Bioinspired and biointegrated materials as new frontiers nanomaterials

Resume : Cerium oxide nanoparticles (CeNPs) possess multiple enzyme mimetic activities to scavenge reactive oxygen species (ROS) in the biological environment as potential nanomedicine. One of the biggest challenges for the biomedical applications of CeNPs is to maintain their colloidal stability and catalytic activity as enzyme mimetics after nanoparticles enter the human cellular environment. This work summarized our latest findings of the influences of CeNP surface properties on their colloidal stability, enzymatic activity, and cellular uptake. Near-spherical CeNPs stabilized via different hydrophilic polymers were prepared through a wet-chemical precipitation method. The mechanism of polymer-cerium oxide was studied in detail using model thin film systems and surface science techniques. The CeNPs interaction with the cell culture media was tested to confirm their colloidal stabilities. Cellular uptake of these CeNPs was characterized by a collective of spectroscopic and microscopic methods. Our study showed that polymers attach to the surface of cerium oxide through a mutual charge transfer adsorption. By controlling the synthesis conditions, we can tune the surface oxidation states of synthesized CeNPs with the same core sizes, morphology, crystal structure, dispersity, and colloidal stability, with the only changing parameter being CeNPs surface oxidation state (Ce3+ percentage). We further investigated the performance of the synthesized CeNPs as enzyme mimetics, such as superoxide dismutase, catalase, peroxidase, and oxidase. It is shown that their enzyme mimetic behavior as well as their abilities are directly linked to their surface oxidation state. We found a strong correlation between CeNPs intrinsic surface properties and the extrinsic influences of the biological environment, such as the presence of biomacromolecules (protein corona formation) and solution properties (pH and ionic strength). We further examined their performance as antioxidants in vitro. Results showed no toxicity of these CeNPs for three different cell lines (osteoblasts, macrophages, and monocytes). A positive relation between the CeNPs surface oxidation state and their ability to reduce the intercellular ROS level is observed. Further microscopic and spectroscopic tests showed the location of these CeNPs during cellular uptake. These results showed that CeNPs could further be tuned by polymer coating to achieve its potential application as nanomedicine.

Resume : Neural activity can be measured or stimulated using electrodes that can be improved with nanotechnology advances. In this work, we propose the use of template-assisted electrodeposition technique to obtain, in a reproducible way, nanostructured metallic surfaces that can work as neural electrodes. On one hand, planar electrodes are used in extracellular experiments and medical applications to register or stimulate neural activity. In the context of the ByAxon project, our results on the fabrication of low-disturbance flexible nanostructured planar electrodes based on vertical metallic nanowires standing over a flexible Au base will be presented. We have obtained low-impedance electrodes by electrodeposition using anodic aluminium oxide templates fabricated at the laboratory, controlling the geometry of the electrode?s nanostructured surface. Biocompatibility studies with these electrodes showed proper neural cell adhesion, growth and differentiation. On the other hand, to perform intracellular in vitro recordings, patch-clamp technique is the most extended one. However, it damages the cell due to perforation size and medium exchange reducing life time when measuring. In this work, our progress in the fabrication of sharp nanostructured metallic electrodes based on the process described above, in order to improve the existing intracellular recordings, will be shown. Work funded by H2020 R&D programme under grant agreement No. 737116 and I D I project DPI2017-90058-R

Resume : Artificial cells (ACs) aim to mimic certain structural and functional features of natural cells*, with the aim ranging from studying the origin of life to developing AC-based therapeutics to support cells and tissues with missing functions. There is a plethora of features to be mimicked of the mammalian cell in the construction of an AC, one of them being cell communication. Living cells communicate by secreting signaling molecules that can activate certain responses in neighboring cells. Multicellular organisms rely on this chemical signaling between individual cells to coordinate collective behaviors and responses to changes in the extracellular environment. Here, we are focusing on a one-way communication from ACs to HepG2 cells using small fluorescent compounds as messengers. The ACs were assembled using alginate hydrogel beads equipped with two different metalloporphyrins that mimic the catalytic function of certain CYP450 enzymes. One catalyze the hydroxylation of coumarin to form 7-hydroxylation while the other one fulfill the dealkylation of resorufin ethyl ether to generate resorufin. The former was directly conjugated to the alginate polymer while the latter was encapsulated in liposomes before entrapping into the alginate beads. The biocatalytic activity of the ACs was optimized while ensuring that none of the compounds affected the viability of the HepG2 cells. Subsequently, the two products produced by the ACs (7-hydroxy coumarin and resorufin) could diffuse and be taken up by the receiving HepG2 cells, leading to an increase of cell mean fluorescence as a simple response. This effort showcases simultaneous communication between mammalian cells and two AC populations, facilitated through the use of metalloporphyrins as artificial enzymes. *Qian, X., Nymann Westensee, I., et al. Cell mimicry as a bottom‐up strategy for hierarchical engineering of nature‐inspired entities. WIREs Nanomed Nanobiotechnol. 2020;e1683.

Resume : We report on the successful deposition of antimicrobial chitosan-biomimetic nanocrystalline apatite –tetracycline thin films by Matrix Assisted Pulsed Laser Evaporation (MAPLE) using a KrF* excimer laser source (λ = 248 nm, ζFWHM ≤ 25 ns). Typical FTIR spectra of the obtained thin films were found to be highly similar to the spectrum of the initial powders. Scanning electron microscopy have evidenced a typical morphology characteristic to the deposition technique, advantageous for medical application, the nanoscale roughness increasing with the chitosan concentration. We have evaluated the antibacterial properties of the thin films containing chitosan and tetracycline deposited by MAPLE on titanium samples, using as model organisms both the Gram-negative E. coli and Gram-positive E. faecalis. The biocompatibility of the obtained films deposited on Ti substrates was evaluated by in vitro tests on human bone osteosarcoma cells. These tests have revealed the morphology and cellular cycle of the cells growing on the obtained thin films. The results have demonstrated that the chitosan- biomimetic nanocrystalline apatite-tetracycline composite thin films have improved the bone formation and further facilitated the anchorage between the bone and prosthesis, thus validating the MAPLE efficiency.

Resume : In nanomedicine, the goal is to develop smart multifunctional hybrid nanoparticles (NPs) to speed up targeted diagnosis, and increase its sensitivity, reliability and specificity for a better management of the disease. Combination of therapies is a way to increase the efficiency of anticancer treatment. Therefore, besides precision diagnosis, other challenges for personalized nanomedicine are to develop multifunctional nanoplatforms to be able to test quickly different treatments and to follow-up the effect(s) of the treatments by imaging. Besides being excellent T2 contrast agents for MRI[1], iron oxide NPs are promising as therapeutic agents by magnetic hyperthermia when correctly designed[2]. To be a good heating agent, iron oxide NPs have to display a high magneto-cristalline anisotropy and ways to increase it are to tune the NPs size and shape [2] [3] [4].Iron oxide nanoparticles have also an interest for photothermal treatment as they express a good photothermal response to laser irradiation[5]. Moreover, promising results showed that iron oxide NPs could be efficient sonosentisizers for anticancer treatment[6]. The goals of this work are to develop iron oxides NPs with different sizes and shapes by optimizing the thermal decomposition method (in particular by tuning synthesis parameters such as the reaction temperature, the heating rate and the nature of surfactants)[2][3] and to evaluate their therapeutic properties. Iron oxide NPs with different sizes in the range 5-20 nm and with nanoplate, octopod and nanocube morphologies were thus synthesized and coated with dendron molecules. The dendron coating was shown through several proofs of concepts to preserve the NPs from an uptake by the reticulo-endothelial system. Therefore, different amount of targeting ligands were grafted on dendronized NPs and their effect on cell internalization was investigated. Then, their in vitro and in vivo MRI properties were determined. Finally, the effect of the NPs size and shape on therapy by magnetic hyperthermia, sonotherapy and photothermia has been investigated allowing to establish the optimal NPs design to combine several therapeutic modes. References: [1] Basly, B. et al. Effect of the nanoparticle synthesis method on dendronized iron oxides as MRI contrast agents. Dalton Trans. 42, 2146–2157 (2013). [2] Cotin, G. et al. Unravelling the Thermal Decomposition Parameters for The Synthesis of Anisotropic Iron Oxide Nanoparticles. Nanomaterials 8, 881 (2018). [3] Baaziz, W. et al. Magnetic Iron Oxide Nanoparticles: Reproducible Tuning of the Size and Nanosized-Dependent Composition, Defects, and Spin Canting. J. Phys. Chem. C 118, 3795–3810 (2014). [4] Cotin, G. et al. Evaluating the Critical Roles of Precursor Nature and Water Content When Tailoring Magnetic Nanoparticles for Specific Applications. ACS Appl. Nano Mater. 1, 4306–4316 (2018). [5] Espinosa, A. et al. Magnetic (Hyper)Thermia or Photothermia? Progressive Comparison of Iron Oxide and Gold Nanoparticles Heating in Water, in Cells, and In Vivo. Adv. Funct. Mater. 28, 1803660 (2018). [6] 1.Ebrahimi Fard, A. et al., Synergistic effect of the combination of triethylene-glycol modified Fe3O4 nanoparticles and ultrasound wave on MCF-7 cells. Journal of Magnetism and Magnetic Materials 394, 44–49 (2015).

Resume : The formation of compartments with cellular functionalities from non-living molecules are not yet well understood in chemistry. Coacervation of peptides into liquid droplets via liquid-liquid phase separation provides a promising route to study the functions of cells. By introducing diverse functionalities like pH-sensitive functional groups, redox responsive moieties and a balance between hydrophobic and hydrophilic groups, short peptide derivatives can be designed to phase separate under well-defined conditions into coacervates. Here, we present a new class of small peptide conjugates with redox responsive functional groups, which have the capability to self-coacervate into micrometer-size droplets. The coacervate droplets retain up to 50 wt % water, and are responsive to pH, reduction and oxidation, and small organic co-solutes. Coacervation can be reversed by reduction using TCEP, DTT, and triggered again by oxidation using common prebiotic oxidizing agents such as peroxides and ferricyanide. The coacervate droplets provide a unique cell-like microenvironment that enables the encapsulation of light-harvesting pigments, catalytic macrocycles, and nucleic acids. Moreover, we demonstrate that these short peptide coacervates act as chemical microreactors that catalyse to enhance the rate of reaction of organic anabolic reactions, such as aldol condensation and hydrazone formation. Furthermore, we are investigating the growth of these coacervates and self-replication of different building blocks to make the synthetic cells with all functionalities of living cell. Our findings show that these peptide-based coacervates are highly versatile and promising protocell models.

Resume : The growing implant market requires advanced Ti-based implants for long-term application, and for the newly engineered biodegradable Mg alloys with controllable dissolution rate s short-term applications. For this reason, Mg-alloys gain much more attention recently. Mg alloys are biodegradable material, but with too high corrosion rate and degradation occurs before the end of healing process. Moreover, during the corrosion, hydrogen released thereby causes pH increase of the surrounding tissue, inducing apoptosis and necrosis of tissue cells. For these reasons, it is a challenge to controlled degradation rate of Mg alloy and to provide sufficient time for the tissue to heal up to complete degradation of Mg implant. The aim of the present paper is to investigate different types of CaP coatings as possible candidate for temporary implants made of MgCa1 alloy. The coatings were prepared by magnetron sputtering and micro-arc oxidation methods. The coatings were investigated in terms of microchemical, microstructural and mechanical properties, corrosion resistance in SBF at 37°C, as well as the biocompatibility with human cell line. We acknowledge the support of the Romanian projects: no. COFUND-ERANET-RUS-PLUS-CoatDegraBac (no. 68/2018), within PNCDI III; Core Program-2020; no. 19PFE/2018 (PROINSTITUTIO).

Resume : Light has been used by nature as a source of energy for billions of years and chloroplasts play a crucial role harvesting this energy for high plants. Several species of deep shade plants show a specialized type of chloroplasts, named iridoplasts, which has evolved to present a well-defined arrangement of the photosynthetic tissue forming a periodic multilayer structure. This multilayer strongly reflects blue light and is an example of naturally occurring structural colour. Although the biological function of the iridoplast is still debated, experimental evidence suggests that the photonic structure might enhance light absorption and increase photosynthesis quantum yield [1]. Iridoplasts show a light sensitive behaviour, shifting between high reflectance and suppressed reflectance under low and high light conditions respectively. The mechanism by which iridoplasts adapt the photonic bandgap to different light conditions remains unknown but studies on non-photonic chloroplasts point towards compression and expansion of the membranes [2]. We use transfer matrix methods to calculate the change in the optical properties of the iridoplasts according to these documented light adaptations of the photosynthetic tissue. Our simulations include realistic structural data taken from the natural system. We find that, under high light conditions, the iridoplast reflection is redshifted and absorption enhancement is reduced comparing to low light conditions. These photonic properties are resilient to biologically realistic levels of disorder in the structure. This analysis is extended to another photonic structure containing chloroplast called bizonoplast. Similar results are concluded pointing towards similar properties in different plant species. Our results suggest that iridoplasts and bizonoplasts could tune their absorption and reflection by changing the photonic response of the multilayer according to the light environment. This is an extraordinary case of photonic properties undertaking an important role in natural light harvesting. Understanding these natural systems can inspire us to develop new technologies for energy harvesting. In this communication we will also present preliminary result in producing biomimetic systems with similar optical properties to the ones found in iridoplast. References: [1] M. Jacobs, M. Lopez-Garcia, O.-P. Phrathep, T. Lawson, R. Oulton, and H. M. Whitney, “Photonic multilayer structure of Begonia chloroplasts enhances photosynthetic efficiency,” Nature Plants, vol. 2, no. 11, 2016. [2] H. Kirchhoff, C. Hall, M. Wood, M. Herbstova, O. Tsabari, R. Nevo, D. Charuvi, E. Shimoni, and Z. Reich, “Dynamic control of protein diffusion within the granal thylakoid lumen,” Proceedings of the National Academy of Sciences, vol. 108, no. 50, pp. 20248–20253, 2011.

Resume : Recently, we used super-hydrophobic surfaces (SHS) to obtain suspended DNA molecules and bundles with a simplified physiological-compatible preparation procedure. A droplet of a saline solution containing nucleic acids is deposited over the SHS and at room temperature it spontaneously dehydrates and retracts from one pillar to the next in line without collapsing. The DNA molecules linked to the top of a pillar are pulled, following the drop movement: with this method we obtained free-standing self-assembled DNA fibers, studied by HRTEM [1,2], Raman Spectroscopy [3,4] and Laser Doppler Vibrometer [5]. The DNA-SHS platform allows characterizing native nucleic acids molecules and the variations to the pristine conditions as the ones occurring after the interaction with ligands such as intercalants, chemotherapeutic drugs and proteins by using different techniques and achieving quantitative information. This approach can find its application in medical-oriented research for personalized drugs administration (e.g., CisPt-DNA adducts), food safety (e.g., mycotoxins-DNA adducts), and the study of environmental pollutants effects on the double helix.

Resume : Dps protein of Escherichia coli (E.coli) belongs to the ferritine-like group and represents a nanoscale hybrid particles consisting of 9 nm organic shell and 5 nm inorganic core. The protein shell is formed by a twelve identical subunits with the known structure as a dodecamer. In present paper the direct experimental information about specificity of iron atoms local surrounding in ferritines immobilized into planar and nanostructured silicon surfaces using a soft X-ray synchrotron radiation spectroscopy have been applied. Additionally, high resolution cryo-transmission electron microscopy, AFM, dynamic light scattering have been performed. The thermal and ion beam treatments were used for surface modification. The presence of both Fe2 and Fe3 ions in the octahedral and tetrahedral surrounding of O atoms in the Dps protein samples consisted of ~10 nm hybrid particles with ~5 nm inorganic cores were observed. Partial Fe restoration followed by the surface post treatment is shown revealing a complex composition of the hybrid particles cores even in the native Dps protein, that has been isolated from aerobically grown bacteria. These proteins containing inorganic iron-oxygen nanoparticles can be considered perspective for a novel low-cost and energy effective technology for the functional low-dimensional materials formation.

Resume : Switchable functional molecules capable of producing mechanical work constitute an active focus in nanotechnologies as they can be a source of components for molecular-based devices and materials. Many examples of such nano-machines operating at the molecular level and including molecular actuators, molecular electronic components, and molecular nano-valves have been developed. However, one of the most fundamental and challenging objectives associated to nano-machines rests on their coupling (in space and time) in order to transfer controlled motions from the molecular arena to the macroscopic scale, similarly to living systems such as muscular tissues. Here, using a combination of organic synthesis and characterization by scattering and microscopy techniques, we will show that nanomachines can be used to build responsive contractile macroscopic materials such as gels or films which can behave as artificial muscles, with possible applications in robotic devices. Two well-defined systems will be presented: i) one based on single contractile nano-switches which can be polymerized to form single-chain supramolecular polymers and further produce micro- and macroscale motions by integration of their nanoscopic movement; ii) a second one based on the connection of rotary motors with the possibility to make them functioning far from equilibrium (that is under light energy supply) and in connection within a cross-linked polymer network.

Resume : Function elements (FE) are vital components of nanochannel-systems for artificially regulating ion transport. Conventionally, the FE at inner wall (FEIW) of nanochannel-systems are of concern owing to their recognized effect on the compression of ionic passageways. However, their properties are inexplicit or generally presumed from the properties of the FE at outer surface (FEOS), which will bring potential errors. Here, we show that the FEOS independently regulate ion transport in a nanochannel-system without FEIW. The numerical simulations, assigned the measured parameters of FEOS to the Poisson and Nernst-Planck (PNP) equations, are well fitted with the experiments, indicating the generally explicit regulating-ion-transport accomplished by FEOS without FEIW. Meanwhile, the FEOS fulfill the key features of the pervious nanochannel systems on regulating-ion-transport in osmotic energy conversion devices and biosensors, and show advantages to (1) promote power density through concentrating FE at outer surface, bringing increase of ionic selectivity but no obvious change in internal resistance; (2) accommodate probes or targets with size beyond the diameter of nanochannels. Nanochannel-systems with only FEOS of explicit properties provide a quantitative platform for studying substrate transport phenomena through nanoconfined space, including nanopores, nanochannels, nanopipettes, porous membranes and two-dimensional channels.

Resume : Organic bioelectronics is an interdisciplinary research area which involves the development of polymer semiconductors for nanomedicine and healthcare applications, such as wearable, implantable, diagnostic or sensing devices.1 Polymers are ideal candidates for bioelectronics, as their mechanical, physical and chemical properties can be tailored to match those of cellular tissues. A possible way to obtain biocompatible materials for bioelectronics is to exploit naturally occurring compounds, either alone or in composite materials. Eumelanin is an amorphous insoluble pigment present in both mammals and invertebrates. Eumelanin consists of amorphous aggregates of DHI (5,6-dihydroxyindole) and DHICA (5,6-dihydroxyindole-2-carboxylic acid) oligomers, interacting via ?- stacking and hydrogen bonding. Synthetic melanins are usually obtained using either DHICA or DHI and present a lower degree of structural disorder; they are being investigated for energy storage/production2 and as composite materials for biomedical applications.3 We present a systematic study of the electronic structure and conformational space of DHICA oligomers, characterized by a linear polymeric structure and strong antioxidant properties. Our computational insight not only fits well within existing experimental evidence, but can also predict the charge transport landscape in the bulk polymer.2 We then use molecular dynamics simulations to study the amorphous structures formed by this material, and investigate its aggregation-dependent excited state properties. Finally, we describe our approach towards the simulation of realistic DHI melanin aggregates using a combination of experimental evidence, statistics and molecular dynamics. (1) Rivnay, J.; Inal, S.; Salleo, A.; Owens, R. M.; Berggren, M.; Malliaras, G. G. Organic Electrochemical Transistors. Nat. Rev. Mater. 2018, 3 (2), 17086. (2) Kumar, P.; Di Mauro, E.; Zhang, S.; Pezzella, A.; Soavi, F.; Santato, C.; Cicoira, F. Melanin-Based Flexible Supercapacitors. J. Mater. Chem. C 2016, 4 (40), 9516?9525. https://doi.org/10.1039/C6TC03739A. (3) Migliaccio, L.; Altamura, D.; Scattarella, F.; Giannini, C.; Manini, P.; Gesuele, F.; Maglione, M. G.; Tassini, P.; Pezzella, A. Impact of Eumelanin?PEDOT Blending: Increased PEDOT Crystalline Order and Packing?Conductivity Relationship in Ternary PEDOT:PSS:Eumelanin Thin Films. Adv. Electron. Mater. 2019, 5 (3), 1?8. (4) Matta, M.; Pezzella, A.; Troisi, A. Relation Between Local Structure, Electric Dipole and Charge Carrier Dynamics in DHICA Melanin, a Model for Biocompatible Semiconductors, ChemRxiv 2019. https://doi.org/10.26434/chemrxiv.11323016.v1

Resume : Dielectric elastomer actuators (DEAs) are often coined as artificial muscles for soft robotic systems. Moreover, when utilized in combination with self-healing materials these artificial muscles take a giant leap towards being like its biological counterparts. With self-healing capabilities, DEAs can “heal” from external damages similar to the body that closes off a wound for recovery. However, while promising for soft robotics, current self-healing elastomers used are lacking intrinsic toughness, causing the actuator to become susceptible to external damages in the first place. In this work, we address this by designing a carboxyl polyurethane (COOH-PU) with high toughness, absorbing energy without fractures. COOH-PU possesses multiple hydrogen bond functionalities to allow dynamic supramolecular interactions to reassociate upon damage for self-healing. However, the main challenge of designing tough self-healing elastomers for DEAs is attaining low elastic moduli for high actuation performances. To overcome this, soft segment of COOH-PU was tuned in accordance to molecular weight, in order for strain hardening to take effect at higher strains. As such, the elastic modulus was drastically reduced from 22.6 to 2.6 MPa, reaching values similar to soft tissues. Concurrently, high toughness of 283.8 MJ m-3 is attained, exceeding the toughness of armored scales of animals such as the armadillos. Furthermore, carboxyl groups provide high dielectric constant critical for achieving high actuation performances. Therefore, through these molecular designs from COOH-PU, artificial muscles can be tough and robust, achieve high actuation performances and even prolong their operations from self-healing effects.

Resume : Precisely defined protein aggregates as exemplified by crystals have applications in functional materials.[1] Consequently, engineered protein assembly is a rapidly growing field. Strategies involving protein assembly via supramolecular ligands are gaining momentum.[2] Anionic calix[n]arenes are particularly useful scaffolds that can mould to cationic protein surfaces and consequently induce oligomerisation.[3,4] Here, we describe the manufacture of protein-calixarene composites via co-crystallization of sulfonato-calix[8]arene (sclx8) with the symmetric and “neutral” protein RSL. Co-crystallization occurred across a wide range of conditions and protein charge states, from pH 2.2-9.5, resulting in three crystal forms. Cationization of the protein surface at pH ~4 drives complexation and yielded two types of porous protein frameworks. Calixarene-masked proteins act as nodes within the frameworks, displaying octahedral-type coordination in one case. The other framework forms millimetre-scale crystals within hours at pH 4, without the need for precipitants or specialised equipment. NMR experiments revealed macrocycle-modulated side chain pKa values, consistent with pH-triggered assembly. The same type of framework was generated with an arginine-enriched RSL variant at high pH. Finally, in addition to protein framework assembly, sclx8 can be used for de novo structure determination via sulfur SAD. 1. Uchida, M., McCoy, K., Fukuto, M., Yang, L., Yoshimura, H., Miettinen, H.M., LaFrance, B., Patterson, D.P., Schwarz, B., Karty, J.A. and Prevelige Jr, P.E., Lee, B.; Douglas, T. Modular self-assembly of protein cage lattices for multistep catalysis. ACS Nano 2018, 12, 942-953. 2. Yang, G.; Ding, H.M.; Kochovski, Z.; Hu, R.; Lu, Y.; Ma, Y.Q.; Chen, G.; Jiang, M. Highly ordered self‐assembly of native proteins into 1D, 2D, and 3D structures modulated by the tether length of assembly‐inducing ligands. Angew. Chem. Int. Ed. 2017, 56, 10691-10695. 3. Alex, J. M.; Rennie, M. L.; Engilberge, S.; Lehoczki, G.; Dorottya, H.; Fizil, A.; Batta, G.; Crowley, P. B. Calixarene-mediated assembly of a small antifungal protein. IUCrJ 2019, 6, 238-247. 4. Engilberge, S.; Rennie, M. L.; Dumont, E.; Crowley, P. B. Tuning protein frameworks via auxiliary supramolecular interactions. ACS Nano 2019, 13, 10343-10350.

Resume : Cryopreservation is critical factor in a fields of biochemical, pharmaceutical, biotechnological, and food industries, when it comes to storing cells, tissues, proteins, drugs, and foods. Antifreeze proteins (AFPs) have attracted huge interest with their cryopreservation activity originated from ice recrystallization inhibition or thermal hysteresis effects, which prevents organisms from freezing at the subzero environment. It is still challenging to develop new cryoprotectants mimicking natural AFPs for practical use due to the lack of understanding of structure-antifreezing activity relationship. The commercially available antifreezing agents show potential cytotoxicity to be applied for a biomedical field. Here, the self-assembled peptide nanoagents mimicking the AFPs were rationally designed by supramolecular chemistry to enhance both antifreeze activity and biocompatibility. The various nanostructures of the peptide nanoagents, changed by the hydrophobicity and hydrophilicity of periodically arranged antifreezing moieties, affect ice binding and resultant ice growth inhibition. Then it was confirmed that the survive rate of frozen-thawed stem and germ cells were increased after cryopreservation of peptide nanoagents and the revitalization of them were evaluated. This research could provide a useful strategy for manufacturing a cryopreservation agents with high performance through supramolecular chemistry and figuring out the mechanism of how AFPs affects cellular cryopreservation.

Resume : Recently we obtained free-standing self-assembled biomolecules fibers, by using a physiological-compatible preparation and super-hydrophobic surfaces (SHS). A droplet of the biomolecule solution is deposited over the SHS. At room temperature, the water in solution evaporates: the droplet decreases in volume and moves from one pillar to the next. With this method the molecules in solution are pulled and linked between micro-pillars. We suspended DNA, DNA/ligands, and cell membranes that were characterized by EM, Raman Spectroscopy and Laser Doppler Vibrometer. The DNA fibers allowed us obtaining background-free TEM direct images and measuring DNA bases and backbone without the use of contrast agents, with a resolution of 1.5 Å. TEM diffraction confirmed the quantities measured. Raman spectroscopy data expanded the EM data with structural/chemical information on DNA monomers, conformation and fluctuations related to the environment. DNA bundles were also used as ultrasensitive mechanical resonators to detect and study deviations to the native form, by administering intercalants and the chemotherapy cisplatin at increasing concentration. Alteration to sizes and Young’s modulus were successfully quantified. Overall, the results show that our approach can be applied to medical-oriented developments such as the optimal chemotherapy titration and the evaluation of the effects on DNA of pollutants and contaminants such as heavy metals.

Resume : Chemical Warfare Agents (CWA) and explosives detection with a high sensitivity and selectivity is crucial due to the growing threats from terrorist organizations to human health. Fast, selective and sensitive sensing methods are required to reduce the threat against CWAs. Microgravimetric sensor platforms with chemo or physico-selective interfaces offer an ideal solution to the previous drawbacks. We developed a bio-inspired nanostructured and functionalized cantilever for the detection of ultralow concentrations of explosives and simulants (DMMP (DiMethyl MethylPhosphonate) of CWA with different materials (TiO2, ZnO, CuO and Cu(OH)2) and morphologies (nanotubes or nanorods) in order to increase the surface area of adsorption and the limit of detection. This strategy of nanostructuration and functionalization promises significant improvements over existing sensors and for the next generation of cantilevers.

Resume : Previously, we developed samples of biocompatible composite based on calcium phosphates – "Syntekost" (synthetic bone). The aim of this work is to optimize the properties of bioactive materials for bone tissue recovery – ensuring their oncoprotective and anti-inflammatory properties. At various temperature conditions, a number of inorganic materials were synthesized: calcium phosphate ceramics, glasses and sitalls, as well as composites based on nanodispersed calcium hydroxyapatite. The effect of synthesis temperature conditions on the structure and properties of the obtained materials is investigated. Doping of a number of samples with bioactive elements was carried out with the aim of their functionalization. Samples of conductive bioactive nanocomposites based on nanodispersed apatite and nanodispersed graphite were obtained, and their properties were studied by electrophysical methods. An analysis of the XPS data of the obtained samples showed that, depending on the conditions of glass synthesis – melt cooling rate, temperature regime, and glass doping, the binding energy of the constituent elements changes. The temperature conditions of the process for producing such materials were optimized. The relative fraction of bioactive calcium phosphates and their crystallinity correlate with synthesis conditions, in particular – temperature regime. The XPS data for the fused glass sample indicate the presence of CaSiO_3 and Mg_2SiO_4, which are associated with bio-sitalls.

Resume : The use of natural and bioinspired materials is an emerging key approach towards development of new-generation safe technology. Going beyond the traditional concept of electronic devices, we convey the idea of making electronics edible. This unconventional approach exploits the electronic properties of natural and food-based materials for developing ingestible functional devices. Critical biomedical, pharmaceutical, and food industry applications are targeted by the proposed field. In this framework, we explore the potential of cost-effective and edible substance, honey, to be used as electrolytic gate viscous dielectric. Honey-gated organic field effect transistors (OFETs) based on both n & p type semiconductors are fabricated. A distinctive feature of these transistors is their long-term stability, reproducibility and low voltage < 1V operation in air. Devices exhibit forward-looking electronic performances, notably, electron and hole mobility–capacitance product of 3.5 × 10–3 μF/Vs and 23 × 10–3 μF/Vs, respectively, surpassing ones of the previously reported water-gated OFETs. Furthermore, the observed devices responsivity to humidity provides promising opportunities for sensing applications. We then demonstrate, for the first time, the implementation of honey-based integrated circuits: inverting logic gate and ring oscillator. Lastly, honey-gated OFETs are fabricated on edible flexible tattoo-paper substrate that acts as a versatile platform for organic edible electronics [1]. [1] Giorgio E. Bonacchini, Caterina Bossio, Francesco Greco, Virgilio Mattoli, Yun‐Hi Kim, Guglielmo Lanzani, and Mario Caironi, Tattoo‐Paper Transfer as a Versatile Platform for All‐Printed Organic Edible Electronics, Advanced Materials 30 (14): 1706091, 2018

Resume : X-ray activated near-infrared luminescence nanoparticles are considered as new alternative optical probes in life sciences. This is due to being free of autofluorescence and the excitation and emission possess a high penetrable nature in-vivo. Chromium-doped zinc gallate nanoparticles proved to have long-lasting persistent luminescence upon X-ray, UV or even visible light activation, allowing the excitation and emission to be separated in time. This paves the way for new types of imaging and even enhanced photodynamic therapy. The photoluminescence quantum yield, however, depends strongly on the dopant concentration and codoping for increased emission efficiency which is challenging because of the enhanced difficulty of handling dopants in the few-ppm-range. Here we report silicon carbide quantum dot sensitization of chromium-doped zinc gallate nanoparticles with enhanced near infrared radiation upon X-ray excitation. Using ultra-small SiC nanocrystals as a seed enables low-temperature hydrothermal synthesis with good crystal quality and optical properties without the need of post-annealing. SiC sufficiently decreases the escape probability and increases the emission efficiency by orders of magnitude upon X-ray excitation.

Resume : Bioactive materials are designed to interface with biological systems to treat, augment, or replace any tissue, organ, or function of the body. Among the different types of biomaterials, the mesoporous bioactive glass-ceramics (MBCs) are containing control amount of different ions with the aim of different activity like as antibacterial, osteogenesis and angiogenesis. Here we report the synthesis, characterization and bioactivity of different composition of silver containing MBCs. Bioactive glass-ceramics were synthesized by used CTAB. The introduction of Ag2O into the MBCs is intended to minimize the risk of microbial contamination through the potential antimicrobial activity of the leaching silver ions. The prepared samples were characterized by small angle X-ray scattering (SAXS), Fourier Transform infrared (FTIR) spectroscopy and high resolution transmission electron microscopy(HR-TEM). The SAXS patterns of samples show the agglomerates of ~15.3 nm average size with high polydispersity in size and size of the agglomerates varies from 2-40 nm range. FT-IR spectra show possible stretching and bending vibration modes of silicate and borate groups. HR-TEM confirms the mesoporous nature of MBCs. Bioactivity of MBCs was investigated by immersion of samples in simulated body fluid (SBF) at different time point followed by XRD and FTIR studies. The XRD patterns clearly show diffraction peaks of bone-like hydroxyapatite after immersion in DMEM. Silver-MBCs nanoparticles and there ionic dissolution extracts exhibited antibacterial effect against both positive and negative bacteria. Keywords:Bioactive glass-ceramics, Biocompatibility, Hydroxyapatite

Resume : Fiber Optic – Surface Plasmon Resonance (FO-SPR) technology has been recognized as a remarkable optical sensing tool in various fields of medicine, agro-food industry and environmental science, as it provides efficient characterization and real-time quantification of various chemical, physical and biological entities. For the FO-SPR sensors fabrication, noble metals (i.e. gold or silver) are used. Beyond these overused plasmonic materials, there are limited studies demonstrating the employment of other metals such as platinum (Pt) for SPR sensing applications. In this work, results on the fabrication and characterization of a SPR sensor using coatings of Pt and polyaniline (PANi) polymer layers over an unclad FO core were reported. The thin Pt layer was deposited using a magnetron sputtering technique, while the sensitive PANi layer was synthetized using an electroless polymerization approach. The PANi based FO-SPR sensor was morphologically characterized and evaluated for two applications: (i) pH monitoring and (ii) p-Nitrophenol pesticide detection. The obtained results showed that the FO-SPR pH sensor exhibited a fast and linear response in either acid or alkali solution (pH operational range 1 to 14). Moreover, the p-Nitrophenol limit of detection was found to be in the low pM concentrations range. Not in the least, the Pt-coated FO-SPR sensor was successfully applied also for Ara h1 peanut allergen detection using aptamers as bioreceptors. Concluding, this work represent a step forward in the fabrication of FO-SPR sensors, not only with improved performance, but also with extended functionality.

Resume : In order to obtain an effective integration between an implant and a bone, implant surfaces should have similar properties with bone tissue surfaces. Especially mimicry of the chemical, mechanical and topographic properties of the implant to the bone is crucial for fast and effective osseointegration. Titanium based biomaterials are more preffered in clinical use and there are studies of coating these implants with oxide layers that has chemical/nanotopographic properties stimulating cell interactions for enhanced osseointegration. There are low success rates of current implantations especially in craniofacial implant applications which are large and vital zones and the oxide layer coating increases bone-implant integration providing long-lasting implants without requiring revision surgery. Our aim in this study is to examine bone-cell behavior on titanium implants with aluminum oxide layer (AAO) on effective osseointegration potential in deformation of large zones with difficult spontaneous healing. In our study, aluminum layer coated titanium surfaces were anodized in sulfuric, phosphoric and oxalic acid which are the most common used AAO anodization electrolytes. After morphologic, chemical and mechanical tests on AAO coated Ti substrates, viability, adhesion and mineralization of adult bone cells on these substrates were analyzed. . Besides with Atomic Layer Deposition (ALD) as a sensitive and conformal technique, these surfaces were coated with pure alumina (5 nm) thus cell studies were performed on ALD-coated nano porous oxide layers with supressed ionic content too. Lastly in order to investigate the effect of the topography on the cell behavior, flat non-porous alumina layers on silicon wafers formed by ALD were compared with the porous ones. Cell viability ratio was similar between anodized surfaces, but pure alumina coated titanium and anodized surfaces showed higher viability ratio compared to bare titanium and bare anodized ones. Alumina coated titanium surfaces which are anodized in phosphoric acid, showed significantly different mineralization ratios after 21 days over other bare titanium and titanium surfaces which anodized in other electrolytes. Bare titanium was the second surface that had highest mineralization ratio. Otherwise, titanium which is anodized in oxalic acid electrolyte demonstrated lowest mineralization. No significant difference was shown between bare titanium and anodized surfaces except AAO titanium surface anodized in phosphoric acid. Currently, osteogenic activities of these cells on genetic level are investigated by quantitative real time polymerase chain reaction (qRT-PCR) analysis results of RUNX-2, VEGF, OPG and OPN genes. Also as a result of the activities of the genes mentioned before, Western Blot will be used for protein detection. The project is supported by The Scientific and Technological Research Council of Turkey. Keywords— alumina, craniofacial implant, MG-63 cell line, osseointegration, oxalic acid, phosphoric acid, sulphuric acid, titanium

Resume : In living tissues, cells are supported by 3D extracellular matrices (ECM) that control and supports the cellular functions (i.e., adhesion, differentiation, migration, polarization etc.). A large variety of engineered nanomaterials, including nanofibers and hydrogels, with 2D or 3D architectures have been engineered to mimic the biochemical and mechanical properties present in natural ECMs. Moreover, a wide range of functional nanomaterials can be added to tissue culture scaffolds to impart them with remotely controllable, localized cellular cueing properties. Among potential scaffold material candidates, hydrogels were widely used to mimic many important functions of extracellular matrices found in living tissues [1, 2]. In this work, we construct hybrid cellular matrices based on hydrogels incorporating, fluorescent probes and plasmonic gold nanoparticles (AuNPs). Plasmonic nanoparticles allow for light-addressable photothermal [3, 4] and electrical stimulation functionalities to control cellular behavior. Localized heating is implemented in hydrogels by functionalizing them with gold nanorods (GNR) with LSPR peak around 785 nm, while the local temperature is reported by Rhodamine B (RhB)-loaded silica particles or quantum dots. We discuss in detail the necessary requirements, limitations and solutions to obtain reliable 2 and 3D temperature measurements in cellular matrices based on these nanoprobes. With the help of the developed experimental framework, we demonstrate that NIR illumination combined with AuNR leads to local temperature gradients in 3D hydrogels that can exceed 10 degrees in amplitude , with no detrimental effect on the network structure. Finally, SH-SY5Y neuroblastoma cells are cultured in the hybrid hydrogels and monitored by optical microscopy and metabolic assays. Satisfactory cellular viability with respect to hydrogel samples and positive preliminary results on cell actuation in 2 and 3D upon localized heating demonstrate excellent prospects for using the hybrid hydrogel scaffolds for localized cellular stimulation in both 2D and 3D cultures. (1) Mark W, T.; Kristi S, A. Biotechnol. Bioeng. 2009, 103, 655-663. (2) Caliari, S.; Burdick, J. Nat Methods 2016, 13, 405–414. (3) Zhu, M.; Baffou, G.; Meyerbröker, N.; Polleux, J. ACS Nano 2012, 6, 7227–7233. (4) Deschaume, O.; De Roo, B.; Van Bael, M. J.; Locquet, J.-P.; Van Haesendonck, C.; Bartic, C. Chem. Mater. 2014, 26, 5383–5393.

Resume : For the advancement of the ubiquitous computing society, it is desirable to develop wearable devices allowing information to be exchanged at all times and in all places. In particular, flexible devices equipped with superior computing performance over Si integrated circuits will be innovative devices such as multi-functional display. Group IV semiconductor Ge has a higher mobility than Si and is expected to be applied to high-speed devices. It also has a low crystallization temperature and can be synthesized directly onto flexible plastics under the heatproof temperature. Based on this background, intensive research has been conducted on the low-temperature synthesis of polycrystalline Ge (poly-Ge) thin films on insulators. However, although various methods have been investigated, the grain size was small (< 1 μm) and the films quality were too poor for practical use. We are focusing on solid phase crystallization (SPC), which is a simple method to directly form poly-Ge thin films on insulating substrates at low temperatures. Recently, in SPC, we found that the densification of an amorphous Ge precursor and adding Sn atoms in the precursor dramatically enlarged the grain size (> 1 μm) and improved hole mobility (> 300 cm2/Vs) [1,2]. The insertion of a GeO2 underlayer further improved the hole mobility of Ge [3]. In this study, we investigated the detailed effect of the GeO2 underlayer on the SPC-Ge, elucidated the mobility enhancement mechanism, and applied this method onto plastic substrate. As a result, we found that a small amount of oxygen diffusion from GeO2 into Ge contributes to the grain size enlargement (> 10 um) and defect compensation. Moreover, due to less thermal expansion difference, the SPC-Ge on a plastic substrate exhibited higher hole mobility than that of bulk Si [4]. This result means that single-crystal wafers are no longer necessary for a high-mobility semiconductor thin film. Besides, the resulting hole mobility 690 cm2/Vs is the highest value to date among those of semiconductor layers directly formed on insulators at low temperatures. This achievement will give a way to realize advanced electronic and optical devices simultaneously allowing for high performance, inexpensiveness, and flexibility. [1] K. Toko et al., Sci. Rep. 7, 16981 (2017). [2] K. Moto et al., Scientific Reports 8, 14832 (2018). [3] T. Imajo et al., Applied Physics Express 12, 015508 (2019). [4] J. C. Irvin and S. M. Sze, Solid-State Electron 11, 599 (1968).

Resume : The highest conversion efficiency of solar cells has been updated with III–V compound semiconductors. However, these solar cells use expensive single-crystal Ge or GaAs-based wafers. Therefore, research to synthesize a high-quality GaAs film on an inexpensive substrate has been continuing for decades in the quest to develop a solar cell that achieves both high-efficiency and low-cost. In particular, GaAs solar cells fabricated on flexible plastic substrates will open up the possibility for developing advanced wearable devices. Therefore, we have recently been studying low temperature synthesis of high-quality GaAs films on insulators and achieved the first demonstration of photoresponsivity of the polycrystalline (poly-) GaAs film formed on glass [1,2]. In this study, we controlled the grain size of the poly-GaAs layer over a wide range (1‒330 μm) using the Ge seed layers formed on glass by solid-phase epitaxy (SPC) [3–5] and Al-induced layer exchange (ALILE) [6]. With increasing grain size, the photoresponsivity corresponding to GaAs increased from 0.01−3 A W-1 under a bias voltage of 0.3 V, indicating the high potential of the large-grained GaAs film. The maximum value approached that of the GaAs film formed simultaneously on a single-crystal Ge wafer and is the highest value ever updated for GaAs films formed at low temperatures on glass. Thus, we experimentally demonstrated the correlation between the grain size of poly-GaAs and its photoresponse property and achieved the pseudo-single-crystal GaAs layer below the heat-proof temperature of general soda-lime glass. Knowledge gained in this study will be essential for designing advanced solar cells based on polycrystalline III–V compound semiconductors using inexpensive substrates. In addition, further lowering the growth temperature (< 500 °C) will lead to novel flexible GaAs solar cells based on plastic substrates. [1] T. Nishida et al., Applied Physics Letters 114, 142103 (2019). [2] T. Nishida et al., AIP Advances 10, 015153 (2020). [3] K. Toko et al., Scientific Reports 7, 16981 (2017). [4] D. Takahara et al., Applied Physics Letters 114, 082105 (2019). [5] M. Saito et al., Scientific Reports 9, 16558 (2019). [6] K. Toko et al., Journal of Physics D: Applied Physics 53, 373002 (2020).

Resume : One of the biggest challenges for the biomedical applications of cerium oxide nanoparticles (CeNPs) is to maintain their colloidal stability and catalytic activity as enzyme mimetics after nanoparticles enter the human cellular environment. This work examines the influences of CeNP surface properties on their colloidal stability and catalytic activity in cell culture media (CCM). Near-spherical CeNPs stabilized via different hydrophilic polymers were prepared through a wet-chemical precipitation method. CeNPs were stabilized via either electrostatic forces, steric forces, or a combination of both, generated by surface functionalization. CeNPs with electrostatic stabilization adsorb more proteins compared to CeNPs with only steric stabilization. The protein coverage further improves CeNPs colloidal stability in CCM. CeNPs with steric polymer stabilizations exhibited better resistance against agglomeration caused by the high ionic strength in CCM. These results suggest a strong correlation between CeNPs intrinsic surface properties and the extrinsic influences of the environment. The most stabilized sample in CCM is poly(acrylic acid) coated CeNPs (PAA-CeNPs), with a combination of both electrostatic and steric forces on the surface. It shows a hydrodynamic diameter of 15 nm while preserving 90% of its antioxidant activity in CCM. PAA-CeNPs are non-toxic to the osteoblastic cell line SAOS-2 and exhibit promising potential as a therapeutic alternative.

Resume : Hydroxyapatite (HA), Ca5(PO4)3(OH), is a natural ceramic with extensive interest in areas such as biomaterials, adsorbents and catalysis. In the last decades, considerable efforts have been devoted to control the nano-texture of HA, in particular for the sake to increase its total specific surface area and finely tune its porosity at a nanoscale level. To aim that, several approaches have been proposed in the literature, specially using surfactants as molecular template during the synthesis. However, no systematic studies have been published in order to correlate and control the texture properties of HA and the surfactant behavior in the experimental conditions of HA synthesis. This work aims to analyze cetrimonium bromide (CTAB) behavior within conditions simulating HA synthesis in order to better understand and control its aggregation level before considering HA synthesis. To achieve that, CTAB micellisation was evaluated by Dynamic light scattering (DLS) in a concentration ranging from 0.4 to 100 mmol*L-1 in HA reaction conditions (pH = 10.5 and presence of phosphate ions) at 25 and 50 ⁰C. Interestingly enough at low concentration (i.e. < 10 mmol*L-1), CTAB tends to exhibit bimodal population of surfactant aggregates. Above 10 mmol*L-1 only unimodal size micelles have been distinguished in the autocorrelation curves derived from DLS analysis. No significant difference in CTAB behavior has been noticed at the two temperatures investigated. In a second step several batches of HA have been synthetized adopting CTAB concentration adjusted in function of their aggregation regime. After purification and drying at 100 °C, HA has been analyzed by FTIR, XRD, TGA, BET and TEM techniques. It was clearly observed that the specific surface area of HA can be increased significantly (up to 150 m2/g) in a narrowed range of CTAB concentration. Moreover, size and shape of HA nanoparticles are remarkably affected by surfactant concentration. From the behavior of CTAB micelles in function of time, temperature and concentrations, the most appropriate medium to perform HA synthesis assisted by CTAB surfactant and its effect in HA texture properties was identified. Additionally, an original feasibility study has highlighted the potency of HA matrix to physisorb, release and keep the stability of Soybean Trypsin Inhibitor (STI), a protein typically adopted as model of Bone Morphogenic Protein (BMP) for tissue engineering purposes.

Resume : Iron oxide nanoparticles (NPs) are versatile building blocks in a variety of biomedical and environmental applications due to their good magnetic performance, ease of production and functionalization by chemical routes, and low toxicity. However, controlling the electronic and magnetic properties of iron oxide NPs remain a challenge because of their crucial dependence on composition, structure, surface chemistry, and interparticle interactions. [1, 2]. In this framework, we studied the effect of the amount of both 1,2-hexadecanediol and the solvent 1-octadecene on the thermal decomposition method with iron (III) acetylacetonate. On the one hand, low amounts of either of the two reagents result in large NPs containing both Fe3O4 and FeO phases but with high values of the reaction yield. On the other hand, above certain threshold of the reagents the NPs are single-phase, single-crystal Fe3O4 NPs with diameters below 10 nm and narrow size distributions, however the reaction yield suffers a slight decrease. Consequently, the samples exhibited two distinct magnetic behaviors depending on the amount of these two reagents. The hysteresis loops at room temperature for the small NPs showed the typical features of superparamagnetism: values of the saturation magnetization close to the bulk one for magnetite with no coercive field. On the contrary, larger NPs showed ferrimagnetic behavior with reduced values of the saturation magnetization, as well as shifted hysteresis loops at 5 K after field cooling the sample at 1 T. The Zero-field cooling-field cooling (ZFC-FC) curves below 200 K for the small NPs showed a peak below room temperature corresponding to the blocking temperature, while those curves for the larger particles displayed two peaks at higher temperatures which can be associated with the Verwey and Neel transitions of magnetite and wüstite phases, respectively. The latter is correlated with the biphasic nature of the large NPs. With this accurate monitoring of the reaction conditions, we have added an extra level of optimization to the synthesis of these NPs. In fact, we have found that, for 1 mmol of iron (III) acetylacetonate, the minimum amounts of 1,2-hexadecanediol and 1-octadecene for the preparation of monophasic, single-crystal Fe3O4 NPs are 2.5 mmol and 5 mL, respectively. This allows us to tune the properties of each sample of iron oxide NPs to its specific application. [3] Acknowledgements The work was supported by Spanish MCIU and AEI (MAT2015-68772-P; PGC2018-097789-B-I00) and European Union FEDER funds. M.E-T. acknowledge Spanish MCIU for BES-2016-077527. References [1] A. Fraile Rodríguez, C. Moya, M. Escoda-Torroella, A. Romero, A. Labarta and X. Batlle. J. Mater. Chem. C, 6, 4, 875–882 (2018). [2] C. Moya, M. P. Morales, X. Batlle and A. Labarta. Phys. Chem. Chem. Phys., 17, 19, 13143–13149 (2015). [3] M. Escoda-Torroella, C. Moya, A. Fraile Rodríguez, X. Batlle and A. Labarta. Langmuir, 37, 1, 35–45 (2021)

Resume : Titanium (Ti) based plates are generally used to built-up mandibular prosthesis and replace the bone. However, the significant difference of the mechanical properties between Ti and the surrounding tissues results in stress shielding which is detrimental for load bearing tissues. To attenuate this effect, a process with the elaboration of Ti/ PMMA-co-PBMA /Ti sandwich materials (SMS) was developed. We employed surface-confined the poly methyl methacrylate (PMMA)-co- n-butyl methacrylate (PBMA) (PMMA-co-PBMA) layers as adhesives to stick the co-polymer core on the Ti skins to design resin-free SMS by pressing the three components together above the glass transition temperature of the co-polymer. The process route was following: (i) an alkali treatment of Ti surface, (ii) its functionalization with a phosphonic acid-containing polymerization initiator and (iii) controlled radical polymerization of MMA and BMA from this initiator. This work deals with the chemical and physical characterizations of the both copolymers: the core and the grafted on Ti skin. To study the last one, a new photocleavable initiator was designed. The grafting density, molecular weight and also melting point of PMMA-co-PBMA polymer brushes grafted on Ti were determined. Some encouraging results will be discussed.

Resume : Label-free sensor systems are effective methods to detect biomarker proteins for many diseases, however they perform poorly at early detection when concentrations are very low. Integration of nanostructured sensing platforms improves the performance of the sensors by providing larger surfaces to increase sensitivity. Increasing selectivity, as well as the sensitivity, is also needed for the sensors to work efficiently. In this regard, we designed and synthesized conductive molecularly imprinted polymer (MIP) nanotubes to detect biomarker proteins at very low concentrations. Oxidative chemical vapor deposition method was employed to synthesize the nanotubes imprinted with model protein of bovine serum albumin (BSA). As the conductive polymer, PPy (polypyrrole) was chosen due to ease of synthesis. Fourier Transform Infrared (FTIR) analyses validated immobilization and removal of the BSA from the PPy nanotubes and scanning electron microscopy (SEM) results confirmed the formation of the molecularly imprinted PPy nanotubes. UV absorption spectrum was used to detect the adsorption of BSA proteins on the MIP nanotubes at low concentrations. The facile method to synthesize the MIP nanotubes introduced in this study can be applied to other model proteins enabling their integration in different types of sensors.

Resume : Protein-based materials are of significance in the search for alternatives to synthetic materials such as plastics. Proteins are highly attractive components for biohybrid materials owing to their biocompatibility and tunable properties. Protein crystals provide order and porosity, which make them interesting for biomaterials. Given the importance of protein materials for biocatalysis, tissue engineering etc., controlled protein assembly is an enabling technology. There are many methods available for protein crystallization, including metal coordination and macrocycle binding(1). The commercially-available, anionic sulfonato-thiacalix[4]arene has potential as a tool in a crystallographer’s toolbox for generating protein assemblies. Thiacalixarenes differ from ordinary calixarenes because of their sulfur bridging atoms, allowing for coordination of metal ions and a more flexible macrocycle due to longer carbon-sulfur bonds. Here, we present different protein-thiacalixarene-metal complexes, including the cationic cytochrome cand the trimeric lectin from Ralstonia solanacearum (RSL). Both zinc and cobalt were studied with these proteins because of their important role in catalysis and protein stability/assembly. The interesting results of our crystal structure analysis will be presented. (1) Guagnini, F., Engilberge, S., Flood, R.J., Ramberg, K.O, Crowley, P.B. Metal-Mediated Protein–Cucurbituril Crystalline Architectures, Cryst. Growth Des. 2020, 20, 6983–6989.

Resume : The use of implants has increased over the years, driven by factors as aging population and desire of patients to maintain the same level of activity and life quality. Furthermore, to tackle the challenges met in the modern medicine, high performance implantable biomaterials must be developed. The most used biomaterial in clinical practice, remain titanium and its alloys, due to their properties and excellent long-term clinical outcomes, being considered “the golden standard”. The paper aim is to assess the impact of different surfaces obtained by metallographic preparation (M), airborne-particle abrasion – (S) and anodization (A) on pure titanium (cp-Ti, grade 2) in terms of bioactivity and corrosion resistance. The M group samples was considered as control and were obtained on SiC papers of different grits (300 ÷1200) and polished with alumina (Al2O3) slurry (particle dimensions of 1 μm). The S group were modified by airborne abrasion with alumina particles with dimensions of 250 μm at an air pressure of 3 bars for 20 s. The incidence angle of particle delivery was maintained at 90°. For the A group, the samples were initially etched in a solution HF:HNO3:H2O (1:4:5; v/v/v) for 1 min, after which the anodic oxidation was carried out with a DC power supply system by applying a constant voltage of 20 V for 60 min at room temperature in 0.5 wt.% HF solution. The obtained surfaces were characterized in terms of surface morphology, elemental and phasic composition, roughness, wettability, corrosion resistance and in vitro bioactivity by immersion in synthetic body fluid (SBF). The surface modification techniques used in this study have indicated that the bioactive character of cp-Ti can be enhanced through simple and cost-effective methods and can be successfully implemented to obtain medical devices with enhanced features. It was noted that a contact angle lower than 90°, which indicates a hydrophilic surface coupled with a roughness in the nanometric scale (under 200 nm) favor the nucleation and growth of a newly apatite layer, thus indicating an enhanced bioactive character and higher osseointegration. The highest mass of apatite gain in SBF media was found for the surfaces modified by anodic oxidation, while poorer results were noted for the S group. Thus, it was shown that the surface morphology, hydrophilicity, and roughness are playing a crucial role in the biomineralization process. The corrosion tests highlighted that the specimens anodized had also the best performance due to the titanium oxide nanotubes layer which acts as a barrier that inhibits the electrochemical reactions. In conclusion, the present study showed that irrespective of the modification techniques used, the properties of cp-Ti can be tuned. Acknowledgement: This research has been funded by a grant of the Romanian Ministry of Education and Research, CNCS - UEFISCDI, project number PN-III-P1-1.1-TE-2019-1331, within PNCDI III (project no. TE 172/2020; 3B-CoatED).

Resume : An alternative method for cancer therapy, which has attracted a significant attention in the past few years, is magnetic hyperthermia. In the presence of RF (radio frequency) magnetic field, the magnetic nanoparticles generate heat, which increase the temperature in tumors in a controlled manner, leading to killing the tumor cells. The interaction between nanoparticles and biological systems depends on the surface modification of magnetic nanoparticles. Cysteine coating enhances colloidal stability, while increasing nanoparticles biocompatibility. Moreover, surface functionalization of magnetic nanoparticles with antitumoral drugs could enable targeted chemotherapeutic delivery during localized hyperthermia. In this study, we report the synthesis of superparamagnetic nanoparticles (SPION NPs) with cysteine, as well as their influence in the hyperthermia study. Biological tests on mouse (B16F10) and human (A375) metastatic melanoma cells confirmed the internalization of magnetic nanoparticles delivering Doxorubicin (Dox), which is used as a chemotherapeutic in the treatment of cancer. The IC50 values of SPION-Cys-Dox were determined for both cell types: 4.26 ug/mL for A375 and 2.74 ug/mL for B16F10 as compared to 60.74 and 98.75 ug/mL, respectively for SPION alone. Treatment of cells with SPION-Cys-Dox has induced decreased pERK activity 3h post-treatment and cell cycle arrest by 48hrs. We have shown that within the first 2hrs of incubation in physiological (pH = 7.4) media ~10-15uM Dox/h is released from a 200ug/mL SPION-Cys-Dox solution, as compared to double upon incubation in citrate (pH = 3), which resembles tumor environment conditions. Based on the obtained results, new perspectives on development of new biocompatible and bio-functional SPION NPs for magnetic hyperthermia are highlighted.

Resume : The main goal of the present research work is the development of a standardized method for obtaining uniform nanomaterials. Specifically, we investigated the efficiency of a microfluidic lab-on-chip device for the synthesis of standardized iron oxide nanoparticles with controlled properties in terms of size, shape, crystallinity, and surface charge. The lab-on-chip device was fabricated using a laser machine for the construction of a polymeric plate with screw orifices, three inlets, one outlet, and one cross-junction channel. The device consists of three polymer chips, namely a top chip (with inlets for sample injection and screw orifices for binding), a middle chip (with the cross-junction channel and screw orifices), and a bottom chip (with an outlet and screw orifices), which will be fixed using 20 M4 screws (0.5 mm pitch, 4 mm diameter) and tightened at 1.5–2 Nm. Using two automated syringe pumps, the solutions were simultaneously injected into the lab-on-chip device through Teflon tubes, as follows: the solution containing the Fe(II) and Fe(III) precursors with three different concentrations was injected at three different flows (20, 40, 60 mL/h) into the central inlet, while the solution containing the precipitating agent, NaOH 1M, was injected into the side inlets at 150 mL/h. The nanoparticle dispersions were dripped from the outlet, washed in order to remove secondary reaction products, and dried at 40°C for 48h. The device was characterized through the scanning electron microscopy both before and after the synthesis of the nanoparticles. The synthesized nanoparticles were characterized in terms of morphology, structure, composition, functionality, and stability through electron microscopy (scanning and transmission), selected area electron diffraction, X-ray diffraction, energy-dispersive X-ray spectroscopy, Fourier-Transform infrared spectroscopy, differential thermal analysis and thermogravimetry, and dynamic light scattering. Results showed a deterioration of the device due to its repeated use, demonstrating a limit of 10 experiments that can be performed. Moreover, results proved the presence of iron oxide as the single mineral phase. Additionally, all nanoparticles exhibited uniform spherical shapes and a significantly narrow size distribution below 10 nm. Finally, dynamic light scattering confirmed the dimensional uniformity of the nanoparticles, as the same hydrodynamic diameter was registered for more than 95% of the nanoparticles. Optimal properties in terms of crystallinity, uniformity, and thermal stability were obtained at increasing concentrations and decreasing flows. Therefore, it can be concluded that the lab-on-chip device is an ideal tool for the synthesis of nanomaterials, ensuring the uniformity and standardization necessary for pharmacological applications. As perspectives, it could allow for the one-step fabrication of functionalized nanoparticles and hybrid drug delivery systems with controllable pharmacokinetics.

Resume : This paper investigates two different intravascular catheter substrates which were polypropylene (PP) and Titanium (Ti) in here. Both surfaces firstly were exposed to oxygen plasma to increase surface area and produce peroxides on their surfaces. Then substrate surfaces were deposited a thin film of plasma polymeric only ethyleneadiamine (EDA), besides EDA and NH3(ammonia) mixtures (1:1, v:v) which is rich in amine groups. Thus, the primary amine groups on the substrate surfaces were used to covalently immobilize heparin. Carboxylic groups of heparin were activated by N-hydroxysuccinimide (NHS) and N-(-3-Dimethylaminopropyl)-N’- ethylcarbodiimide hydrochloride (EDC) or 1,1’-Carbonyldiimidazole (CDI). Eight different plasma modification parameters and two crosslinking agent performances were examined and optimized. The density of immobilized heparin was determined by the Toluidine blue (TB) colorimetric method after immersed in 37o C DI water with constant shaking for 30 minutes then measured at 630 nm wavelength. Heparin stability tests were achieved in phosphate buffer saline (PBS, pH:7.4) and sodium chloride solution (ClNa) media separately to observe media charge effects on them. The surface-modifed PP and Ti substrates were characterized by attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. The surface topography and hydrophilicity of the films were investigated by atomic force microscopy, scanning electron microscopy and water contact angle measurements.

Resume : Osteomyelitis, is the infection of bone with a microbial pathogen-usually Staphylococcus aureus and the treatment remains to be a challenge despite the advances in surgical techniques and antimicrobial agents. The difficulties in current clinical approaches are associated with the need for long-term high dose antibiotic therapy and autologous bone grafting to replace the removed necrotic bone tissue. Systems that deliver antibiotics locally have become particularly interesting because of their ability to deliver high concentrations of drugs locally while reducing the systemic toxicity. Moreover, antibiotic loaded implants offer an attractive alternative, as they can not only deliver high-dose antibiotics locally but also replace the dead tissue and promote new bone formation1-3. Metal-organic frameworks (MOFs) composed of metals connected by organic linkers offer many opportunities in biomedical field. Their superior properties like, high porosity, and high drug loading capacity made them attractive in drug delivery applications. Among these structures UiO-66 has recently gained attention due to its non-toxic structure and ease of synthesis. Herein, a potential bone substitute and drug carrier system was prepared to be used in treatment of serious bone infections like osteomyelitis. Fosfomycin, as an antibiotic was loaded into UiO-66 nanocrystals for a pH responsive controlled release. The antibiotic loaded UiO-66 nanocrystals were then incorporated into chitosan scaffolds which were prepared by wet-spinning. Characterization of scaffolds were performed to determine the morphology, swelling behavior and pH controlled fosfomycin release. Antibacterial activity studies were performed to investigate the effectiveness of the scaffolds against Staphylococcus aureus. The results showed that fosfomycin loaded into UiO-66 nanocrystals was released in a pH controlled manner from the chitosan scaffolds. Chitosan scaffolds showed a strong effect in the reduction of Staphylococcus aureus activity in comparison to chitosan scaffolds alone. References [1] A. Karakeçili et.al, Mat Sci Eng C, 105:110098, (2019). [2] C. Makarov et.al, Eur J Pharm Sci, 62:49-56, (2014). [3] W. Jia et.al, Acta Biomater, 6:812-819, (2010).

Resume : Metal organic frameworks (MOF) are a new class of material that has a great potential in drug delivery systems. They possess unique physical and chemical characteristics including large surface area, high drug loading capacity and versatile functionality1,2. UiO-66 is a zirconium-based MOF with very high surface area and unprecedented stability. High chemical, thermal, and mechanical-stability of UiO-66 makes it a perfect candidate for pioneering studies of mechanism and universal applications of general metal-organic frameworks3. Moreover, UiO-66 has recently gained attention as a drug carrier and drug delivery system. In the present work, antibiotic loaded UiO-66 MOF structures have been synthesized for pH controlled delivery. Fosfomycin a small molecule from a unique drug class that acts by inhibiting pyruvyl transferase was loaded to UiO-66 MOF structure both in-situ. The antibiotic loaded UiO-66 nanocrystals were characterized by powder X-ray diffraction, scanning electron microscopy, thermal gravimetric analysis and Fourier-transform infrared spectroscopy. The loading efficiency was determined by liquid chromatography/mass spectrometry analysis. The antimicrobial activity of Fosfomycin loaded UiO-66 nanocrystals were tested against Staphylococcus aureus and Escherechia coli by using the well diffusion technique. The results demonstrated that a high loading efficiency of ~90% was achieved. The FTIR spectrum for UiO-66 loaded nanocrystals showed the characteristic peaks of pure UiO-66 only, and no bands attributed to fosfomycin indicating the encapsulation of the drug. The crystallinity was reduced but still conserved after encapsulation. The drug loaded UiO-66 nanocrystals showed high antimicrobial activity. References [1] Moghaddam et.al, Spectrochim Acta A, 194:72-82, (2018). [2] Ayşe Karakeçili et.al, Mat Sci Eng C, 105:110098, (2019). [3] Zou et.al, Mater Today Chem, 12:139-165, (2019).

Resume : The purpose of this study was to obtain and assess the impact of a novel magnetite (Fe3O4) nanosystem functionalized with the natural origin compound and antibiotics on the virulence behaviors of some wound pathogens in order to advance research aimed to find alternative and personalized therapeutic approaches for the efficient management of chronic wounds. Magnetite-based nanosystems are efficiently used for the encapsulation and targeted delivery of different biologically active compounds. These nanoparticles have significant potential for the administration of pharmacological substances, as they can enhance biocompatibility, ensure targeted, controlled and prolonged release of therapeutic compounds and reduce the amount of bioactive compound needed for the healing effect desired in many biomedical applications. The crystalline structures of Fe3O4 core/shell nanoparticles was identified by X-ray diffraction (XRD) and their dimensions and shapes is observed by high resolution transmission electron microscopy (TEM). Differential Thermal Analysis (DTA) and Thermo Gravimetric analysis (TGA) are coupled in order to determine the stability and thermal degradation of core/shell nanoparticles’ components. Our results demonstrated that the use of these nanosystems can ensure optimum intra- and inter-cellular active concentrations, their efficacy being proven in treating different wound infections caused by both Gram-positive and Gram-negative bacteria. Acknowledgments: This work was supported by a grant of the Romanian Ministry of Education and Research, CCCDI - UEFISCDI, project number PN-III-P2-2.1-PED-2019-4926, within PNCDI III.

Resume : Low concentrations of reactive oxygen species (ROS) mediate various signaling processes in phagocytic cells (e.g. macrophages) when infected by bacteria [1]. Production of a suitable probe is needed to measure these events. However, most methods used to investigate the intracellular ROS share the same problems, including photobleaching, low sensitivity, lack of spatial and temporal resolution [2]. Here, we elucidate the utility of diamond magnetometry for studying the transient free radical response of macrophages upon Staphylococcus aureus (S. aureus) infection, without influence on the intracellular redox reactions or enzymatic activity. Nitrogen-Vacancy (NV) defect centers in diamond crystals can detect magnetic noise nearby (< 10 nm), which is produced by the spin of unpaired electrons of free radicals3. Diamond magnetometry is specific for paramagnetic ROS also called free radicals (for example nitric oxide, superoxide anion radicals, or hydroxyl radical) [4]. They are particularly important since they are the most reactive ROS[1,5,6]. In this study, we report the formation and characterization of nanodiamond-bacteria conjugates, S. aureus-FNDs. By using these conjugates, we can optically monitor the transient free radicals in phagosomes via measuring the spin-lattice relaxation (T1) of NV defects after macrophages internalized the conjugates. In conjunction with appropriate control groups, bacteria-FNDs conjugates appear to be a powerful tool for unraveling bacteria-infected pathways and pathogenesis that involve free radicals. References [1] Dupré Crochet, S.; Erard, M.; Nü’e, O., ROS production in phagocytes: why, when, and where? Journal of leukocyte biology 2013, 94 (4), 657-670. [2] Nüsse, O., Biochemistry of the phagosome: the challenge to study a transient organelle. TheScientificWorldJOURNAL 2011, 11. [3] Perona Marti?nez, F.; Nusantara, A. C.; Chipaux, M.; Padamati, S. K.; Schirhagl, R., Nanodiamond Relaxometry-Based Detection of Free-Radical Species When Produced in Chemical Reactions in Biologically Relevant Conditions. ACS Sensors 2020. [4] Morita, A.; Nusantara, A. C.; Martinez, F. P. P.; Hamoh, T.; Damle, V. G.; van der Laan, K. J.; Sigaeva, A.; Vedelaar, T.; Chang, M.; Chipaux, M., Quantum monitoring the metabolism of individual yeast mutant strain cells when aged, stressed or treated with antioxidant. arXiv preprint arXiv:2007.16130 2020. [5] McCord, J. M.; Fridovich, I., The utility of superoxide dismutase in studying free radical reactions I. radicals generated by the interaction of sulfite, dimethyl sulfoxide, and oxygen. Journal of Biological Chemistry 1969, 244 (22), 6056-6063. [6] Wang, Q.; Ding, F.; Zhu, N.; Li, H.; He, P.; Fang, Y., Determination of hydroxyl radical by capillary zone electrophoresis with amperometric detection. Journal of Chromatography A 2003, 1016 (1), 123-128.

Resume : New advances in biomedicine field have concentrated on producing novel and stable surfaces that can stimulate a specific cellular response toward the demands of implants and medical devices. Among these materials, polyvinylidene fluoride (PVDF) are considered of high interest for biomedical research area due to its a number of characteristics that make it a versatile biomaterial, insolubility, stability in biological media, in vitro and in vivo non-toxicity, or even piezoelectric properties. Nonetheless, the most important disadvantage of PVDF-based biointerfaces is associated to the absence of the functional groups on the fluoropolymer and its hydrophobic character conducting to a deficiency of cell adhesion and proliferation. Within this context, this work aims to investigate the obtaining of PVDF coatings by matrix assisted pulsed laser evaporation (MAPLE) and the in vitro response of MC3T3-E1 pre-osteoblast cells towards the surface microarchitecture. MAPLE deposition parameters and post-deposition thermal treatment were studied for optimizing and designing the morphological features of the coatings, while maintaining the chemical characteristics similar to those of the pristine material. In vitro studies with MC3T3-E1 pre-osteoblasts indicated good biocompatibility, with no significant alteration of the cell adhesion and viability after the thermal treatment of the coatings. The physico-chemical characteristics of the deposited coatings along with favorable in vitro osteoblast response demonstrate that MAPLE is an adequate method for obtaining PVDF coatings for future bio- applications.

Resume : Oriented and self-organized DNA filaments were obtained by micro-fabricated super-hydrophobic surfaces (SHS). The bio-macromolecule, suspended over the SHS, can be characterized by using several techniques, such as electron microscopy and optical spectroscopy. DNA direct imaging by high resolution TEM (HRTEM) allowed solving the base pairs with a resolution of 1.5 Å [1,2] and the metrological details can be effectively corroborated by Raman spectroscopy data [3,4]. Raman spectra in the range 600-1800 cm-1 were acquired on suspended DNA filaments and on the droplet residual. The spectra obtained at the same working conditions on DNA samples and buffer deposited over a CaF2 window were used as negative control. The study of the spectra revealed the absence of physiologically compatible buffers on suspended filaments while their contribution is strong in the DNA spectra acquired on CaF2 windows and on the droplet residual. This suggests that the optimized SHS platform separates small molecules from the suspended DNA and the non-interacted material is concentrated in the droplet residual. The SHS-DNA platform revealed a strong potential for the study of polarized Raman spectra as the DNA filaments are autonomously oriented with different angles over the device and for the analysis of the presence and influence of molecules affecting the DNA double helix such as chemotherapeutic compound (Cisplatin), heavy metals and methylations.

Resume : Understanding nanoscale energy dissipation is nowadays among few priorities particularly in solid state systems. Breakdown of topological protection, loss of quantum information and disorderassisted hot electrons scattering in graphene are just few examples of systems, where the presence of energy dissipation has a great impact on the studied object. It is therefore critical to know, how and where energy leaks. High sensitivity pendulum geometry Atomic Force Microscope (AFM), oscillating like a pendulum over the surface, is perfectly suited to measure tiny amount of dissipation. The tip position on the sample is controlled with atomic accuracy owing to a tunneling current line and the enhanced sensitivity allows to distinguish between electronic, phononic or van der Waals types of dissipation. Measurements can be performed in a wide range of temperatures from 5K to room temperature and in magnetic elds spanning from B=0T to B=7T. The design of the sample holder allows to perform dissipation measurements while passing electric current in the plane of the sample surface. In this work we performed energy dissipation measurements on a suspended graphene sheet at room temperature under UHV. The graphene is deposited on a hole patterned substrate in order to have suspended circular (with a diameter of 6.5 µm) graphene sheet. The experiments allow to investigate the phononic and electronic energy dissipation of the suspended graphene.

Resume : Due to its role in the operation of nervous response and renal, hormonal and cardiovascular systems, quantitation of dopamine (DA) in vivo has received great interest. Electrochemical sensing allows detection of nanomolar dopamine concentrations, and carbon-based electrodes are particularly suitable for this application due to their biocompatibility, ease of manufacture, low cost and functionalisation potential. However, carbon electrode current responses are influenced by DA-surface interactions and suffer from fouling by adsorption and accumulation of oxidation by-products, collectively called ‘polydopamine’ (PDA). Herein, we present a study of DA adsorption at carbon electrodes functionalised with N-/O-groups and the fouling properties thereof at physiological pH. Electrodes with smooth, reproducible morphologies, tuneable functionality types and concentrations and, crucially, tuneable sp3/sp2 ratios were synthesised via sputtering deposition and thermal/electrochemical treatments. The influence of surface graphitisation and surface chemistry was investigated using cyclic voltammetry and x-ray photoelectron spectroscopy to rationalise the connection between DA adsorption and electrode fouling, with preliminary AFM studies characterising the surface roughness. The ability of fouled surfaces to recover their sensing ability was also evaluated using acid cleaning and repeated fouling, to elucidate factors which promote/inhibit PDA adsorption. Our results suggest effective methods for optimising carbon electrode composition as a means of minimising fouling in DA electroanalysis.

Resume : Antimicrobial resistance is an increasingly serious threat to global public health and immediate action must be taken to prevent its ever-increasing spread. One approach to overcome this problem is the development of new materials and coatings with bactericidal action; in particular those which tackle biofilm formation specifically. Polyoxometalates (POMs) are oxoclusters of early transition metals which have found applications in various fields from catalysis to material science or biomedicine. Among their numerous biochemical applications, POMs possess antibacterial activity and have been described as inhibitors of Amyloid-β peptide aggregation, a peptide involved in the development of Alzheimer’s disease (AD). Importantly, POMs can be derivatised through the direct conjugation of organic or bio-molecules to further enhance their physicochemical properties and diversify the chemistry that can be carried out through the post-functionalization. Such hybridization can also lead to unique structural, morphological, and self-assembly properties. We will present results on new hybrid materials based on the functionalization of POMs with antimicrobial peptides, which possess dual-functional bactericidal and anti-biofilm properties, by tackling both the amyloidogenic proteins in biofilm and the bacteria. Metal-mediated Amyloid-β peptide aggregation and ROS production, are well known to play an important role in the development of Alzheimer’s disease. For this reason, one of the proposed therapies is based on the chelation of implicated metal ions such as Cu, Zn and Fe. Such chelators could remove the metal ions from the amyloid aggregates and recover the normal metal homeostasis. We have studied the interaction of different Keggin-structure POMs with Cu, and how, through their interaction, they can modulate the metal-mediated aggregation of amyloid- β peptides. We will also present preliminary results on new hybrid materials based on the functionalization of POMs with antimicrobial peptides, which possess dual-functional bactericidal and anti-biofilm properties, by tackling both the amyloidogenic proteins in biofilm and the bacteria.

Resume : Alginate based hydrogels are widely employed as biomaterial inks (bioinks) in 3D extrusion bioprinting for the fabrication of polymer scaffolds for osteochondral regeneration. Alginate bionks behave as entangled polymer solutions with poor rheological properties being the elastic moduli only slightly higher than the viscous moduli, which leads to scaffold instability during bioprinting. Therefore, alginate is typically pre-crosslinked before 3D bioprinting or combined with other materials, such as gelatin or nanocellulose crystals to increase its stiffness. In this communication we report on the optimization of alginate bioinks for 3D bioprinting of scaffolds for osteochondral regeneration. To that aim, formulations based on alginate pre-crosslinked with Ca2+ and bioactive hydroxyapatite nanoparticles were prepared. Additionally, a biocompatible self-assembly tripeptide, Fmoc-FFpY, was incorporated into the biomaterial ink to promote cell adhesion and proliferation. Previous studies have demonstrated that the self-assembly of this peptide within polymer hydrogels promoted the cell adhesion of human dermal fibroblasts, as well as the antibacterial properties against gram positive Staphylococcus (1). A thorough rheological characterization was carried out in order to optimize selected bioink formulations for 3D extrusion bioprinting as a function of the alginate concentration, alginate/crosslinker ratio and concentration of the hydroxyapatite nanoparticles through measuring of their viscosity, elastic moduli and shear thinning behavior. Overall, the alginate bioinks presented herein showed a shear thinning behavior and a rapid recovery of their elastic properties after deformation, which made them optimal candidates for 3D bioprinting. References: 1. Criado-Gonzalez M., Iqbal M. H., Carvalho A, Schmutz M., Jierry L., Schaaf P., Boulmedais F. Surface Triggered Self-assembly of Fmoc-tripeptide as an Antibacterial Coating Front. Bioeng. Biotech. 2020, 8, art. 938

Resume : The combination of a few nanometers inorganic particles with nature-like objects can play a crucial role in engineering of novel low-dimensional hybrid materials. One of the convenient objects for such kind of technology development is E.coli bacterial culture. The surface properties play an important role for such systems. PhotoEmission Electron Microscopy (PEEM) can play a key-role by providing the powerful ability to perform chemically sensitive small spot spectromicroscopy surface analysis at one time. The crucial point is bio-objects stability under special conditions of surface sensitive vacuum experiments. X-ray photoelectron spectroscopy (XPS) and Scanning Electron Microscopy (SEM) control studies were performed before and after PEEM experiments with E.coli cells. PEEM images were collected under Hg lamp irradiation and with the use of tunable high intensive synchrotron light. Obtained results demonstrate a possibility of effective PEEM bioimaging of the E.coli cells under ?hard? conditions. The surface topology of single bacteria has been detected by PEEM that well correlates with the SEM studies results. Only partial bacteria shell damage have been shown. Our observation strongly suggests that PEEM spectromicroscopy surface analysis can be applied up to a single E.coli cell structure and composition studies without significant bioobject destruction. The study was supported by Russian Science Foundation (Pr. 19-72-20180).

Resume : SU-8 is an epoxy-based photoresist which has been used as a novel platform for biomedical applications due to its chemically tunable and biocompatible surface in addition to its relatively high stiffness, chemical resistance, optical transparency and ease of processing properties. In this work, we tailor SU-8 surface properties to investigate single cell motility and adhesion of the bacteria Xylella fastidiosa. Different SU-8 samples have been prepared using UV illumination, thermal processing, and oxygen plasma treatment. Atomic Force Microscopy and X-Ray Photoelectron Spectroscopy were used to determine nanoscale surface properties; ex-vivo studies at the level from single cell to biofilm formation were carried out with Confocal Laser Scanning Microscopy (CLSM). The mean velocity and displacement of single cells have been extracted from CLSM tracking information data and the size and quantity of biofilms are compared for different samples. We observed a significant difference in bacterial cell motility, adhesion and also biofilm architecture on SU-8 as nanoscale surface property changes. Larger density of carboxyl groups in SU-8 surfaces provide enhanced cell motility, while denser biofilms are found in untreated SU-8. Our results can improve understanding of the role of nanoscale properties on bacteria-surface interaction and thereby create strategies to preventing microbial adhesion and consequently, biofilm development of pathogenic species.

Resume : In biomedical applications, it is new challenge to reducing the implant failure risk due to bacterial infection and/or poor osteointegration. The best solution is to develop new implants’ generation with highly customized and made of resorbable materials. The aim of the current poster is to investigate the CaP doped Mg coatings as possible resorbable material used for biomedical applications. The coatings were prepared by RF magnetron sputtering method on silicon wafers substrates. Comparatively investigations were carried out in terms of their elemental and phase composition, mechanical characteristics (roughness, hardness, adhesion, elastic modulus), and degradation rate in SBF and DMEM at 37°C. CaP coating without Mg addition was used as reference coating. We acknowledge the support of the Romanian Ministry of Education and Research, CNCS - UEFISCDI, project ERANET-M-ISIDE-1, no. 171/2020 (INOE2000 partner) or 112/2020 (UPB partner), within PNCDI III, and no. 19PFE/2018 (PROINSTITUTIO) – institutional project.

Resume : Polymer-coated stents with antiproliferative drugs and growth factor have been proposed to defeat adverse reactions which occur in cardiovascular treatment. We report on successful deposition of functionalized thin films of (everolimus and paclitaxel) drugs encapsulated in complex matrices [either blends of poly(L-lactide) and collagen or nanoparticles of poly(lactic-co-glycolic acid) - polyvinyl alcohol] containing vascular endothelial growth factor (VEGF) by Matrix Assisted Pulsed Laser Evaporation (MAPLE). The morphology, hydrophilicity, and biodegradability of the composite coatings have been investigated. The main recipes of the drug functionalized polymer matrices, synthesized by MAPLE, have been validated by biological investigations, drug release profiles, and physical-chemical investigations. In vitro evaluation tests performed on the fabricated thin films have revealed great biocompatibility, that may endorse them as competitive candidates for the development of improved non-toxic surfaces resistant to microbial colonization. The proposed functionalized thin films apart from preventing the restenosis (due to selected drug inhibitors), also could eliminate the risk of late thrombosis (as the covered stent is replaced by connective tissue thanks to VEGF addition) and are expected to act as improved/appropriate/effective coatings for the next-generation drug-eluting stents.

Resume : Computed tomography (CT) is an X-ray based whole body imaging technique widely used to enhance the contrast among human body tissues because it allows both enhanced tissue penetration and resolution imaging. Currently, clinically approved CT contrast agents are iodinated molecules or barium suspensions, but to provide a good image contrast, high doses are required, and their short circulation time limits their applications. Nanoparticles (NPs) show several advantages in comparison with small molecules, such as longer blood residence times, and a high potential for cell-tracking and targeted imaging applications due to their easy surface functionalization. Bi2S3 NPs are interesting as they present a large X-ray attenuation coefficient because of the Bi atoms, which strongly enhances the image contrast for small variations in the concentration of NPs present in the target tissue. Moreover, Bi is less expensive and exhibits lower toxicity than other metals with a similar X-ray attenuation coefficient. In addition, the combination of Bi2S3 with Au offers the possibility of adding extra functionalities to these nanostructures. In particular, Au NPs exhibit strong absorption associated with localized surface plasmon resonances and show biocompatibility, stability, and low toxicity, making them suitable for photothermal therapies. In this work, Bi2S3 NPs with different size and shape have been prepared by tuning the temperature and the reaction time in the hot-injection synthesis of a sulfur precursor. On the one hand, when the injection is performed at 105 ºC with short reaction times, spheroid-shaped particles are obtained that grow preferentially along the direction [001] as the reaction time increases, giving rise eventually to needle-shaped particles. On the other hand, injecting at 165 ºC, rod-shaped NPs are obtained regardless of the reaction time. Once the structural features of the Bi2S3 NPs were controlled, we added an additional step to the synthesis process to achieve hybrid materials with both Bi2S3 nanoneedles and Au nanospheres attached on the surface. With this combination, we expect to prepare a novel, multifunctional, hybrid material with potential for theranostics. Acknowledgements The work was supported by Spanish MCIU and AEI (MAT2015-68772-P; PGC2018-097789-B-I00) and European Union FEDER funds. M.E-T. acknowledges Spanish MCIU for PhD grant BES-2016-077527.

Resume : Despite the technological progress of the last decade, dental caries is still the most frequent oral health threat in children and adults alike. Such condition has multiple triggers and is caused mainly by enamel degradation under acidic attack of microbial cells, which compose the biofilm of the dental plaque. The aim of this study was to elaborate a cold plasma based method in order to modulate microbial attachment and biofilm formation and to improve the retention of fluoride in an enamel-like model composed of bioinspired hydroxyapatite (HAP). HAP model was obtained by hydrothermal method using synthWAVE Microwave Synthesis System and characterized by FTIR spectroscopy, SEM, TEM and SAED. HAP fluoridation was done by applying an optimized Plasma gun treatment under atmospheric pressure. Antimicrobial analysis was done by qualitative and quantitative methods using Gram positive (Staphylococcus aureus) and Gram negative (Pseudomonas aeruginosa) model strains. The obtained results revealed the obtained HAP particles have nanometric sizes and needle type crystalline morphology, ranging 10-20 nm. Purity and basic properties of the obtained HAP correspond to ICSD-203027 (Cod.Ref.: 01-080-7087). Plasma gun treatment revealed that Fluoride content is increased in the HAP treated samples, after the application of fluoridated gel, as compared to plasma untreated samples. Microbial viability assay demonstrated that the obtained plasma treated HAP bear significant antimicrobial properties, since both S.aureus and P aeruginosa viability is drastically decreased after less than 4 h of exposure. The obtained cold plasma treated HAP structure could be efficiently used in dental applications and prevention of dental caries, by inhibiting the development of microbial pathogens.

Resume : Immune checkpoint blockade has been extensively explored as a novel and promising antitumor treatment, these checkpoints help keep immune responses from being too strong and sometimes can keep T cells from killing cancer cells. When these checkpoints are blocked, T cells can kill cancer cells more efficiently. Yet this is largely challenged by low frequency of response, and the risk of developing autoimmune side effects. Whether and how the regulation of T-cells by the clustering of activating and inhibitory receptors is tumor dependent, and patient dependent is still to be investigated. Furthermore, does this regulation correlates with the patient sensitivity to PD-1 blockade by a commonly used PD-1 blocker Pembrolizumab (KEYTRUDA)? If it does, can it be exploited to predict patient responsivity to the checkpoint blockade? To address these questions, we developed nanochip devices for the precise assessment of anti-tumor immunotherapy. These devices were designed with various nanoclusters of activating and inhibitory ligands which engage the receptors of T-cells. These nanochips were used as an artificial tumor cell, and help test T-cells from different patients on different nanochip arrays, with and without the PD-1 blocker drug Pembrolizumab, in order to study how the T-cells response to different patterns of the ligand clusters correlates with patient sensitivity to PD-1 blockade. This research has provided an important insight into the fundamental mechanisms of immune checkpoint blockade, and pave the way to the development of a novel nanochip technology for the personalization of this promising antitumor immunotherapy.

Resume : From ingested food, to the use of daily products that can be easily ingested, and also to the use of nanosized drug delivery systems for therapy, resident microbiota is exposed to nanoparticles (NPs) in widely undiscovered ways. The aim of this study is to investigate the in vitro interactions among inorganic NPs widely encountered in common practices and cultivable microbiota and probiotic isolates. Four types of inorganic NPs which are widely encountered in daily use products, namely CuO, Ag, Fe3O4 and ZnO were synthesized in this study. CuO and ZnO NPs were obtained by hydrothermal method, Ag by chemical reduction and Fe3O4 by co-precipitation. All NPs were physico-chemically characterized by SEM, TEM and FTIR spectroscopy. Microbiological analysis was performed by using four microbiota isolated strains with probiotic potential (2 strains of Enterofoccus faecalis and 2 strains of Lactobacillus rhamnosus), which were identified from newborn stool by MALDI-TOF. Our results demonstrated that the obtained NPs have round shape and variable size, ranging between 10-100 nm, depending on their type. Lowest size was obtained for the Fe3O4 NPs (10-15 nm). E.faecalis and L.rhamnosus strains were exposed to the obtained NPs for various type periods and the results demonstrated that Ag NPs are the only to exhibit a significant antimicrobial effect in the tested conditions. The other tested NPs showed however some effects in the attachment and other phenotypes which are important for the anti-pathogenic effects of microbiota and probiotic strains. The obtained data supports the idea that inorganic NPs could interfere with some biological processes in microbiota strains with probiotic potential, and this could impact on the development of some metabolic diseases.

Resume : Gold nanoparticles (GNPs) and their assemblies have been widely used as building blocks for the fabrication of (bio)sensing devices, grace to their unique optical and electronic properties, large surface to volume ratio and easy surface modification. The effectiveness of such nanostructures as transducing elements in optical sensors based on surface plasmon resonance (SPR), surface-enhanced fluorescence (SEF) or surface-enhanced Raman spectroscopy (SERS) was repeatedly demonstrated and many efforts have been devoted to tailor and control the morphology, solubility, surface functionality and stability of GNPs’ constituent elements. In this work we propose an optical biosensor assay capable of exploiting both SPR and SERS-based detection of the recombinant human B-lymphocyte antigen CD20, a protein involved in the regulation of B-cell activation and proliferation. The device consists of micro-stripes that were formed via oriented self-assembly deposition of closely packed spherical GNPs within pre-patterned polymeric grooves. The stripes formation was characterized by optical and scanning electron microscopy. The effect of particle size and shape, lateral periodicity of grooves and antigen concentration on the detection sensitivity in various matrices, was thoroughly investigated. By using a Raman reporter in the detection scheme, herein Fluorescein isothiocyanate (FITC) pre-conjugated onto anti-CD20 antibodies, the proposed device is able to function for the multimodal detection and identification of the targeted analyte. Such nanoparticle-based sensing platforms fabricated by a nontoxic and simple route are promising for applications in biochemistry and the medical field. Acknowledgement: This work was supported by the project PN-III-P1-1.1-TE-2016-0919.

Resume : Iron oxides/water interfaces are involved in many fundamental and technological processes (Q. A. Pankhurst, J. Connolly, S. K. Jones, and J. Dobson, J. Phys. D: Appl. Phys. 36, R167 (2003); A. K. Gupta and M. Gupta, Biomaterials 26, 3995 (2005)), therefore accurate force field parameters for the description of the bond between surface iron sites and water oxygens are critical to perform useful molecular dynamics simulations in this fast-developing research field. In a previous work by my group (H. Liu, E. Bianchetti, P. Siani, and C. Di Valentin, J. Chem. Phys. 152, 124711 (2020)), the behaviour of water multilayers with increasing thickness up to 12 nm on the low-index (001) Fe3O4 facet has been investigated comparing density functional tight binding (DFTB U) results with molecular mechanics molecular dynamics simulations. However, the classical model that we used,3 although catching the general aspects of the water structure and of solvation, has shown limited accuracy in the description of the details of the water coordination to the exposed surface undercoordinated iron sites. In the abovementioned model, longer distances (~2.7-2.8Å) between the superficial iron atoms and the oxygen atoms of adsorbed water molecules (Fe-Owater) have been observed compared to higher-level calculations using hybrid density functional theory (HSE06) and DFTB U methods that predict Fe-Owater distances about 2.2 Å. In the new work by my group (P. Siani, E. Bianchetti, H. Liu, and C. Di Valentin, J. Chem. Phys. 154, 034702 (2021)), a set of CLASS2 force field parameters is optimized to properly describe the Fe-Owater cross interaction through comparison with hybrid DFT (HSE06) calculations of the potential energy function for a single water molecule adsorbed on the Fe3O4 (001) surface and with DFTB U molecular dynamics simulations for a water tri-layer on the same surface. The performance of the new parameters is assessed through the analysis of the number density profile of a water bulk (12 nm) sandwiched between two magnetite slabs of large surface area. Their transferability is tested for the water adsorption on the curved surface of a spherical Fe3O4 nanoparticle of realistic size (2.5 nm).

Resume : The development of antimicrobial coatings with increased efficiency for the protection of critical surfaces is an important goal in finding new systems for medical area surfaces. The aim of the present study was to develop a novel photocatalytic activated product based on resins, in order to prevent and control the microbial pathogens implicated in healthcare associate infections. To achieve the purpose, the research team designed different formulations based on acrylic / acrystyrene-styrene resins in aqueous dispersion and formulations based on acrylic resin dilutable with OH approx. 2.5%, with additional anatase grade TiO2 pigment doped with metal oxides. All samples were chemical (UV-VIS, IR spectra) and physical characterized, including the optimal lifetime test (by exposure to different chemical and physical external-environmental factors). The antimicrobial activity was evaluated using qualitative and quantitative methods (according whit adapted CLSI 2020 standard method), after incubation in different conditions of light radiation, including darkness. The microbial strains used for the experiments were represented by both clinical and standard microbial strains (Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, Candida albicans ATCC 10231). Our results demonstrated that the obtained photocatalytic activated resins formula showed very good viscosity, hardness and drying time, with stability over time. Also, the antimicrobial tests showed significant inhibitory effect, with the decrease of CFU/ml values by at least 4 log., especially when the incubation was performed by exposure to radiation with the spectral range between 450 nm and 500 nm. This results demonstrated that the tested formula induced toxic biological effects after photocatalytic activation, considering them as light-activated antimicrobial agents-LAAAs and offering long time antimicrobial and mechanical protection of surfaces with high risk of contamination, in order to prevent and combat the spread of pathogenic microorganisms.

Resume : Nanostructured coatings for surface modification of metallic implants are of great interest for orthopedic and orthodontic applications, especially given their potential to boost an implant’s osseointegration and to provide local antimicrobial activity. The aim of this study was to modify metallic surfaces with nanostructured bioactive coatings based on hydroxyapatite (HAp) nanoparticles and biomolecules, so as to improve biological activity and limit the formation and development of Gram-positive and Gram-negative bacterial biofilms. The obtained composite materials based on HAp were proposed as multifunctional coatings for hard tissue implants. The functionalized nanoparticles were characterized by TEM, SAED, SEM, EDS, XRD and FT-IR. Composite coatings were fabricated by Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique, following thorough fluence studies to identify optimum conditions for laser processing. Complementary IRM and SEM investigations were performed in this respect. The biological activity of nanostructured samples was quantitatively and qualitatively assessed on eukaryotic cells, which evidenced the highly biocompatible behavior of proposed materials. Microbiological results have demonstrated that the bioactive HAp-based coatings significantly inhibited the contamination and colonization of different microbial species. The laser processed nanostructured coatings developed in this study could represent an efficient approach in developing bioactive platforms with anti-infective ability to be used in implantology. Acknowledgments: Contract PN-III-P1-1.1-PD-2019-1185, project number: PD 142/2020

Resume : The purpose of this study was to obtain and evaluate a novel magnetite nanosystem functionalized with natural-derived eugenol (Fe3O4@E), as well as to assess its impact on the most frequently isolated pathogens from skin infections, including strains responsible for G-tube-related complications. Physicochemical results demonstrated that the average size of obtained nanosystem was 10-20 nm, particles were relatively homogenous and had a reduced tendency to form aggregates. Subinhibitory concentrations of Fe3O4@E limited biofilm formation in a time- and strain-dependent manner, and significantly inhibited the production of toxin pore forming enzymes. Inflammatory cytokine release was assessed in human diploid cell cultures grown in the presence of Fe3O4@ core-shell nanosystem and as-modified G-tube surfaces. Besides excellent anti-adherence and antibiofilm effects, the proposed nanomaterials proved high biocompatibility, allowing the normal development and growth of human endothelial cells. This approach could be successfully applied for the optimization of medical devices’ surfaces in order to control and prevent microbial contamination and colonization and biofilm-associated infections. Acknowledgments: Contract PN-III-P2-2.1-PED-2019-3829, project number: PED 505/2020

Resume : Graphite is composed of layers of linked carbon hexagons. Between the layers, base metals such as potassium and the like, but also metal compounds can be incorporated, forming new substances (GIV). In high-temperature electrolyses any GIV formed may destroy the carbon electrodes. In other processes, such as the production of graphite foils, a versatile material with outstanding chemical and physical properties, make GIV the crucial intermediate. The electrochemical behavior of GIV opened up the possibility of constructing new high-performance lithium-GIV battery systems. New carbon compounds are found and their reaction behaviour characterized [1]. In addition to graphite and diamond, the group of fullerenes is the third carbon form, which has been experimentally accessible by graphite evaporation in the carbon arc. In the case of graphite evaporation, in addition to the fullerenes, similarly constructed carbon tubes. Buckminsterfullerene is soluble in organic solvents and gives a brownish product in the solid state. Fullerenes with many inorganic and organic substances react to form derivatives that have interesting physical properties and potential applications in the field of superconductivity and nonlinear optics. Fullerene research is an area of research in chemistry, materials science, physics and medicine. [2]. Considering of CNTs, our research is focused on the study of CNT synthesis and growth mechanisms upon thermal chemical vapour deposition, and their electrochemical properties. The functionalization of CNTs, through a chemical attachment of either molecules or functional groups to their sidewalls, is an effective way to improve their solubility and to enhance their physical properties that make them of potentially useful for technological applications ranging from nanoelectronics, sensors and electrochemical devices to composite materials. Graphene is the carbon fourth form: the 2D material graphene, made of carbon atoms arranged in a honeycomb lattice, has its peculiar mechanical, electronic, optical, and transport properties. Many of these features result solely from the symmetry properties of the honeycomb lattice. The chemical modification can be achieved via either covalent or non-covalent interactions. Covalent modifications often destroy some of the graphene conjugation system, resulting in compromising some of its properties.[3]. 1. Gupta, Vinay; Scharff, Peter; et al., C60 intercalated graphite: a new form of carbon. - In: Fullerenes, nanotubes & carbon nanostructures : An international and interdisciplinary journal.: Taylor & Francis, 13.2005, Suppl. 1, S. 427-430, http://dx.doi.org/10.1081/FST-200039421 2. H.M. Kuznietsova, O.V. Lynchak, N.V. Dziubenko, V.L. Osetskyi, O.V. Ogloblya, YuI. Prylutskyy, V.K. Rybalchenko, U. Ritter, P. Scharff, Water-soluble C60 fullerenes reduce manifestations of acute cholangitis in rats // Applied Nanoscience (2018), P.1–8, DOI: 10.1007/s13204-018-0700-5 3. Szroeder,PawełTsierkezos, Nikos G.; Walczyk, Mariusz; Strupi´nski, Włodzimierz; Górska-Pukownik, Agnieszka; Strzelecki, Janusz; Wiwatowski, Kamil; Scharff, Peter; Ritter, Uwe, Insights into electrocatalytic activity of epitaxial graphene on SiC from cyclic voltammetry and ac impedance spectroscopy. - Journal of Solid-state electrochemistry: current research and development in science and technology. - Berlin: Springer, 18 (2014), 9, 2555-2562,

Resume : The presentation focuses on a characterization of the production and fundamental parameters of carbon nanomaterials based on nanocarbons from carbon nanotubes powders to multi-walled carbon nanotubes (MWCNTs) and nanofibres on oxidized silicon substrate by means of chemical vapor deposition technique using acetonitrile as carbon source and ferrocene as catalyst [1 -6]. The aligned MWCNTs are well-ordered due to their structure, and have the so-called bamboo-like structure. Such bamboo-shaped nanotubes are known to contain nitrogen incorporated into their structure [2.3]. Surface chemistry of these carbon materials using special ? COOH, - COO and other functional groups developed. Electrochemistry of nanocarbons is researched for the electrochemical response of MWCNTs-based films towards oxidation of various molecules with biological interest, such as glucose and cholesterol which was tested by means of standard electrochemical techniques. And anodic peak corresponding to oxidation of studied biomolecules was observed on MWCNTs-based electrode. The successful oxidation of investigated biomolecules on MWCNTs-based film in the absence of their enzymes at relative low oxidation potential reveals the great electrocatalytic activity of nitrogen-doped MWCNTs. The enhanced detection ability and sensitivity of fabricated MWCNTs-based film towards investigated biomolecules make them quite suitable for further applications in biosensing. Novel sensing principles on carbon surface have developing. Its determine hybrid nanomaterials nanocarbon surface covered by biomolecules engineering for biomedical nanomaterials. References: 1. N.G. Tsierkezos, U. Ritter, Pawe? Szroeder, Application of Films Consisting of Carbon Nanoparticles for Electrochemical Detection of Redox Systems in Organic Solvent Media // Fullerenes, Nanotubes, Carbon Nanostruct. 19, 2011, P. 505-516; DOI: 10.1080/1536383X.2010.494782 2. N.G. Tsierkezos, U. Ritter, Electrochemistry of tris(2,2´-bipyridine)ruthenium(II) on nitrogen-doped multi-walled carbon nanotubes, Chemical Sensors 2013, 3, 8; http://www.cognizure.com/abstract.aspx?p=107637251 3. P. Shroeder, N.G. Tsierkezos, P. Scharff, U. Ritter, Electrocatalytic properties of carbon nanotube carpets grown on Si-wafers // Carbon 2010, 48, 4489-4496. http://dx.doi.org/10.1016/j.carbon.2010.08.009 4. Adrian Simon, N. Reger-Wagner, Martin Seyring, U. Ritter, Influence of carbon source and synthesis temperature on structural and morphological properties of carbon nanofibers synthesized on tubular porous ZrO2 layers // Diamond and Related Materials, 78, 2017, DOI: 10.1016/j.diamond.2017.08.006 5. Shereen haj othman, Eoin K. McCarthy, N. Tsierkezos, U. Ritter, Synthesis and electrochemical characterization of nitrogen-doped and nitrogen?phosphorus-doped multi-walled carbon nanotubes // Ionics 23(8) · March 2017, DOI: 10.1007/s11581-017-2049-2 6. M. Seyring, I. Voigt, A. Simon, U. Ritter, Quantitative crystallographic analysis of individual carbon nanofibers using high resolution transmission electron microscopy and electron diffraction // Carbon116:347-355, 2017, DOI: 10.1016/j.carbon.2017.01.107,

Resume : Nitrogen-doped, nitrogen-phosphorous- doped and boron –doped multi-walled carbon nanotubes, were studied as and nitrogen-doped MWCNT’s were decorated with metal nanoparticles (Rh, Pd, Ir, Pt, Au) and applied for simultaneous analysis of ascorbic acid (AA), dopamine (DA), and uric acid (UA). In N-MWCNTs/MNPs composite films three well-separated (not overlapped) oxidation waves were obtained for AA, DA, and UA analytes permitting their simultaneous analysis. Slight dependence of separation between oxidation waves of studied biomolecules on type of nanoparticles used for modification of N-MWCNTs was observed. Consequently, within the MNPs studied, AuNPs appear to improve better the electrocatalytic activity and sensitivity of N-MWCNTs. Namely, on N-MWCNTs/AuNPs the oxidation overpotential of AA decreases significantly and well-separated oxidation waves for interfering AA and DA compounds can be obtained. In addition, on N-MWCNTs/AuNPs well-separated oxidation waves for DA and UA can be observed. Consequently, the detection ability of N-MWCNTs/AuNPs towards simultaneous oxidation of AA, DA, and UA appears to be greater compared to other composite films. References 1. Haj Othman, Shereen; Ritter, Uwe; McCarthy, Eoin K.; Fernandes, Diogo; Kelarakis, Antonios; Tsierkezos, Nikos G. Synthesis and electrochemical characterization of nitrogen-doped and nitrogen-phosphorus-doped multi-walled carbon nanotubes. - In: Ionics: international journal of ionics : the science and technology of ionic motion. - Berlin: Springer, ISSN 18620760, Bd. 23 (2017), 8, S. 2025-2035, https://doi.org/10.1007/s11581-017-2049-2 2. Tsierkezos, Nikos G., Othman, Shereen Haj; Ritter, Uwe; Hafermann, Lars; Knauer, Andrea; Köhler, J. Michael; Downing, Clive; McCarthy, Eoin K., Electrochemical analysis of ascorbic acid, dopamine, and uric acid on nobel metal modified nitrogen-doped carbon nanotubes. - In: Sensors and actuators / B. - Amsterdam [u.a.] : Elsevier Science, ISSN 09254005, Bd. 231 (2016), S. 218-229, http://dx.doi.org/10.1016/j.snb.2016.03.032 3. Tsierkezos, Nikos G.; Ritter, Uwe; Thaha, Yudi Nugraha; Downing, Clive; Szroeder, Paweł Scharff, Peter, Multi-walled carbon nanotubes doped with boron as an electrode material for electrochemical studies on dopamine, uric acid, and ascorbic acid. - In: Microchimica acta: an international journal on micro and trace analysis. - Wien [u.a.] : Springer, ISSN 14365073, Bd. 183 (2016), 1, S. 35-47, http://dx.doi.org/10.1007/s00604-015-1585-64201 4. Multi-walled carbon nanotubes modified with platinum, palladium, rhodium and silver nanoparticles in electrochemical sensing. - In: Journal of nanoparticle research : an interdisciplinary forum for nanoscale science and technology. - Dordrecht [u.a.] : Springer Science + Business Media B.V, ISSN 1572896X, Bd. 16Bd. 16.2014, 10, Article 2660, insges. 13 S., http://dx.doi.org/10.1007/s11051-014-2660-3 5. Tsierkezos, Nikos G. ; Knauer, Andrea; Ritter, Uwe, Multi-walled carbon nanotubes modified with gold nanoparticles with various diameters for the simultaneous analysis of dopamine and uric acid in a single experiment. - In: Sensor letters. - Stevenson Ranch, Calif. : American Scientific Publishers, ISSN 15461971, Bd. 12 (2014), 1, S. 153-159, http://dx.doi.org/10.1166/sl.2014.3231 6. GRAPHENE 18. Szroeder, Paweł; Tsierkezos, Nikos G.; Walczyk, Mariusz; Strupi´nski, Włodzimierz; Górska-Pukownik, Agnieszka; Strzelecki, Janusz; Wiwatowski, Kamil; Scharff, Peter; Ritter, Uwe, Insights into electrocatalytic activity of epitaxial graphene on SiC from cyclic voltammetry and ac impedance spectroscopy. - In: Journal of solid state electrochemistry: current research and development in science and technology. - Berlin: Springer, ISSN 14330768, Bd. 18 (2014), 9, S. 2555-2562, http://dx.doi.org/10.1007/s10008-014-2512-1

Resume : Nanostructured interfaces can be shaped for the molecular control of physical/chemical adsorption, with enhanced surface area to promote interfacial chemistry, nano-catalysis, and bio-inspired interfaces. For instance, connecting nanostructured materials to biological compartments is a crucial step in prosthetic applications, where the interfacing surfaces should provide minimal undesired perturbation to the target tissue. Ultimately, the (nano)material of choice has to be biocompatible and promote cellular growth and adhesion with minimal cytotoxicity or dis-regulation of, for example, cellular activity and proliferation. In this context, carbon nanomaterials, including nanotubes and graphene, are particularly well suited for the design and construction of functional interfaces. This is mainly due to the extraordinary properties of these novel materials, which combine mechanical strength, thermal and electrical conductivity. Our group has been involved in the organic functionalization of various types of nanocarbons, including carbon nanotubes, fullerenes and, more recently, graphene. The organic functionalization offers the great advantage of producing soluble and easy-to-handle materials. As a consequence, since biocompatibility is expected to improve upon functionalization, many modified carbon nanomaterials may be useful in the field of nanomedicine. In particular, we have recently shown that carbon nanotubes and graphene can act as active substrates for neuronal growth, a field that has given so far very exciting results. Nanotubes and graphene are compatible with neurons, but, especially, they play a very interesting role in interneuronal communication. Improved synaptic communication is just one example. During this talk, we will discuss the latest and most exciting results obtained in our laboratories in these fast developing fields.

Resume : Graphene and other related materials are considered unique systems for many applications in different fields, including biomedicine. They are offering the possibility of original chemical functionalization and design of complex multifunctional systems that allow further their exploitation in therapy, imaging and diagnosis. In this lecture, I will present the chemical strategies to functionalize graphene-based nanomaterials with appropriate functional groups and therapeutic molecules in view of their biomedical applications. I will present few examples of their use in cancer therapy and imaging. I will also describe how it is possible to enhance the biodegradability and tune the toxic effects of these different materials.

Resume : Cylindrical self-assembly of uniform polystyrene nanoparticles with fructose was carried out by hydrothermal treatment in the presence of both carbon nanofiber and sodium alginate, which is followed by heat treatment in an inert atmosphere. The carbonization generated fructose-derived honeycomb-like carbon walls with helically-aligned nanopores left after the polystyrene decomposition. The diffuse reflectance circular dichroism measurements gave peaks with opposite signs for the D- and L-fructose-derived cylindrical carbons. Circularly polarized light sensitivity in transient photoconductivity was confirmed apparently in the carbon-based helical structures. This sensitivity as well as straightforward formation of composites with another component to give helicity showed potential applications of the helically-aligned pores.

Resume : There is increasing interest in laser methods for direct-write formation of graphitic and graphene-like carbon structures from polymers, especially under ambient conditions. Applications include direct incorporation of sensing functionality (e.g., electrochemical, temperature, humidity, strain) onto plastic components. While the most popular material for laser-induced graphitization is polyimide, laser-induced graphitization of renewable materials through “multiple lasing” processes has been explored recently. Chitosan, the second most abundant natural polysaccharide after cellulose, is derived from partial deacetylation of chitin (found in insect exoskeletons, some crustaceans and fungi cell walls). Here we report on site-selective laser-induced formation of porous 3D graphene on flexible and water-soluble chitosan films using low-cost lasers. Raman spectroscopy demonstrates formation of high-quality graphene through the presence of sharp 2D peak. Measured full-width at half maximum intensity values (FWHM) values for the 2D peak were FWHM(2D) < 100 cm-1 (wavenumbers). We have also demonstrated proof-of-principle electrochemical sensing of with two redox systems: outer-sphere [Ru(NH3)6]3 /2 and inner-sphere [Fe(CN)6]3-/4-. Quasi-reversible Nernstian behavior was observed in cyclic voltammetry measurements for both systems over time scales ~ 20 minutes. Measurements at longer time-scales showed evidence of electrode degradation, consistent with dissolution of the biopolymer substrate. These results showcase the potential of these exciting materials for development of compostable sensors which could be used in sustainable packages for perishable food, e.g., dairy or meat products.

Resume : The development of novel optical and optoelectronic devices that harness the properties of two-dimensional (2D) nanocarbons such as graphene and carbon nanotubes (CNTs) depends on the ability to develop techniques that maximise the integration between these nanocarbons and the optical field. These techniques must be compatible, scalable, and also enable a suitable level of control of the light-matter interaction, in order to suit the particular application. Free-standing graphene is only able to absorb a small percentage of light, and thereby remains blind for most optical applications. In addition, current methods to obtain graphene (such as growth by chemical-vapour deposition) require growth temperatures circa 1000°C. As such, many of today’s devices are suited only for a limited range of experimental purposes, but are far from ideal for industrialisation. Here we show the viability of a low-temperature technique that has already proven commercial implementations for the case of multiwalled nanotube growth. We present our in-house development for the purpose of producing graphene layers on the surface of “moth-eye” nanostructures, to arrive at a super-absorbing surface. With this, we demonstrate the ability to produce strong levels of optical absorption, despite the absorber layer being ultrathin. We also show the means to integrate this nature-inspired structure into a commercial micro-electromechanical device. With this, we demonstrate a complete solution that enables strong light-matter interaction with graphene layers across a wide range of the electromagnetic spectrum, spanning from the ultraviolet to the mid-infrared. Although the details for the absorption mechanism are not fully understood, our computer model shows the moth-eye is able to funnel light along channels that maximise the extent of the interaction of the wave with the graphene absorber. In addition, we further show this growth method can be used to produce patterned arrays of vertically-aligned (VA) CNTS, to produce a nanostructure that feature a highly anisotropic absorption coefficient. The nanostructures can be encapsulated into a transparent polymer, to produce a material with remarkable optical properties. We show examples of this material, and how it can be used to mimic the effect of flat-lensing. When wrapped around curved surfaces, the material features close resemblance to the compound fly’s eye. With this, we conclude in the realization of bio-inspired carbon-based technologies that enhance the coupling to light across a wide range of wavelengths, and thereby opens the field of opto-electronics to these. This development, together with the fabrication capabilities described here, pave the way to new fabrication methodologies for optical devices requiring light management at the nanoscale, and allow us to harness new opportunities that will significantly improve our way of life.

Resume : Inspired by the biomimic turbinate-like structure in dog nose of biological olfaction, a biomimetic artificial nose for hydrogen (H2) detection based on 3D porous laser-induced graphene (LIG) decorated with Palladium (Pd) nanoparticles has been developed for room temperature (RT) hydrogen (H2) detection. Compared with a traditional chemical vapor deposition (CVD) method, the 3D porous biomimetic turbinate-like network of graphene was synthesized by simply irradiating an infrared laser beam onto a polyimide (PI) substrate, which could also be further transferred onto another flexible substrate such as polyethylene terephthalate (PET) to broaden its application. The sensing mechanism is based on the catalytic effect of the Pd nanoparticles on the surface of the depleted biomimetic LIG turbinate-like microstructure, which allows the adsorption and desorption of electrons to the nonpolar H2 molecules across the biomimetic artificial nose. Also, the LIG based H2 sensor showed good mechanical flexibility and robustness for potential wearable and flexible device applications.

Resume : Understanding nanoscale energy dissipation is nowadays among few priorities particularly in solid state systems. Breakdown of topological protection, loss of quantum information and disorder-assisted hot electrons scattering in graphene are just few examples of systems, where the presence of energy dissipation has a great impact on the studied object [1]. It is therefore critical to know, how and where energy leaks. Pendulum geometry Atomic Force Microscope (pAFM), oscillating like a pendulum over the surface, is perfectly suited to measure such tiny amount of dissipation [2,3], since a minimum detectable power loss is of the order of aW. We report on a low temperature (T=5K) measurement of striking singlets or multiplets of dissipation peaks above graphene nanodrums surface. The stress present in the structure leads to formation of few nanometre sized graphene wrinkles and the observed dissipation peaks are attributed to tip-induced charge state transitions in quantum-dot-like entities. The dissipation peaks strongly depend on the external magnetic field (B=0T-2T). The magnetic field induce Peierls phase that shit the peaks to lower energy. At large magnetic field this shift induces the vanishing of the peaks. [1] – D. Halbertal, et.al., Nanoscale thermal imaging of dissipation in quantum systems, Nature539, (2016), 407–410. [2] - B.C. Stipe, et.al., Noncontact Friction and Force Fluctuations between Closely Spaced Bodies, Phys. Rev. Lett.87, (2001), 096801. [3] - M. Kisiel, et.al., Suppression of electronic friction on Nb films in the superconducting state, Nature Materials10, (2011), 119-122.

Resume : Due to its role in the operation of nervous response and renal, hormonal and cardiovascular systems, quantitation of dopamine (DA) in vivo has received great interest. Electrochemical sensing allows detection of nanomolar dopamine concentrations, and carbon-based electrodes are particularly suitable for this application due to their biocompatibility, ease of manufacture, low cost and functionalisation potential. However, carbon electrode current responses are influenced by DA-surface interactions and suffer from fouling by adsorption and accumulation of oxidation by-products, collectively called ‘polydopamine’ (PDA). Herein, we present a study of DA adsorption at carbon electrodes functionalised with N-/O-groups and the fouling properties thereof at physiological pH. Electrodes with smooth, reproducible morphologies, tuneable functionality types and concentrations and, crucially, tuneable sp3/sp2 ratios were synthesised via sputtering deposition and thermal/electrochemical treatments. The influence of surface graphitisation and surface chemistry was investigated using cyclic voltammetry and x-ray photoelectron spectroscopy to rationalise the connection between DA adsorption and electrode fouling, with preliminary AFM studies characterising the surface roughness. The ability of fouled surfaces to recover their sensing ability was also evaluated using acid cleaning and repeated fouling, to elucidate factors which promote/inhibit PDA adsorption. Our results suggest effective methods for optimising carbon electrode composition as a means of minimising fouling in DA electroanalysis.

Resume : Understanding nanoscale energy dissipation is nowadays among few priorities particularly in solid state systems. Breakdown of topological protection, loss of quantum information and disorder–assisted hot electrons scattering in graphene are just few examples of systems, where the presence of energy dissipation has a great impact on the studied object. It is therefore critical to know, how and where energy leaks. High sensitivity pendulum geometry Atomic Force Microscope (AFM), oscillating like a pendulum over the surface, is perfectly suited to measure tiny amount of dissipation. The tip position on the sample is controlled with atomic accuracy owing to a tunneling current line and the enhanced sensitivity allows to distinguish between electronic, phononic or van der Waals types of dissipation. Measurements can be performed in a wide range of temperatures from 5K to room temperature and in magnetic fields spanning from B=0T to B=7T. The design of the sample holder allows to perform dissipation measurements while passing electric current in the plane of the sample surface. In this work we performed energy dissipation measurements on a suspended graphene sheet at room temperature under UHV. The graphene is deposited on a hole patterned substrate in order to have suspended circular (with a diameter of 6.5 µm) graphene sheet. The experiments allows to investigate the phononic and electronic energy dissipation of the suspended graphene.

Resume : Potential applications of cylindrical carbon with helically aligned pores were explored based on its concomitant properties. The first example is transient photoconductivity (ϕΣμ), in which ϕ is the photocarrier generation yield and Σμ is the sum of the charge-carrier mobilities. The flash-photolysis time-resolved microwave conductivity (FP-TRMC) technique was conducted using circularly polarized light excitation at 532 nm. The ϕΣμ difference at the cylindrical carbon synthesized using D-fructose was observed for the left- and right-handed circularly polarized light. In contrast, no appreciable ϕΣμ difference was observed for the cylindrical carbon synthesized using the racemic fructose. These results indicated the potential to form an optoelectronic device that could change the conductivity by the circularly-polarized light. The second example is the feasibility to form composites with the helical structure due to easy access of the constituents to the pores. A composite of the cylindrical carbon and colloidal Au nanoparticles (Au NPs) was formed by immersing the cylindrical carbon in the colloidal Au dispersion in toluene and rinsing with the dispersion medium. The Au NPs clusters were helically aligned like stepping stone. This simple formation method enabling the helical alignment of the Au NP clusters implied the potential of the cylindrical carbon as a platform for feasible generation of helical structures.

Resume : Glaucoma is the second most common cause of blindness worldwide [1]. It is estimated that in 2020, 80 million people worldwide had some form of glaucoma. Glaucoma is a group of ophthalmic diseases that lead to progressive damage of the optical nerve responsible for the transfer of information in the brain. With the appropriate treatment, glaucoma can be cured. The reduction of intraocular pressure (IOP) is associated with slowing down the risk of disease progression to a great extent. Nowadays, the majority of people with glaucoma use eye drops to tackle the problem. The biggest hurdle arising from their continued use is that many patients do not comply with their treatment. In attempting to address the above problem, various drug delivery systems have been developed to ensure consistent administration of the appropriate drugs [2], but have failed to overcome significant limitations, such as the delivery of hydrophobic drugs and their high cost. Therefore, it is necessary to develop new and innovative systems, including features such as: i) the use of biocompatible materials (graphene oxide and biodegradable polymers) with the appropriate biological, electrical and mechanical properties; ii) the appropriate glaucoma drugs; iii) a controlled pharmacokinetic mechanism based on the use of ultrafast lasers for micro-nano patterning of the ocular devices; and iv) the inter-relation of the intraocular pressure and controlled drug release rate by the ocular patch. Ultrafast pulsed laser irradiation is considered a simple and effective microfabrication method to produce structures controlling the structure geometry and pattern regularity [3]. Such structures have been shown to enhance cellular growth and alignment (eg in neuronal cells [4,5]). Additionally, due to their biocompatibility, graphene and its derivatives have been used in a number of different biomedical applications, such as biosensors, tissue engineering and drug delivery systems. In this study, graphene oxide and a series of reduced graphene oxide preparations, prepared using green reducing agents, were tested for cytotoxicity, as well as better drug deposition and release. The structures were characterised in terms of their homogeneity, morphology and optical properties. The cytotoxicity of the functionalised structures with a fibroblast cell line and with corneal cells is further investigated. This research has been co‐financed by the European Union and Greek national funds under the calls RESEARCH – CREATE – INNOVATE (project code: Τ1EDK-02024, MIS:5030238), NFFA (EU H2020 framework program) and H2020 FET-open (project name: Biocombs4NanoFibers, Grant Agreement No. 862016). [1] Blomdahl S. et al., Acta Ophthalmol Scand 1997; 75 (5): 589–591. [2] Knight, O.J. & Lawrence, S.D., Curr Opin Ophthalmol. 2014; 25(2):112-7. [3] Ranella A. et al., Acta Biomaterialia 2010; 6: 2711. [4] Simitzi C. et al. Biomaterials. 2015; 67:115-128. [5] Angelaki D. et al., Mater. Sci. Eng. C, 2020; 115:111144.

Resume : The trend of organic thin films research toward conductivity - photovoltaic chip has allowed using the/films from ds-DNA –templated naocarbons molecular layers obtained by biotechnology. On the base of the review deals to analysis of electronic properties, photosensitivity, photoelectron moving force (PhEMF) and their stability under UV-vis irradiation for nanocarbon films with DNA molecules, we selected the thin films from silf-assembled layers of fullerene C60/C60 oxygen derivatives/ds-DNA on silicon for the detail investigations. The developing model of conductivity, and photovoltaic effect, in these layerss takes in account that C60 molecule is an acceptor of electrons. And the effect enhances with formation of C60 oxygen derivatives: 6-5 open fullerene C60 as we showed in first time [1].The evidence of self-assembling of these layers with (ds-DNA) in the nanostructured films on Si surface were obtained on the base of STM and SEM images of the films with the assembles (8-10 and 30-40 nm in diameter).The conductivity of the films was modulated by diode characteristics of fullerene C60/6-5 open fullerene C60 and C60/ ds-DNA contacts for n-type semiconductors fullerenes witch were determined by STP - tunneling spectroscopy. The discovered dynamic behavior of photosensitivity to 200-400 nm irradiation and PhMF appearance (0,25-0,37 eV) at 400-1000 nm irradiation (during 10 min - 1 h) of these films with several structures allow to consider these nanostructured layers/films as conducting/ photovoltaic chips. The examples for an application of these chips based on conductivity/photovoltaic models which have been developed for organic nanostructured thin films from C60 fullerene/ds-DNA molecular assemblies are discussed. Ref.,{1] E. Buzaneva, A. Gorchinskiy, P. Scharff, K. Risch, A. Nassiopoulou, C. Tsamis, Yu. Prilutsyy, O. Ivanuta, A. Zhugayevych, D. Kolomiyets, A. Veligura, DNA, DNA/Metal Nanoparticles, DNA/Nanocarbon and Macrocyclic Metal Complex/Fullerene Molecular Building Blocks for Nanosystems: Electronics and Sensing, In Book Frontiers of multifunctional integrated nanosystems, Eds: Eugenia Buzaneva and Peter Scharff, NATO Science Series, II-Mathematics, Physics and Chemistry–Vol 64, Kluwer Akademic Publishers, Dordrecht, 251-276, 2004.

Resume : Osteoporosis is a skeletal disease characterized by bone loss and bone microarchitectural deterioration. The increasing life expectancy calls for innovative and effective approaches to compensate for bone loss.1 Due to their well-documented regenerative and anti-inflammatory potential, stem cells represent a promising option. The knowledge of bone piezoelectricity and of bioelectricity as a further cue to influence cell fate, in addition to biochemical and mechanical ones, has elicited for the use of physical stimulation together with electroactive materials as smart alternatives for bone tissue engineering. The combination of smart substrates, stem cells and physical stimulation to induce cell differentiation is therefore a new avenue in the field. Biomimetic scaffolds were prepared by combining the conducting polymer PEDOT:PSS with collagen type I, the most abundant protein in bone. Pores sizes, mechanical and impedance properties were measured as a function of scaffolds composition. Two populations of stem cells were used to understand the impact of scaffold composition on cell behaviour. Preliminary electrical stimulation experiments were run to evaluate its use in combination with the developed electroactive scaffolds in the frame of a bioelectronic approach to bone tissue engineering. Recent results on devices developed to assess stem cell differentiation will be presented.

Resume : Since its early days, ex vivo mammalian cell culture has been conducted on flat two-dimensional (2D) glass or polystyrene surfaces. Although 2D cell culture is still widely used, it is known to result in unnatural cell polarity and morphology in addition to lacking the three-dimensional extracellular matrix. These drawbacks are especially evident if the cultivated cells are clinically relevant cell types including but not limited to stem cells. In this context, 2D cultivation is known to interfere with stem cell proliferation and to alter the cell phenotype. In this talk, different approaches to stem cell cultivation, differentiation, and assessment of migration in 3D will be discussed. In particular, biocompatible natural scaffolds for the cultivation of adult human neural crest-derived stem cells and human mesenchymal stem cells of different origins will be presented. Moreover, the impact of 3D cell culture on the regenerative potential of stem cell secretome will be discussed.

Resume : The 400 000 artificial hip joint operations made every year in the word and there are 25 000 000 people with a total hip replacement. The wear and risk of the implant loosening increases so that after 10 years 10-20% of the implants have to be renewed. Biomaterials used for implant should possess some important properties in order to long-term usage in the body without rejection. The biocompatibility, mechanical, chemical and surface properties play a key role in the creation of sufficient and long term functional replacements. New fundamental research outcomes with industrial perspectives are given for understanding the applications of ceramics in load-bearing and low-load-bearing bioimplants with directions for future developments. Nowadays, Si3N4 is a new bioceramic with extremely good mechanical properties. Hydroxyapatite (HA) is a widely used bioceramic in implantology considering its high bioactivity. A bioactive coating (HA) on the bioinert ceramic implant?s surface (Si3N4) could help avoid the rejection from the body in the critical early few days after the operation. The preparation of bioceramics will be showed from traditional technologies to novel applications. The main trends and fundamental scientific problems will be discussed.

Resume : Ultrashort pulse laser interaction has been extensively studied for the modification of material properties in various materials. Femtosecond laser applications to microprocessing have received great attention in recent years. This is due to the characteristics of ultra-short laser-material interaction expressed in extremely high-peak power and femtosecond pulse duration which is less than material thermal relaxation time. Moreover, the effects of temperature distribution during material processing can be strongly minimized with ultrashort pulses leading to non-thermal and spatially localized effects that can facilitate volume ablation without collateral thermal damage. Using femtosecond processing laser-induced surface structures provide a response by the formation of micro/nano scale structures, which are acquired with respect to laser processing parameters. Such surface feedback can be applied to finely tune and control diverse properties like wettability, reflectivity and biomimetics. By simply controlling the laser parameters, diverse surface roughness can be achieved, thus influencing cellular dynamics like adhesion, migration, and differentiation which can be tuned via altering topographical properties and chemical composition of the surface. In the current study polylactic acid (PLA) polymer surfaces were modified by Ti:sapphire femtosecond laser at different laser energies and number of applied laser pulses. Thus, implant surface modifications have been examined, and different laser based surface treatments were applied to obtain structures with hierarchical geometries. The results demonstrate that the control of the laser parameters can obtain bioactive surfaces by the nondestructive laser modification process.

Resume : Regenerative medicine stands before the problem to replace non-functional tissues or improve the wound healing. Therefore, many laboratories try to develop resorbable tissue scaffolds that could support the patient´s cells or breathable wound dressings that could immobilize biocide particles. The scaffold material should be biocompatible, biodegradable, and easy to manufacture, thus economically viable. A possible answer is to produce a structure made of a biodegradable polymer that mimics extracellular matrix (ECM), which would be peacefully received and gradually degraded when the new tissue has formed. The solution for wound dressings can also benefit from the nanofibrous structures that have bioactive surface able to immobilize biomolecules and particles. One of the promising polymers is FDA-approved polycaprolactone (PCL) due to its relatively low cost, excellent processability and mechanical properties, non-toxicity and low immunogenicity. However, the pristine form of PCL has a bioinert and hydrophobic surface causing problems with protein adsorption resulting in reduced cell adhesion. Our previous publications showed that PCL nanofibrous mats could be efficiently modified by plasma polymerization, which leads to the formation of bioactive surface exhibiting increased cell attachment and proliferation, offering also a possibility to attach proteins [1,2,3]. We have also shown the filamentary sub-structure of electrospun PCL/poly(ethylene oxide) (PEO) mixtures and changes of their functional properties for varying PCL:PEO ratio and plasma processing [4]. In this conference contribution, we will discuss processing aspects of the plasma-polymer-coated nanofibrous mats, the penetration depth of plasma polymerization and bioactivity of functional plasma polymer surfaces. [1] P. ?ernochová et al., Cell type specific adhesion to surfaces functionalised by amine plasma polymers, Scientific Reports 10 (2020) 9357 [2] I. Nemcakova et al., Behaviour of Vascular Smooth Muscle Cells on Amine Plasma-Coated Materials with Various Chemical Structures and Morphologies, International Journal of Molecular Sciences 21 (2020) 9467 [3] E. Makhneva et al., Cyclopropylamine plasma polymer surfaces for label-free SPR and QCM immunosensing of Salmonella, Sens. Actuator B-Chem. 276 (2018) 447-455 [4] V. Kupka et al., Well-Blended PCL/PEO Electrospun Nanofibers with Functional Properties Enhanced by Plasma Processing, Polymers 12(1403) (2020) 16

Resume : In the last decades, there is an increased interest in developing strategies for improving biointerfaces in the field of orthopedic or dental implants. Various coating materials were used as nano and micro-structured interfaces to fine-tune the cellular response. Among these, ceria (CeO2) nanostructures are thought to improve the biointerface mechanical properties, but also to stimulate the regenerating tissue biochemical activity by neutralizing the oxidative stress and stimulating cells proliferation. Within this context, this work presents for the first-time pyramid-shaped nanostructured ceria films obtained by Pulsed Laser Deposition (PLD) targeting the early response of human osteosarcoma cells (SaOs-2). SEM and AFM images of the nanostructured surfaces revealed shapes from the quasi-pyramidal, with rounded edges and dimensions of 90 - 120 nm, to the sharp edges and dimensions up to 350 nm, obtained by varying the number of pulses. The transition from hydrophobic to moderate hydrophilic behavior, as well as the increase of the polar component for the samples with more prominent features, were correlated to the topographical characteristics and further to cell behaviour. The influence of pyramidal-shaped ceria on the in vitro biological performance of SaOs-2 cells was demonstrated by the differences in early adhesion and distribution of phenotype SaOs-2 cells. Nevertheless, as the adhesion and spreading characteristics are cell line specific, mesenchymal stem cells (MSCs) were used for comparing the different cytoskeleton response as response to the ceria nanostructure type. In perspective, the behavior of mesenchymal progenitor cells is foreseen to be analyzed in view of establishing an osteogenic response on these biomaterials and the best-suited processing approach in order to use them as substrates for future bone regeneration applications. Keywords: Pyramidal shaped ceria nano-biointerfaces, PLD, cells response Acknowledgement This work was supported by the National Authority for Research and Innovation in the frame of the Nucleus Program and grants of the Romanian Ministry of Research and Innovation,CCCDI-UEFISCDI, project numbers PN-III-P1-1.2-PCCDI-2017- 0637 (MultiMonD2).

Resume : Dr. Ashwini B. Salunkhe currently working as a Assistant Professor in Department of Physics, Rajaram College, Kolhapur. She has completed her M.Sc. with specialization in Solid state Physics from Shivaji University Kolhapur in 2009 and Ph.D. in Physics in 2012 from Centre for Interdisciplinary Research, D.Y. Patil Education Society, Kolhapur. Her research is focused on the Development of magnetic nanoparticles for cancer theragnostic. Based on her research work she has received gold medal with certificate of ?Excellence in research? by D.Y. Patil University, Kolhapur. She is 2 times recipient of a PEIN fellowship by University of Santiago de Compostela, Spain (2012 & 2014) and European Union?s EUPHARATES postdoctoral fellowship in 2015. She is also recipient of Government of INDIA?s Dr. D.S. Kothari postdoctoral fellowship for 2014-2016 to develop magnetic nanoparticles for stem stell labelling in University of Pune, Pune. She has published 28 research articles with 2 review articles. High magnetic moment Fe3O4 nanoparticles (NPs) are synthesized through simple co precipitation method by using new generation base Diisopropylamino (DIPA) which plays dual role as reducing agent and surface stabilizer. Spherical NPs with ~ 15 nm size and high magnetization value of about 92 emug-1 at room temperature are obtained by this novel method. High specific absorption rate value of ~717 wg-1 is obtained for Fe3O4 NPs in water at an alternating magnetic field of 20 kAm-1 and frequency of 267 KHz, which is attributed to high magnetization value. Magneto-polymeric micelle structure is formed by using Pluronic F127, anticancer drug Doxorubicin is conjugated in micelle by covalent linking with ligand molecules for magneto-chemotherapy. Finally, the magnetic resonance imaging (MRI) guided magneto-chemotherapy is achieved on breast cancer (MCF7) cells with ~ 96 % killing of cancer cells.

Resume : Bisphosphonates are known for its attested properties to positively influent on bone remodulation, mainly decreasing the osteoclast activity leading to an increased osteoblast growth and activity. Although exhibiting beneficial properties, these compounds are also related to jaw osteonecrosis from intravenous and oral administration in patients. Having that in mind, surface modification of implants using bisphosphonates is a suitable alternative to overcome this collateral effect. Different studies have reported that BP’s when immobilized on surface can promote bone growth through local release and/or coordinating the calcium on hydroxyapatite crystals. Despite BP’s strong bind to HA, implants’ surfaces are currently made of titanium alloys, which surface is mainly composed of titanium dioxide. In this way, a detailed study of adsorption of BP’s is necessary in order to advance and explore its potential use. Aiming to elucidate aspects of bisphosphonates adsorption on titanium dioxide the purpose of this work is to functionalize titanium dioxide in two different phases using etidronate, alendronate and risedronate. As a first step, the adsorption of bisphosphonates will be evaluated using FTIR and measuring the solution concentration after adsorption through UV-Vis. Then, the desorption will be evaluated using simulated body fluid in order to mimic the body condition. Again, the concentration will be evaluated through UV-Vis. In order to provide deeper understanding from the obtained results, some molecular simulations will be performed. Simulations of the electronic structure using methods as DFT (density functional theory) will take place, once techniques like Condensed to Atoms Fukui Indexes (CAFIs) can provide a good understanding of the reactivity of the molecules. The Condensed to Atoms Fukui Indexes uses the electronic population of each atom in order to calculate the Fukui Indexes, parameters that can be used to analyze the system reactivity and determine the most probable adsorption way of each molecule. Some vibrational calculations will also be made, aiming to compare the theoretical and experimental results from the FTIR experiments. In this way, it is expected that this work helps to establish the optimum procedure to functionalize oxide surfaces using bisphosphonates keeping its osteogenic properties.

Resume : Nanogels are hydrogel-based nanoparticles that are highly tunable in chemical composition and physicochemical properties. These nanoparticles are highly versatile in their uses and allow for several functions to be combined including antimicrobial properties, fluorescence and MRI tracking and imaging, anti-adhesive, controlled release, and responsiveness to various stimuli. Because of this variety of functions and properties, the particles are used in controlled delivery, imaging, theranostic approaches and functional biomedical multi-modal coatings. The studies presented provide insights in the capabilities of such nanogels, the preparation, modification, and the use of them together with biological systems ranging from in vitro studies to in vivo uses. The ease of scaling, the diversity, and ease of applicability make these particles very powerful and tremendously complement the existing nanotoolbox of liposomes, polymersomes, protein-based nanostructures, and inorganic nanoparticles.

Resume : It has been long known that cytotoxic lymphocytes ? the sentinels of our immune system ? differentiate between pathogens and healthy cells by sensing environmental chemical cues, which are delivered by the ligands expressed on the surface target cells. Yet, it is becoming progressively clear that lymphocytes sense also physical environmental cues, such as ligand arrangement, mechanical stiffness, and topography. In the first part of my talk, I will review our recent study of the role of the ligand arrangement in the immune function of Natural Killer (NK) cells, using nanoengineered stimulating platforms based on patterned arrays of ligands. The first generation of such platforms was based on arrays of nanoimprinted metallic nanodots functionalized with activating ligands, which allowed us to discover the minimal spatial requirement of ~ 1 ligand per sq. micron needed for the activation of NK cells. The next, more advanced generation of arrays came to examine how the segregation between activating and inhibitory ligands affects the inhibition of activating signaling in NK cells. The platform was based on ordered arrays of nanodots of two metals selectively functionalized with activating and inhibitory ligands, whose segregation was systematically tuned between 0 nm to 40 nm. Surprisingly, we found that inhibition efficiency increased with the spacing between the ligands within the probed range, and rationalized this finding by physical modeling of the ligand-receptor binding kinetics. In the second part of my talk, I will review our recent study of the role of environmental elasticity and topography in the function of cytotoxic lymphocytes. Stimulation of NK cells on planar elastomers functionalized with activating ligands revealed a bell-shape trend of activation vs. elastic modulus3. A more complex stimulating platform was based on ligand functionalized nanowires aimed at delivering the chemical, nano-topographical, and mechanical cues, whose combination produced an enhanced immune response of NK cells. To separately reveal the effect of each cue, we recently stimulated NK cells and CD8+ T cells on nanowires with varied length and bending moduli and found that these physical parameters of nanowires greatly affects the signaling and the immune function of the lymphocytes. Overall, our work provides an important insight into the way the physical cues regulate the function of NK cells and T cells.

Resume : The development of portable and wearable sensors is of high importance in several ?elds, such as point-of-care medical applications and environmental monitoring. To this end, Organic Electrochemical Transistors (OECTs) offer consistent advantages such as easy and cheap readout electronics, low supply voltage (usually < 1 V), low power operation (< 100 ?W), bio-compatibility, ease of integration. Moreover, the transistor configuration provides intrinsic amplification of the output signal and gives design freedom in terms of device geometries and substrates (flat/flexible). Here we report a new biosensing platform inspired by the organic electrochemical transistor (OECT), based on a composite material of PEDOT:PSS (poly(3,4-ethylenedioxythiophene) poly(styrene sulfonate)) and Ag/AgnX nanoparticles, where X refers to the ion to be detected in the fluid of interest (e.g. Cl-, Br-, I- and S2-). The Ag/AgX NPs act as a gate electrode embedded into the conductive polymer channel, thus combining an intrinsically amplified response with a simple two terminal electrical connection. Electrostatic Force Microscopy and Electrochemical Impedance Spectroscopy analyses demonstrate the electronic coupling between the electrochemically active NPs and the semiconducting polymer, which allows to explain the sensor ampli?ed transduction. The analytical signal is the current that ?ows in the composite polymer and its variation is directly proportional to the logarithm of Cl- concentration in the range 10?4 to 1 M. The simple, two terminal configuration of the here proposed biosensors has relevant positive implications on the read-out electronics, on the adaptability to unconventional geometries and on the response time, faster than for a conventional OECT endowed with a standard Ag/AgCl gate electrode [1]. Moreover, its ability to operate by sampling only a few microliters of fluid is ideal for wearable, non-invasive bio-fluid sampling. The analysis of concentrations of ions in biofluids, such as sweat, is crucial for several health conditions. In particular, the evaluation of Chloride concentration in sweat for infants and children is a method for diagnosing Cystic Fibrosis. Moreover, the presence of different ion concentrations in sweat can be directly related to dehydration and its real-time monitoring while training can help athletes control and improve their performance. The main bottlenecks for developing such non-invasive biosensors are the relatively large amount of biofluid needed for such analyses and the sensitivity and portability of the sensing system, issues that are fully overcome by the here proposed biosensors. We demonstrate their operation and performance in artificial sweat and we validate the implementation of our biosensors in a fully textile electronic device, fabricated directly onto a cotton yarn for real-time sweat monitoring. [1] I. Gualandi, M. Tessarolo, F. Mariani, T. Cramer, D. Tonelli, E. Scavetta and B. Fraboni, Sensors & Actuators: B. 273, 834 (2018)

Resume : All implantable biomedical systems face several risks once in contact with the host tissue: excessive immune response to the implant and development of bacterial biofilms. A multifunctional surface coating that can address all these two issues concomitantly would significantly improve clinical outcomes. Polyarginine (PAR), a synthetic highly cationic polypeptide, can act on macrophages to control innate immune response and also as an antimicrobial agent due to its positive charges. We developed a new polyelectrolyte multilayer film based on PAR and hyaluronic acid (HA). The layer-by-layer PAR/HA films have a strong inhibitory effect on the production of inflammatory cytokines released by human primary macrophages subpopulations [1]. Next, we show that PAR/HA films were very effective to inhibit pathogenic bacteria associated with infections of medical devices [2] [3]. We demonstrate that exclusively films constructed with poly(arginine) composed of 30 residues (PAR30) acquire a strong antimicrobial activity. This system can also be fabricated in the form of hydrogel [4], useful to provide antibacterial properties to porous implants like surgical meshes. Recent developments to render these systems smart and responsive have also been made to obtain a release and activity only when bacteria are closed to the implants. [1] Özçelik, H. et al. Adv. Healthc. Mater. 2015; 4, 2026-36. [2] Mutschler, A. et al. Chem. Mater. 2016; 28, 8700-09. [3] Mutschler A. et al. Chem. Matter., 2017; 29, 3195?01. [4] Knopf-Marques H. et al. Mat. Sci. Engineer., 2019, C, 104, 109898-07.

Resume : Albumin membranes formulated by evaporation in the presence of salt represent a new class of materials (EU patent submitted). In the present study, solutions of bovine serum albumin (BSA) and various salts are evaporated at 37 °C and pH 6 in order to prepare albumin-based material. Among others, NaBr allows the formation of stable and water-insoluble albumin membranes, thus providing a solid material exclusively composed of albumin after thorough washing. The conditions for obtaining BSA/NaBr membranes are assessed, and the molar ratio salt/albumin proves to be a key parameter for their formation. The Young modulus (E) of the materials lies around 0.86 ± 0.13 MPa. Biological assays show that these albumin membranes are not cytotoxic, do not induce an inflammatory response and allow cell adhesion. Therefore, due to their interesting properties, these materials are suitable candidates for the development of scaffolds for tissue engineering and biodegradable implantable devices.

Resume : Efficient neurite outgrowth, mechanoresponse and the increasing of the survival rates are critical for the successful cultivation of cortical neurons in vitro[1] and the potential of central nervous system regeneration in vivo, after maturation of these cells[2]. Polyhydroxyphenylvalerate (PHPV), an aromatic polyester of bacterial origin[3], was electrospun into nanofibers and blended with polycaprolactone (PCL) and electrospun in nanofibers for use in a 3D (CellCrown?) configuration and in a 2D coverslip coated configuration. Contact angle and nanoindentation tests by atomic force microscopy (AFM) showed that PHPV has a higher hydrophilicity and adhesion when compared to pure PCL. Height images derived by AFM scan identify a mixed roughness/smoothness ratio of the PHPV/PCL blend, where PHPV is responsible for the smoother component while PCL gives the roughness component of the blend. Nanoindentation tests of the electrospun fibers, done by AFM, exhibit correlated force-map curves that can identify the Young?s modulus of the materials[4]. PHPV, other than increased adhesion, has a more viscoplastic behaviour in the stress/strain response (where the plastic modification of the material is evident at an earlier stage than PCL) but is too soft and show poor mechano-response for cell cultivation. PCL has a strain hardening behaviour under stress[5] and higher elasticity, but it is hydrophobic and too tough and stiff, hindering cell survival. PHPV/PCL shows a superior behaviour compared both to PCL and PHPV. The same rheological results have been confirmed by stress/strain tests at macroscale by Universal Tensile Machine (UTM); PHPV/PCL has a measured stiffness and an elastic modulus 2.3 and 2.4-fold lower than PCL, respectively. The PHPV/PCL blend maintains the mechanical solidity but having a higher hydrophilicity, softness and a relatively low stiffness can sustain for longer the attachment of neuronal cells, and improves their adhesion and their neurite elaboration, facilitating synaptic contacts. In facts, electrospun PHPV/PCL allow a 2.3-fold increase in the life-span of human induced pluripotent stem derived cortical neuronal cells (hiPS) compared to pure PCL fibers. HiPS-derived cortical neuronal cells grown on PHPV/PCL fibers show a 3.8-fold higher cumulative neurite elaboration compared to neurites grown on PCL fibers only. 96% of cortical neuronal cells die after 8 days of growth when plated on PCL fibers alone while more than 83% and 55% are alive on PHPV/PCL fibers on day 8 and day 17, respectively[6]. An increased migration rate of cortical neuronal cells is also promoted by the blend compared to the PCL fibers alone. The critical survival rate improvement of hiPS derived cortical neuronal cells on PHPV/PCL blend holds promise in using these biocompatible nanofibers as implantable materials for regenerative purposes of an active cortical neuronal population after full maturation in vitro[6]. References [1] D.E. Koser, A.J. Thompson, S.K. Foster, A. Dwivedy, E.K. Pillai, G.K. Sheridan, H. Svoboda, M. Viana, L.D. Costa, J. Guck, C.E. Holt, K. Franze, Mechanosensing is critical for axon growth in the developing brain, Nature Neuroscience 19(12) (2016) 1592-1598. [2] W. Ma, T. Tavakoli, E. Derby, Y. Serebryakova, M.S. Rao, M.P. Mattson, Cell-extracellular matrix interactions regulate neural differentiation of human embryonic stem cells, Bmc Developmental Biology 8 (2008). [3] K. Fritzsche, R.W. Lenz, R.C. Fuller, AN UNUSUAL BACTERIAL POLYESTER WITH A PHENYL PENDANT GROUP, Makromolekulare Chemie-Macromolecular Chemistry and Physics 191(8) (1990) 1957-1965. [4] N.D. Wanasekara, S. Ghosh, M. Chen, V.B. Chalivendra, S. Bhowmick, Effect of stiffness of micron/sub-micron electrospun fibers in cell seeding, Journal of Biomedical Materials Research Part A 103(7) (2015) 2289-2299. [5] Q.H. Liu, S.C. Yuan, Y.H. Guo, A. Narayanan, C. Peng, S.J. Wang, T. Miyoshi, A. Joy, Modulating the crystallinity, mechanical properties, and degradability of poly(epsilon-caprolactone) derived polyesters by statistical and alternating copolymerization, Polym Chem-Uk 10(20) (2019) 2579-2588. [6] F. Cerrone, T. Pozner, A. Siddiqui, P. Ceppi, B. Winner, M. Rajendiran, R. Babu, H. S. Ibrahim, B.J. Rodriguez, J. Winkler, K.J. Murphy, K.E. O?Connor Polyhydroxyphenylvalerate/polycaprolactone nanofibers improve the life-span and mechanoresponse of human IPSC-derived cortical neuronal cells. Material Science Engineering C. 111, 110832

Resume : In modern medicine, the development of systems for the selective delivery of drugs directly into the affected cells is relevant, without affecting the healthy cells. In recent years, the possibility of using nanocomposites based on polymers as targeted delivery of photosensitizers (PS) for photodynamic antitumor therapy (PDT) is actively explored. Nanocomposites containing PS have a number of advantages over the initial photosensitizing drugs, since they prevent the aggregation of PS molecules, which leads to a decrease in its activity. In addition, nanocomposites based on polymers can be additionally loaded with various drugs, which in turn enhance the effect of treatment. Polymer matrices on the base of Dextran core Polyacrylamide (neutral and anion forms) or poly(N-isopropylacrylamide) (PNIPAAm) as well as systems consisting of incorporated in a polymer matrix of gold nanoparticles and photosensitizer molecules or doxorubicin (2), triple systems ?D-g-PAA/AuNPs/PS or Dox?(3), and, finally, the systems?D-g-PAA /AuNPs/PS/Dox" (4) have been sequentially investigated by methods of optical spectroscopy (spectrophotometry, photoluminescence, luminescence excitation spectra) . The measurements of spectra at various concentrations were carried out to determine the optimal composition of nanosystems. It was found that in the presence of a photosensitizer or doxorubicin, an insignificant aggregation process in the system occurs as a result of the aggregation of the polymeric component due to the change in the hydrophilic-hydrophobic balance of the polymer matrix. This confirms the fact that Chlorine e6 and Doxorubicin interact with Polymer matrices.Aggregation processes are significantly enhanced in the four-component nanosystem D-g-PAA /AuNPs/Chlorine e6 /Doxorubicin, but the size of the gold nanoparticles does not change.

Resume : In this study, we employed a novel one step electrospinning process to fabricate poly(ethylene oxide) (PEO)/poly(3,4-ethylenedioxythiophene): polystyrenesulfonate (PEDOT:PSS) core/shell nanofiber structures with improved water resistance and good electrochemical properties. We then integrated a biocompatible polymer coating with three-dimensional (3D) PEDOT-based nanofiber devices for dynamic control over the capture/release performance of rare circulating tumor cells (CTCs) , as well as the label-free detection by using organic electrochemical transistors (OECTs). The detailed capture/release behavior of the circulating tumor cells was studied using an organic bioelectronic platform comprising PEO/PEDOT:PSS nanofiber mats with 3 wt % (3-glycidyloxypropyl)trimethoxysilane as an additive. We have demonstrated that these nanofiber mats deposited on five-patterned indium tin oxide finger electrodes are excellent candidates for use as functional bioelectronic interfaces for the isolation, detection, sequential collection, and enrichment of rare CTCs through electrical activation of each single electrode. This combination behaved as an ideal model system displaying a high cell-capture yield for antibody-positive cells while resisting the adhesion of antibody-negative cells. Taking advantage of the electrochemical doping/dedoping characteristics of PEDOT:PSS materials, the captured rare cells could be electrically triggered release through the desorption phenomena of PLL-g-PEG-biotin on device surface. More than 90% of the targeted cancer cells were captured on the 3D PEDOT-based nanofiber microfluidic device; over 87% of captured cancer cells were subsequently released for collection; approximately 80% of spiked cancer cells could be collected in a 96-well plate. For the OECT design, it was demonstrated for monitoring CTC-capture performance and identifying cancer cell phenotypes. This 3D PEDOT-based bioelectronic device approach appears to be an economical route for the large-scale preparation and detection of systems for enhancing the downstream characterization of rare CTCs.

Resume : Our attempt to develop a new type of radiation therapy by using gadolinium-loaded mesoporous silica nanoparticles and synchrotron-generated monochromatic X-rays will be discussed.

Resume : Medical applications of multifunctional nanoparticles are expected to be one of the most important possibilities in innovative medicine. Organosilica nanoparticles are novel nanomaterials that are prepared from a single organosilicate coupling agent (organotrialkoxysilane) such as 3-mercaptopropyltrimethoxysilane. Organosilica nanoparticles are both structurally and functionally different from typical silica nanoparticles (inorganosilica nanoparticles) prepared from tetraalkoxysilane. The organosilica nanoparticles contain both interior and exterior functionalities such as mercaptopropyl residue as prepared. The organosilica nanoparticles allow for facile surface and internal functionalization, offering new opportunities to create multifunctionalized nanoparticles. Over the last two decades, research on the internal functionalization of organosilica nanoparticles has evolved. Various sizes of fluorescent organosilica nanoparticle containing various types of fluorescent dye including near infrared (NIR) dye can be prepared using a one-pot synthesis. In addition, functional fusions of organosilica nanoparticles and other functional nanoparticles such as quantum dots, gold nanoparticles, and iron oxides are possible based on organosilica particles technology. These multifunctionalized organosilica nanoparticles are useful for various imaging techniques such as in vivo imaging, cell labeling, time-lapse fluorescent imaging, and multimodal imaging. Multifunctionalized organosilica nanoparticles have high potential to create novel imaging systems and provide novel information of cell characteristics and functions. In recent year, we have launched additional research on surface functionalization of organosilica nanoparticles using biomolecules and polymers. Surface-functionalized organosilica nanoparticles revealed various alterations of the interaction with cells including tumor cells and macrophages. We applied multifunctionalized NIR organosilica nanoparticles to tumor-bearing mouse. The particles showed an accumulation on tumor tissue on NIR in vivo imaging, and damaged tumor cells by using photodynamic effect. Imaging and therapy using multifunctionalized organosilica nanoparticles allow for nano-theranostics.

Resume : My laboratory has been developing various types of activatable and dual-targeted photosensitizing agents as smart theranostics for selective near-infrared fluorescence imaging and photodynamic therapy (PDT) of cancers and inflammatory diseases. Recently a fucoidan-based theranostic nanogel (CFN-gel) consisting of a fucoidan backbone, redox-responsive cleavable linker, and photosensitizer was developed to achieve activatable near-infrared fluorescence imaging of tumor sites and an enhanced PDT to induce the complete death of cancer cells. A CFN-gel has nanomolar affinity for P-selectin and VEGF. Moreover, a CFN-gel is non-fluorescent and non-phototoxic upon its systemic administration due to the aggregation induced self-quenching in its fluorescence and singlet oxygen generation. After internalization into cancer cells and tumor neovascular endothelial cells, its photoactivity is recovered in response to the intracellular redox potential, thereby enabling selective near-infrared fluorescence imaging and an enhanced PDT of tumors. It also provides a significant antitumor effect in the absence of light treatment in vivo. Our study indicates that a fucoidan-based theranostic nanogel is a new theranostic material for imaging and treating cancer with high efficacy and specificity.

Resume : The native tissues are complex structures consisting of different cell types, extracellular matrix materials, and biomolecules. Traditional tissue engineering strategies have not been able to fully reproduce biomimetic and heterogeneous tissue constructs because of the lack of appropriate biomaterials and technologies. However, recently developed three-dimensional bioprinting techniques can be leveraged to produce biomimetic and complex tissue structures. To achieve this, multicomponent bioinks composed of multiple biomaterials (natural, synthetic, or hybrid biomaterials), different types of cells, and soluble factors have been developed. In addition, advanced bioprinting technologies have enabled us to print multimaterial bioinks with spatial and microscale resolution in a rapid and continuous manner, aiming to reproduce the complex architecture of the native tissues. In this study, we developmented a new formulation of bio-ink which is based on methacrylated keratin and methacrylated glycol chitosan. The feasibility of this bioink was tested with human adipose-derived stem cell toward specific differentiation conditions.

Resume : Nerve-cell culture takes an irreplaceable role in molecular and cellular neuroscience. However, its use in studies at the systems level has been limited due to the substantial difference between in vivo in vitro network dynamics. The dynamics is affected by the difference in the intercellular connectivity (Yamamoto et al., Sci. Adv. 4, eaau4914 (2018)), as well as by the excessively strong excitatory synapses in cultured neurons. Recently, a study was reported that stiff scaffolds enhance the strengths of excitatory synapses in cultured hippocampal neurons (Zhang et al., Sci. Rep. 4, 6215 (2014)). As neuronal cultures are generally performed on polystyrene or glass, which is approximately 10^6 to 10^7 times stiffer than the brain tissue, we hypothesized that the in vitro artifact in excitatory synaptic strength can be reduced by using a scaffold that mimics the elasticity of the brain tissue. Here we employed an ultrasoft silicone elastomer, whose elastic modulus resembles that of the brain tissue (~0.5 kPa), as a scaffold for culturing rat cortical neurons. We investigated the effect of the biomimetic elasticity on the strength of excitatory synapses and the spontaneous network activity (Sumi et al., Soft Matter 16, 3195-3202 (2019)). We found that the amplitude of excitatory postsynaptic currents was smaller on softer scaffolds. Although globally synchronized bursting activity in cortical cultures were still observed when the cells were grown on the ultrasoft substrate, neuronal correlation was significantly reduced as compared to the cultures on stiffer (>14 kPa) substrates. In the latter half of the talk, we will show how the multielectrode array devices with the ultrasoft cell-device interface can be fabricated by taking advantage of additive manufacturing technologies, such as inkjet printing (Yamamoto et al., Adv. Biosys. 3, 1900130 (2019)). Our device employs 3D micropillar electrodes, which can be fabricated relatively easily by inkjet printing. Such devices facilitate the stimulation and recording of cultured neuronal networks grown on biomimetic scaffolds, for both basic research and pharmacological studies.

Resume : Molecular environments inside cells are surprisingly crowded with numerous number of biomolecules. About 40 percent of the cell volume is occupied by biomolecules. Biochemical reactions are subject to be temporally, spatially, and specifically controlled. From biochemical and biophysical point of views, it is incredible that selective interactions and specific functionalization of biomolecules in the temporal and spatial-specific manner can be achieved under the complex molecular crowding environments. One of the key futures to achieve the specific interaction of biomolecules is collective biomolecular behavior. In recent years, biomolecular localization and compartmentation systems using droplets via liquid-liquid phase separation (LLPS) inside cells, become one of the hottest research topics in biology. Droplets are temporarily formed, and their formation is reversible and responsive to various external signals, which are in contrast with aggregation of biomolecules which is generally irreversible. In this presentation, we will show a model system of a droplet in a test tube, in which we use nucleic acids (RNA and DNA) which form G-quadruplexes and arginine-rich peptides which do not have any stable structure. By mixing these two components, a rapid LLPS was observed. It was suggested that the G-quadruplex structure is critical for undergoing LLPS. In the talk, we would like to discuss property of the droplet as a biomaterial.

Resume : Plasmonic metal nanostructures (e.g., Au, Ag) have proven to be a versatile platform for a broad range of optical applications. They are attractive for their surface plasmon resonance (SPR) properties. In this talk, I will introduce our recent work on the fabrication of multi-functional nanocomposite hydrogel system composed of metal nanostructures and silk fibroin hydrogel (SFG) for novel cancer treatments. First, we developed an injectable, biodegradable SFG platform synergistic the photothermal therapy with chemotherapy against in situ breast cancer. This system can simultaneously carriage the photothermal agent, hollow gold nanocages (HGNs), and chemotherapeutic drug, doxorubicin (DOX). HGNs have considerably great absorption in the NIR region and efficient conversion of light to heat for photothermal therapy. DOX is one of extensively used drug for the treatment of many solid tumours, such as breast and liver cancer. This multifunctional SFG subsequently encapsulated the HGNs and DOX among the tumor region to prolong the retention time of therapeutic agents, avoiding the limit of intravenous injection and clearance of circulation. After that, we further constructed a self-sufficient hybrid enzyme system, consisting of Pt-decorated hollow Ag-Au trimetallic nanocages (HGN@Pt) and glucose oxidase (GOx), to continuously supply O2 and concurrently consume nutrients for synergistically enhancing the anti-cancer efficacy of combined starvation and photothermal therapy, especially under hypoxic tumor microenvironment. In this system, the HGN@Pt would be trapped in the SFG, which could provide constant O2 supplement and conducting repeated photothermal treatments. Also, the light-heating would benefit the catalytic activity of the HGN@Pt during the laser exposures. Moreover, the GOx would be gradually released from the SFG to tumor microenvironment for glucose depletion, leading to glucose starvation-induced cancer cell death. Noted that the O2 supplied from the HGN@Pt could efficiently lift the oxygen concentration in the microenvironment for reliving hypoxia and thus promoted the starvation therapeutic efficacy of GOx via the glucose consumption.

Resume : Mesoporous silica nanoparticles (MSNs) is a promising nanocarrier for delivering anti-tumor drugs to cancer. Polyethylene glycol (PEG) has been linked to many nanocarriers to increase the dispersity, bioavailability and circulation time of nanoparticles. However, on the other hand, PEGylation could limit the cellular uptake and endosomal escape of MSN, resulted in significant loss of activity of the delivery system. In this study, to overcome the “PEG dilemma”, we synthesized pHR-MSN-PEG/DA@EPIs, in which pH-responsive (pHR) core-shell MSNs were utilized as nanocarriers, the anti-tumor drug epirubicin (EPI) was encapsulated by electrostatic interaction, and the amine-containing (DA) functional groups were introduced to control the loading and release of EPI. In vitro studies showed that the plain pHR-MSN-PEG/DA is non-toxic and the cleavage of PEG from carriers was achieved in response to acidic environment, result in high efficiency of cellular uptake. In addition, pHR-MSN-PEG/DA@EPIs showed considerable cytotoxicity towards 4T1 tumor cells. For in vivo studies, pHR-MSN-PEG/DA showed excellent passive targeting behavior due to the enhanced permeability and retention (EPR) effect, and strong tumor inhibition effects in a chicken embryo chorioallantoic membrane (CAM) tumor model.

Resume : Our ability to control cell behavior by properly engineered materials and microenvironments is tightly coupled to understanding the mechanisms of cell-matrix interactions. Anisotropy of extracellular matrix (ECM) drives cell alignment and directional migration during processes like development and wound healing, but also in cancer cell migration and invasion. So far, migrational persistence whether on flat isotropic or anisotropic surface patterns and fibers was mostly studied as local phenomenon asking how specific integrins are responsible for the recognition of the spatial ECM cues. Yet, cell alignment and directional migration in response to external ECM cues requires signal integration across length scales. By producing patterned 2 µm ECM stripes, which lead to cell alignment, and testing the previously described pan-integrin null fibroblast cells, we indeed observed that cell alignment and directional migration on patterned stripes were lost when β1 integrin was absent. By combining nanopillar arrays with printed cell-adhesive fibronectin (FN) stripes, we could probe subcellular force distributions at submicron resolution. While it was previously recognized that the αv- and β1-class integrin signaling pathways are coupled, via myosin II contractility, we discover here that myosin III coupling of these integrin signaling pathways requires a stiff cell nucleus. Importantly, directional migration along adhesive patterned stripes was also impaired for lamin A/C knockout cells, incapable of forming an actin cap and restored upon lamin A/C rescue. Together, our data suggest that β1 integrin is required for the recognition of spatial ECM cues and that force transmission to the nucleus via lamin A/C is essential for subsequent directional migration.

Resume : Potassium (K+) and sodium (Na+) ions existed under inter- and extra-cells and regulates membrane potential. They have an integral role in nerve and brain action and their aberrance encompasses severe disease such as a cardiac arrest. It is very important to analyze K+ and Na+ concentration in of blood and this analysis is one of health checking item. Until now, K+ and Na+ concentrations were detected with ion-selective electrode and high performance ion-selective electrode has been developing. However, imaging reagents of K+ and/or Na+ under homogenous aqueous medium are delayed. The K+ sensing reagent under aqueous medium has been reported as a basic skeleton of the crown ether coupled with chromophore and is not discriminated between K+ and Na+ because of their similar diameter as 266 pm and 190 pm, respectively. On the other hand, G4 DNA structure has the stacked G-quartet planes and has the created space in the center between G-quartet planes incorporates K+ with the stabilization. Use of this characteristics lead to K+ sensing system. We were firstly reported the fluorometric K+ sensing system. They synthesized oligonucleotide carrying human telomere sequence and fluorescent resonance energy transfer (FRET) chromophore pairs of FAM and TAMRA. This molecule folds to G4 structure in the presence of K+ and two chromophores closes each other to observe FRET signal. Since the amount of G4 formation is correlated with K+ concentration, K+ is quantified FRET signal change under homogeneous aqueous medium. The high selectivity of K+ over Na+ was realized in this system whereas azacrown ether or troazacrown ether shows only 30-times preference of K+/Na+. This reagent was named as potassium sensing oligonucleotide (PSO). Flurometric Na+ imaging was also reported azacrown type chromophore, SBFI, where its selectivity of Na+/K+ was 2.6-times. We developed oligonucleotide carrying FRET pair enhanced in the presence of Na+ by noticing the difference of G4 structures in the presence of K+ or Na+: Basket and hybrid types were formed for Na+ and K+, respectively. Use of human telomere sequence, they constructed the oligonucleotide giving enhanced FERT signal in the presence of Na+. They named as sodium sensing oligonucleotide, SSO. PSO or SSO developed by our group was stabilized in the presence of K+ or Na+ and this stabilization effect was monitored as melting temperature, Tm, in a melting curve plotted FRET signal change against temperature: the temperature in the presence of 1:1 of G4 and single stranded DNA is Tm. Here, we tried to improve selectivity of SSO based on systematic sequence change of G4 sequence and we found the sequence of G4 carrying higher preference for Na+ than for K+. Introduction of FRET dyes for this G4 sequence give fluorometric detection of Na+ in living cell.

Resume : Regulation of higher-order DNA structures is interesting from the viewpoint of the development of nano-materials and drugs. Here, supramolecular interaction was applied to the regulation of higher-order DNA structures by DNA interacting molecules. Naphthalene diimide is known to bind to double stranded (ds) DNA by threading intercalation. We tried to establish a double-stranded DNA bundling method using host-guest complex formation between β-cyclodextrin (β-CD) and adamantane (Ad). This method also makes it possible to easily assemble nanostructures regardless of DNA complementarity. Naphthalene diimide aving two adamantanes (NDI-Ada2) and benzene derivatives carrying two β-CDs (bis-β-CD derivative) were synthesized.When NDI-Nme-Ad2 was added 12 meric double-stranded DNA in 100 mM AcOK-AcOH, a large hypochromic effect was observed by UV/vis spectra. The binding constant (K) of NDI-Ada2 with double stranded DNA was determined by UV/vis spectral titration to be 9.1×105 M-1. This suggested that NDI-Ad2 binds to double-stranded DNA in threading intercalated mode. As a second staep, we tried to bundle duplex DNAs bound to NDI- Ada2 through bis-β-CD derivative. Gel electrophoretogram of the linear duplex DNA fragments of pBR322 (4361 bp) in the absence or presence of NDI- Ada2 and the bis-β-CD derivative showed the retarded DNA bands only in the presence of NDI- Ada2 and the bis-β-CD derivative. When NDI-Ada2 was added to pUC19, an extended DNA structure was observed at 0.75 μM NDI-Ada2, 0.75 μM pUC19 by AFM measurement. However, the DNA form changed spherically at 0.75 μM NDI-Ada2, 0.75 μM pUC19, and 0.75 μM bis-β-CD derivative. Since a random coil was observed in the case of DNA alone, this shape change is considered to be due to DNA bundling. This result is consistent with the result of gel electrophoresis, indicating that duplex DNAs are bundled each other through the host-gest interaction between adamantane and β-CD.

Resume : Various anti-cancer drugs have been developing for chemotherapy for cancer. Recently, tetraplex DNA ligands targeting for tetraplex structure of teromere DNA with low side effects. This comes from the selective inhibition of telomerase activity with the stabilization of tetraplex structure of telomere DNA and subsequently inducement of apoptosis in the cancer cell. We have been developing the cyclic naphthalene diimide (cNDI) derivative as teraplex DNA selective ligand: cNDIs stacked with G-quadruplex plane of tetraplex DNA whereas they didn’t bind to double stranded DNA with steric hindrance under intercalation process [1]. On the other hand, ferrocene is known to generate hydro radical (OH･) from Fenton reaction with hydro peroxide in our body and this leads to cell damage of our body. Combination between ferrocene and cNDI should lead to more effective anti-cancer drug. We successfully synthesized cyclic ferrocenylnaphthalene diimide derivatives (cFND) and showed high binding constant for tetraplex DNA with 10^6 M^-1 order than that for DNA duplex. Circler dichroism (CD) spectra of tetraplex DNA with or without cFND showed induced CD, which suggested the effective stacking interaction between naphthalene chromophore and G-quartet plane of tetraplex DNA [2]. Furthermore, TRAP assay in the presence of the varied amount of cFND showed the inhibition of telomerase activity with cFND. cFND also led to apoptosis of HeLa cell with several micro molar of IC50.