Smart biointerfaces for functional biomaterials

Resume : This talk will discuss the synthesis of a “non-fouling”—protein and cell resistant—polymer brush and its use for the fabrication of a point-of-care clinical diagnostic. In the first part of my talk, I will describe the in situ synthesis of a PEG-like brush polymer, poly(oligo(ethylene glycol) methyl ether methacrylate) (poly(OEGMA)), by surface-initiated atom transfer radical polymerization (ATRP) from different surfaces. I will then describe the use of the POEGMA brush for the fabrication of protein microarrays by inkjet printing antibodies into a macroscopically dry brush on glass. Interestingly, despite the lack of covalent attachment chemistry, this simple methodology results in highly stable and fully bioactive microarrays with femtomolar limits-of-detection in serum and whole blood. Finally I will discuss how this antibody microarray was converted to a point-of-care diagnostic, in which all reagents are printed and stored on the brush.

Resume : Hydrogels are known for their dynamic swelling response to aqueous environments. Chemical functionalization of the hydrogel surface can be used to add other stimuli-responsive functionalities to the swelling response and thus obtain a smart material that responds to more than one stimulus. Modifying the hydrogel surface with solution-based methods is often problematic due to the damages caused by the permeation of the solvent in the hydrogel. This issue is completely circumvented by the use of solvent-free techniques. A novel multi-responsive hydrogel has been synthetized by initiated chemical vapor deposition (iCVD). The hydrogel incorporates responsiveness to light irradiation and exposure to aqueous environment. The light irradiation modifies the degree of swelling within thin hydrogel film and in turn the mechanical properties. Cross-linked polymers of 2-hydroxyethyl methacrylate (HEMA) were chemically modified by iCVD to introduce azobenzene groups, as confirmed by IR spectroscopy and X-ray photoelectron spectroscopy (XPS). The modified hydrogel swelled in water from 7 to 12 % depending on the percentage of cross-linker and in humidity in the range 2 to 30 %. Through photoisomerization of the azobenzene, the polarity within the hydrogel is modified and as a consequence the affinity to water increases. A clear correlation between light irradiation and swelling properties of the hydrogel will be demonstrated. The materials are all biocompatible and therefore suitable for a great variety of applications, e.g. for cell cultures. Cells respond differently to substrates with different stiffnesses. One extremely innovative use of this material will be that a single substrate can be used to control the cell growth instead of different substrates with different stiffnesses.

Resume : Molecular detection in liquid environments is an essential step in a wide variety of applications. Electrolyte-Gated Organic Field-Effect Transistors (EGOFETs) have recently attracted considerable attention as liquid-phase sensors because of their low biasing voltages and the intrinsic presence of an electrolyte [1]. In this communication, we propose a novel strategy for the utilisation of EGOFETs as sensors in liquid and physiological media, consisting in the employment of a stimuli-responsive polymer gel (acting as transducing material and electrolyte at the same time), electrochemically deposited on the gate electrode. A pH-sensitive poly(acrylic acid) (PAA) hydrogel was grown on the surface of gold electrodes. These electrodes were characterised at different pH in terms of Electrochemical Impedance Spectroscopy (EIS). Such electrodes were then used as gate electrodes in pBTTT – based EGOFETs which were electrically characterised at different pH. EIS results show an electrochemical capacitance variation in response to pH which is also clearly reflected in the transistors electrical parameters. These preliminary results demonstrate that our devices can be used for the detection of molecular reactions where protons are produced. Moreover, the carboxylic groups contained in PAA chains make these gate electrodes particularly suitable for the functionalisation with bioreceptors able to bind specific target molecules. [1] L. Kergoat et al. Org. Elec. 13 2012, 1-6.

Resume : Over the past 10 years, a plethora of nanoparticles for biomedical applications have been proposed exhibiting different sizes - from a few tens to a few hundreds of nanometers; shapes – spherical, cylindrical, discoidal, stellar; and surface properties. Only recently, a few papers have introduced the notion that a fourth parameter – the mechanical stiffness – can also be used for modulating macrophage uptake and blood longevity. Here, 1,000400 nm Discoidal Polymeric Nanoconstructs (DPNs) are engineered with controlled mechanical stiffness. A modified hydrogel-template approach is employed resulting in a precise control of DPN size, shape, surface properties and, most importantly, mechanical stiffness. DPNs are constituted by chains of poly(lactic-co-glycolic acid) (PLGA) and polypropylene glycol (PEG2000) entangled toghether. By changing the paste composition, soft and rigid DPNs (s- and r-DPNs) are synthesized presenting the same geometry and surface charge (-14 mV) but different mechanical stiffness: 1.3 and 15 kPa, respectively. Flow cytometry and in vivo intravital microscopy analyses demonstrate that s-DPNs are less susceptible (~ 4-time) to internalization by macrophages as compared to r-DPNs. Also, PET-CT imaging in mice bearing skin or brain malignancies demonstrate for s-DPNs a ~ 24h circulation half-life and tumor accumulations up to 20% of the injected dose per gram tissue. These unique properties suggest that DPNs can be efficiently used for cancer theranosis.

Resume : Surfaces colonization by microorganisms leads to biofilms formation, i.e., bacteria aggregates in which cells are embedded in a self-produced extracellular polymeric matrix (EPS). In this state, bacteria are highly resistant to antimicrobials, thus giving rise to health and environmental problems1. In this perspective, the inhibition of biofilm growth is a crucial issue in the prevention of bacterial infections. Metal/Teflon (Me-CFx) composites deposited via ion beam sputtering (IBS) are well-known antimicrobials2. Specifically, Ag-CFx thin films are considered novel materials of exceptional in-plane morphological and chemical homogeneity. In the present study, Ag-CFx composites were characterized in detail, morphologically and spectroscopically. They were deposited onto IR-inactive regions of a ZnSe attenuated total reflection (ATR) crystal identified following a literature procedure3. This approach allowed monitoring P. fluorescens biofilm growth inhibition induced by the antimicrobial coating. These findings were corroborated by AFM imaging of bacteria incubated on Ag-CFx films, which were deposited onto sterile glass slides. Morphological analyses confirmed that bacterial stress was induced by the composite, leading either to membrane leakage or to bacterial lysis as a function of incubation times. 1 E. Denkhaus et al., Microch. Acta 158 (2007), 1. 2 M.C. Sportelli et al., Sci. Adv. Mat. 6 (2014), 7 and refs. therein. 3 G. T. Dobbs et al., Appl. Spectroscopy 60 (2006), 573.

Resume : In Western countries, Neurodegenerative Diseases are a major cause of death and considered to be the pandemic of 21st century. Nanomedicine comes to bear new approaches towards this direction, with great advancements in peripheral nerve reconstruction. Fabrication of suitable scaffolds for neural engineering is critical for the successful nerve regeneration. Electrospinning, a versatile method for nanofiber production has been used to fabricate fibrous scaffolds, with great similarity to the Extracellular Matrix (ECM). To this end, we fabricated conductive nanofiber scaffolds, consisted of biodegradable Polyvinyl alcohol and conductive Poly (3, 4-ethylenedioxythiophene) Polystyrene sulfonate, and proceed towards the evaluation of their surface and mechanical properties, along with degradation rates, emphasizing on the way that manipulate cell growth and adhesion. PC12, a neural cell-line was deposited onto the scaffolds in order to evaluate their cytocompatibility and ability to differentiate into sympathetic neurons in vitro. Biofunctionalization process with biological factors, like peptides and RGD laminins, along with treatment with Nerve Growth Factor took place in order to control and manipulate cell’s differentiation into neurons. MTT assay revealed excellent compatibility along with Confocal microscopy, fact that further reinforced scaffold’s ability to promote neuritis outgrowth. Results indicated that the conductive non-woven scaffolds are represent a unique microenvironment, that can mimic the ECM, promoting cell attachment and proliferation, and via proper surface modification, constitute a promising property that gives impetus to further Nerve Tissue Regeneration applications.

Resume : Thermal Nanoimprint Lithography (NIL) is a high-throughput and low-cost micro/nanolithography technique that can be applied to a broad range of thermoplastic materials. In fact, by simply applying the right pressure and temperature it is possible to transfer a pattern from a rigid mold surface to the chosen polymer. Usually, high-resolution and large-area NIL molds are difficult to fabricate and very expensive. They are typically made by silicon or other hard materials like nickel or quarts, but after a not very large number of imprinting cycles they starts cracking, becoming unusable. Here, we present the innovative use of perfluoropolyether (PFPE) polymer as material to produce intermediate molds. PFPE intermediate molds allow us to preserve the nanostructured silicon master while transfering micro and nanopatterns to thermoplastic polymers with high fidelity, improving the throughput of the process without affecting the original mold. Several geometries and materials were tested, such as nanometric gratings and nanoripples, and cyclic olefin copolymer (COC) and polyethylene terephthalate (PET). We finally applied this new process to the fabrication of substrates to direct the growth and the differentiation of neuronal and glial cells for possible implementation in devices for peripheral nerve reconstruction after injury.

Resume : We present a cellular test device based on Nb:TiO2 (niobium dooped titania) transparent conductive oxide (TCO) as bio-electrodes. The device is intended to easily provide electrical stimuli to a given cell tissue and to monitor its response. The Nb:TiO2 thin film deposition were performed with combinatorial chemical beam epitaxy (C-CBE) which allows for linear and well controlled gradients of both Nb concentration (ranging from 3% to10%) and oxide thickness in predefined directions (usually orthogonal). We have systematically characterized the Nb:TiO2 films with Atomic Force Microscopy, Scanning White-light Reflectometry, and sheet resistance Finally, we show the device, i.e the electrodes design and patterning in order to perform to electrical stimuli to the various ways to measure the cell’s response.

Resume : Stimuli-responsive surfaces are in the focus of interest for a multitude of applications such as sensors[1], anti-fouling coatings [2] and cell culture substrates [4]. For the latter, coatings made of thermoresponsive Poly-(N-isopropylacrylamide) pNIPAm microgels have been found to allow reversible switching of cell adhesion upon heating and cooling [3-5]. In these works the microgel layer had to be deposited on the substrate intended for use by printing or spin-coating. Hence, the dimensions and material properties of the substrate can strongly influence the adsorption of the microgel particles. The present contribution will review our efforts in this area. Moreover, the preparation of free standing trnasferable membranes from cross-linkable microgels will be presented. Such membranes can be transferred to different surfaces and overcome problems arising from direct deposition of microgels. The approach is based on the deposition of microgels, containing aromatic moieties, by spin-coating the particles on a sacrificial-polyelectrolyte layer. During this work three new monomers, N-(1-Phenylethyl)acrylamide, N-(2,3-dihydro-1H-indene-1-yl)acrylamide and N-Benzhydrylacrylamide, for copolymerization with NIPAm have been synthesized. In a precipitation reaction using a solvent mixture copolymer particles from NIPAm and the aromatic comonomers were obtained, with different comonomer concentration, 2.5 mol-%, 5 mol-% and 10 mol-%. To confirm the incorporation of the aromatic compon[4] S. Schmidt et al., Adv. Func. Mater., 2010, 20, 3235. [5] A. Burmistrova et al. J. Mater. Chem., 2010, 17, 3502.

Resume : Stimuli-responsive materials are able to react to a stimulus provided by their environment and consequently to tailor their properties. Since many phenomena locally occur at the surface of the material, our group work on the design of smart interfaces with switchable properties, which can be elaborated on any kind of material. More specifically, our aim is the elaboration of smart polymer coatings reacting to a temperature change and able to control the immobilization and release of biomolecules at/from a surface. In that context, surface functionalization by plasma polymerization is used to provide these dynamical properties to any material. A thermodynamics study has been carried out to characterize Diels-Alder interfacial reversible reaction on these coatings in comparison with self-assembled monolayers. The reaction progress of cycloaddition was monitored by several surface characterization techniques. It can be noticed that Gibbs free energy is rather similar whatever the accessibility and the density of chemical groups on the substrates are. However, the entropy and enthalpy contributions differ. Plasma polymer thin films seem to be less reactive than monolayers, yet chemically analogous, but the transition-state complex was more ordered. Therefore, the surface characteristics have a strong impact on surface reactivity. Consequently, a fine tuning of surface properties is a key issue to control the immobilization and release of biomolecules via a thermal stimulus.

Resume : Porous silicon powder finds several applications in different areas due to number of properties that make it an attractive material. Within this context, a facile method for the low-cost and large-scale production of Porous silicon (pSi) microparticles, in diverse sizes and shapes, has been used. This method consists of exposing silicon powder to a mixture of HF/HNO3 at specific conditions. Tow samples of the silicon microparticles were analyzed which include the starting metallurgical grade silicon powder and the sample that have been exposed to chemical vapor etching (CVE) . This method lead to the formation of porous silicon nanosponge microparticles. The nanostructured powder has been functionalized with 3-aminopropyl triethoxysilane ( APTES) molecules. These later were intended to work as coupling agent for biosensing applications. Morphologies of pSi microparticles were characterized by scanning electron microscopy (SEM). Fourier transform infra-red (FTIR) and Raman spectroscopic analyses have shown that the APTES molecules are attached to the surface of porous silicon powder.

Resume : The design of topographical and chemical features for engineering smart bio-interfaces with multiple and synergetic functionalities, represent the key point in effective use of hierarchically topographical and chemical bioplatform targeting controlled regulation of stem cell differentiation.Particularly, human mesenchymal stem cells (hMSCs) are of great promise in both basic developmental biology studies and in regenerative medicine, as progenitors of bone cells. Their fate can be affected by various key regulatory factors (e.g soluble growth factors, intrinsic, extrinsic environmental factors) that can be delivered by a fabricated scaffold. For example, when cultured on engineered environments that reproduce the physical features of the bone, hMSCs express tissue specific transcription factors and consequently undergo an osteogenic fate. Therefore, producing smart bio-interfaces with targeted functionalities, represent the key point in effective use of hierarchically topographical and chemical bio-platforms. In this work, we present laser based approaches (e.g. laser texturing) used for design of bio-interfaces aimed at controlling stem cells behavior in vitro. We showed that substrates can be developed to direct hMSCs spatial orientation using laser irradiation to modulate surface microtopography. Various patterns were obtained with progressive smaller inter-trough spacing and depths by decreasing the laser beam overlapping area or using masks systems. The increase in surface area induced increased spreading of cell on all directions, which triggered cell morphology modification towards polygonal shape and consequently increased circularity of stem cell nuclei. Our results demonstrate potential use of laser micropatterned substrates to modulate cell fate during bone implantation.

Resume : Polyoxometalates (POMs) are known as a class of nanosized metal-oxygen polyanionic clusters with rich chemical composition and diverse structural topology that can lead to interesting applications. To combine the functional features with their dispersivity, porosity, size controllability, and biocompatibility, POMs were used to organize into various media and/or carriers for enhanced functions. But, in general, it is hard to use these clusters in materials and bio-relevant applications directly. An alternative approach is to coassemble them with organic components via forming hybrid supramolecular complex. Considering the anionic feature for all POMs, cationic components are normally chosen for the purpose. Following our previous strategy, herein we would like to report some recent results on the self-assembly and functional properties of hybrid complexes that the organic cations covered on the surface of inorganic clusters through electrostatic interaction (for example in Scheme 1). We designed and synthesized a series of cationic surfactants, linear and dendritic cations bearing oligo(ethylene glycol) monomethyl ether terminal groups, oligopeptide, and used them to combine paramagnetic polyoxometalate K13Gd(β2-SiW11O39)2 and other clusters. The obtained complexes not only constructed interesting self-assemblies, but also performed temperature sensitivity. More significantly, the complexes and their assemblies were found to be potential contrast agent for magnetic resonance imaging. The in-vitro and in-vivo measurements demonstrated the structure and property stability in physiology conditions. References 1.H. L. Chen, Y. Yang, Y. Z. Wang, L. X. Wu, Chem. Eur. J., 2013, 19, 11051–11061. 2.T. Zhang, H.-W. Li, Y. Q. Wu, Y. Z. Wang, L. X. Wu, Chem. Eur. J., 2015, 21, 9028 – 9033.

Resume : Biosensing technology is a rapidly advancing field that benefits from the possibility to use the properties of functional advanced materials to analyse biological systems. In particular, nanomechanical systems are very attractive for biological sensing since mechanical interactions are fundamental to biology. Indeed, nanomechanical devices allow measuring forces, displacements and mass changes from cellular processes, and provide high sensitivity and fast responses, which is necessary for the observation of biological processes [1]. On the other hand, among all the functional materials, PSi constitutes an ideal substrate for developing new chemistries owing to its biocompatibility, well-established fabrication methods and large adsorption surface, which allows an enhanced sensitivity [2]. In this work, we will start by reviewing the processes for the PSi formation on microcantilevers and their biofunctionalization in order to trigger its sensitivity as biosensing platform. Secondly, we will describe current approaches based upon modification by self-assembled silane monolayers, which critically depend on the type of process for the activation of PSi. Depending on the molecular structure of the monolayers, the surface presents hydrophobic/hydrophilic properties, allows a molecular selectivity, and a local control of the biomolecular interactions. The surface of the functionalized material will then be biologically activated for the detection of specific genomic or proteomic species applying surface immobilization techniques. Finally, the process of formation of the biorecognition interface will be applied to composite porous silicon-crystalline silicon cantilevers and preliminary sensing results will be shown. [1] M. Calleja, P.M. Kosaka, A. San Paulo, J. Tamayo, Nanoscale. 4, 4925-4938 (2012) [2] S. Stolyarova, S. Cherian, R. Raiteri, J. Zeravik, P. Skladal, Y. Nemirovsky, Sensors and Actuators B, 131, 509-515 (2008)

Resume : In recent investigations we discovered with surprise that nanoscaled phyllosilicates, especially Laponite® RD, exhibit outstanding adsorption properties even for uncharged, non-polar molecules.[1] Laponite® RD (Na0.7(H2O)n{(Li0.3Mg5.5)[Si8O20(OH)4]}) is a commercially available product[2] with unusual properties: for example, clear dispersions in water can readily be obtained due to the morphological and charge characteristics of this nanoclay, and may thus be perceived as a “shuttle” for dyes and even for nanoparticles, eventually enabling its application in the field of smart bioassays. To increase the “playground” of our nanoclays, the rims of the clay platelets can be modified with functional groups, such as amine, thiol or carboxylates, by silanisation of the laponite’s rim Si-OH groups.[3, 4] The attached groups can carry light emitting molecules, plasmonic particles as well as molecules for coupling to organisms and their biofunctions, like sugars or antibodies, for targeted interactions between the clay nanoparticles and biomolecules. This remarkable and widespread scope of laponite properties makes them attractive as smart platforms for new biohybrid materials. References [1] M. M. Lezhnina, T. Grewe, H. Stoehr and U. Kynast, Angew. Chem. Int. Ed., 2012, 51, 10652. [2] http://www.byk.com, 15 January 2016. [3] T. Felbeck, et al., J. Phys. Chem. C, 2015, 119, 12978. [4] G. Kaup, T. Felbeck, M. Staniford and U. Kynast, J. Lumin., 2016, 169, Part B, 581.

Resume : Phthalocyanines (Pc’s) exhibit unique optical properties, which have raised the interest of numerous scientists. Generally, Pc’s possess very strong absorptions in the deep red spectral range, making them highly interesting for biomedical applications, such as photodynamic therapies of tumours (PDT) and the inactivation of microbial pathogens (PIA), both of which rely on the production of singlet oxygen aided by the Pc [1]. Due to their notorious tendency to agglomerate and insolubility in water, applications of pristine phthalocyanines are hardly realisable, since singlet oxygen generation requires monomeric Pc’s, the aggregation in aqueous ambience persisting even on equipment of the Pc with ionizing substituents. Only recently, we were able to solubilize native MPc’s (M = Al, Cu) with the aid of laponite, a synthetic smectite nanoclay, which furthermore substantially reduced the degree of aggregation and thereby enhanced their fluorescence and singlet oxygen quantum yields. However, for intimate interactions with bacteria, further modifications on the laponite itself were required [2,3]. Next to aqueous solutions of these hybrids, stationary imbeddings into membranes also retained their cytotoxicity, opening a new pathway to antimicrobial surfaces. References 1 M. C. DeRosa, R. J. Crutchley, Coord. Chem. Rev., 2002, 233-234, 351. 2 M. C. Staniford et al, Chem. Commun., 2015,51, 13534. 3 M. Grüner et al, ACS Appl. Mater. Interfaces, 2015, 7 (37), 20965.

Resume : Magnetic nanoparticles (MNPs) have emerged as promising technology for their applications in biomedicine. MNPs offer the possibility to deliver drugs and heat at specific locations. The development and characterization of the nanosystem are therefore important steps to ensure that the nanosystem has the desired properties to be used for both magnetic hyperthermia and drug delivery. For example, functionalisation of the MNPs with a suitable polymer layer can provide biocompatibility, colloidal stability, drug loading capability and stimuli-responsive behavior. Magnetic nanosystems that respond to both a change in pH and temperature can give spatial and temporal control over the release of the drug, by making use of the acidic pH found in tumor microenvironment and heat generated from the MNPs when exposed to an alternating magnetic field (AMF) as triggers for the drug release. Moreover, heat has been found to greatly enhance the intracellular drug uptake and the cytotoxic effect of many chemotherapeutic drugs, resulting in a synergistic effect of the therapy. This work aims to develop a dual pH- and thermo-responsive magnetic nanosystem allowing for the triggered release of chemotherapeutic drugs as a consequence of hyperthermia and acidic tumor microenvironment, through breakage of pH and heat labile Schiff base bonds that bind the drug molecules to the polymer. Iron oxide NPs were synthesized by a microwave-assisted co-precipitation method. The thermo-responsive polymer p(DEGMA-co-OEGMA-b-[TMSPMA-co-VBA]), synthesized using RAFT polymerization, was then grafted onto the MNPs surface via a silanisation reaction and the functionalization parameters were optimized. The nanocomposites were characterized by XRD, SQUID, TEM, DLS and TGA. Finally, the heating performances of the nanohybrids were investigated using a magnetic AC hyperthermia system. The MNPs exhibit a superparamagnetic behavior with a saturation magnetization around 75 emu/g. The LCST of the polymer could be easily tuned by varying the initial monomers ratio to be in the hyperthermia temperature range. FTIR analyses confirmed the successful grafting of the polymer by the presence of characteristic carbonyl ester bonds at 1750 cm-1. By varying the MNPs to polymer ratio and the pH of the solution during the functionalization step, suspensions with long term colloidal stability could be obtained. Their potential as magnetic hyperthermia agents was confirmed, demonstrating at the same time the importance of colloidal stability on the heating performances.

Resume : In dental and orthopaedic implants, the poor implant-bone bonding and infections with both bacteria and funguses are the most serious problems, leading to implantation failure. Therefore, many efforts were directed for finding a solution to obtain a novel implant with high osteoconductive and antibacterial properties, resistant to specific conditions inside the human body. The hydroxyapatite was proposed to be used for coating the metallic implants to increase their osteoconductive ability. However, the low mechanical strength of hydroxyapatite, the relatively low bone bonding rate, high dissolution rate and low antibacterial properties restrict its use in biomedical applications. The aim of the work was to enhance the antibacterial properties of the hydroxyapatite by Ag addition into its structure. The coatings, with different Ag contents, were deposited on Ti based alloy substrates by magnetron sputtering method. The coatings were characterized in terms of elemental and phase composition, morphology, corrosion resistance and antibacterial activity (Staphylococcus aureus MRSA, ATCC 29213, Salmonella Typhimurium ATCC 14028). The influence of the Ag content on the film properties was also analysed. Incorporation of a small amount of Ag into the hydroxyapatite structure resulted in an improved antibacterial efficacy versus Gram-positive bacteria. The best hydroxyapatite with Ag content of 0.7 at. % proved to have the best resistance to the bacteria attack.

Resume : Magnetic scaffolds have recently attracted significant attention in tissue engineering, due to the prospect of improving bone formation by acting as a “fixed station” able to accumulate/release targeted growth factors and other soluble mediators in the defect area under the influence of an external magnetic field. Further, magnetic scaffolds are envisaged to improve implant fixation when compared to not-magnetic implants. In a series of experimental studies we investigated the possibility to boost bone regeneration in rabbit femoral condyle defect by implanting hydroxyapatite (HA), polycaprolactone (PCL) and collagen/HA hybrid scaffolds in combination with permanent magnets. The results clearly indicate that the osteoconductive properties of the scaffolds are well preserved despite the presence of a magnetic component. Interestingly, when using bio-resorbable collagen/HA magnetic scaffolds, the reorganization of the magnetized collagen fibers under the effect of the static magnetic field generated by the permanent magnet produces a highly-peculiar bone pattern, with highly-interconnected trabeculae orthogonally oriented with respect to the magnetic field lines. In contrast, only partial defect healing is achieved within the not magnetic control groups. These results open new perspectives on the possibility to improve implant fixation and control the bone morphology of regenerated bone by synergically combining static magnetic fields and magnetized biomaterials.

Resume : Living organisms have capability to form bio-minerals with diverse composition and structure. Many of them are composite materials with excellent physical and mechanical properties [1, 2]. Rodents have opposing long pairs of continuously growing incisors. The front surface of the incisors is enamel; the inner part is softer dentine [3]. The surface of incisors shows characteristic orange-brown color and is identified with the presence of iron [4]. In our study the microstructure and the chemical composition of incisors from the feral coypu (Myocastor coypus Molina) were investigated using transmission electron microscopy (TEM) methods and were combined with the mechanical testing experiments. The layer with variable thickness located at the outer surface of the teeth was detected, possessing a much higher amount of iron compared to the concentration values reported by now. Within the iron-rich surface layer multiple iron containing varieties were identified where iron is detected predominantly in the 3 valence state. With the present discoveries we will deepen understanding of iron incorporation at the nanoscale level and its effect on the microstructural properties. [1] UGK Wegst and MF Ashby, Philos Mag 84 (2004), 2167. [2] AP Jackson and JFV Vincent, J Mater Sci 25 (1990), 3173. [3] BA Niemec in “Small animal dental, oral & maxillofacial disease” (2010), Manson Publishing Ltd, London. [4] EV Pindborg JJ Pindborg and CM Plum, Acta Pharmacol 2 (1946), 294.

Resume : Curcumin is a natural compound that can be used in imaging because it is not toxic and it has even anti-cancerigenic properties. Hemicurcuminoids are based on half of the π-conjugated backbone of curcuminoids. The synthesis of a series of such systems and their borondifluoride complexes are described. The emissive character of those dipolar dyes was attributed to an intraligand charge transfer process, leading to fluorescence emission that is strongly dependent on solvent polarity. Quasi quantitative quenching of fluorescence in high polarity solvent was attributed to photoinduced electron transfer. Those dyes were shown to behave as versatile fluorophores. Indeed, they display efficient two-photon excited fluorescence emission leading to high two-photon brightness values. Furthermore, they form nanoparticles in water whose fluorescence emission quantum yield is less than that of the dye in solution, owing to aggregation-induced fluorescence quenching. When cos7 living cells were exposed to those weakly-emitting nanoparticles, one- and two-photon excited fluorescence spectra showed a strong emission within the cytoplasm that originated from the individual molecules. Dye uptake thus involved a disaggregation mechanism at the cell membrane which restored fluorescence emission. This off-on fluorescence switching allows a selective optical monitoring of those molecules that do enter the cell, which offers improved sensitivity and selectivity of detection in bioimaging purposes.

Resume : The development of organic and hybrid surfaces made of synthetic polymers alone or combined with biomolecules for biomedical applications has the potential to revolutionize the treatment of a wide variety of medical conditions. Due to their excellent electrochemical, chemical, and optical properties, conjugated conducting polymers are promising candidates for biomolecule immobilization and subsequent fabrication of nanostructured polymer-based devices for biomedical devices (e.g., biosensors, electrochemical actuators, substrates for tissue engineering, and nanowires). Within this context, I will summarize our most recent findings in the field of polymer-based interfaces for biomedical applications, which involves not only the development of nanostructured polymers and hybrids but also the modulation of their properties through physical treatments (e.g., applying nanoperforation techniques and corona discharge plasma processes).

Resume : A new generation of sensors, designed for being implanted in the human body and entirely made of biodegradable materials, is currently emerging. These sensors open the field for new smart and safe diagnostic techniques, without need for a second surgery to remove the devices after their predefined period of use. In the present work, we demonstrate a highly sensitive sensor, entirely made of biodegradable materials, that can measure both strain and pressure. This sensor is designed to monitor the progress of tendon repair after surgery. Classical surgical techniques include sewing the torn ends of the tendon and performing an allograft in case of largely damaged tissues. In addition, new treatments are under investigation at Stanford, where an hydrogel loaded with various bio-species is injected locally in order to stimulate the cellular growth. It is of great interest for surgeons to monitor in situ the recovery after surgery and the healing status of the tissues, with the objective to provide an appropriate care to each patient based on improved diagnosis. The biodegradable sensor, fixed on the tendon, can measure both strain and pressure. The strain is measured with two thin film comb electrodes sliding relative to each other, mounted between two highly flexible elastomer layers. The pressure is measured with a flexible capacitor, where the key element is a microstructured elastic dielectric layer placed between the top and bottom electrode. The combination of strain and pressure sensing capabilities, the biodegradability of the selected materials, the high sensitivity, fast response time and long-term stability of the presented sensor allows its use for tendon tissues recovery monitoring.

Resume : The lack of an epithelial layer can significantly decrease the functionality of engineered tissues in respiratory tract, such as engineered trachea. Although incorporation of autologous epithelial cells in the engineered tissue is possible; the necessary amount of cells to cover large surfaces is deterrently high. In order to obviate this problem, we developed a double thin film based epithelial patch that can be applied in-situ for triggering the re-epithelialization. Enzymatically crosslinked gelatin films were first seeded with fibroblasts. Then, a second film layer was incorporated as a support for epithelial cells. In addition, each film layer was loaded with growth factors relevant to the cells they acted as a substrate. By using epithelial model, we have demonstrated the efficacy of growth factor release on cells and the stability of the structure for 7 days. Such patches can be used for fast epithelialization in respiratory tissue engineering while decreasing the necessary number of epithelial cells.

Resume : Biomaterial-associated infections present a significant threat to patients. The cascade of biofilm formation involves the initial microbial attachment, the formation of microcolonies and proliferation, matrix production and biofilm maturation with propagation of infection. In order to prevent biofilm formation and implant-associated infections several approaches have been reported with the aim of depositing an antimicrobial layer on material surface. Among these strategies, bio-inspired coatings have recently emerged to meet the criteria of low cytotoxicity and long-term stability while minimizing the development of bacterial resistance. Antimicrobial peptides (AMPs) are a vast group of molecules offering several advantages like high efficacy at low concentrations and low propensity for developing bacterial resistance. In this study, Magainin II (Mag II) which is a 23-residue AMP has been immobilized on poly(lactide-co-glycolide) (PLGA) or PLGA/gelatin fibrous membranes prepared by electrospinning. Covalent binding was achieved by carbodiimide/N-hydroxysuccinimide chemistry. The surface immobilization was characterized by X-ray Photoelectron Spectroscopy, Scanning Electron Microscopy and Atomic Force Microscopy studies. The antibacterial activity of the bound Mag II was tested against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. Bacterial adhesion tests, SEM and confocal analyses revealed that Mag II played an effective role in reduction of bacterial activity and reduced the number of adhered bacteria more than 50%. AMP immobilization strategy was introduced as a new perspective for modulation of antibacterial properties on PLGA and PLGA/gelatin membranes prepared by electrospinning.

Resume : Although transplantation of autologous cells has been tested by injection of cell suspensions using a syringe, limited regeneration results were observed due to the low viability of the injected cells, and restricted cell integration into the host tissue. To address these issues, a new approach would be to locally deliver the cells using engineered, cell-loaded substrates. The aim of this study is to develop the flexible nanoribbons from biodegradable polymer that can be aspirated and safely injected into tissues through a conventional syringe needle. In this study, we developed microfabricated poly (lactic-co-glycolic acid) (PLGA) nanoribbons, in order to generate freestanding ribbons loaded with murine skeletal myoblasts (C2C12). Injectability of cell-loaded nanoribbons has been studied using different gages of syringe needles. We observed flexibility of the nanoribbons reduces the mechanical stress on the attached cells. Cell viability, activity, and functionality were not affected after injection of cells adhered to the nanoribbons. In addition cells could safely undergo myogenesis and show the myotubes formation after moving cells to differentiation medium. We anticipate that the injectable nanoribbons promote the formation of muscle tissue and could be a useful tissue engineering technique for local delivery of cells while maintaining the cellular organization, viability, and functionality.

Resume : Surface engineering and modification plays a crucial role in biomedical research regarding implants. Since cells are there in contact with artificial solid surfaces, the interface is the part that determines success of a neural implant [1]. Many micro- and nanostructured materials have been employed to provide chemical and physical stimuli to cells. A considerable attention was directed toward 3D, nanostructured polymers. In this work, we explored the role of asymmetric polymeric columnar films on the adhesion and maturation of primary neurons. Poly(chloro-p-xylene) (PPX) can easily be transformed into nanostructured films with high surface area and nanoscale spatial dimension. By means of immunofluorescence staining, SEM and FIB-SEM, we quantified the influence of the nanotextured surface on cell growth in comparison to a planar PPX. The impact of the substrate topography became apparent on the neural development regarding soma size, neuritogenesis, and polarity. We demonstrate that the nanostructures act as geometrical constraints and facilitates an enhancement in neurite branching, axon elongation, and affects growth cone size. Also we observed that the asymmetric orientation of nanofilaments strongly influences the initiation direction of the axon formation, however this directionality is not so pronounced during later stages of axon pathfinding. [1] A. Belu, J. Schnitker, S. Bertazzo, E. Neumann, D. Mayer, A. Offenhäusser, F. Santoro, Journal of Mocroscopy, 2016, accepted

Resume : Because the small intestine plays a crucial role in absorbing nutrients and drugs, research into understanding its working mechanisms has been expanding over last few decades. Various models have been developed to better investigate absorption and metabolism, among which the Caco-2 cell model is the most widely used. However, this monolayer cell model may lead to inaccurate experimental results and faulty conclusions due to its over-simplification. In our present study, an innovative three-dimensional cell model which simulates in vivo small intestine epithelium, subepithelial fibroblast network and extracellular matrix was developed to enhance the relevance of the drug absorption research. In comparison with the Caco-2 monolayer cell model, the 3D model shows reduced transepithelial electrical resistance (TEER) and higher levels of alkaline phosphatase (ALP) activity in microvilli. Two main efflux transporters – P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) were also studied, and the decreased P-gp activity and increased BCRP activity indicated a better simulation to the in vivo intestine functioning. In conclusion, our reconstructed 3D cell model is better than the widely used Caco-2 monolayer cell model and much closer to the human small intestine at the structural, physiological and functional levels.

Resume : Although the neutralizing mechanisms of two,rare neutralizing antibodies (NAbs), 2F5 and 4E10, which bind to membrane-proximal external region (MPER) of viral gp41, represents a promising framework for the design of new HIV-1 liposomal vaccine candidates, this mechanism remains poorly understood. It is known that 2F5 and 4E10 are required to first associate with HIV-1 lipids before binding to the target MPER antigen, however, little is known about how lipid membranes contribute to NAb-antigen binding. To this end we focused on recreating the lipid phase organization (i.e., domain formation) of native membranes by using supported lipid bilayers (SLBs). To recreate the HIV-1 envelope, we used amphipathic, α-helical peptides as a catalyst to generate complex SLBs that have a high cholesterol content and contain multiple lipid types, and contain a liquid-disorderd (Ld) and liquid-ordered (Lo) phase. We used atomic force microscopy (AFM) to visualize membrane domains, antigen presentation, and antibody-membrane interactions on our SLB surfaces. Our experiments on complex SLBs demonstrate that 2F5/4E10 do not interact with the highly ordered gel and Lo domains in the SLB but exclusively bind to the Ld phase. This suggests that 2F5/4E10 require low membrane order and weak lateral lipid-lipid interactions to insert into the hydrophobic membrane interior. Thus, vaccine liposomes that primarily contain an Ld phase are more likely to elicit the production of lipid reactive, 2F5- and 4E10-like antibodies, compared to liposomes that contain an Lo or gel phase. Furthermore, we show that the presence of the MPER656 antigen can severely limit the Ld area available for antibody interactions. Subsequently, this reduces the amount of MPER656 that is accessible for 2F5/4E10 binding. If Ld forming lipid components are used in vaccine liposomes, it is thus important to ensure that the presence of antigen does not inhibit large-scale Ld formation.

Resume : Microgels are weakly cross-linked polymer colloids, which can be designed to display responsive volume transitions triggered by a range of parameters. In the context of drug delivery, microgels are of particular interest as carriers for biomacromolecular drugs, such as peptides and proteins, since they offer a water-rich environment for incorporated macromolecular drugs, thus reducing detrimental conformational changes and aggregation within the delivery system. Furthermore, microgels offer various additional benefits as delivery systems for such drugs, including protection against enzymatic degradation and controlled or triggered release. While microgel suspensions and their use as delivery systems are becoming increasingly understood, much less is known about surface-bound microgels as carriers of biofunctional molecules. Addressing this, we here report on work done to elucidate factors determining volume transitions of electrostatically triggered surface bound microgels, as well as their use as delivery systems for peptides. In doing so, we investigate effects of microgel charge density, pH, and ionic strength on microgel volume transitions at surfaces, surface-induced microgel deformation and nanomechanical properties, as well as consequences thereof for peptide loading and release, using a battery of experimental techniques, including AFM PeakForce QNM, QCM-D, ellipsometry, and confocal and cryoTEM microscopy.

Resume : Supported lipid membranes represent an elegant way to design smart fluid biointerfaces able to mimic the physico-chemical properties of biological membranes, providing an excellent model system for studying the surface chemistry of the cell. Furthermore, supported lipid membranes are accessible to a wide variety of surface-specific analytical techniques, providing smart biointerfaces for biotechnological applications [1], such as the design of chemical and biomedical sensors. In this contribution we describe a new lipid-based sensor for the detection of the thymidine phosphorylase (TP) enzyme, one of the most known biological markers of solid tumors. This enzyme promotes tumor growth and metastasis and is overexpressed in the presence of cancers, so that also its blood levels increase [2]. To achieve this goal, one of the most used anticancer drugs, i.e. the pyrimidine analogue 5-fluorouracil (5-FU) [3] has been properly functionalized with a C-12 aliphatic chain in order to be inserted into gold supported lipid membranes. The interaction of TP with the 5-FU inhibitor and its derivatives has been firstly evaluated in solution by fluorescence measurements, then the derivatives have been inserted into a lipid bilayer linked to a gold surface. The supported lipid biointerfaces have been characterized by ellipsometry, AFM and electrochemical techniques. The TP interaction with the substrate has been quantitatively evaluated by quartz crystal microbalance, following the oscillation frequency of the QCM crystal, making this system a very promising sensor for the detection of TP concentration in blood. [1]. Castellana, E. T.; Creme, P. S. Solid supported lipid bilayers: From biophysical studies to sensor design. Surface Science Reports 61, 429–444 (2006). [2]. Haraguchi, M.; Komota, K.; Akashi, A.; Furui, J.; Kanematsu, T. Occurrence of hematogenous metastasis and serum levels of thymidine phosphorylase in colorectal cancer. Oncol. Rep. 10, 1207-1212 (2003). [3]. Malet-Martino, M.; Martino, R. Clinical studies of three oral prodrugs of 5-fluorouracil (capecitabine, UFT, S-1): a review. The Oncologist 7, 288-323 (2002).

Resume : Recently, polymersomes have proven to be interesting model systems for studying polymeric membranes1, in vivo tumour-shrinkage2 and drug delivery vehicles3. Polymersomes are composed of amphiphilic block copolymers, that is, they consist of a hydrophilic or polar part and a hydrophobic or apolar part. Some of their advan-tages are their ability of encapsulating drugs and molecules, as well as a low leakage rate, which can be tuned by adjustment of the hydrophobic block size. This makes them ideal model systems for investigations on the carrying and release activities of drugs and dyes in the human body.4 Nevertheless, information of the interaction of polymersomes with proteins is not widely explored. Polymersomes are also capable of forming 2-D lipid bilayers on solid supports, therefore making them attractive for the application as novel biosensors.5 In this study, the adsorption behaviour of different polymersomes (charged and neu-tral) and liposomes on gold has been studied in phosphate buffered saline solution with the Electrochemical Quartz Microbalance (EQMB; or Quartz Crystal Microbal-ance, EQCM). Moreover, the influence of Bovine Serum Albumin on the stability of the adsorbed vesicles has been investigated. 1. D. Wu, M. Spulber, F. Itel, M. Chami, T. Pfohl, C. G. Palivan and W. Meier, Macromolecules, 2014, 47, 5060-5069. 2. F. Ahmed, R. I. Pakunlu, G. Srinivas, A. Brannan, F. Bates, M. L. Klein, T. Minko and D. E. Discher, Molecular Pharmaceutics, 2006, 3, 340-350. 3. E. Amstad and E. Reimhult, Nanomedicine, 2012, 7, 145-164. 4. K. Sato, E. Abe, M. Takahashi and J. I. Anzai, Journal of Colloid and Interface Science, 2014, 432, 92-97. 5. S. May, M. Andreasson-Ochsner, Z. Fu, Y. X. Low, D. Tan, H.-P. M. deHoog, S. Ritz, M. Nallani and E.-K. Sinner, Angewandte Chemie, 2013, 125, 777-781.

Resume : Bacteria are differentiated into two main groups, Gram-positive or Gram-negative, based on the Gram stain which detects the thick peptidoglycan cell wall of gram positive bacteria. Gram-negative bacteria are of particular biomedical and technological interest due to their role in disease, the increasing antibiotic resistance of some species and their utility in many biotechnological processes. The Gram-negative bacterial outer membrane (GNB-OM) is asymmetric in its lipid composition with a phospholipid-rich inner leaflet and an outer leaflet predominantly composed of lipopolysaccharides (LPS). LPS is a polyanionic molecule, with numerous phosphate groups present in the Lipid A and core oligosaccharide regions. Using a series of systems1-4 we have attempted to create GNB-OM assays which are amenable to molecular level characterisation. These systems are always planar samples deposited at either air/liquid or solid/liquid interfaces and range from simple anionic phospholipid monolayers to asymmetrical GNB-OM models which float ~2 nm above a solid/liquid interface. These membrane models have provided new insights into the OM and interactions with it; from providing conformation of the activity of anti-bacterial proteins and the role of the lipopolysaccharide polysaccharide chains in blocking antimicrobial protein binding to describing the importance of divalent cations in stabilising the OM. References 1. Clifton, L. A., Skoda, M. W. A., Daulton, E. L., Hughes, A. V, Brun, A. P. Le, Lakey, J. H., Holt, S. A., and Hughes, V. (2013) Gram-negative bacterial outer membrane mimic Asymmetric phospholipid : lipopolysaccharide bilayers ; a Gram-negative bacterial outer membrane mimic. J. R. Soc. Interface 10, 20130810 2. Clifton, L. A., Holt, S. A., Hughes, A. V., Daulton, E. L., Arunmanee, W., Heinrich, F., Khalid, S., Jefferies, D., Charlton, T. R., Webster, J. R. P., Kinane, C. J., and Lakey, J. H. (2015) An Accurate In Vitro Model of the E. coli Envelope. Angew. Chemie Int. Ed. 54, 11952–11955 3. Clifton, L. A., Skoda, M. W. A., Le Brun, A. P., Ciesielski, F., Kuzmenko, I., Holt, S. A., and Lakey, J. H. (2015) The Effect of Divalent Cation Removal on the Structure of Gram-negative Bacterial Outer Membrane Models. Langmuir 31, 404–412 4. Le Brun, A. P., Clifton, L. A., Halbert, C. E., Lin, B., Meron, M., Holden, P. J., Lakey, J. H., and Holt, S. A. (2013) Structural Characterization of a Model Gram-negative Bacterial Surface Using Lipopolysaccharides from Rough Strains of Escherichia coli. Biomacromolecules 14, 2014–2022

Resume : Complications related to infectious diseases have significantly reduced, particularly in the developed countries, due to the availability and use of a wide variety of antibiotics and antimicrobial agents. However, excessive use of antibiotics and antimicrobial agents increased the number of drug resistant pathogens, and this has resulted in a significant threat to public health. The inexorable rise in the incidence of antibiotic resistance in bacterial pathogens, coupled with the low rate of emergence of new clinically useful antibiotics, has refocused attention on finding alternatives to overcome antimicrobial resistance. Novel strategies aiming to reduce the amount of antibiotics, but able to prevent and treat animal and human infections should be investigated, evidenced and approved. Among the various approaches, the use of nanotechnology (engineered nanoparticles) is currently the most promising strategy to overcome microbial drug resistance. Due to their small size, nanoparticles can surmount existing drug resistance mechanisms, including decreased uptake and increased efflux of drug from the microbial cell, biofilm formation, and intracellular bacteria. Herein, we propose to use Prussian blue nanoparticles (PB NPs) as efficient photothermal agents under NIR (810 or 980 nm) irradiation for efficient ablation of virulent and antibiotic resistant pathogens, including virulent strains of E. coli associated with urinary tract infection, and methicillin-resistant S. aureus. Although, PB NPs have been investigated for photothermal ablation of cancer cells in the wavelength range of 700-800 nm, to the best of our knowledge there has been no report on the use of these nanoparticles for bacteria treatment. Moreover, the use of 980 nm wavelength has never been described before. Our results clearly show that PB NPs are very effective killing of Gram positive and Gram negative bacteria under 810 or 980 nm irradiation in a concentration-dependent manner. Moreover, under 980 nm irradiation mammalian Hela cells exhibited minimal toxicity up to a PB NPs concentration of 100 µg mL-1, while at this concentration a 100% bacteria killing was achieved. This interesting finding suggest thats these nanoparticles could be potentially used for selective targeting of bacteria over mammalian cells.

Resume : Bacterial resistance to antimicrobials is a global threat that requires development of innovative therapeutics that circumvent its development. We designed a novel nanostructured antibiotic, composed of a bolaamphiphile (12-bis-THA) and an oligonucleotide (transcription factor decoy, TFD). The hypothetical mechanism of action of 12-bis-THA/TFD consists of two steps: 1) the positively charged assemblies destabilize bacterial membranes; 2) once internalized and released the TFD interferes with RNA transcription, inhibiting essential genes required for growth or disease progression. To get mechanistic insights of specific targeting toward bacterial membranes, we studied the interaction of 12-bis-THA/TFD with model membranes of different composition and curvature. Fluorescence and Dynamic Light Scattering on liposomes revealed the specific role of a typical bacterial lipid, cardiolipin, in the destabilization of the membrane and release of the TFD from the assembly. Confocal Microscopy coupled with Microfluidics and Fluorescence Correlation Spectroscopy (FCS) on Giant Unilamellar Vesicles (GUVs) highlighted the role of lipopolysaccharides in determining the interaction and penetration of the TFD inside the GUVs. Finally, Confocal Microscopy and FCS data on E. coli, Gram-negative prototypical bacteria, confirmed the findings on membrane models, validating our synthetic model and allowing to hypothesize an interaction pathway of the nanostructured antibiotic with bacteria.

Resume : Human hair exhibits obvious macroscopic variations, in terms of colour, structure, form and physical strength. This is most obvious between individuals of different ethnic backgrounds. The aim of this work was to investigate the origins of the structural variations between the nanoscale, supramolecular and or sub-molecular distance scales, using high resolution X-ray microfocus studies allied with PCR. Results indicate a structural correlation in terms of amount of lipid and orientational ordering in the different hair types.

Resume : In this talk, I will first introduce the historic development of the vectors that can mediate cell membranes and aid the internalisation of proteins, DNA and siRNA, followed by describing recent advances in the design of synthetic polymers and peptides as new vectors, with several examples coming out of my own research group. I will end my talk by pointing to some of the major technical challenges that still constrain the practical application of this attractive technology.

Resume : It remains a big challenge to effectively deliver molecules, in particular macromolecules, through membrane barriers. There is a need to better understand the mechanisms of entry into the cell cytoplasm and nucleus in order to design optimal delivery systems for agents of pharmaceutical interest. This presentation will cover our recent efforts to design, synthesis and in- vitro/in-vivo evaluation of novel bio-functional polymers. The pH-responsive, metabolite-derived polymers are designed to mimic factors that enable efficient viral transfection. Strict control over the size, structure, hydrophobicity- hydrophilicity balance and aromaticity of the polymers can effectively manipulate their conformational characteristics and dynamic behaviour in aqueous solution and their interactions with lipid membrane, cell and tissue models. It has been demonstrated that the biomimetic polymers can traverse the extracellular matrix in 3-D multicellular spheroids, reach individual cells in the tumour models, and enable efficient cellular entry of therapeutic payloads (e.g. siRNA and therapeutic proteins) and imaging moieties into the cytoplasm or the nucleus. This could represent a promising therapeutic delivery platform, suitable for research and theranostic applications in the treatment of various diseases including cancer.

Resume : We show that polymer microgels with a diameter of about 55 nm can be embedded within films of non-lamellar lipid liquid crystalline films to form responsive nanostructured surfaces. A simple spin-coating procedure is developed to form these hybrid films from the solubilized components followed by equilibration in excess water. The mixed lipid layers, which are composed of glycerol monooleate and diglycerol monooleate lipids with poly(Nisopropylacrylamide)(PNIPAM) microgels, form hybrid films with reverse bicontinuous cubic phase structure that are capable of responding to temperature stimulus. The thickness, hydration and internal structure of the films are characterized by spectroscopic ellipsometry, attenuated total reflectance FTIR, neutron reflectivity and small angle X-ray scattering. We demonstrate that the microgel particles act as thermoresponsive controllers for the hydration of the lipid films. When the temperature is increased to reach the volume phase transition point of the PNIPAM microgels, i.e. the particles change from the swollen to the collapsed state, water is release from the surface film while the lipid matrix remains intact. The observed surface structure and control of layer hydration can be used to manipulate properties of non-lamellar lipid liquid crystalline layers. These new nano-materials based on lipid-polymer-based responsive layers opens up for new sensor applications where temperature triggered control of the layer hydration are required.