loss power (SLP) can be calculated by using the following formula: SLP= C*(m_s/m_i)*(dT/dt) where C contains the specific heat capacity of magnetic nanoparticles and solvent, mi is the mass of iron oxide in the liquid, ms is the total mass of magnetic liquid (magnetic nanoparticles suspend in organic solvent), dT/dt is the initial temperature rising rate, which was defined at the moment of a few seconds after starting the heat. We obtain SPL 1.5 W/kg for 50 mg/ml concentration of nanoparticles. In a further step we optimize the ratio between size of nanoparticles and value of SPL parameter. We also examine the impact silicon shall on hyperthermia properties, improving the insertion of particles into the cell. Acknowledgements The research was partially supported by the EU project „Development of the cluster center of biomedical engineering” implemented under Economy Operational Program (project no. UDA-POIG.05.01.00-00), the EU Research Project FP7-People-2012-IRSES-BRASINOEU (Grant Agreement Number: PIRSES-GA-2012-318916), the grants of PNSC 2013/11/B/NZ1/00089, NN UMO-2013/08/A/ST3/00297, DEC-2012/07/B/ST5/02080 and DEC-2014/15/D/ST5/02604. This research was also co-financed by the Swiss National Science Foundation through the Nano-Tera.ch Focused Project (NTF), ‘NanoUp’.

Resume : Following the success of the symposia I - VI due to the reports and discussions on rapidly development bioinspired, biomimetic technologies for next generation biomedical nano – materials, - systems, - robotic devices, the symposium VII is aimed to give overview of recent development for fundamentals of nanotechnologies for biomedical engineering multifunctional materials in biomedical healthcare field, environmental control and security. Newest nanotechnologies and bio - materials, - systems, - robotic devices fields which determine developing biomimetic cells and skin, bone tissue engineering, remodeling ones and adaptation to a regeneration of neural systems using created implantable bionic systems. Organizers of the Symposium K kindly invite everyone to participate.

Resume : Our recent progress on the laser-assisted biomimetic processing of materials will be reviewed. The first part is focused on neural tissue engineering applications. We show that the artificial surfaces obtained by femtosecond laser texturing of solids comprise dual scale quasiperiodic structures at the micro- and nano- length scales that better simulate the morphology of the extracellular matrix. The ability to precisely control the structures? geometry and pattern regularity is an important advantage for the use of the laser-fabricated surfaces as models to study the dependence of growth, division and differentiation of cells on topographical cues. It is shown that the geometrical characteristics of the biomimetic surfaces alone could drive the directional outgrowth of neurons, glial cells as well as complex cell cultures of the peripheral nervous system. This distinct inherent property of the microstructures to direct cell outgrowth, combined with the conductance of the material, could potentially be useful for patterning neurons into artificial networks. The second part of the talk will be devoted to the presentation of the objective and the public summary of the LiNaBioFluid Project (www. laserbiofluid.eu). LiNaBioFluid is a Research and Innovation Action funded by the European Community?s Horizon 2020 - FET Open Programme, which supports early-stage research on any idea for a new technology (Grant Agreement no: 665337). It brings together 7 partners from 4 different countries. The project consortium is strongly interdisciplinary combining renowned experts from the fields of zoology, physics, mechatronics, life sciences, materials sciences, laser-matter interaction, production technology, tribology, and biomimetics.

Resume : Neural stem cells (NSCs) are able to differentiate into neurons, emerging as important players in the regeneration of the injured or diseased central nervous system (CNS). Except from biochemical cues, the behavior of NSCs is affected by topographical cues such as the discontinuities and differences in roughness of the ECM molecules. We have investigated the effect of topological parameters such as pattern and size on the proliferation and differentiation of embryonic NSCs. Using laser precision 3D micro/nano-fabrication techniques on silicon (Si) substrates parallel oriented elliptical microcones (of high, medium and low roughness), microgrooves, and nanoripples were fabricated. We observed similar NSCs proliferation to control (glass) on the microgrooved Si substrate, whilst on the nanorippled substrate the NSCs showed reduced viability and proliferation. In addition, NSC proliferation was higher on microcones of low and intermediate roughness compared to high roughness, although overall it was lower compared to control. Interestingly, it is observed that NSCs become preferentially oriented parallel to the ellipsoidal structure of the medium and high roughness microcones. Moreover, when the differentiation of NSCs was induced, the dendrites of the derived neurons were longer on surfaces of low and intermediate roughness microcones. These observations provide a better understanding on the different roles of topographical cues on NSC behavior.

Resume : Recently, the surface of the wings of the Psaltoda claripennis cicada species have shown to possess bactericidal properties.[1] It has been suggested that the nanostructure present on the wings is responsible for bacterial cell death on such surfaces. We have studied the nanostructure and bactericidal activity of the wings of five different cicadas in order to correlate the relationship between the observed surface topographical features and their bactericidal properties. Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) performed in this study revealed that the surface of the wings contained a highly uniform, nanopillar structure, which results in prominent hydrophobic properties and low surface energies. The height, pitch and diameter of the nanopillars were found to vary from species to species, and often between different areas of the wings themselves. The bactericidal properties of the cicada wing was assessed by studying the viability of Pseudomonas fluorescens cells following static adhesion assays and targeted dead-cell fluorescence staining through direct microscopic counting method. These experiments revealed a 20 to 25% bacterial surface coverage on all tested wings species and significant bactericidal properties were observed in two species. The combined results suggest a strong correlation between the bactericidal properties of the wings and the scale of the nanotopography present on the wing surface. Furthermore, soft lithography methods enabled the fabrication of polymeric biomaterial replicas of the cicada wing surfaces with exceptional resolution and precision, the bactericidal activity of which were also investigated. These polymeric materials showed the same level of antibacterial activity against Gram negative bacteria as the original cicada wings, and the effect can be attributed to the nanostructure present on the biomaterial.

Resume : Carbon nano-onions, CNOs, provide high effective surface areas, when compared with other allotropes of carbons, such as carbon nanotubes, graphene, graphite etc [1, 2], due to their spherical and concentric graphene multi-layered structure. Percolation of electric charge competes with trapping. CNO and conducting polymer (CP) composites are highly conducting due to the conjugated bond structures of the CPs and the intrinsic electronic properties of the CNOs. Structural and electrical heterogeneity of the CNO/CP composites, which can be used as electrode materials energy storage supercapacitors and biocompatible electrodes, are expected to yield high static dielectric constant values. Broadband Dielectric Spectroscopy (BDS) conducted from 15 K to room temperature in the frequency range between 1 mHz and 1 MHz reveals high dielectric permittivity values for electrically conducting polyaniline/carbon nano-onion (PANI/CMO) composite. A relaxation mechanism with intensity comparable to the observed huge static dielectric constant values evidences about a correlation between intense capacitance effects and relaxation. Typical spatial scale of relaxation estimated within the Mott-Davis model are comparable to the size of the CNOs. Furthermore, electric modulus and the dc conductivity analyses indicate a couple of hopping mechanisms. The distinction between thermally activated processes and the determination of cross-over temperature were achieved by exploring the temperature dependence of the fractional exponent of the dispersive ac conductivity and the bifurcation of the scaled ac conductivity isotherms. The granular metal model is likely to explain inter-grain charge tunneling of extended electron states located within mesoscopic highly conducting polyaniline grains and a 3D variable range hopping model can describe phonon assisted tunneling within the carbon nano-onions and clusters. References [1] D. Ugarte, Nature 359, 707 (1992) [2] J. L. Delgado, M. A. Herranza and N. Mart?, J. Mater. Chem. 18, 1417 (2008)

Resume : Since the discovery of unique properties of graphene in 2004 [1] a tremendous research effort has been dedicated to preparing graphene monolayers in significant quantities, which could enable their incorporation into a variety of devices and composite structures for applications ranging from nanoelectronics, sensors and energy storage to nanofluidics and bio-medical devices [2]. Liquid-phase chemical approaches offer advantages of the scalable production of free-standing graphene sheets that can be deposited on substrates of the different shapes and chemical composition or inserted into composites with organic or inorganic compounds. Several solution-based approaches have been studied, among those, however, only the exfoliation of pre-formed stage-1 graphite intercalation compounds (GICs) gives an appreciable yield of monolayer sheets. The first intercalation reaction of graphite with sulfuric acid and oxidizing agents was discovered in 1840 [3] and in 1855 a lamellar graphite oxide (GO) was prepared by the similar reaction [4]. GO is an ultimate stage-1 product of the oxidative intercalation by Brønsted acids that contains oxygen functionalities covalently bound to the carbon atoms of the graphene layers. Since then in the numerous following studies it has been established that graphite intercalation must involve host-guest charge transfer, resulting in partial oxidation, reduction, or covalent modification of the graphene layers. Many of the so prepared GICs can be exfoliated to give colloids of the single-layer graphene sheets, the electronic structure of which, however, becomes irreversibly altered [5]. Very recently we have revisited this 170-year-old concept and shown that graphite can be reversibly intercalated by non-oxidising Brønsted acids to give stage-1(or 2) GICs with phosphoric, sulfuric, dichloroacetic, and alkylsulfonic acids [6]. Here we describe synthesis and characterization of these GICs. X-ray photoelectron and vibrational spectra indicate that the graphene layers are not oxidized or reduced in the intercalation process. These observations are supported by density functional theory calculations that indicate a dipolar interaction between the guest molecules and the polarizable graphene sheets. We then discuss the exfoliation to monolayers of the stage-1 GICs that were prepared by both the non-oxidative (e.g. GIC-H3PO4 [6]) and oxidative (e.g. GO) intercalation by acids. GIC-H3PO4 can be exfoliated by stirring or sonication in several organic solvents of medium polarity (e.g. DMF) to give relatively stable (for several hours) solutions, from which the monolayer graphene sheets can be deposited on substrates by dropcasting. More sophisticated methods of manipulating these sheets are currently under investigation in our lab. In contrast, GO that has a high concentration of oxygen functionalities embedded in the carbon layers readily exfoliates in water and other polar solvents and forms very stable and viscous colloids of negatively charged monolayer sheets of oxidized graphene that are interconnected by H-bonds [7]. Due to large amount of the sp3 hybridized C atoms GO is an insulator but its electrical conductivity can be increased by several orders of magnitude by chemical, electrochemical or thermal reduction that remove majority of the oxygen groups and partially restore sp2 system of graphene. Monolayers of the reduced GO (RGO) can be thought of as graphene with high concentration of structural defects. The GO sheets can be easily incorporated in various nanoheterostructures with organic and inorganic species, which allows for a wide variety of applications in thin films, electrodes, catalysis and composites [e.g. 7, 8, 9]. These applications are briefly reviewed in the end of the talk. Acknowledgements This research was partially supported by the US Army Research Office MURI grant W911NF-11-1-0362. I thank my colleagues Thomas Mallouk, Vincent Crespi, Mauricio Terrones, Yuanxi Wang, Aise Berkdemir, Rodolfo Cruz-Silva, Ben Martin, Patricia Ollivier, Eugenia Buzaneva, Alexandr Gorchinskiy, and Sergey Chizhik, who contributed to the work described in this article. References 1. Novoselov, K. S., Geim, A. K., Morozov, S. V., Jiang, D., Zhang, Y., Dubonos, S. V., Grigorieva, I. V., Firsov, A. A. Electric Field Effect in Atomically Thin Carbon Films, Science 306, 666 (2004). 2. Geim, A.K. Graphene: Status and Prospects, Science 324, 1530 (2009). 3. Schafhäutl, C., Ueber die Verbindungen des Kohlenstoffes mit Silicium, Eisen, and anderen Metallen, welche die verschiedenen Gattungen von Roheisen, Stahl und Schmiedeeisen bilden, J. Prakt. Chem. 21, 129-157 (1840). 4. Brodie, M. B.-C., Note sur un nouveau procédé pour la purification et la désagrégation du graphite, Ann. Chim. Phys. 45, 351-353 (1855). 5. Dresselhaus, M. S. & Dresselhaus, G. Intercalation compounds of graphite. Advances in Physics 51, 1-186 (2002). 6. Kovtyukhova, N. I., Wang, Y., Berkdemir, A., Cruz-Silva, R., Terrones, M., Crespi, V., Mallouk, T. E., Non-oxidative intercalation and exfoliation of graphite by Brønsted acids. Nature Chem., 6, 957-963 (2014). 7. Kovtyukhova, N., Ollivier, P. J., Martin, B., Mallouk, T. E., Chizhik, S., Buzaneva, E., Gorchinskiy, A. Layer-by-layer assembly of ultrathin composite films from micron-sized graphite oxide sheets and polycations, Chem.Mater., 11, 771-778 (1999). 8. Kovtyukhova N, Buzaneva E., Senkevich A., Ultrathin Supported Graphite Oxide and Carbon Films, Carbon, 36, No 5-6, 549-554 (1998). 9. Zhu, Y., Murali, S., Cai, W., Li, X., Suk, J. W., Potts, J. R. & Ruoff, R. S. Graphene and graphene oxide: synthesis, properties, and applications, Adv. Mater. 22, 3906-3924 (2010).

Resume : Drug delivery across the skin is an extremely attractive route for both topical and systemic drug administration. Despite offering many advantages compared to oral or intravenous routes, it is still little explored and highly challenging because of the difficulties in overcoming the stratum corneum, considered the major permeability barrier and the rate limiting step for the delivery. The use of nanotechnology in this area has been proposed in order to tackle the limitations and maximize the ability in delivering drugs. By manipulating chemical structures and consequently improving the physico-chemical properties of the polymers constituting the nanocarriers, better skin permeation and improved efficacy of the delivery systems can be achieved. The work describes the design and the synthesis of new and bio-inspired amphiphilic block copolymers based on a novel combination of hydrophilic and hydrophobic monomers (the structure of the monomers cannot be disclosed as currently under patent consideration). Reversible Addition-Fragmentation chain Transfer (RAFT) polymerization was used to obtain copolymers with constant hydrophobic block and varying hydrophilic segment, ranging between 10 and 200 monomer units. The best synthetic conditions were identified and the physico-chemical properties of the copolymers were investigated. Two copolymers with suitable characteristics allowed to form micelles of 30 to 15 nm of diameter via self-assembly in aqueous based media, as confirmed by DLS, TEM, Cryo-TEM and AFM. Their critical micelle concentration was also assessed. Computational modelling correctly predicted the impact that the variation of the blocks ratio had on the morphology of the particles, and molecular dynamic simulations of the self-assembly support the data experimentally obtained. The toxicological aspects were studied in vitro in keratinocytes and fibroblasts, the most representative skin cells, where no evidence of acute toxicity was found at micelle concentrations below 100 µg/mL. Furthermore, cell internalization in keratinocytes was confirmed for polymers covalently labelled with a fluorescent tag, together with some preliminary studies of in vivo toxicity using zebrafish. Finally studies of biological effectiveness of the micelles such as drug loading, drug release profiles and the permeation of a polymeric membrane simulating the skin, suggested the potential to use the novel block copolymer micelles as dermal drug delivery carrier.

Resume : As a result of dwelling fossil resources and pressing environmental issues, the utilization of sustainable materials gains more and more impact nowadays. Among various natural resources, wood and wood-based materials will certainly be an essential part of the future challenges. The benefits of this green material are ease of processability, light weight, low cost, wide availability, excellent mechanical properties, and attractive appearance. In addition, wood possesses a unique hierarchical microstructure, which itself allows the design of future bio-derived materials. However, dealing with wood also bears some drawbacks, mainly due to its hygroscopic and anisotropic behaviour. Chemical modifications of the lignocellulosic scaffold are a simple yet versatile tool to alter wood properties. In this work, Thiol-Michael additions were chosen as a promising candidate for a “grafting to” method to modify lignocellulosic materials. It was shown in our previous studies (using EDX mapping,Raman and FTIR) that acrylated wood can be modified by simple click thiol approach. Given the availability of more complex alkene containing structures (such as organosilane vinyl, polymer-brushes and dendrimers), there is a large potential for further modification by click-thiols. The structural and chemical anisotropy of the wood surface represents a challenge for the implementation of such a technique. We currently aim to develop a straightforward protocol in green conditions to adapt the approach to wood. While preserving the surface and the wood scaffold intact, the goal is to bring novel functionalities to the wood surface, such as superhydrophobicity through microstructuring inspired by plant surfaces. Such a modification would be highly desirable to protect wood from external aggressions.

Resume : The optical reflectance of butterfly wings and beetle elytra often show peculiar features. Metallic-like reflectance, i.e., scattering angle selection is related to the photon momentum conservation, which follows from total or partial translational symmetry of the structure. Large angle scattering, by contrast, seems to always involve [1] some form of long-range disorder. Using disordered butterfly scale optical nanostructures as blueprints we constructed bioinspired 3D printed microwave device structures (absorbers, beam splitters, sensors, etc) active in a wide angle- and wavelength range. Utilizing a combination of dielectric- and conducting ingredients (plastic and nanocarbon composite) [2] it is possible to fabricate devices with predefined BRDF (Bidirectional Reflection Distribution Function) and BTDF (Bidirectional Transmittance Distribution Function). 3D printing of bioinspired microstructures offers a flexible and cheap technology to produce complex structures with tuneable electromagnetic characteristics, which provides a new route for microwave devices. 1. G. I. Mark et al, Phys. Rev. E 80 (2009) 051903. 2. A. Paddubskaya et al, J. Appl. Phys. 119 (2016) 135102.

Resume : Polydimethylsiloxane (PDMS) is a biomaterial broadly used in medicine and more recently, its use has spread to the fabrication of microfluidic chips in the last decade. PDMS has many advantages but it is high hydrophobic and has low surface energy which often represents a challenge for example in controlling sealing, adhesion and flow in microfluidics and for supporting cell adhesion with the subsequent biofilm growth. To make PDMS more hydrophilic, its surface can be modified using different processes most notably via dry oxidation processes such as plasma or corona discharge. However, oxidized PDMS surfaces exhibit hydrophobic recovery, a process by which shorter and relatively mobile PDMS chains diffuse through the polymer and rearrange at the surface so as to lower surface free energy. We discuss a novel method for the modification of PDMS surfaces via a two-step activation-functionalization process using glycans that bear highly reactive anchoring groups. Modified PDMS surfaces were characterized using a combination of Atomic Force Microscopy, Attenuated Total Reflectance Infrared Spectroscopy, X-Ray Photoelectron Spectroscopy, water contact angle measurements and fluorescence microscopy. Results show that functionalization with glycan groups yields hydrophilic PDMS surfaces with no evidence of hydrophobic recovery after 14 days. Immobilized glycans were also found to impart resistance to protein fouling, with important implications of the application of these coatings to biodevices and microfluidic systems.

Resume : The process of up-conversion of near infrared light (NIR) to visible light (VIS) has the potential for numerous biomedical applications. In particular, certain nanomaterials, such as NIR-active up-conversion nano-phosphors (UCNPs), can be used as local light sources for pathological tissue imaging and in situ generation of reactive oxygen species (ROS). The ROS production occurs via energy transfer from the VIS-light emitting UCNPs to the photosensitizer molecules incorporated into their surface. UCNPs based on lanthanide ions doped hexagonal ?-NaYF4 nanoparticles are of particular interest since they offer the highest quantum yield of up-conversion luminescence (UCL) and reveal a very wide spectral tunability in the visible range. Thus, appropriately functionalized ?-NaYF4 nanoparticles can find applications in both photodynamic diagnosis (PDD) and therapy (PDT). Additionally, multifunctional superparamagnetic nanoconstructs designed around ?-NaYF4 nanoparticles can be used for nanoparticles tracking with the external magnetic field, enhanced contrast in magnetic resonance imaging (MRI), as well as for diseased tissue eradication via local heating with alternating magnetic field (AMF), that is by hyperthermia. In this work, we sensitized opto-magnetic multifunctional nanoconstructs based on rare earth ions ? doped ?-NaYF4 nanoparticles, having sizes < 20 nm and revealing a high UCL efficiency. These ?-NaYF4 nanoparticles were co-encapsulated in SiO2 with superparamagnetic Fe3O4 nanoparticles (SPIONs), thus leading to the formation of UCNPs&SPIONs@SiO2 nanoconstructs. The thorough characterization confirmed that UCNPs&SPIONs@SiO2 nanoconstructs combine the capability of NIR-to-VIS light up-conversion with useful superparamagnetic properties. We also demonstrated that, under illumination with NIR light, the UCL emission of rare earth ions ? doped ?-NaYF4 efficiently excited molecules of selected photosensitizers (e.g. Rose Bengal, Methylene Blue, hematoporphyrin, silicon phthalocyanine dihydroxide), towards ROS generation. The ROS generation was measured with optical spectroscopy and electron spin resonance (ESR). The hyperthermia effects due to the superparamagnetic properties of SPIONs was measured as a function several experimental parameters, including: the time of application of AMF, the size and concentration of nanoparticles, as well as the type of the solvent. The intrinsic loss power (ILP) factor was determined. Toxicity remains one of the fundamental issues concerning biological and medical application of advanced materials. Therefore, we tested our nanoconstructs in living HeLa and HEK293 cells using commercial viability tests, i.e. MTT and Presto Blue assays. We demonstrated that the opto-magnetic nanoconstructs are relatively non-toxic and are, therefore, potentially useful for selected medical applications. Acknowledgements The research was partially supported by the EU within European Regional Development Fund, through the grant Innovative Economy (POIG.01.01.02-00-008/08), the project ?Development of the cluster center of biomedical engineering? implemented under Economy Operational Program (project no. UDA-POIG.05.01.00-00), the EU Research Project FP7-People-2012-IRSES-BRASINOEU (Grant Agreement Number: PIRSES-GA-2012-318916), the grants of PNSC 2013/11/B/NZ1/00089, NN UMO-2013/08/A/ST3/00297, DEC-2012/07/B/ST5/02080 and DEC-2014/15/D/ST5/02604. This work has been done in the NanoFun laboratories co-financed by the European Regional Development Fund within the Innovation Economy Operational Program, the Project No. POIG.02.02.00-00-025/09/. This research was also co-financed by the Swiss National Science Foundation through the Nano-Tera.ch Focused Project (NTF), ?NanoUp?.

Resume : The principal aim of the study was to synthesize bio-luminescent markers based on oxide nanoparticles. The markers opens up new perspectives for selective treatment of local tissues and for early diagnosis neoplastic diseases. The Gd2O3 and ZnAl2O4 matrixes were doped with rare earth (RE) ions, erbium (Er3+) and ytterbium (Yb3+). The effect of transition metals (Zn, Mo) and alkali metal (Li) doping on the upconversion quantum yield has been determined. We selected the oxide matrices, because the high phonon energies permit to obtain red luminescence, resulting from the near infrared excitation (NIR) at 980 nm. Preferred by us, the visible luminescence is in the biological window of low scattering, low absorption and low autofluorescence from of biological objects. The independent ZnAl2O4: Er3+, Yb3+ nanoparticles [1], useful to functionalization, were synthesized by combustion aerosol method. The upconverting nanoparticles emit primarily the red light. The incubated with HeLa tumor cells penetrate the cells by endocytosis. Furthermore, using the popular combustion method we synthesized the Gd2O3: Er3+, Yb3+, Zn2+ [2] nanoparticles. The zinc content was optimized. An optimal content of zinc was determined in order to achieve the highest red luminescence efficiency of the upconversion process. The zinc dopant ions and generated parallel oxygen vacancies alter the local symmetry around the rare-earth ions and the distance between the sensitizer (Yb) and the activator (Er). The results confirmed that the NPs, at the concentration up to 50 ?g?ml-1 (PrestoBlue and MTT assay), are highly biocompatible. The nanoparticles were localized in the cellular matrix in the lysosomes. Due to large Gd3+ ions magnetic moment they can be used as a MRI agent, as well. In the presence of other RE ions the Gd3+ ions are paramagnetic. The obtained nanostructures, based on the oxide matrix, can contribute to the development of diagnostically useful materials. The red luminescence permits to obtain a high value of signal to noise ratio thus can be potentially useful for bio-imagining. ACKNOWLEGMENTS The research was partially supported by the EU within ER DF, through grant IE (POIG.01.01.02-00-008/08) and was partially supported by the grant from the PN SC 2013/11/B/N21/00089 and partially supported by the grant DEC-2012/07/B/ST5/02080 of the NS Center of Poland and Center of Excellence. This work has been done in the NanoFun laboratories co-financed by the ER DF within the IE OP, the Project no. POIG.02.02.00-00-025/09/. This research has been co-financed with the EU funds by the ES Fund and was partially supported the cluster of Biomedical Engineering Center co-financed by EU funds under the Operational Programme Innovative Economy (project number UDA-POIG.05.01.00-00). Acknowledgements to Dr. Eng. Krzysztof Kopczy?ski, (Institute of Optoelectronics, Military University of Technology, Warsaw) for providing access to measurements of EXC-EMISS maps NPs REFERENCES [1] I Kami?ska, K Fronc, B Sikora, K Koper, R Minikayev, W Paszkowicz, K Sobczak, T Wojciechowski, M Chwastyk, A Reszka, B J Kowalski, P St?pie?, D Elbaum. RSC Adv., 2014, 4, 56596-56604 [2] I. Kami?ska, K. Fronc, B. Sikora, M. Mouawad, A. Siemiarczuk, M. Szewczyk, K. Sobczak, T. Wojciechowski, W. Zaleszczyk, R. Minikayev, W. Paszkowicz, P. St?pie?, P. Dziawa, K. Ciszak, D. Pi?tkowski, S. Ma?kowski, M. Kaliszewski, M. W?odarski, J. M?y?czak, K. Kopczy?ski, M. ?api?ski, D. Elbaum, RSC Adv., 2015, 5, 78361?78373.

Resume : Magnetic nanoparticles (MNPs) and their ability to convert magnetic energy into heat are currently explored around the globe for various kinds of biomedical applications, with a particular emphasis on hyperthermia treatment. The heating power of these materials is dictated by a myriad of internal (e.g. NP size, polydispersity or crystallinity) and external (e.g. magnetic field strength or frequency) phenomena. However, experimentally conveying the effective heating power is not always straightforward, reproducible or easily feasible with conventional methods (e.g. fiberoptic cables, thermocouples or standard IR imaging). Variations among synthetic batches are not promotive either, as this requires every individual sample to be investigated and validated before administration. Our group is thus dedicated to developing more reliable and precise experimental methods to evaluate the heating power of the respective MNPs. In this context, we present an abstract approach based on lock-in thermography to rapidly screen the thermal signatures of the MNPs at unprecedented thermal resolutions to subsequently evaluate their therapeutic potential. Superparamagnetic iron oxide nanoparticles exposed to an alternating magnetic field (AMF) were used as model NPs to validate the setup, and their thermal properties were investigated in different states of matter. This included NPs in liquid, semi-solid and aggregated state. Compared to conventional techniques, this approach is fast, sensitive, non-invasive alternative and capable of probing multiple and dilute specimens simultaneously. In turn, this would contribute in speeding up screening procedures or facilitating comparative studies.

Resume : Over the last decades vast efforts were devoted to understand and utilize the unique properties of transition metal dichalcogenide (TMDC) layered compounds. Such compounds have strong (covalent) bonds in the layer (a-b plane) and weak van der Waals forces along the c-axis which hold the layers together. Tenne et al., showed that, due to the high energy stored in the dangling bonds at the periphery of the nanoscopic sheets, the TMDC layered compounds are prone to form closed-cage nanostructures (NS). [1] Due to their unique properties and promising applications, the study of these NS is a rapidly growing field. Recently, it was learned that the semiconducting MS2 (M=Mo,W) NS, maintains the excitonic structure of the bulk together with a new plasmonic scattering resonance (which does not exist in the bulk). [2] The optical properties of such NS can be modified and controlled by verity of methods, including doping, size, aspect ratio etc. [3-5] Thus, in addition to current application as solid lubricants and host of intriguing medical applications and for biopolymer reinforcement [6], MS2 NS can be used for nano-optoelectronics. Here nano-imaging is used to study the properties of plasmonic and excitonic photo-induced response in an individual WS2 nanotube (NT) in the visible and IR region. Surface waves were detected and imaged with 2-5 nm resolution at 633 nm using a scattering-type scanning near-field optical microscope (s-SNOM) (Fig. 1). Interestingly, these waves were not observed at 1500 nm. These findings coincide with the assumption that WS2 NT plasmons occur mainly in the visible and near IR region. The standing wave appears with specific incident light polarization and is anticipated to be induced by interference between the tip-excited wave and its reflection from the NT. In addition, single particle spectroscopy microscopy (SPSM) was used in order to measure absorption and scattering of individual NTs over the spectral range of 420-720 nm. Here again, surface waves with specific incident light polarization were detected in the visible light range (Fig. 2). The s-SNOM or SPSM techniques provide a unique way to study the light-matter interactions in a single NS. Furthermore, the combination of these techniques and the unique properties of MS2 NS allow generation of exciton and/or plasmon resonances over a wide spectral range (400-2500nm). Since the optical modes in MS2 NS vary as a function of incident waves, polarization etc., they can be used for nanophotonic circuitry and as saturable absorbers. Moreover, the MS2 NS are not toxic and are optically active in the visible area, thus can be used for optical tracking during medical diagnostics, targeted drug delivery or medical diagnostics. _____ 1. Tenne, R., et al., ?Polyhedral and cylindrical structures of WS2?, Nature, 1992. 360(6403); 2. Yadgarov. L., et al., ?Plexciton in WS2 nanotubes?, In preparation 2016.; 3.Yadgarov, L., et al., ?Dependence of the absorption and optical surface plasmon scattering of MoS2 nanoparticles on aspect ratio, size and media? ACS nano, 2014. 8(4). ; 4. Sun, Q.C., Yadgarov. L., et al., et al., ?Observation of a Burstein?Moss shift in Re-doped MoS2 nanoparticles?, ACS nano, 2013. 7(4); 5. Yadgarov L., et al., ?Controlled doping of MS2 (M= W, Mo) nanotubes and fullerene?like nanoparticles, Angew. Chem. Int. Ed., 2012. (51); 6. Visic, B. and R. Tenne, 2015, Wiley-VCH Verlag; 7. Pardo, M, et al. "Low cytotoxicity of inorganic nanotubes and fullerene-like nanostructures in human bronchial epithelial cells: relation to inflammatory gene induction and antioxidant response." Environmental science & technology 48.6 (2014): 3457-3466.

Resume : Doxorubicin (Dox) is one of the most frequently chemotherapeutical drug used worldwide; however, some important side effects such as cardiac toxicity and bone marrow aplasia are relate to Dox. To solve these inconvenient, different types of nanocarriers were developed trying to decrease the toxicity and improve the efficacy of Dox. The first nanoformulations developed, e.g. Dox liposomes are composed of nanocarriers with the active compound physically entrapped inside nanostructures. In these situations, drug release to plasma or others sites depends on the movement of the compounds in a concentration gradient. An evolution of those systems involves the association of prodrug complexes with nanocarriers to improve the delivery of active drugs to specific target tissues. Prodrug complexes, such as macromolecular prodrugs are defined as an active compound (e.g. Dox) linked to a macromolecule that has to be metabolized in vivo to release the linked active drug. One of the main advantages of these systems is the possibility to interpose specific linkers between the active compounds and the macromolecules that could be externally triggered to release drugs in specific situations such as acid environments. In this abstract we present a prodrug composed of a 16 hexadecane alkyl chain linked to Dox through a pH-sensitive linker associated with a lipid nanoemulsion. Our in vitro (bench) results proved that the prodrug (C16-Dox) and the nanoemulsion containing it (NE-C16-Dox) were able to release Dox in acidic, similar to tumor tissues, conditions. In addition, NE-C16-Dox was useful to deliver specifically Dox to tumor sites and was able to impair tumor growth and prevent the development of distant lung metastasis. Taken together, these results indicate that NE-C16-Dox is promising for breast cancer treatment, thus creating possible opportunities to translate these nanotechnologies concepts to clinical applications.

Resume : Recently, selol, a mixture of selenitetriacylglycerides, has been studied for its anticancer activity. As this compound is highly hydrophobic, it was associated, in a previous study, to poly(methyl vinyl ether-co-maleic anhydride)-shelled nanocapsules in order to improve its compatibility with aqueous media. Following this line of research, the present report aimed at improving the in vitro specificity of the selol nanocapsules to cancerous cells by conjugating folic acid to their surface. It is known that several cancer cells overexpress receptors to folate. Stable folic acid-decorated selol nanocapsules were obtained, which showed to be spherical, with a hydrodynamic diameter of 364 nm, and zeta potential of -24 mV. In comparison to non-decorated selol nanocapsules, folic acid-decorated selol nanocapsules presented higher activity against 4T1, MCF-7 and A549 cancer cells. Moreover, the decoration of nanocapsules with folic acid did not alter its toxicity towards normal murine fibroblasts, NIH-3T3 cells. These results show that the decoration with folic acid increased the toxicity of selol nanocapsules to cancer cells, but not to normal cells. These nanocapsules, besides enabling to disperse selol in an aqueous medium, increased the toxicity of this drug in vitro, and may be useful to treat cancer in vivo, potentially increasing the specificity of selol towards cancer cells.

Resume : Hybrid nanoscale materials are nowadays focus of intensive scientific and industrial research pushed by expectations from fields as diverse as microelectronics and medicine. Bottom-up manipulation of objects allowed by the layer-by-layer (LbL) approach, while controlling position and inter-particle distances has made possible the construction of nanostructures with properties tailored at the nanometer level. In particular, LbL polymeric nanofilms can be assembled on a broad of substrates aiming to load, as for instance, colloidal nanoparticles. Further, these assemblies can be designed as erodible multilayers to be applied in transcutaneous drug delivery. LbL assembly can be driven by different types of intermolecular including ionic interaction, hydrogen bonding, complexation, biospecific recognition, hybridization, hydrophobic interaction, and covalent attachment; influencing polymer assembly and the properties of nanofilms. As colloidal particles, iron oxide nanoparticles (ION) offer an ideal and unique platform for development of multifunctional theranostic agents. In a single system they combine superparamagnetism, biocompatibility, and a controllable surface chemistry. In this study, we fabricated LbL nanofilms comprising citrate-coated ION (10 nm) assembled with different polymers, chitosan or polyvinyl alcohol aiming to study the influence of ION-polymer interactions on the end properties of the nanofilms and their citoxicity. Built-up of the nanofilms was monitored using UV-Vis spectroscopy, while the morphology and structure was studied by Raman spectroscopy, field emission scanning electron microscopy and atomic force microscopy. In addition, toxicity tests were performed via cell viability in vitro in cultures of NIH-3T3 cells using MTT assay. Both assembled nanofilms exhibited no toxicity, and the study of disassembly in biological conditions, aiming transcutaneous drug delivery, is being conducted.

Resume : With a predicted ageing population and increasing expectations regarding quality of life in old age, there is an ever increasing demand for procedures such as total hip replacements, bone reconstructions, and spinal fusions, resulting from conditions such as articular cartilage degeneration and osteoporosis. Commercial calcium phosphate composites for bone regeneration are restricted to applications that require only moderate load bearing abilities. High toughness bioinert materials are used in the articulating couple of artificial joint implants, but they do not support direct bone/material interfaces or bond. To date there is no tough and strong ceramic in regular clinical use with ability to create a strong, biologically relevant, interface with bone. New advances in biomaterials, with improved processing, bioactivity and/or tailored shapes, providing enough structural integrity and bone integration/regeneration are currently in development at the laboratory scale. However, due to the gap between academic R&D and commercial production, and between materials scientists and clinicians, medical application of these new materials will never be possible unless companies and medics are involved in the development. This COST Action, NEWGEN, aims at creating the seed for the European research and industry collaboration, combining basic knowledge from academic laboratories, R&D centres, medical units from hospitals, and a significant number of companies More than 160 groups are involved in our consortium, with a large part of R&D centres, industrials and medical groups. Since the start of the Action, in October 2013, the collaboration between partners has become more and more efficient, resulting in several successfull European proposals in the framework of H2020, as well as joint scientific publications in reknowned journals and conference proceedings. But the COST Action networking tools that has attracted more and more importance during the progress of our Action are the Short Term Scientific Missions (STSM), i.e. giving the opportunity to exchange visits between researchers involved in the consortium, and allowing scientists to visit an institution or laboratory in another COST country (member of the Action). They are aimed at fostering collaboration, sharing new techniques and infrastructure that may not be available in other participants' institutions or laboratories. STSM are first intended especially for young researchers (PhD students and Early Career Investigator). Up to now, more than 30 STSM's has been approved in NEWGEN, and their main scientific subjects were well balanced between the 4 Working Groups defined in our Action: - WG1 : Design and Synthesis of Raw Materials - WG2 : Manufacturing and characterization of 3D-porous scaffolds - WG3 : Functionalization of implants for improved functional and therapeutic effects - WG4 : In vitro an in vivo evaluation of the performance Scientists reports requested at the end of each mission clearly indicate the interest of the opportunity to experience in a second laboratory, and all relate future joint publication of their results, as obvious output of this mission.

Resume : ?Special Session: Advanced Materials and Technologies for Bone Engineering? Ideal scaffolds should mimic the matrix of the tissue to be replaced, acting as a three-dimensional template. In particular, scaffolds should possess a micro/macro structure close to that of natural bone, made by an interconnected macro-porous network which allows cell penetration, tissue ingrowth and vascularization. Hydroxyapatite (HA, Ca10(PO4)6(OH)2) has proved to be an attractive material for this application, due to its chemical composition close to that of mineral bone. In addition, it was recently demonstrated that the incorporation of small amounts of silicon within the HA lattice improves the HA solubility and rate of bone apposition, as well as the proliferation of human osteoblasts in vitro. In this work, biocompatibility data obtained on a newly designed three-dimensional nano-structured porous scaffold made of pure and silicon-substituted HA are discussed. In fact, in order to tailor the porosity features (in terms of shape, size and volume of pores) a modified gel-casting procedure was set-up. This method exploits agar as the gelling agent and polyethylene spheres as the pore formers. The sintered components were characterized by tailored macro- and micro-porosity features, as required for the development of engineered ceramic scaffolds. The structure was composed by spherical pores (porosity of about 60 vol%) within a well densified ceramic skeleton. The mechanical properties were tested on reference dense samples as well as on the porous materials, showing compressive strength in the range 200-350 MPa for the dense samples and of 7-10 MPa for the porous ones. Biocompatibility was tested by using murine embryonic stem cells (ES). Cell culture analysis indicated that ES cells adhere well on both pure and Si-substituted HA scaffolds; however, it was demonstrated that the Si-substitution improved the subsequent ES cell proliferation rate.

Resume : Special Session: Advanced Materials and Technologies for Bone Engineering Bone replacement materials must fulfill various requirements, such as biocompatibility and appropriate mechanical properties. In particular, the latter include suitable stiffness and sufficient strength. Finding such so-called biomaterials with adequate mechanical properties based on experimental trial-and-error approaches is cumbersome and ineffective, thus mathematical is considered a promising complement. Here, a hydroxyapatite-based, granular biomaterial, developed as bone replacement material with the human mandible as targeted application region, is studied. This material exhibits a distinctive hierarchical organization, with different types of pore spaces of characteristic lengths ranging from nanometers to millimeters. Additionally, once exposed to the targeted physiological environment (i.e. the immediate vicinity of mandibular bone tissue), new bone tissue forms around the biomaterials granules, whereas the hydroxyapatite crystals undergo resorption. The presented work aims at estimation of both stiffness and strength of this material, taking into account the compositional changes due to bone ingrowth and hydroxyapatite resorption. For this purpose, micromechanical homogenization techniques are employed, yielding a three-step stiffness homogenization scheme, giving access to the macroscopic stiffness tensor of the scaffold material. On the other hand, the micromechanical model is extended by a failure criterion relating to the hydroxyapatite needles, based on which the loading type-specific macroscopic strength of the scaffold material can be deduced. The above-sketched micromechanical model gives access to stiffness and strength estimates for the scaffold material, as functions of various material and design parameters of the material, including the macro-porosity, the granule size, the density of cracks, as well as the rates of bone formation and scaffold resorption. The presented modelling approach provides insights beneficial both for the scaffold material design process and for a clinician actually applying such material. Namely, the aforementioned material and design parameters could be tuned based on model predictions, to optimize the mechanical properties of the scaffold material. Complementing this way the experimental trial-and-error strategy that, in this respect, still is the gold standard, would lead to a significant improvement of the design process.

Resume : “Special Session: Advanced Materials and Technologies for Bone Engineering” One of the most important approaches of biomedical field is the development of new, effective and non-invasive medical diagnosis, and treatments that have such requirements as advanced technologies for tumor imaging. Gadolinium (Gd) compounds can be used as MRI contrast agents, however the release of Gd 3+ ions present some adverse side effects such as renal failure, pancreatitis or local necrosis. The present work proposes a strategy that combines therapeutics and diagnosis on a single platform. The main aim of the work was the development and optimization of Gadolinium (Gd) based nanoparticles coated with silica to be used as drug delivery and tumor imaging agent. Gd based particles were prepared through a precipitation method and afterwards, these particles were covered by silica using Stöber method with ammonia. Results showed that nanoparticles were homogeneous regarding chemical composition, silica layer thickness, total size, morphology and silica. In vitro cell tests showed very a good cell proliferation and drug delivery tests clearly showed that gadolinium based silica coated nanoparticles have improved drug release efficiency in acidic medium and decreased the amount of cumulative drug released in neutral medium. This release behavior is desirable for cancer treatment, where most of the drug remains inside the nanoparticle during blood circulation, but when it reaches the acidic tumor tissue, the low pH triggers drug release. In conclusion, our results showed that Gd based nanoparticles coated with silica for imaging and drug delivery applications were successfully produced by a well-controlled method.

Resume : INTRODUCTION Bioceramic scaffolds exhibit exceptional compressive strength (Young’s Modulus) and excellent biocompatibility due to their chemical and structural similarity to the mineral phase of native bone1. The main deficiency is their brittle nature, which poses a concern in high load-bearing biological applications2. Polymers on the other hand have insufficient strength to meet the mechanical requirements of bone graft substitutes in vivo, whilst suffering from the inability to induce mineralisation3. However polymers can be developed by tailoring their physicochemical properties4 hence do not suffer from brittleness. Hence the current study will assess a polymeric-bioceramics composite hydrogel scaffold to determine if this combination acts synergistically to overcome the limitations of either individual component. MATERIALS AND METHODS Polyethylene glycol dimethacrylate (PEGDMA) and acrylic acid monomeric solution was added to α-wollastonite and β-tricalcium phosphate scaffold (W-TCP), and polymerised using free radical photopolymerisation technique. The resultant composite material was characterised by FTIR, SEM, swelling studies, gel fraction and compression testing, whilst biological analysis included cytotoxicity, antimicrobial assay and simulated body fluid analysis. Statistical analysis of the data was performed using a Tukey test Post hoc test. RESULTS AND DISCUSSION FTIR and SEM analysis of the resultant composite illustrated that the polymer had penetrated the bioceramic scaffold. Swelling studies in buffer solution pH 7.4 showed a significant decrease in swelling (p<0.05) when the polymer was incorporated into the bioceramic scaffold. Additionally incorporation of the monomeric solution into the bioceramic scaffold was found not to disrupt the network connectivity and in all cases gel formation occurred. Compression testing demonstrated that the incorporation of the polymer into the bioceramic scaffold resulted in an increase in the mechanical properties. Cortical bone has a compressive strength of 100-200MPa5, hence providing scaffolds with the required mechanical stability for use as a bone substitute material is essential. Compression results (>100MPa) revealed a significant increase in the compressive strength of the polymer-bioceramic composite when compared to the polymer control hydrogel (p<0.05). This improvement in mechanical properties may be attributed to the reduction in the degree of swelling, the bioceramic scaffold absorbing the compressive load and the polymer within the scaffold distributing the load hence reducing brittleness of the bioceramic. Preliminary bioactivity results indicate hydroxyapatite formation on the surface of the composite scaffold. Cytotoxicity and antimicrobial results are ongoing and will be presented at the conference. REFERENCES 1. O'Brien, Biomaterials and scaffolds for tissue engineering. Materials Today 14(3) 1-21, 2011 2. Shrivats (et al.), Bone tissue engineering: state of the union. Drug Discovery Today 19(6) 781-786, 2014 3. El-Sherbiny and Yacoub, Hydrogel scaffolds for tissue engineering: Progress and challenges. Global Cardiology Science and Practice 38 316-342, 2013 4. Vo (et al.), Strategies for controlled delivery of growth factors and cells for bone regeneration. Advanced Drug Delivery Review 64 1292-1309, 2012 5. Bose (et al.), Recent advances in bone tissue engineering scaffolds. Trends in Biotechnology 30 (10), 546-554 2012 Acknowledgments This work has been supported through COST action NEWGEN STSM funding and AIT Presidents Seed Fund. Authors want to acknowledge the Ministry of Economy and Competitiveness of Spain for financial support under projects MAT2013-48426-C2-1R and CSIC-201460E066.

Resume : "Special Session: Advanced Materials and Technologies for Bone Engineering" In our research work Ag, Zn, Mg and Sr containing biocompatible and biodegradable coatings were prepared onto implant materials by pulse current deposition process with different parameters. Cell proliferation tests with reagent WST-1 were carried out to study the biocompatibility properties of layers and LDH test were also performed to determine the cytotoxic effects of modified CaP coating on MG 63 cells. The main goal of this research is to develop a new type of coating onto medical implants, which simultaneously possesses antibacterial and biocompatible properties.

Resume : “Special Session: Advanced Materials and Technologies for Bone Engineering” Alendronate (Al) and zoledronate (Zol) belong to the family of bisphosphonates (BPs), which are widely used to treat a variety of diseases with excessive bone resorption. Although their mode of action has to be fully elucidated yet, it is known that BPs bind very strongly to hydroxyapatite (HA), and as a result are taken up by bone. It has been reported that Zol displays a greater binding affinity than Al towards HA surface. Due to its important role as precursor of biological HA, octacalcium phosphate (OCP) is a good candidate for the preparation of composites for bone tissue repair. In this work we have investigated the interaction of OCP with Al and Zol, in order to develop new materials useful for treatment of various diseases of bone metabolism. We obtained OCP as the unique crystalline phase in presence of both Al and Zol, as confirmed by the results of X-ray diffraction analysis and FT-IR and Raman spectroscopy. Al and Zol content in the solid products was about 5.5% and 3.5%, respectively. BPs presence caused a reduction of the mean length of the coherently scattering domains and a reduction in the dimensions of the composite crystals compared to those of pure OCP. The data suggest different mechanisms of interaction of Zol and Al with OCP structure, which can be justified by the results of the study of calcium coordination environment. In order to mimic physiological microenvironment in vitro, a triculture model involving osteoblast, osteoclast and endothelial cells, was used to test the biological response. The results show that composite materials significantly affected cells behavior, downregulating osteoclast differentiation, enhancing osteoblast activity, and supporting endothelial cells proliferation.

Resume : “Special Session: Advanced Materials and Technologies for Bone Engineering” Hydroxyapatite ceramics are widely used as scaffolds for bone filling. Because of their potential enhanced bioactivity, silicon substituted hydroxyapatites (SiHA) have been investigated for many years. These ceramic scaffolds are osteoconductive, i.e. they allow bone ingrowth into their porous network. However, their use for large bone defects would result only in a partial colonisation by newly formed bone at the peripheral region of the implant. Osteoinduction properties are required to overcome this limitation. In this context our work proposes to immobilise Bone Morphogenetic Protein (BMP2), which is a potent osteoinductive factor, via organic cross-linkers onto SiHA ceramic surface. SiHA microspheres were produced by a spray drying process. To control the density and the release of the immobilised biomolecules, a covalent grafting of BMP2 was performed via ethoxysilanes and cleavable polyethylene glycols. A method based on Kaiser's test was used to assay the free amino groups available at the ceramic surface for BMP2 immobilisation. The chemical composition of the modified surface and the nature of the organic-inorganic bonds were analysed by X-ray photoelectron spectroscopy and thermogravimetry coupled with mass spectrometry. It was shown that the majority of molecules were covalently bonded but residual adsorption could not be excluded. Kinetics of BMP2 release from these functionalized microspheres was investigated in vitro and compared to those obtained from BMP2 adsorbed. The in vitro assessment of the biological activity of functionalized BMP2 is under progress and will be also presented. This work is supported by the French Agence Nationale de la Recherche (“CeramOs” project, ANR-13-BSV5-0002).

Resume : SPECIAL SESSION: ADVANCED MATERIALS AND TECHNOLOGIES FOR BONE ENGINEERING The use of electrospun nanofibres for guided bone regeneration or bone scaffolds align with next-generation healthcare, especially as electrospun nanofibres are highlighted as being particularly effective in tissue engineering. However, optimization of the electrospinning process for cell growth and their interaction with nanofibre surfaces is yet to be determined. To understand cell proliferation and migration into the nanofibrous scaffolds we use direct 3D imaging at high spatial resolution based on focus ion beam and scanning electron microscopy (FIB-SEM). FIB–SEM uses both FIB to section through a material and SEM to image exposed surfaces following the FIB sectioning, which is typically referred to as ‘slice-and view'. The interactions between cells, their adhesion and integration with the scaffolds via filopodia growth can be visualized in great details by using 3D tomography. Especially the proliferation depth with regard to the spacing between nanofibres can be analyzed and quantified by 3D image analysis. The presented 3D imaging technique therefore shows a new approach in high resolution visualization the cell growth on electrospun nanofibers, and potentially other biomaterials, that will develop and design new biomaterials for a range of clinically important applications including orthopaedics and especially for bone tissue engineering.

Resume : Titanium-based implants were successfully used to replace osteoarthritic joints for many years. Due to, increasing number of aseptic loosening incidences of such implants, surface modification of titanium alloys is required. Electrochemical process, called micro-arc oxidation (MAO) was used to deposit coatings on Ti6Al7Nb alloy. This process allows to obtain rough, porous, ceramic layer at the Ti-base substrate, in order to improve bone-implant integration. The effect of different MAO reaction times (30-600 s) on the microstructure and properties of formed coatings was evaluated. Thickness, chemical composition, roughness, adhesion to the substrate, wettability as well as preliminary biocompatibility of coated samples was investigated. The longer the reaction time the, greater thickness, roughness and hydrophilicity was observed in prepared coatings. Ceramic layers were mainly composed of titanium dioxides. However, in the coatings after at least 3 min long MAO process, calcium titanate and hydroxyapatite were detected at XRD spectra as well. MG-63 cells adhered at the surface of all tested samples and proliferated over the incubation period; no cytotoxicity effect was observed. Thus, micro-arc oxidation was found to be a simple and low cost method, that enables to deposit functional and well adherent coatings on titanium alloys. Acknowledgement The study was realized within OPTYMED research project (nr 2013/08/M/ST8/00332) financed by National Science Centre of Poland.

Resume : Bone tissue engineered (TE) scaffolds typically sacrifice porosity for improved mechanical properties (1). This research uses layer by layer assembly to tailor the mechanical properties of bone TE scaffolds whilst maintaining high porosity. Polyurethane (PU) foams (98% porosity) were deposited with 15-60 multilayer coatings (polyethylenimine+/polyacrylic acid-/polyethylenimine+/nanoclay-)n. Planar substrates were coated to determine coating thickness and mass. Micro-computer tomography (MicroCT) was performed to examine coating thickness on 3D porous structures. Coated foams were mechanically tested under uniaxial compressive loading within the linear elastic regime. Sample characterization was conducted under ambient conditions and hydrated conditions (1 h post-submersion in deionised (DI) water). Uncoated PU foam cylinders demonstrated a compressive elastic modulus of 99.8±7.13 kPa; the elastic modulus increased to 4.90±0.46 MPa on application of 60 multilayers with a coating thickness of 5.81±0.95 µm and density of 1953 kg/m3. Testing the 60 multilayer 3D structure under hydrated conditions system reduced the elastic modulus (97.8±9.11 kPa) and increased the coating thickness (7.61±1.58 µm). Post-desiccation the elastic modulus recovered to 5.16±0.60 MPa. The increase in coating thickness and reduction in mechanical stiffness is due to the plasticising effect of the water, as observed in previous studies (2). Preliminary studies have crosslinked the coating to retain a portion of the ambient mechanical properties of under hydrated conditions. [1] Giannoudis P V, Dinopoulos H, Tsiridis E. Bone substitutes: an update. Injury (2005) [2] Hariri H, Lehaf A, Schlenoff J. Macromolecules. 2012; 45(23):9364–72

Resume : Metallic biomaterials possess the combination of properties required for load-bearing applications. However, there are still an undesirable number of implants failures. In order to overcome such concerns, improvements could be achieved by designing biomaterials where the surface is independently tailored. Therefore, the objective of this contribution is to improve Ti-surfaces osteointegration adding organic and biomolecules. We hypothesize that the -OH groups presented in TiO2 surface will interact with the functional groups of the organic molecules enhancing the osteogenic peptide interaction and improving cell differentiation. TiO2 deposition upon Tic p substrates was performed by spin coating technique. The samples were functionalized with four different organic spacers. Peptide ESQES and QESQSEQDS derived from DMP1 were diluted in the ratio 1:4, respectively. Surface measurements demonstrated that biofunctionalized titanium presented higher surface roughness, which has shown improved cell adhesion. XPS analysis revealed an increase in the intensity of C 1s for all samples, indicating the success in the functionalization process. Proliferation assay showed that TiO2 coated with MPA (3-mercaptopropionic acid) and the peptides presented best results with hMSC-GFP cells. These findings suggest that the bio-functionalization of Ti substrates could possibly open the door for designing better implants and their use in regenerative medicine.

Resume : Ti-6Al-4V alloys are commonly used as biomaterial in dental and orthopedic implants. In the body, they may suffer mechanical wear and electrochemical corrosion (tribocorrosion), leading to the release of metallic-based compounds or debris. Consequently, toxic potential effects of such alloying elements must be evaluated, in special regarding to vanadium, considering that there are few reports about the toxicity of this element and its compounds. Furthermore, vanadium may induce ambiguous cellular responses whose toxicity is dependent of oxidation state and dose. In this contribution, in vitro studies were performed using commercial vanadium pentoxide (oxidation state +V) and commercial Ti-6Al-4V metallic powder against mouse fibroblasts (NIH3T3 line) and pre-osteoblasts (MC3T3-E1 line). Different concentrations (from 0.2μg/ml to 2,000μg/ml) were tested indirectly (contact with culture cell medium) in three different periods (24h, 48h and 72h) and evaluated by MTT and Crystal Violet assays. Optical microscopy was used to verify possible changes in the cell morphology. The obtained results show no statistic difference for any concentration or period in cell viability in comparison with the control in both cell lines for Ti-6Al-4V powder. However, a significant decrease in live cells was observed for the three higher concentrations of V2O5 in all periods and cell lines. Additional tests against kidney and liver cells are under progress.

Resume : Special Session: Advanced Materials and Technologies for Bone Engineering Introduction: Advanced age, osteoporosis and unhealthy life-style diminish bone formation and remodeling rate so fusion enhancement techniques could be beneficial for patients with osteoporosis who need spinal arthrodesis. Herein we investigated the posterolateral fusion rate in ovariectomized (OVX) rats using two new materials: strontium substituted hydroxyapatite (SrHA) nanocrystals and alendronate functionalized HA (HA-AL) nanocrystals. HA was synthesized at increasing Sr concentrations (SrHA5; SrHA10) and alendronate content (HA-AL7; HA-AL28). Materials and Methods: A posterolateral spinal fusion model in twenty-five Sham-Operated and in twenty-five OVX female rats was used. Materials were bilaterally implanted between transverse processes of lumbar vertebrae. Sham and OVX animals were divided in five groups: HA, SrHA5, SrHA10, HA-AL7 and HA-AL28. The assessment of bone fusion was carried out by micro-CT, histology and histomorphometry. Results: Some gaps between the transverse processes were observed by micro-CT in OVX HA group, while they were not present in the other groups. These results were consistent with histological and histomorphometrical analyses showing that in OVX animals SrHA and HA-AL materials displayed significantly higher BV/TV and Tb.Th and significantly lower Tb.N and Tb.Sp in comparison with HA alone. Discussion: Results suggest that in spinal fusion the incorporation of Sr, as well of AL, improves the biological performance of HA in a dose dependent way, and represents a promising strategy especially in osteoporosis patients with high risks of spinal fusion failure. Results also suggest that HA-AL28 could be the candidate biomaterial for spinal fusion in osteoporotic subjects.

Resume : “ Special Session: Advanced Materials and Technologies for Bone Engineering ” Calcium phosphate (CaP) based scaffolds were prepared by in situ gas foaming method. The composite precursor was composed of reactants of rigid polyurethane foams, CaP powder (and silica). Polymer burnout and sintering resulted in ceramic scaffolds having both large interconnected pores up to 600 μm and small pores below 10 μm. The total porosity (70 to 95%) and pore sizes were tuneable by changing the ratio of reactants and by controlling the air pressure. Scaffolds were characterised by thermal analysis, X-ray diffraction analysis and scanning electron microscopy. Biological properties, mainly biodegradability and biocompatibility were tested in vitro. Mechanical properties were evaluated by compression test. The compressive strength was significantly higher than the strength of scaffolds of the same composition and porosity prepared by polymer replica technique. The best results were achieved if scaffolds contained silica. Considering open 3D structure, mechanical and biological properties, scaffolds prepared by this method fulfil the requirements for synthetic bone grafts and have a potential to find an application in tissue engineering.

Resume : Freeze-casting, fabrication of porous structures by removing the solvent after its solidification, has been studied for the last decade and this technique appears to be very interesting. The unique structure and properties of porous freeze-casted ceramics opened new opportunities in the field of porous ceramics. In this work, a 30 wt.% slurry of mixed diopside (60 wt.% and β-TCP (40wt.%) were used . A rheological study showed that the optimum viscosity was reached with 3 wt.% of dispersant (based of powder content) and present a viscosity of about 35 mPa•s at shear rate of 1000 s-1. At this amount of dispersant, zeta potential reach a value of -23.2 mV, which assured a stable suspension. Scaffolds were fabricated by freeze casting (at low freezing and high freezing rate) and the macroporous structure were processed by laser ablation (longitudinal channels) on green bodies. The hole diameters are 700 - 800 microns and they are separated by 1 mm. There is a significant difference in pore size scaffolds fabricated using high freezing rate (length: 17.8 µm, width: 7.4 µm) and low one (length: 165 µm, width: 12 µm) while total bulkdensity and porosity are similar, around 0.52 ± 0.02 and 1.53 ± 0.09 for the porosity and the bulk density respectively. Mechanical tests (diametral compression) were performed on the sintered freeze casted sample (wihtout laser machining) as a function of freezingrate. Better mechanical properties are reached by increasing the freezing rate.

Resume : Special Session: Advanced Materials and Technologies for Bone Engineering. Nanostructured bone replacement materials are of high importance. Calcium phosphates (CaP) are one of them because of their outstanding response to living tissue. Aim was to develop new synthesis route to prepare amorphous CaP (ACP) nanoparticles with high specific surface area (SSA) and to study their structural and thermal properties. Current approach was chosen to show way for preparation of CaP nanoparticles with specific crystallinity degree from ACP by thermal treatment. The new and improved ACP was prepared by rapid reprecipitation from solution made of CaP salt dissolved in acid. For comparision ACP was obtained by classical double salt decomposition as well. Products were analyzed to obtain structural (FTIR, XRD), thermal (DSC-TGA) and physical (BET, SEM) characteristics. ACP obtained by new synthesis route showed higher SSA (126-154 sqm/g), than classical method (46-64 sqm/g). Study revealed new aspects on crystallization phenomena of amorphous and low crystalline CaP and a way of tuning CaP crystallinity to specific needs and maintaining reasonaly high specific surface area at the same time. Acknowledgements: National Research Programme No. 2014.10-4/VPP-3/21 “MultIfunctional Materials and composItes, photonicS and nanotechnology (IMIS2)” Project No. 4 “Nanomaterials and nanotechnologies for medical applications” and COST Action MP1301 NewGen".

Resume : Special Session: Advanced Materials and Technologies for Bone Engineering Calcium phosphate (CP) are currently used for bone tissue engineering scaffolds. Today, the challenge is to control the degradation rate, to tightly balance the scaffold resorption and the natural bone formation. To reach such ambitious goal, both the composition and the architecture of the scaffold should be carefully controlled. In fact, crystalline CPs have long degradation time in vivo, typically in the order of months or even years, and - among the different compositions of CPs - hydroxyapatite shows the slowest degradation rate. Such issue has motivated the research towards composite materials for tissue engineering scaffolds, by combining CPs with natural or synthetic polymers, which offer the advantages of higher biodegradability. In this way, the physical and mechanical properties of the constituent materials can be combined, thus to closer match the mechanical and physiological demands of the host tissue. The porous structure of the scaffold is important as well, since it allows vascularization and bone ingrowth. The scaffold microstructure must ensure cell migration as well as attachment and differentiation at the pore surfaces. For this purpose, it is generally recognized that porosities higher than 80% with pore sizes in the range 100–500 m are suitable. The shortcoming of these structures are the poor mechanical properties, which limit their use to not-bearing applications. For large bone defects, it can be interesting to combine sufficient mechanical resistance with proper biological functions. To this aim, we have designed a new compositionally and functionally graded scaffold, in order to combine a high bioactivity/degradation rate at the surface of the scaffold, to stimulate bone regeneration, with a low degradation rate at the core. Therefore, aim of this work is the development of a structure made by three different layers, having different functions: (i) a dense hydroxyapatite (HAp) core, (ii) an intermediate layer made of porous biphasic calcium phosphate (BCP, i.e. HAp/β-TCP composite) and (iii) an external layer of porous polycaprolactone (PCL)/BCP composite. First, the dense HAp sample is produced by a gel-casting process, followed by a pre-sintering treatment at 900°C. Then, a foamed suspension of biphasic calcium phosphate is created by direct foaming method and poured around the pre-sintered HAp core. This bi-layer material is then sintered at 1200°C. Finally, the external layer made by PCL/BCP composite is fabricated by a combination of solvent casting and salt leaching methods, with sodium chloride crystals used as pore formers. This PCL/BCP solution containing the salts is poured around the bi-layer ceramic material. The final material is obtained after rinsing of the salt with distilled water. Mechanical, microstructural and biological properties of this innovative multi-layer material are investigated.

Resume : Due to the ageing of the population and some sports related injuries, there are more and more degenerative changes in the joints which reduce the activity of the people. Among the more painful are osteochondral lesions, where due to the severe damage of articular cartilage, underlying subchondral bone is damaged as well. Such osteochondral defects demand treatment of two different tissues. The effective material for osteochondral regeneration should induce bone regeneration on the bone side of the defect and at the same time allow cartilage regeneration on the cartilage side of the defect. Therefore in this study 3D scaffolds combining fibroin and bioactive glass were prepared. Bioactive glass is amorphous osteostimulative inorganic material, clinically proven to be safe and efficient for bone regeneration in vitro, in vivo [1], whereas silk is a natural biopolymer that has been widely studied in tissue engineering due to its good biocompatibility and mechanical properties such as elasticity and high tensile strength [2]. As bioactive glass is soluble material it does not affect only the bone regeneration but also has a great impact on the biopolymer itself. Ca2+ ions released from the bioactive glass change the fibroin secondary structure similarly as in nature B. mori silkworm does during the spinning process. We demonstrated using HRTEM analysis how the Ca2+ ions released from bioactive glass, result in the reduction of -sheet domain size that effectively controls important scaffold's properties, such as degradation, mechanical stiffness, acellular bioactivity as well as cell response. [1] N. Drnovšek, S. Novak, U. Dragin, M. Čeh, M. Gorenšek, M. Gradišar, (2012), Bioactive glass enhances bone ingrowth into the porous titanium coating on orthopaedic implants, Int. Orthop., 36, 2012. [2] D. N. Rockwood et al., Materials fabrication from Bombyx mori silk fibroin, Nat. Protocols, 6, 2011. “Special Session: Advanced Materials and Technologies for Bone Engineering”

Resume : “Special Session: Advanced Materials and Technologies for Bone Engineering” Bone is a solid material, which is relatively hard and lightweight. It is composed of hydroxyapatite and of the type I collagen. Bone has poor ability to self-repair and for this reason bone regenerative medicine has been an important issue in the clinical field [1]. Natural polymers, for example collagen and chitosan can be used for preparation biomaterials for bone defects replacement [2,3]. Polymeric composites based on natural polymers with hydroxyapatite can offer better bone regeneration than pure polymer [4]. The aim of the study was preparation and characterization a new composite based on the blends of three biopolymers: collagen, chitosan and hyaluronic acid with addition of hydroxyapatite. Collagen, chitosan and hyaluronic acid are miscible [5] and during the mixing nano-hydroxyapatite was added in 20, 50 and 80 wt% based on polymers content. 3D porous structures were obtained in a freeze drying process. The structure of 3D composites was studied by infrared spectroscopy and SEM. Mechanical and thermal properties were measured. The results showed that appropriate mixing of three natural polymers can lead to new materials for hydroxyapatite incorporation. [1] Uto S. et al; Biomed Res. 2013, 34, 281. [2] Sionkowska A.; Prog. Polym. Sci. 2011, 36, 1254. [3] Sionkowska A. et al; Int. J. Biol. Macromol. 2016, 89, 442. [4] Gleeson J.P. et al.; Eur. Cell Mater. 2010, 20, 218. [5] Lewandowska K. et al.; J. Mol. Liq. 2016, 220, 726. ACKNOWLEDGEMENTS Financial support from the National Science Centre (NCN, Poland) Grant No UMO-2013/11/B/ST8/04444 is gratefully acknowledged.

Resume : Special Session: Advanced Materials and Technologies for Bone Engineering The bioactivity of synthetic bone implants is highly impacted by their surface topography, especially by the presence of micro-patterns likely to generate cells growth guidance. In this study, laser machining technology was employed in order to obtain controlled regular micro-patterns on dense calcium phosphate surfaces, without any contamination. According to literature, this kind of laser patterning is usually performed on metallic alloys, but there are few works dealing with calcium phosphate ceramics because of the unwanted phase transformations induced by the thermal impact of such a process. In the present study, the choice of the source was directed towards a femtosecond pulsed laser, to limit this thermal impact. Substrates with perfectly controlled micropatterning and without any secondary phase were obtained by optimization of the process parameters (laser power, scanning speed, pulse frequency). The microstructural characteristics were investigated by microscopy (optical, confocal, scanning electron) and the phase identification was performed by XRD completed by spectroscopic analyses. This work allowed to highlight the effects of the process parameters on the patterning. The high benefits of the laser treatment on wettability was shown by contact angle assays. Relationships between surface topography and wettability mechanisms were established thanks to a wide variety of micropatterned designs, allowed by the precision of the femtosecond laser process. This technique seems to provide an interesting alternative to conventional surface treatments of calcium phosphates. In order to demonstrate the influence of the micro-patterns on cell behavior, in vitro experiments are currently being performed on sintered, polished and patterned surfaces. Acknowledgement: the authors are grateful to the Walloon Region for the financial support, within the BEWARE program (BEcome a WAlloon REsearcher, convention n°1510392) co-funded by the European Union (FP7 – Marie Curie Actions).

Resume : “Special Session: Advanced Materials and Technologies for Bone Engineering” The optimization of titania nanotubes (TNTa) production on the surface of Ti6Al4V alloy, in terms of their biomedical applications, has been carried out. Titanium dioxide nanotube coatings were produced by the anodic oxidation process in the range of voltage 3-20V. In our studies, Ti6Al4V foil and implants made from Ti6Al4V have been used as substrates. Structural and morphological characterization of these materials was carried out using X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), and scanning electron microscopy (SEM). The biocompatibility and antibacterial properties of TNTa coatings, as well as their photocatalytic activity, have been estimated. The MMT assay has been carried out in order to estimate of L929 murine fibroblasts adhesion and proliferation. The antimicrobial properties of produced TNTa coatings were estimated against Staphylococcus aureus strain (ATCC 29213). The photoactivity of titania nanotubes was analyzed based on the methylene blue degradation process. Among all studied TNTa samples, titania nanotubes produced at 5V were the most appropriate for medical applications – they act as antibacterial agent and in the same time they posses optimal biocompatibility. The same sample was the most photocatalytic active, exhibiting the potential for environmental applications.

Resume : “Special Session: Advanced Materials and Technologies for Bone Engineering” The natural extracellular matrix of bone tissue contains specific signals that direct and control biomineralization. Both fibrous and non-fibrous component are important in modulation of not only biomineralization but also other cellular processes, which they maintain through binding to cell surface receptors. These cellular processes include cell adhesion, proliferation and differentiation. Thus, it is vital to control both cellular processes and biomineralization for bone regeneration. In this study, we mimicked both fibrous and non-fibrous components of natural bone extracellular matrix by using self-assembling peptide amphiphile molecules which form bioactive peptide nanofibers. We extensively characterized the physical and chemical characteristics of these molecules and in situ biomineralization on these nanofibers. In addition, we cultured osteoprogenitor cells and stem cells on these scaffolds and analyzed their osteoinductive and osteoconductive properties. Our results show that controlling both biomineralization and intracellular osteogenic signaling are both critical for bone regeneration and these biomineralizing bioactive nanofibers are excellent materials for inducing this process.

Resume : ''Special Session: Advanced Materials and Technologies for Bone Engineering'' To achieve an enhanced integration of biomaterials into the human body, additional functionalization of the material surface will help to mimic the natural environment of the cells. 3D Poly-?- caprolactone (PCL) matrices were produced by fused deposition modelling method for bone tissue engineering. In this study, fs laser modification experiments were performed to improve the surface properties of the PCL construct. Fs laser processing is a non-contact method associated with production of large diversity of surface patterns, minimized heat-affected zones, reproducibility and precision. Altering the porosity of PCL scaffold could improve the compatibility of biomaterial by influencing osteconductivity and osteointegration. The processed surface of the PCL matrix was examined for the influence of laser parameters such as laser energy, pulse repetition rate, number of applied pulses. The modified zones were characterized by means of: scanning electron microscopy (SEM), confocal microscopy, X-ray computed tomography, contact angle measurements. The obtained results showed the morphology changes of the processed surface in relation to applied laser parameters. The effect of fs laser irradiation on the wettability properties of poly(?-caprolactone) tissue scaffolds was examined. Decrease in the water contact angle was monitored after fs laser processing of the fiber meshes. This work showed that by applying different number of laser pulses laser pulses at different energy rates, precise control of the surface properties can be achieved. The induced micro-modifications induce MG63 osteoblast-like cell orientation. The analysis of MG63 osteoblast adhesion morphology indicates regulation of cells migration in volume.

Resume : Special Session: Advanced Materials and Technologies for Bone Engineering Recently, a significant growth of interest in the use of additive manufacturing (AM) technologies for fabrication metallic implants has been detected. AM can be described as a process for joining materials layer by layer, to produce items based on 3D model data. The Selective Laser Melting (SLM) is a powder in bed AM method which can be used to produce metallic scaffolds for bone tissue engineering using laser beam. However, this process also shows some disadvantages. One drawback is microstructure and mechanical properties anisotropy which is caused by layerwise production method. The second disadvantage is the necessity of post-processing to improve the surface parameters, such as roughness, and to remove the unmelted powder particles. In this study, we have investigated the influence of chemical polishing of SLM fabricated titanium scaffolds on their mechanical strength and in-vitro cell response. The scaffolds were designed in Magics software (Materialise NV, Leuven, Belgium) with bimodal 200+500 µm pore size. The designed models were fabricated from commercially pure titanium powder (CP Ti) using a SLM50 3D printing machine (Realizer GmbH, Borchen, Germany) and chemically treated in HF/HNO3 solutions. The cell viability seeding efficiency and mechanical strength was compared between as made and chemically polished scaffolds. The mechanical properties of the fabricated cellular structures were similar to those of human bone, which might minimize the stress-shielding effect. Scaffolds exhibit martensitic type of microstructure with plates aligned in [10-11] and [0001] directions. Post-processing methods resulted in removal of unmelted powder particles and improved cell response. Furthermore, X-ray computed microtomography confirmed that scaffolds after polishing meet the dimensions of the CAD models. The present study showed that post-processing methods of AM fabricated implants strongly influence the material properties and in-vitro cell response. Acknowledgements The authors would like to thank the NCBiR (National Center for Research and Development) for providing financial support to project LasIMP (Grant No. PBS3/A5/53/2015) and COST (European Cooperation in Science and Technology) for financial support to Action MP1301.

Resume : Special Session: Advanced Materials and Technologies for Bone Engineering Fabrication of biomaterials using natural origin and bioadhesive polymers are in huge demand. Hence, focuses has been given on characterization of polymeric hydrogels, prepared individually as well as in combination to achieve porous hydrogel scaffold/ composite biomaterials. Biopolymer i.e. bacterial cellulose (BC), synthesized by acetogenic bacteria and synthetic but bioadhesive polymers like: carboxymethyl cellulose (CMC) and polyvinylpyrrolidone (PVP) are. used in this study. These scaffolds are termed as “BC”, “CMC”, “PVP”, “BC-CMC”, “BC-PVP” and “PVP-CMC”. FTIR confirmed the interaction between BC, CMC, PVP and with other ingredients which constituted these hydrogel scaffolds. SEM prove the three-dimensional polymer network of hydrophilic polymers. Water absorptivity study showed that BC based hydrogles have lower capscity to absorbe water compared to CMC. Viscoelastic behavior and mechanical property exhibited that BC based hydrogel scaffolds have greater stiffness compared to other hydrogels. In conclusion, it can be mentioned that all six hydrogels could be applicable in the field of biomedical and biotechnology; such as bone tissue engineering; soft tissue replacement (e.g. cartilage, tendon, cardiovascular tissue or ligament) as well as wound dressing materials. Acknowledgment This work is principally supported by Internal Grant (IGA/FT/2014/015 and IGA/CPS/2015/008) of Tomas Bata University in Zlin. This work also partially supported by the Ministry of Education, Youth and Sports of the Czech Republic-Proram NPUI (LO1504). Moreover, this work was conducted within the framework of COST Action MP1301 “New Generation Biomimetic and Customized Implants for Bone Engineering” – www.cost.eu.

Resume : "Special Session: Advanced Materials and Technologies for Bone Engineering" Biomimetic porous scaffolds are ideal target for bone tissue engineering applications. Researchers already reported about many different biomaterials that can compete with the trabecular architecture of cancellous bone. Cancellous bone is not as hard as compact bone but spongy in nature and protects the bone marrow. This type of bones are not easily regenerated after certain age in human-beings, experiencing long term healing effects during its fracture. Hence, structural bioinspired materials development is an active area of investigation and has steered to form porous scaffolds, and composites with unique and superior mechanical properties. In current endeavour, effort has been given for the fabrication of PVP-CMC hydrogel scaffold to form bioinspired materials that mimic the formation of microstructural features as nacre. The PVP-CMC hydrogel film, comprised with [PVP (0 2), CMC (0.8), PEG (1.0), Agar (2.0), Glycerene (1.0) and water (95.0) w/v %], acts as catalysts and templates for the nucleation and growth of the inorganic phase when deep in ionic solutions (Na2CO3 and CaCl2. H2O) with varying concentration for 90 min. These biomineralized scaffolds were designated as “PVP-CMC-CaCO3” This biomineralized hydrogel scaffold is expected to be applicable as biomedical implants for bone repair and replacement. The basic structural and mechanical properties of the said biomaterial were evaluated. Cytotoxicity and biocompatibility assay had also been performed using cell lines MG 63 (human osteosarcoma) and L929 (murine fibroblasts) as well as primary cultures established from murine bone explants. Acknowledgement This work is supported by the Ministry of Education, Youth and Sports of the Czech Republic-Proram NPUI (LO1504) and the work was conducted within the framework of COST Action MP1301 “New Generation Biomimetic and Customized Implants for Bone Engineering” – www.cost.eu.

Resume : Special Session: Advanced Materials and Technologies for Bone Engineering Tissue engineering (TE) approaches typically envisage the functional and structural regeneration of previously damaged tissue in situ – thereby facing fundamental challenges concerning the integrity of the applied biomaterial, which in turn is a necessity to ensure an adequate supply with oxygen and other vital nutrients essential for regeneration. A three-dimensional (3-D) environment is pivotal for the production of extracellular matrix (ECM) by the cells incorporated in the scaffold material. However, the 3-D architecture is concurrently also limiting the nutrient and oxygen supply to cells inside the construct. Since the oxygenation within tissue is based on the diffusion of oxygen from the ambient blood vessels, the physical diffusion limit of 200 µm marks a critical threshold in vivo. The lack of sufficient oxygen manifests itself in locally accruing hypoxic areas within the scaffold material and tissue – a phenomenon referred to as hypoxia. Hypoxia per se is a critical factor affecting all TE constructs of certain size. As a consequence, cells in a hypoxic state adjust their physiological status in order to survive. In line with this, the production of ECM is altered. These mechanisms are thought to be critical for cell fate decisions, which are of particular interest in the field of TE. Based on the material in use and its structural design and composition, the efficiency of the oxygen supply can be engineered. Thus, material-related parameters such as pore sizes and -distribution, as well as the cross-linking level of gel-based systems may tailor the level of dissolved oxygen. Especially composite materials offer a plethora of opportunities to favour cell-matrix interactions via functional modifications for optimized nutrient supply. In our study, we intended to analyse the level of dissolved oxygen within several musculoskeletal TE constructs in vitro, embracing cell-loaded gel-based constructs, as well as 3-D printed polycaprolactone (PCL) scaffolds, respectively. For the analysis of the oxygen level in situ, a fibre-optical micro sensor set-up (Fibox 3, PreSens), as well as a novel camera supported non-invasive optical sensor foil technique (VisiSens, PreSens) was applied. These complementary techniques enable on the one hand the two-dimensional visualization of the oxygen distribution (VisiSens), as well as the coordinated oxygen measurement at any desired spot within the (gel-) construct (Fibox 3) over time. Both measuring techniques are based on the principle of dynamic luminescence quenching – enabling the measurement of the ambient oxygen level in situ without using up the oxygen itself. Thus, the local oxygenation is unaffected by the measurement process. Human adipose-derived mesenchymal stem cells (hAMSCs) cultured in collagen I gels featured after 21 days in vitro a mean value of dissolved oxygen (pO2) of 5.24 ± 0.30 mg/L. Upon prolonged cultivation (35d), the pO2 within the gels increased, reaching to values of 6.69 ± 0.34 mg/L, respectively. The pO2 increased due to the metabolic activity of the cells, which loosened the structural appearance of the scaffold material. As a consequence, the oxygen diffusion across the material was facilitated. Thus, the pO2 is a rather dynamic measurement parameter, which depends on the structural integrity of the scaffold material, as well as on the metabolic activity of the cells within the TE construct. Hence, we proclaim the employed measurement systems as ideal for the evaluation of multiple culture parameters affecting the oxygen distribution in vitro, including the gel composition, applied cell types and duration of cell culture experiment, respectively.

Resume : A major challenge in joint repair is soft tissue to bone reattachment, which can compromise clinical success. We propose that sustained, localised nanoparticle (NP) delivery of an amphipathic peptide (RALA) and bioactive hydroxyapatite (HA) will promote osteogenesis and enhance interfacial tissue formation. NPs will be delivered from a polycaprolactone (PCL) nanofibre reinforced novel Alg-co-PNIPAAm thermoresponsive hydrogel. Alginate and NIPAAm were synthesised and coupled via free radical polymerisation to form Alg-co-PNIPAAm hydrogel. Aligned PCL nanofibres were created using a bi-electrospinning method. RALA/HA NPs were prepared at differing mass ratios. Particle size and zeta potential (ZP) were measured to determine optimal formulation. Fluorescent SiHA (f-SiHA) synthesis was used for intracellular NP tracking. Cell viability was determined by MTS and live/dead assays. Expression of osteogenic markers was determined using standard immuno-cytochemistry and real-time PCR methods up to 28 d. The Alg-co-PNIPAAm solution showed thermoresponsive properties at 32oC. The NP size and zeta potential was 57±9 nm and 17.8±6.2 mV. The NP size and shape was confirmed by TEM. Cell viability decreased 24 h post-transfection with the RALA/HA-NP treatment, but by 7 d cytotoxicity decreased to match the untreated group. SiHA-MPTS-TRM NPs were successfully formulated and exhibited fluorescence at 585 nm. The PCL reinforced hydrogel was successfully produced. The RALA/HA NPs were biocompatible and stable over a temperature range and period. Transfection of cells with NPs showed increased extracellular collagen-I by 21 d. Dual hydrogel functionality for bone regeneration and osteoconductive NP delivery will be assessed in vivo.

Resume : Special Session: "Advanced Materials and Technologies for Bone Engineering" The dramatic increase in average life expectancy during the 20th century ranks as one of society?s greatest achievements. At the same time, an increased quality of life is expected as well. As a result, there is currently an ever increasing demand for biomedical devices with a perfect reliability and lifetime longer than 60 years. In the field of bone tissues, synthetic inert biomaterials have been developed and clinically used as bone grafts, but most of them differ substantially from natural bone either compositionally or structurally. Therefore, they have a limited survivability, approximately of 15 years, depending upon clinical uses. Bioactive materials are most promising, as they better mimic the natural bone-tissue biological behaviour. However, they have relatively poor mechanical properties, which limits their use in not-bearing applications. Musculoskeletal tissue reconstruction is the ultimate objective in orthopaedic surgery, which can be achieved by developing new engineered scaffolds, characterized by a superior ability to adapt in the biological environment and that would encourage local and systemic biological functions. Such ambitious goal is stimulating the research towards new materials, innovative and more complex architectures and advanced manufacturing methods. All these scientific and technological challenges have been addressed in the recent Cost Action ?NEWGEN? (New Generation Biomimetic and Customized Implants for Bone Engineering), a wide European network which collects many competences in the frame of bone tissue engineering from material scientists, surgeons, engineers, biologists and industrials. This presentation aims at giving an overview on all components needed for making bone tissue engineering a successful therapy. It begins by giving a brief background on bone components and biology, followed by an overview of the current strategies and future trends concerning materials, architecture, scaffolds, cells and manufacturing technologies. Finally, since most of the advances are currently achieved at the laboratory scale, this presentation aims at highlighting the role of NEWGEN in reducing the gap between academic research, clinical use and commercial production to reach the industrial development of the newly designed products.