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Smart biointerfaces for functional biomaterials

The symposium on “Smart Biointerfaces for Smart Biomaterials” aims to bring together scientists from universities, research institutes and industries to review the current frontiers in the strongly interconnected areas of Nanobiotechnology, Biointerfaces and Biomaterials. The symposium will focus on a set of interdisciplinary topics, spanning from advanced drug delivery systems to novel tissue engineering strategies, from smart diagnostic and nano-resolved imaging techniques to safety of nanomaterials.


The field of Smart Biointerfaces is markedly interdisciplinary, bridging together bionanotechnologies, biomimetic devices, tissue engineering and biohybrid systems. The key to achieve important advances in the field of biointegrated devices resides in the successful integration of these technological and scientific areas. In this context, diverse but complementary contributions are needed on new biomaterials, multi-signal patterning methodologies, multiscale modelling, advanced characterization and processing technologies for the desired biomedical and biotechnological applications. Thus, the concept of Smart Biointerfaces is constantly gaining new valences. Chemical structures of the interfaces along with the electrical, mechanical and morphological properties at nanoscale appear equally relevant to drive the interactions between living and synthetic systems. A central aspect is then the ability to optimize the functional properties with high spatial resolution, creating materials that are able to control the interaction with the biological surrounding at the nanoscale thus guiding the responses of biomolecules, cells and tissues. Accordingly, by responding to changes in the biological environment, or transformation from one state to another in the presence of biological systems, functional biomaterials must not only improve device integration and control tissue regeneration, but also use controlled responses to power hybrid biodevices. In this view, the symposium will seek to integrate the experimental and theoretical research endeavours drawing the strengths from all the aspects of interface design and fabrication as well as characterization of the interactions at the material/biological systems interface.

Hot topics to be covered by the symposium:

  • Responsive biointerfaces
  • Small biointerfaces
  • Cell material interactions
  • Functional biomaterials
  • Drug delivery systems
  • Cell instructive materials
  • Tissue engineering scaffolds
  • Biomedical implants
  • Novel polymers and biopolymers
  • Stimuli and cell responsive materials
  • Biomolecules surfaces interaction
  • Bionterfaces engineering
  • Surface treatments for biomedical applications
  • Nanoparticles-biological interaction
  • Nano and micropatterning for biomedical application
  • Smart biohybrid materials
  • Porous and composite biomaterials
  • Biomedical Microsystems
  • Micro and nanosystems for biological recognition
  • Antibacterial surfaces
  • Blood- and tissue-material interactions
  • Modelling of cell material interaction and biological recognition


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Authors : G.M.L. Messina1, M. De Zotti2, A. Rapisarda1, F. Formaggio2 and G. Marletta1
Affiliations : 1 Laboratory for Molecular Surfaces and Nanotechnology, Dept. of Chemical Sciences, University of Catania, Catania, I-95125, Italy 2 Department of Chemistry, University of Padova, Padova, I-35131, Italy

Resume : Biomolecule-based materials that change properties in response to different local stimuli are increasingly being studied in the context of several applications, with particular attention to bioelectronics. Peptides are ideally suited for this purpose because of the range of distinct physical properties available from the amino acids. This diversity allows several non-covalent interactions including electrostatic (acidic and basic amino acids), hydrophobic, p-stacking (aromatic amino acids), hydrogen bonding (polar amino acids) as well as covalent (disulfide) bonds and steric contributions (strand directing amino acids). Crucially, these interactions depend by different factors such as ionic strength, pH and temperature. In this work, we study the properties of a particular peptide able to respond to specific external stimuli by adopting one of two well-defined conformations. The Trichogin GA IV here used, belongs to the family of peptaibiotics, antimicrobial peptides rich in the helix-inducer α-aminoisobutyric acid (Aib) residue. One of its analogs, in which four Lysines positive charged residues have been introduced, is able to reversibly switch its conformation between two, well-defined, different helical conformations in response to pH variations. In particular, it is shown that this peptide can contract and stretch in response to a short range of pH variation. In this contribution, we describe our latest results obtained from the study of stimuli-responsive smart surfaces, formed by gold substrates decorated with trichogin GA IV and its positively-charged analog. The peptides were anchored to the gold surfaces through a N-terminal lipoic acid moiety. The loading and the conformational switching properties of the surface-bound peptides were investigated by means of several techniques, such as Quartz Crystal Microbalance with Dissipation monitoring and Localized Surface Plasmon Resonance. Applications in the emerging field of the bio-inspired nanotechnology are suggested.

Authors : Nicoletta Giamblanco, Nunzio Tuccitto, Gabriella Zappalà, Antonino Licciardello, Giovanni Marletta
Affiliations : Laboratory for Molecular Surfaces and Nanotechnology, Department of Chemical Science, University of Catania, viale A. Doria n° 6, 965125, Catania, Italy and CSGI

Resume : Characterization of protein adsorption from an aqueous solution onto a surface is an important element of research in surface science, from both fundamental and practical perspectives. During the last few years, we focused our attention on protein layer adsorption in terms of adsorbed amount, structure of the layer and adsorption kinetics. Spontaneous surface adsorption of proteins results in the formation of molecular films having peculiar thickness and structural conformation. We present an original study concerning the adsorption of human serum albumin (HSA) and lactoferrin (LF) onto Fe(II) and Cu(II) terpyridine-based complexes self-assembled on a gold surface. This contribution deals with an integrated characterization approach aimed to obtain detailed insights into the nature of the surface-induced conformational changes in co-adsorbed proteins. This approach involves time-of-flight secondary ion mass spectrometry measurements coupled with multivariate data treatment and parallel experiments using quartz crystal microbalance with dissipation monitoring (QCM-D). In particular, Principal Component Analysis (PCA) was used to identify similarities and differences in TOF-SIMS spectra of protein-based films and to classify the spectra into groups. PCA results shown that single-protein films can certainly be discriminated. Films prepared by mixed-component solutions revealed peculiar positions in the scores plot. The ToF-SIMS spectra of proteins adsorbed onto Fe(II) complex were clustered close to the HSA single-component layer. Similarly, films prepared on Cu(II) have surface mass spectra similar to that of the FN single-component film. On the other hand, QCM-D studies show that HSA exhibits a strong affinity with the Cu(II)-containing self assembled monolayer, whereas LF interacts much strongly with Fe(II)-based SAMs rather than with HSA. Consequently, we conclude that the PCA results on TOFSIMS data can be interpreted in terms of competitive multilayer adsorption. In other words, when allowing a mixed-component (HSA/FN) protein to interact with the metal complex monolayer, HSA competitively interacts with Cu(II)-based complexes and adsorbs on them. This stage is followed by the subsequent adsorption of FN on top of the HSA layer. By contrast, the low interaction of HSA with Fe(II) complex promotes the formation of a first layer of LF, followed by the adsorption of HSA on top of it. Sequential adsorption QCM-D experiments confirmed such interpretations of the peculiar physico-chemical process.

Authors : Kristin Hyltegren, Tommy Nylander, Mikael Lund, Marie Skepö
Affiliations : Division of Theoretical Chemistry, Lund University; Division of Physical Chemistry, Lund University; Division of Theoretical Chemistry, Lund University; Division of Theoretical Chemistry, Lund University

Resume : Histatin 5 is a saliva protein that acts as the first line of defence against oral candidiasis caused by Candida Albicans. The antimicrobial activity has been ascribed to the high content of basic amino acids. Histatin 5 also participates in the formation of a protective layer on smooth tooth surfaces, and thereby prevents microbial colonization and stabilizes mineral–solute interactions. Thus, the adsorption of histatin 5 to surfaces in the oral cavity is important for our oral health. Our aim is to understand how the lack of structure of histatin 5 in solution relates to its function in the adsorbed state. The focus of this study is to see how pH, ionic strength and charge regulation of the protein affects surface adsorption. For this purpose a combination of ellipsometry and coarse-grained Monte Carlo simulations have been used. By applying the Langmuir adsorption isotherm, a surface coverage could be calculated from the single-protein simulation results, enabling a direct comparison with experiments. The results show that inclusion of an attractive interaction of 2.9 kT per amino acid is necessary to get close to experimental results. The main reason is that our coarse-grained model overestimates the entropy of the free histatin 5 chain. The rest of the potential represents van der Waals interactions, hydrogen bonding and possibly charge regulation of the surface. Preliminary results will be shown for the influence of charge regulation of the surface.

Functionalised and responsive surfaces I : Giovanni Marletta
Authors : John Webster
Affiliations : ISIS neutron facility, Rutherford Appleton Laboratory, STFC, Chilton, Didcot, Oxon OX11 0QX

Resume : In this invited talk, I will first introduce the unique capability of neutron reflection aided by the isotopic contrast variation via H/D exchanges at studying protein adsorption, followed by illustrating the main structural features that can be revealed at different interfaces. I will then show how a typical globular protein interacts with different model surfactants leading to structural unfolding and changes in interfacial structure and composition, emphasising the importance of the appropriate isotopic constrasts to be used. Using IgG as examples, I will how neutron reflection can be used to study its adsorption and desorption at the air/water and solid/water interfaces, thereby improving our understanding about how surface and interfacial adsorption could cause structural destabilisation.

Authors : MUTSCHLER Angela, SCHAAF Pierre, LAVALLE Philippe and VRANA Nihal Engin
Affiliations : Institut National de la Santé et de la Recherche Médicale, INSERM Unité 1121, 11 rue Humann, 67085 Strasbourg, France

Resume : -

Authors : Li Deng, Yurong Zhao, Peng Zhou, Hai Xu*1, and Yanting Wang*2
Affiliations : 1) Centre for Bioengineering and Biotechnology, China University of Petroleum (East China) 2) Institute of Theoretical Physics, Chinese Academy of Sciences

Resume : Nanostructures self-assembled by cross-β peptides are with highly ordered hierarchical structures and high mechanic properties have potential applications in biomaterials.and formed by lateral stacking of cross-β sheets. Quantitatively studying the intermolecular force and driving forces in of different hierarchical structures at the microscopic atomistic level is essential for understanding the mechanism to form various morphologies and nanomechanics of nanostructures self-assembled by various kinds of peptides. In this work, we investigate the thermodynamics of intra-sheet and inter-sheet structures self-assembled by KIIIIK with the umbrella sampling technique applied toby atomistic molecular dynamics simulations. Combining combining steered molecular dynamics simulation with umbrella sampling., the potential of mean forces (PMF) of both structures have been calculated. It is found that The the mechanical properties of intermolecular bond stiffness intra-sheet and inter-sheet structure are highly anisotropic and their intermolecular bond stiffness of are 5.58 N/m and 0.32 N/m respectively. By analyzing the entropic and enthalpic contributions for association of intra-sheet and inter-sheet structure, we find that the mechanical anisotropy comes from that the difference between their driving forces to keep the equilibrated structures stable. The enthalpy keeps intra-sheet structure stable, but the entropy keeps inter-sheet structure stable. Furthermore, the driving forces in the association process of intra-sheet and inter-sheet structure are different due to that the van der Waals and electrostatic interactions between peptide and peptide and that between peptide and solvents in different shells have play different roles in association of these structuresthe processes. Especially, the interactions between peptide and solvent in hydration shell have significant effects on the peptide self-assembly. The For the intra-sheet structure of KIIIIK is stabilized by hydrogen bond interaction, so the electrostatic interaction between peptide and peptide dominate the association of strands but the electrostatic interaction between peptide and the solvent in the hydration shell is disadvantageous to association of strands. However, for the inter-sheet structure of KIIIIK is stabilized by hydrophobic interaction, so the van der Waals (VDW) interaction between peptides promotes the association of sheets and the interaction between peptide and the solvent in the hydration shell also is advantageous to promote the aggregationassociation of sheets.

Authors : Alexandra Tibaldi, Vincent Noel, Marion Woytasik, Benoit Piro, Laure Fillaud, Giorgio Mattana
Affiliations : University Paris Diderot, ITODYS, UMR 7086 University Paris Saclay, IEF, UMR 8622

Resume : Highly sensitive, robust and miniaturized transduction systems could overcome the typical problems associated with the early diagnostic of diseases that requires the simultaneous identification and quantification of several biomarkers (proteins) at the trace level. A new kind of organic field-effect transistor architecture, the so-called "Electrolyte-Gated Field Effect Transistor" (EGOFET) offers a new analytical tool with an extremely high sensitivity of its electrical characteristics toward any physicochemical phenomenon occurring in the vicinity of the gate and / or transistor channel. To perform simultaneously a precise quantification of proteins at the trace level (up to 10-12 M), we adapt the standard ELISA (Enzyme-Linked Immunosorbent Assay) setup by replacing the conventional enzyme label (i.e., usually an enzyme producing a chromophore detected by UV-Vis spectroscopy) by an acetylcholinesterase. This enzyme converts the acetylthiocholine in thiocholine (TC). The TC has a thiol group that spontaneously chemisorbs on the EGOFET gate (Au), leading to a drastic change of the transistor characteristics. The proof of concept of an ELISA read-out performed using an organic field effect transistor will be presented as well as the current device figures of merit. This work paves the way to the development of new ultra-sensitive protein sensors that are compatible with the integration of microfluidic systems as well as large-scale and low-cost fabrication processes.

Authors : Tugba Isik, Nesrin Horzum, Ü. Hakan Yildiz, Mustafa M. Demir
Affiliations : Tugba Isik - Materials Science and Engineering Department, Izmir Institute of Technology, Turkey ; Nesrin Horzum - Biomedical Engineering, Izmir Katip Çelebi University, Turkey ; Ü. Hakan Yildiz - Chemistry Department, Izmir Institute of Technology, Turkey ; Mustafa M. Demir - Materials Science and Engineering Department, Izmir Institute of Technology, Turkey

Resume : Biomarkers have been used in clinical diagnosis. They are measurable indicators for the physiological state of the body. Recent studies demonstrate that the change in the level of biomarkers indicates the early stages of cancer or cardiovascular diseases. Therefore, the separation and concentration of biomarkers for further analysis have high potential in early detection. This study asserts a convenient approach to develop affinity membranes for the separation of nucleic acid biomarkers. The separation efficiency of membranes was examined with bovine serum albumin (BSA) as model protein and single stranded DNA (ss-DNA) as biomarker. The membranes made of poly styrene (PS) and poly (methyl methacrylate) (PMMA) were fabricated by electrospinning. The sorption efficiency of membranes suggests that separation of ss-DNA and proteins are possible. The preliminary results revealed that electrospun PS membranes (after surface modification) are promising for BSA uptake with 111 mg g-1 sorption capacity. Also, PS membranes show better affinity to BSA molecules by hydrophobic interactions. In the model mixture of BSA and ss-DNA, by virtue of anti-fouling property of BSA, ss-DNA cannot be held on the surface and the ratio of BSA/DNA in eluted solution introduced three-fold decrease by increasing the adsorbed BSA on the membranes. The proposed technology promises fast and effective separation of biomarkers from both blood and body fluids.

Authors : A. Varesano1, C. Vineis1, D.O. Sanchez Ramirez1, R.A. Carletto1, F. Truffa Giachet1, S. Spriano2, S. Ferraris2, L. Rimondini3, N. Bloise4, L. Visai4
Affiliations : 1CNR-ISMAC, Istituto per lo Studio delle Macromolecole, BIELLA, Italy; 2Politecnico di Torino, DISAT, TORINO, Italy; 3Università del Piemonte Orientale, NOVARA, Italy; 4Università di Pavia and S. Maugeri Foundation, IRCCS, PAVIA, Italy

Resume : Electrospinning is a simple method to produce nanofibres with high specific surface. Keratin is a biocompatible and biodegradable protein [1], it supports fibroblasts [2] and osteoblasts [3] growth. Moreover, electrospun keratin-based nanofibers (EKNs) were made insoluble to water by a thermal treatment inducing cross-linking [4]. For dental applications, pure keratin has been electrospun from solutions of formic acid to deposit nanofibers onto titanium substrates. The aim is the improvement of soft tissue adhesion avoiding epithelial down-growth and bacterial infiltration on the collar. Water stability of EKNs was evaluated by 28 days soaking. EKNs were found to greatly improve fibroblast cells growth already at 24h. In bone regeneration, nano-hydroxyapatite (HAp) was used in composite EKNs. Unfortunately, HAp particles are not stable in acids; therefore, water was used as solvent to produce HAp-EKNs. Better processability was attained by blending keratin with polyethylene oxide (PEO). PEO is an amphiphilic and water-soluble polymer added as a sacrificial material. HAp-EKNs were subjected to heating and washing to obtain pure keratin nanofibres. HAp-EKNs have been tested for osteoblasts cells adhesion and growth, showing biocompatibility by cell viability assay and SEM. [1] Yamauchi et al. J Biomater Sci Polym Ed 9 (1998) 259. [2] Tachibana et al. J Biotechnol 93 (2002) 165. [3] Tachibana et al. Biomaterials 26 (2005) 297. [4] Varesano et al. J Appl Polym Sci 131 (2014) 40532.

Authors : Muling Zeng, Anna May-Masnou, Anna Roig, Anna Laromaine
Affiliations : Institut de Ciència de Materials de Barcelona, Campus UAB, 08193 Bellaterra, Spain.

Resume : Cellulose from microbial origin, commonly known as bacterial cellulose (BC), is becoming a commodity material since it incorporates desirable structural properties for biomedical applications. Here, we present the production and characterization of bacterial cellulose (BC) films of less than a hundred microns thick produced by Gluconacetobacter bacteria. These thin films are processed using three different drying methods: 1) room temperature, 2) freeze drying and 3) supercritical drying. The different processes confer the cellulose films a hierarchical porous network, high purity and crystallinity, flexibility and strength (high Young modulus at room and elevated temperatures) and large water holding capacity that can be tailored and controlled for different applications. In this work, we used BC films as a platform to incorporate magnetic functionality by the incorporation of iron oxide nanoparticles and gold nanoparticles as potential catalysts. Using the microwave-assisted method in a rapid and cost effectively manner, we magnetically coated the whole structure of our BC films uniformly. By evaluating different precursor´s concentrations and taking advantage of the different drying methods, we achieved magnetic bacterial films with different magnetic strength. We obtained magnetic, flexible and robust BC composites within a few minutes in a clean, easy and reproducible method. We present different options to increase the complexity of these BC films, including the attachment of metallic or oxide nanoparticles, or patterning the BC films with different hydrophobic domains.

Authors : T. Aschl, A. Moraillon, F. Ozanam, P. Allongue, A.-C. Gouget-Laemmel
Affiliations : Physique de la Matière Condensée, Ecole Polytechnique-CNRS, France

Resume : Aptamer-based biochips are well suited to the identification of targets like proteins, toxins or bacteria because they allow rapid and sensitive detection [1]. The prerequisite for achieving selective target recognition is depositing a bioreceptive organic layer, whose chemical properties allow the controlled immobilization of suitable aptamers (probes) and also minimize non-specific target adsorption. In this work we aim at detecting Ochratoxin A (OTA), a well-known mycotoxin which has nephrotoxic, teratogenic and immunotoxic effects, using fluorescence measurements. The biochip is composed of an Al-on-glass back reflector covered by a thin film of amorphous Si-C alloy [2], which is adjusted to obtain constructive interferences at the film surface. A carboxyl-terminated organic layer is then grafted to the surface via stable Si-C bonds. Surface activation with succinimidyl ester groups is performed for the amidation of the well-known 36mer AntiOTA aptamer. ATR-IR characterizations of the assembly, until aptamer / OTA duplex formation, will be presented at the conference to discuss the organic layer composition and estimate the surface concentration of immobilized OTA in various physiological media. Complementary fluorescence assays will also be presented. Preliminary results indicate successful interaction of OTA with the immobilized aptamers. [1] F. Radom et al. Biotechnol. Adv. 2013, 31, 1260. [2] L. Touahir et al. Biosens. Bioelectron. 2009, 25, 952.

Authors : Benedetta Castroflorio, Alessandro Rapisarda, Grazia ML Messina, Carmela Bonaccorso, Valentina Spampinato, Domenico Sciotto, Giovanni Marletta
Affiliations : Department of Chemical Sciences, University of Catania, Catania, I-95125, Italy

Resume : Biofouling is an important issue affecting numerous applications ranging from biomedical implants to biosensors. Therefore, there is a constant need to develop versatile, convenient and cost-effective autifouling strategies in healthcare. Among the others, surface functionalization with antifouling structure is a convenient way for giving adhesion resistance. Since to construct protein resistant surfaces would require to have no net charge and/or polar functional groups, a strategy involving the surface immobilization of zwitterionic units has been investigated, as a potentially attractive method to prepare antiprotein fouling surface. Potential optimal candidates to build up effective antifouling surfaces for in vivo application are natural amino acids, in their zwitterionic form. In this study we describe the anchoring of calix[4]arene-crown-5 self-assembled monolayer on gold surface, to be used as containers of aminoacids, and the interaction between surface-anchored calix and amino acid residues in aqueous environment. The amino acid inclusion in the calix was studied by using Quartz Crystal Microbalance with Dissipation monitoring (QCM-D) technique. As the amino acids exhibit pH-dependent behavior, the pH values in the aqueous environment strongly influence the molecular recognition process in solution due to the combined effect of electrostatic and hydrophobic interactions. In particular, it was found that the inclusion efficiency, while depending in a minor way on the hydrophobicity, appear to critically depend on the flexibility of the amino acids, i.e., from the matching of the steric constrains and conformational change of the including amino acids. The antifouling properties of the functionalized zwitterionic surfaces have been tested against Human Serum Albumin and Lysozyme.

Authors : C. Vineis1, A. Varesano1, C. Tonetti1, D. O. Sánchez Ramírez1, R. A. Carletto1, S. Ortelli2, M. Blosi2, A. L. Costa2
Affiliations : 1CNR-ISMAC, Institute for Macromolecular Studies – National Research Council of Italy, Giuseppe Pella 16, I-13900 Biella, Italy; 2CNR-ISTEC, Institute of Science and Technology for Ceramics – National Research Council of Italy, Via Granarolo 64, I-48018 Faenza (RA), Italy

Resume : Multi-component organic/inorganic nanofibers were produced by electrospinning water solutions of keratin extracted from wool containing nanosols of titanium dioxide or metal silver. The resulting hybrid keratin-based nanofibers were made insoluble to water by treatments at high temperature. Nanofibers were observed by SEM before and after the heat treatments, and after the contact with water. Energy Dispersive X-ray analysis was performed with the aim of confirm the presence of inorganic nanoparticles. Finally, the functional properties (antibacterial property and photo-catalytic activity) of the nanoparticles embedded into the electrospun nanofibers were quantified on treated samples. The TiO2 reactivity was tested in both cases under UV light irradiation. Antibacterial tests were carried out using E. coli following the ATCC 100 Test Method on nanofibers treated with silver or TiO2. Both electrospun hybrid nanofibers showed excellent antibacterial properties confirming that the nanoparticles can exert their functions even if they are embedded in keratin nanofibers. Photocatalytic tests based on model reaction of Rhodamine B dye degradation showed promising photocatalytic property for the hybrid TiO2/keratin electrospun nanofibers. The results demonstrated that electrospun keratin nanofibers doped with active nanophases preserve nanoparticle properties, allowing the design of highly versatile hybrid multifunctional media.

Authors : A. Vladescu1, M. Braic1, A.Gherghilescu2, A.Kiss1, C. M. Cotrut2, I.Titorencu3, V.Jinga3, V.Braic1
Affiliations : 1National Institute for Optoelectronics – INOE 2000, 409 Atomistilor Str., RO77125, Magurele, Romania 2University Politehnica of Bucharest, 313 Splaiul Independentei, RO 060042, Bucharest, Romania 3Institute of Cellular Biology and Pathology Nicolae Simionescu of the Romanian Academy, 8 B.P.Hasdeu, Bucharest, Romania

Resume : Hydroxyapatite coatings enriched with Ti were prepared as a possible candidate for biomedical applications especially for implantable devices that are in direct contact to the bone. The coatings were prepared by RF magnetron sputtering method on Ti based alloy using pure hydroxyapatite and TiO2 targets. The content of Ti was modified by changing the RF power fed on TiO2 target. The formation of the hydroxyapatite compound was not influenced by the addition of Ti. The Ca/P ratio of the Ti doped hydroxyapatite coatings was ranged from 1.64 to 1.68, being close to the stoichiometric hydroxyapatite coating. The roughness of the doped hydroxyapatite coatings were increased by increasing the RF power on TiO2 cathode. The in vitro corrosion performances of uncoated substrate were significantly improved by hydroxyapatite coating with or without Ti addition. The Ti additions led to an increase in cell viability of hydroxyapatite coatings, after 5 days of culture. The scanning electron microscopy showed that more cells were seen on the surface of hydroxyapatite enriched Ti than those observed on the surface of the uncoated Ti6Al4V alloys or hydroxyapatite without Ti addition.

Authors : Nirmalya Tripathy,1 Rafiq Ahmad, 2 Yoon Bong Hahn,2 Gilson Khang1
Affiliations : 1Department of BIN Fusion Technology, Department of Polymer-Nano Science & Technology and Polymer BIN Research Center, Chonbuk National University,567 Baekjedaero, Deokjin-gu, Jeonju561-756, South Korea; 2School of Semiconductor and Chemical Engineering, and Nanomaterials Processing Research Center, Chonbuk National University, 567 Baekjedaero, Deokjin-gu, Jeonju561-756,South Korea

Resume : Intelligently designed surface nano-architecture provides defined control over the behavior of biomolecules and cells at the solid-liquid interface. Well-designed, mono-dispersed sodium-doped zinc oxide nanoparticles (Na-ZnO NPs) were prepared through wet chemical route at low temperature, and further formulated as paint to achieve thin film on glass surface. Surface morphological characterizations of the as-coated glass surface shows a uniform film thickness (~100±10nm) with homogeneous distribution and good attachment of nanoparticles to the glass surfaces. Photoluminescence spectra of Na-ZnO NPs exhibit exciton recombination emission along with deep and shallow trap emissions, attributed to oxygen deficiency associated with Na-dopant content. Antibacterial and antibiofilm assay showed remarkable reductions in bacterial growth and biofilm formation (Escherichia coli and Staphylococcus aureus) especially upon UV activation by reducing recombination of electrons/holes, compared to that of uncoated glass. The investigated mechanism reveals that the nanoparticles efficiently penetrate and generate intracellular reactive oxygen species (ROS) inside bacteria, which eventually enhances lipid peroxidation and cause cell death. Highlighting the superior efficacy of Na-ZnO NPs over ZnO NPs, this state-of-the-art design of Na-ZnO NPs based paint promises wide applicability in biomedical and industrial arena.

Authors : R.A. Picca, M.C. Sportelli, R. Quarto, N. Ditaranto, A. Valentini, N. Cioffi
Affiliations : R.A. Picca: Dipartimento di Chimica, Università degli Studi di Bari “Aldo Moro”, via Orabona 4, 70126 Bari, Italy; M.C. Sportelli: Dipartimento di Chimica, Università degli Studi di Bari “Aldo Moro”, via Orabona 4, 70126 Bari, Italy;R. Quarto: Dipartimento di Chimica, Università degli Studi di Bari “Aldo Moro”, via Orabona 4, 70126 Bari, Italy; N. Ditaranto: Dipartimento di Chimica, Università degli Studi di Bari “Aldo Moro”, via Orabona 4, 70126 Bari, Italy; A. Valentini: Dipartimento Interateneo di Fisica “M. Merlin”, Università degli Studi di Bari “Aldo Moro”, Bari, Italy; N. Cioffi: Dipartimento di Chimica, Università degli Studi di Bari “Aldo Moro”, via Orabona 4, 70126 Bari, Italy

Resume : Copper-based nanoantimicrobials are often proposed as suitable tools to control/inhibit the growth of undesirable pathogens [1]. In our laboratory, we developed a successful approach for the electrochemical synthesis of highly stable copper nanoparticles (NPs) with proven bioactivity [2], in the presence of tetraalkylammonium salts as stabilizers. In this way, CuNPs can be employed for the modification of industrial products in order to confer them peculiar antimicrobial properties. Diluted solutions of CuNPs were used as impregnation baths for samples of polyurethane foams, used for matrasses. Two different stabilizers were chosen for CuNPs production: tetrabutylammonium chloride and tetraoctylammonium chloride, differing in the alkyl chain length. All the materials treated with CuNPs were characterized morphologically and spectroscopically. Pristine CuNP colloids were characterized by transmission electron microscopy. X-ray photoelectron spectroscopy was used to evaluate the surface chemical composition of pristine and treated polyurethanes. Copper ion release was investigated by Atomic Absorption Spectroscopy to correlate process parameters and release properties. The total amount of released Cu2 was found to be a function of alkyl chain length of the chosen stabilizer, as well as of CuNP loading into the final composite material. [1] A.P. Ingle et al., Appl. Microbiol. Biotechnol. 98 (2014) 1001. [2] “Nanomaterials for metal controlled release and process for their production” N. Cioffi, N. Ditaranto, L. Sabbatini, L. Torsi, P.G. Zambonin, EP n. 2123797B1.

Authors : D.M. Vranceanu1, A. Vladescu2, M. Dinu2, A.I. Gherghilescu1, M. Tarcolea1, C.M. Cotrut1
Affiliations : 1University Politehnica of Bucharest, 313 Independentei Street, Bucharest, Romania 2National Institute for Optoelectronics, 409 Atomistilor Str., Magurele, Romania

Resume : In order to improve the bioactive behaviour of titanium, nowadays one major direction is to modify the surface by coating its with bioactive films. Formation of hydroxyapatite (HAp) coatings on Ti implants combines the favourable properties of both materials. Electrochemical deposition (ELD) is a cost-effective and versatile technique, in which the process parameters can be well controlled thought adequate conditions of the process. In this study, HAp was prepared by electrodeposition using a standard three electrode cell set-up in which Ag/AgCl was used as reference electrode, platinum electrode as counter electrode and the sample (Ti substrate) as working electrode. The electrolyte was prepared by dissolving Ca(NO3)2 and NH4H2PO4, in ultrapure water. A Potentiostat/Galvanostat operating in potentiodynamic mode was employed to a cathode potential of -1.4 V vs Eref for 2 h, at different temperatures in order to obtain the HAp coatings. The obtained HAp coatings have been characterized as follows: phase identification, morphology, chemical composition, roughness, contact angle and corrosion resistance. The linear polarization technique was used to obtain the polarization resistance (Rp), corrosion current densities (icorr) and corrosion rates (CR). As a conclusion it can be said that the temperature has influenced not only the morphology but also the corrosion resistance. A more stable behaviour being registered for the samples obtained at a higher temperature.

Authors : Yong-Tae Kim, Ji Hun Kim, Yong Ho Kim
Affiliations : Yong-Tae Kim, Ji Hun Kim, Yong Ho Kim, SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, 440-746, South Korea; Yong Ho Kim, Department of Chemistry, Sungkyunkwan University, Suwon, South Korea

Resume : Supramolecular protein assembly is an ubiquitous process that physical and chemical principles of Mother Nature have achieved great complexity and stability to build up architectures of a life in molecular level. There have been so many trials of understanding how to construct supramolecular protein assembly and also a lot of successes have been built up. The stacked principles have recently been applied for designing the hybrid nanoparticle-protein superstructures that can show unique physical properties and potential application in the areas of plasmonics, molecular sensing, and nanoscale electronics. Here we show an unique nanostructure of self-assembled peptides that would allow for the wrapping of single walled carbon nanotubes (SWNTs) with specific helicities. We also demonstrate that the selection rule whereby precisely controlling position of functionality within such superstructures constrains a variety of arrangement of bimetallic AuPt nanoclusters for the purpose of enhancing catalytic activity of oxygen reduction reaction (ORR). The elected positions of functionality from the selection rule precisely alter their arrangement and density of catalytic nanoparticles and result in a significant change on ORR activity and durability. The remarkable electrochemical property of nanoparticle-protein-SWNT superstructures corresponding to controlling of interparticle distance, particle size and alloy composition of single-phase nanoparticles suggests a route to the construction of new functional protein nanomaterials tailored to unique energy applications.

Authors : Jiyoung Nam, Yong-Tae Kim, Yoo Young Ahn, Nam Hyeong Kim, Ji Hun Kim, One-Sun Lee, Yong Ho Kim
Affiliations : Jiyoung Nam, Yong-Tae Kim, Yoo Young Ahn, Nam Hyeong Kim, Ji Hun Kim,Yong Ho Kim, Sungkyunkwan Advanced Institute of Nanotechnology(SAINT), Sungkyunkwan University,Suwon 440-746, South Korea; One-Sun Lee, Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, P.O. Box 5825, Doha, Qatar

Resume : Supramolecular protein assembly governs most of important biological phenomena such as cell division and enzyme activities and thereby understanding the principle of such interaction gives insights to elucidate the relationship of structure to its function. Self-assembled biomolecules such as DNA and peptide are widely studied for developing new materials as they offer possibilities to integrate biocompatibility into the material applications. Recently, rationally designed self-assembling peptide has been highlighted as a molecular building block because it enables precise modulation of material properties by programming the sequences of peptide that controls the predefined hierarchical structures in a molecular level. Herein we rationally designed a unique nanostructure fiber with self-assembled β-peptide hexameric units. Interestingly, β-peptide nanofibers would allow for associating with single walled carbon nanotube bundles with specific helicities in a manner of superhelical wrapping. We analyzed the structure of β-peptide fibers by small-angle X-ray scattering (SAXS) data that revealed consecutive longitudinal assembly of -peptide hexamers forming nanofiber. The association of -peptide fibers with carbon nanotubes (CNTs) induced extremely stable superhelical protein structure on the surface of CNTs which retained its helical propensity above 100 ℃. The mechanism of superhelical interaction between β-peptide nanofibers and CNTs was fully speculated with MD simulation that calculates the free energy of superhelical wrapping -peptide fibers on CNTs. Furthermore we investigated the electrochemical property of -peptide-CNTs complex through changing the ratio of CNTs to -peptide fibers. The geometrically and electrochemically enhanced superstructure holds a promising future in development of biomaterials applying for biosensors, regenerative medical device, and tissue engineering

Authors : Su Yeon Park, Yong-Tae Kim, Yong Ho Kim
Affiliations : SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 440-746, Korea

Resume : Inducing functionalities on coated surface has been devoted for many years for biomedical uses. Various techniques for immobilizing target function were developed on diverse surfaces. Especially, using biomaterials to control specific functions have been highlighted in biomedical applications. Because this kind of material was advanced in achieving biocompatible and preventing the side effects. However, these materials were only designed for delivering one specific function. Therefore, we suggest a novel strategy to bring multifunctional property synchronically using recombinant proteins. This strategy brought ability to derive two different functions at a time on immobilized bioactive surface. We used mussel based dopamine self-polymerization protein via mussel adhesive protein to tether on the surface and release dual functions by modifying each termination of mussel adhesive protein. The desired functional peptide motif can be recombinant with mussel adhesive protein in E.coli. This recombinant hybrid protein enabled the efficient coating on the surface and more than one functions could be generated for specific targets. As one demonstration, we selectively chose the antimicrobial peptides (AMPs) for one terminal of mussel adhesive protein to enhance the antimicrobial activity. Therefore, the surface was simply functionalized with immobilization of AMPs and successfully examined antimicrobial activity against both gram negative and gram positive bacteria. Therefore, we have collected the list of peptides for specific functions such as wound healing peptide, hormone inducing peptide that can be used in diverse biomedical fields.

Authors : Meryem Hatip, Mustafa O Guler
Affiliations : Material Science & Nanotechnology, Bilkent University, Ankara, Turkey

Resume : Supramolecular peptide self-assembly is a powerful bottom-up technique to design and manufacture dynamic complex structures at the nanoscale through non-covalent interactions. Recent advances showed us that the self-assembled peptide nanostructures provide an appealing platform for regenerative medicine, tissue regeneration and stem cell differentiation due to self-supporting and extracellular matrix mimicking properties. Dynamic nature, morphology and supramolecular chirality of the self-assembled peptide nanostructures may affect biological responses. Here, we study various self-assembly conditions and self-assembly mechanism for peptide amphiphile molecules including supramolecular chirality. Change in the environment such as pH or electrostatic interactions, and amino acid sequence of the peptide amphiphiles lead to self-assembled nanostructures with different morphologies. We showed that, type of amino acid residues and trigger forces cause morphological changes. These supramolecular chiral peptide nanostructures were studied in detail by several spectroscopic techniques and imaged by TEM and AFM.

Authors : Maria Teresa De Angelis 1, Antonio Paciello 2,3, M. Gabriella Santonicola 1
Affiliations : 1 Department of Chemical Materials and Environmental Engineering, Sapienza University of Rome, 00161 Rome, Italy; 2 Center for Advanced Biomaterials for Healthcare, Istituto Italiano di Tecnologia, 80125 Naples, Italy; 3 Interdisciplinary Research Centre on Biomaterials, University of Naples Federico II, 80125 Naples, Italy

Resume : Interest in stimuli-responsive polymers is steadily increasing especially in the fields of controlled and self-regulated gene delivery. The insertion of appropriate genes into the cells that will repair or replace, is an essential step in gene therapy. Also termed ‘environmental-sensitive’ or ‘smart’, stimuli-responsive polymers experience rapid and reversible changes in their microstructure from a hydrophilic to a hydrophobic state triggered by small changes in the environment, at level of pH, temperature, as well as light, magnetic and electric fields. In this work, we investigate the electrochemical properties of a highly hydrophilic hydrogel based on supramolecular polymers derived from methacrylation of branched polyethyleneimine (PEI-MA). We use electrochemical impedance spectroscopy (EIS) to study the charge transfer at the interface electrode/hydrogel for different applied voltages and buffer solution pH, and we analyze the hydrogel behavior in terms of equivalent circuit models. Results show that the PEI-MA hydrogels respond to both pH and electric fields to an extent that is related to their degree of methacrylation. In addition, we show that DNA can be released in a controlled manner from the hydrogel under the effect of an applied potential, thus demonstrating the possibility of in vitro gene delivery applications for these intelligent hydrogels.

Authors : A. De Bonis, M. Curcio, J.V. Rau, M. Fosca, A. Santagata, R. Teghil
Affiliations : Dipartimento di Scienze, Università della Basilicata, Via dell’Ateneo Lucano 10, 85100 Potenza, Italy; Istituto Struttura della Materia – CNR, U.O.S. Potenza, via S. Loja, 85050 Tito Scalo, Italy; Istituto Struttura della Materia – CNR, Via del Fosso del Cavaliere, 100-00133 Rome, Italy

Resume : Since the discovery of the first bioactive glass by Hench, an increasing amount of bioactive glasses have been proposed in order to improve their osteo-conductive behaviour. Recently the incorporation of metallic ions in glass-ceramic materials is considered a new strategy to increase the material bioactivity. Since the biological response is mainly related to the interaction of the device surface with the biological surrounding, these materials are often produced in form of coating of different thickness. Here we report the Pulsed Laser Deposition (PLD) of thin films obtained by ablating a composite target obtained mixing a glass ceramic material of innovative composition (RKKP) [1] with fullerite, in order to improve the coatings mechanical properties. The RKKP-C60 target has been ablated in vacuum by a frequency doubled Nd:YAG laser (t = 7 ns,  = 532 nm, 10 Hz repetition rate), in a wide temperature range, from room up to 600 °C. The characteristics of the deposited coatings have been investigated by microscopical, spectroscopical and diffractometric techniques, namely: Scanning Electron Microscopy, Transmission Electron Microscopy, Atomic Force Microscopy, Fourier Transform Infrared Spectroscopy, micro-Raman spectroscopy, Angular and Energy Dispersive X-ray Diffraction. Vickers microhardness measurements of the composite film–substrate systems have been performed, and the intrinsic hardness of films separated from the composite. The in vitro bioactivity of the obtained films has been studied by soaking sample in Simulated Body Fluid (SBF). [1] A. Krajewski, A. Ravaglioli, A. Tinti, P. Taddei, M. Mazzocchi, R. Martinetti, C. Fagnano, M. Fini, J. Mater. Sci.: Mater. Med. 16 (2005) 119–128.

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Functionalised and responsive surfaces II : Tommy Nylander
Authors : Ashutosh Chilkoti
Affiliations : Department of Biomedical Engineering Duke University, Durham, NC 27708, USA

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.

Authors : Katrin Unger, Anna Maria Coclite
Affiliations : Institute of Solid State Physics, Graz University of Technology, Petersgasse 16, 8010 Graz, Austria

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.

Authors : Laure Fillaud, Thomas Petenzi, Giorgio Mattana, Vincent Noël, Benoît Piro
Affiliations : Université Paris Diderot, Sorbonne Paris Cité, ITODYS, UMR 7086 CNRS, 15 rue J-A de Baïf, 75205 Paris Cedex 13, France

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.

Authors : Palange AL1, Key J2, Colasuonno M1, Rizzuti I1, Francardi M1, Di Mascolo D1, Decuzzi P1
Affiliations : 1 Laboratory of Nanotechnology for Precision Medicine, Fondazione Istituto Italiano di Tecnologia (IIT), via Morego 30,16163 Genova, Italy 2 Department of Biomedical Engineering, Yonsei University, Yonseidae-gil, Wonju, Gangwon-do, 220-710, Republic of Korea

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.

Authors : M. C. Sportelli, E. Tütüncü, R. A. Picca, M. Valentini, A. Valentini, C. Kranz, B. Mizaikoff, N. Cioffi
Affiliations : M.C. Sportelli: Chemistry Department, University of Bari, V. Orabona, 4-70126 Bari, Italy; E. Tütüncü: Institute of Analytical and Bioanalytical Chemistry, Ulm University, Albert Einstein Allee, 11 – 89081 Ulm, Germany; R.A. Picca: Chemistry Department, University of Bari, V. Orabona, 4-70126 Bari, Italy; M. Valentini: Dipartimento Interateneo di Fisica “M. Merlin”, Università degli Studi di Bari “Aldo Moro”, Bari, Italy; A. Valentini: Dipartimento Interateneo di Fisica “M. Merlin”, Università degli Studi di Bari “Aldo Moro”, Bari, Italy; C. Kranz: Institute of Analytical and Bioanalytical Chemistry, Ulm University, Albert Einstein Allee, 11 – 89081 Ulm, Germany; B. Mizaikoff: nstitute of Analytical and Bioanalytical Chemistry, Ulm University, Albert Einstein Allee, 11 – 89081 Ulm, Germany; N. Cioffi: Chemistry Department, University of Bari, V. Orabona, 4-70126 Bari, Italy.

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.

Authors : F. Pappa, V. Karagkiozaki, E. Pavlidou, Th. Choli-Papadopoulou, S. Logothetidis
Affiliations : Nanomedicine Group, Lab for “Thin Films- Nanobiomaterials, Nanosystems & Nanometrology”, Department of Physics, Aristotle University of Thessaloniki, Greece ; Department of Physics, Aristotle University of Thessaloniki, Greece ; Biochemistry Laboratory, Department of Chemistry, Aristotle University of Thessaloniki, Greece

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.

Authors : Cecilia Masciullo 1, Ilaria Tonazzini 1-2, Marco Cecchini 1
Affiliations : 1 NEST, Scuola Normale Superiore and Istituto Nanoscienze-CNR, Piazza San Silvestro 12,Pisa 56127,Italy; 2 Fondazione Umberto Veronesi, Piazza Velasca 5, Milano 20122, Italy

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.

Authors : Marc Jobin, Cédric Pellodi, Cosmin Sandu, Giacomo Benvenuti, Antonin Sandoz, Luc Stoppini
Affiliations : M.J., C.P., L.S. and A.S. ; hepia, University of Applied Sciences of Western Switzerland (HES-SO), 4 rue de la Prairie, CH-1202 Genève, SWITZERLAND . S.C and G.B. : 3D-Oxide, 70 rue G. Eiffel Technoparc, F-01630 St-Genis Pouilly, FRANCE

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.

Biomaterials prepared by external stimuli : Jianbin Huang
Authors : Johannes Bookhold, Thomas Hellweg
Affiliations : Bielefeld University, Department of Chemistry, Physical and Biophysical Chemistry

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.

Authors : Frédéric Siffer, Vincent Roucoules, Florence Bally-Le Gall
Affiliations : Institute of Materials Science of Mulhouse (IS2M), CNRS/Université de Haute-Alsace, Mulhouse, France

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.

Authors : Abderrahmen Hamdi 1.2,Chohdi Amri 1.2, Rachid Ouertani 1, Hatem Ezzaouia 1
Affiliations : 1. Laboratory of Semi-conductors, Nano-structures and Advanced Technologies, Research and Technology Centre of Energy, Borj-Cedria Science and Technology Park, BP 95, 2050 Hammam-Lif, Tunisia. 2. Faculty of Science of Bizerte, University of Carthage, 7021 Zarzouna, Tunisia.

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.

Authors : V. Dinca1, L.E. Sima2, A. Bonciu2,3, L. Rusen1, I. Iordache(Urzica)1 and M. Dinescu1
Affiliations : 1National Institute for Lasers, Plasma, and Radiation Physics, Magurele RO-077125, Romania 2Institute of Biochemistry of the Romanian Academy, 296 Splaiul Independentei, 060031,Bucharest, Romania 3University of Bucharest, Faculty of Physics

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.

Assemblies of organic and inorganic materials : Junbai Li
Authors : Lixin Wu
Affiliations : State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, China

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.

Authors : C. Rodriguez, V. Torres Costa, O. Ahumada, M. Manso Silván
Affiliations : C. Rodriguez; V. Torres Costa; M. Manso Silván Department of Applied Physics, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain. O. Ahumada Mecwins, S.L., Parque Científico de Madrid PTM, C/ Santiago Grisolía 2, Tres Cantos, Madrid, Spain

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)

Authors : Gina Kaup, Tom Felbeck, Marina Lezhnina, Mark Staniford, Ulrich Kynast
Affiliations : Fachhochschule Münster University of Applied Sciences Münster, Stegerwaldstr. 39, 48565 Steinfurt, Germany

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], 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.

Authors : Mark C. Staniford1, Marina M. Lezhnina1, M. Gruener2, Christian A. Strassert2 and Ulrich H. Kynast1
Affiliations : 1 Fachhochschule Münster, Univeristy of Applied Sciences, Stegerwaldstraße 39, 48565 Steinfurt 2 Physics Institute and CenTech, Westfälische Wilhelms-Universität Münster, Heisenbergstraße 11, 48149 Münster,

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.

Authors : Aziliz HERVAULT, Lim MAY, Cyrille BOYER, Alexander DUNN, Toshiaki TANIIKE, Kazuaki MATSUMURA, Derrick MOTT, Shinya MAENOSONO, Nguyen Thi Kim THANH* Email:, http:/
Affiliations : Aziliz Hervault;1,2,3 May Lim;4 Cyrille Boyer;4 Alexander Dunn;4 Toshiaki Tanikee;3 Kazuaki Matsumura;3 Derrick Mott;3 Shinya Maenosono;3 and N. T. K. Thanh.1,2 1. Department of Physics & Astronomy, University College London, Gower Street, London, WC1E 6BT, UK E-mail:; 2. UCL Healthcare Biomagnetics and Nanomaterials Laboratories, 21 Albemarle Street, London W1S 4BS, UK 3. School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa 923-1292, Japan. 4. School of Chemical Engineering, The University of New South Wales, Sydney, NSW2052, Australia

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.

Authors : A.Vladescu1, M.Badea2, M.Braic1, A.Kiss1, M.Moga2, V.Braic1, E. Posna2, M.Dinu1, M.Balaceanu1
Affiliations : 1National Institute for Optoelectronics, 409 Atomistilor St., Magurele, Romania 2”Transilvania” University of Brasov, 29 Eroilor Blvd., Brasov, Romania

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.

Authors : Michele Bianchi, Alessandro Russo, Maria Sartori, Annapaola Parrilli, Silvia Panseri, Alessandro Ortolani, Marco Boi, Donald M Salter, Maria Cristina Maltarello, Gianluca Giavaresi, Milena Fini, Valentin Dediu, Anna Tampieri, Maurilio Marcacci
Affiliations : Bianchi; Russo; Sartori; Parrilli; Ortolani; Boi; Maltarello; Giavaresi; Fini; Marcacci: Rizzoli Orthopaedic Institute, via di Barbiano 1/10 Bologna 40136, Italy. Silvia Panseri; Anna Tampieri: Institute for Science and Technology for Ceramics (ISTEC) – National Research Council, via Granarolo 64 Faenza 48018, Italy. Donald M Salter: Institute of Genetics and Molecular Medicine, University of Edinburgh, EH4 2XU Edinburgh, United Kingdom. Valentin Dediu: Institute of Nanostructured Materials (ISMN) – National Research Council, via Gobetti 101, Bologna 40129, Italy.

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.

Authors : Vesna Srot1, Ute Salzberger1, Birgit Bussmann1, Julia Deuschle2, Boštjan Pokorny3,4, Ida Jelenko Turinek3 and Peter A. van Aken1
Affiliations : 1. Stuttgart Center for Electron Microscopy, Max Planck Institute for Solid State Research, Stuttgart, Germany. 2. Institute of Materials Science, University of Stuttgart, Stuttgart, Germany. 3. ERICo Velenje, Ecological Research and Industrial Cooperation, Velenje, Slovenia. 4. Environmental Protection College, Velenje, Slovenia.

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.

Authors : Eunsun Kim,a Abdellah Felouat,b Elena Zaborova,b Jean-Charles Ribierre,a JeongWeonWu,a Sébastien Senatore,c Cédric Matthews,c Pierre-François Lenne,c Carole Baffert,d Artak Karapetyan,b,e Michel Giorgi,f Denis Jacquemin,g,h Miguel Ponce-Vargas,i Boris Le Guennic,i Frédéric Fages b and Anthony D’Aléob
Affiliations : a: Department of Physics, CNRS-Ewha International Research Center, Ewha Womans University, Seoul, South Korea b: Aix Marseille Université, CNRS, CINaM UMR 7325, Campus de Luminy, Case913, 13288 Marseille, France c: Aix Marseille Université, CNRS, IBDM UMR 7288,13288Marseille, France d: Aix Marseille Université, CNRS, BIP UMR7281, Marseille, France e: NAS Armenia, Inst Phys Res, Ashtarak2, 0203, Armenia f: Aix-Marseille Université, CNRS, Spectropole FR 1739, 13397 Marseille, France g: Laboratoire CEISAM, UMR CNRS 6230, Université de Nantes, 2 Rue de la Houssinière, BP 92208, 44322 Nantes Cedex 3, France h: Institut Universitaire de France, 103 Boulevard Saint-Michel, 75005 Paris Cedex 05, France i: Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS-Université de Rennes 1, 263 Avenue du Général Leclerc, 35042 Rennes Cedex, France

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.

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Materials for biomedical devices : Martin Malmsten
Authors : Carlos Alemán
Affiliations : Departament d’Enginyeria Química, ETSEIB, Universitat Politècnica de Catalunya, Diagonal 647, 08028 Barcelona, Spain

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).

Authors : Clementine M. Boutry (1), Anaïs Legrand (2), Bob C. Schroeder (1), Paige Fox (2), Zhenan Bao (1)
Affiliations : (1) Departement of Chemical Engineering, Stanford University, Stanford, CA, USA; (2) Plastic & Reconstructive Surgery Stanford University Medical Center, VA Palo Alto, CA, USA

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.

Authors : Sait Ciftci, Julien Barthes, Philippe Lavalle, Hayriye Özçelik, Christian Debry, Agnes Dupret-Bories, Nihal Engin Vrana
Affiliations : Sait Ciftci a,b#; Julien Barthes a,c#; Philippe Lavalle a,d; Hayriye Özçelik a,d; Christian Debry a,b; Agnes Dupret-Bories a,b; Nihal Engin Vrana a,c a Institut National de la Santé et de la Recherche Médicale, INSERM Unité 1121, 11 Rue Humann, 67000 Strasbourg, France b Hôpitaux Universitaires de Strasbourg, Service Oto-Rhino-Laryngologie, 67098 Strasbourg, France c Protip SAS, 8 Place de l’Hôpital, 67000, Strasbourg, France d Faculté de Chirurgie Dentaire, Université de Strasbourg, 8 rue Sainte Elisabeth, 67000 Strasbourg, France

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.

Authors : Ayşe Karakeçili, Emre Yüksel
Affiliations : Ankara University Chemical Engineering Department

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.

Authors : Sahar Salehi, Toshinori Fujie, Serge Ostrovidov, Ramin Banan Sadeghian, Ali Khademhosseini
Affiliations : Sahar Salehi WPI-Advanced Institute for Materials Research, Tohoku University, Japan Serge Ostrovidov WPI-Advanced Institute for Materials Research, Tohoku University, Japan Ramin Banan Sadeghian WPI-Advanced Institute for Materials Research, Tohoku University, Japan Toshinori Fujie Department of Life Science and Medical Bioscience, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, Japan Ali Khademhosseini WPI-Advanced Institute for Materials Research, Tohoku University, Japan; Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, USA; Harvard-MIT Division of Health Sciences and Technology Massachusetts Institute of Technology, Cambridge, MA, USA;Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA; College of Animal Bioscience and Technology, Department of Bioindustrial Technologies, Konkuk University, Hwayang-dong, Kwangjin-gu, Seoul, Republic of Korea; Department of Physics, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia

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.

Authors : Andreea Belu 1,3, Gokhan Demirel 2, Elmar Neumann 1,3, Dirk Mayer 1,3 and Andreas Offenhaeusser 1,3
Affiliations : 1 Institute of Complex Systems/ Peter Grünberg Institute (ICS-8/PGI-8), Forschungszentrum Jülich, Jülich, Germany; 2 Bio-inspired Materials Research Laboratory (BIMREL), Gazi University, Ankara, Turkey; 3 JARA-Fundamentals of Future Information Technology, Jülich, Germany

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

Authors : Jing Zhang, Jeff Penny, Jian R Lu
Affiliations : Biological Physics Laboratory, School of Physics and Astronomy, University of Manchester

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.

Interactions with Lipid membranes 1 : John Webster
Authors : Gregory Hardy, Gene Wong, Joseph Shapter, Munir Alam, and Stefan Zauscher
Affiliations : Duke University

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.

Authors : Lina Nyström
Affiliations : Department of Pharmacy, Uppsala University, P.O. Box 580, SE-752 32 Uppsala, Sweden

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.

Authors : E. Gatto (a), R. Lettieri (a), A. Colella (a), F. Leonelli (b), L. Stella (a), M. Venanzi (a)
Affiliations : (a) Dipartimento di Scienze e Tecnologie Chimiche, Università degli Studi di Roma Tor Vergata, Roma, Italy; (b) Dipartimento di Biologia Ambientale, Università degli Studi di Roma La Sapienza, Roma, Italy

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).

Authors : Thomas Werzer1, Oliver Bixner2, Günter Trettenhahn1, Eva-Kathrin Sinner2 Wolfgang Kautek1
Affiliations : 1 University of Vienna, Department of Physical Chemistry, Vienna, Austria 2 University of Natural Resources and Life Sciences (BOKU), Institute of Synthetic Bioarchitectures, Vienna, Austria

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.

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Interactions with lipid membranes 2 : Giovanni Marletta
Authors : Luke Clifton, Maximilian Skoda, Stephen Holt, Anton le Brun, Arwel Hughes, Jeremy Lakey
Affiliations : ISIS Pulsed Neutron and Muon source, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxford; ISIS Pulsed Neutron and Muon source, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxford; Bragg Institute, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia; Bragg Institute, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia; ISIS Pulsed Neutron and Muon source, Rutherford Appleton Laboratory, Harwell Science and Innovation Campus, Didcot, Oxford; Institute for Cell and Molecular Biosciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, United Kingdom

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

Authors : Houcem Maaoui, Roxana Jijie, Radouane Chtourou, Sabine Szunerits and Rabah Boukherroub*
Affiliations : biomaterials

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.

Authors : Costanza Montis, Alejandro Marín Menendez, Chiara Magnani, Teresa Diaz Calvo, Pierre Joseph, Kostas Hatzixanthis, Christopher Morris, Michael McArthur, Debora Berti
Affiliations : University of Florence and CSGI, Department of Chemistry “Ugo Schiff”, 50019, Sesto, Florence, ITALY; Procarta Biosystems ltd, Norwich Bioincubator, Norwich NR4 7TJ, UK; University of Florence and CSGI, Department of Chemistry “Ugo Schiff”, 50019, Sesto, Florence, ITALY; School of Medicine University of East Anglia, Norwich NR4 7TJ, UK; LAAS – CNRS, Nano Engineering and Systems Integration, BP 54200 31031 Toulouse cedex 4, FRANCE; School of Pharmacy
 University of East Anglia, Norwich NR4 7TJ, UK; School of Pharmacy 
University of East Anglia, Norwich NR4 7TJ, UK; School of Medicine
 University of East Anglia, Norwich NR4 7UQ, UK; University of Florence and CSGI, Department of Chemistry “Ugo Schiff”, 50019, Sesto, Florence, ITALY

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.

Authors : Dr Ian M Tucker, Dr M Wade, Prof T Wess
Affiliations : Dr Ian M Tucker, Unilever R&D Port Sunlight Dr M Wade, School of Optometry, University of Cardiff Prof T Wess, Executive Dean, Charles Sturt University, Wagga Wagga, New South Wales, Australia

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.

Authors : Nigel Slater
Affiliations : Department of Chemical Engineering and Nanotechnology, University of Cambridge

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.

Authors : Rongjun Chen
Affiliations : Department of Chemical Engineering, Imperial College London, South Kensington Campus, London, SW7 2AZ, United Kingdom

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.

Authors : Aleksandra P. Dabkowska, Christopher Hirst, Meina Wang, Maria Vadeperas, Gunnar K. Pálsson, Luke Clifton, Justas Barauskas, Sofi Nöjd, Sebastian Lages, Nina-Juliane Steinke, Björgvin Hjörvarsson, Tommy Nylander,
Affiliations : Division of Physical Chemistry, Lund University, P.O. Box 124, SE-22100 Lund, Sweden and NanoLund, Lund University, P.O. Box 118, SE-22100 Lund, Sweden; Institut Laue Langevin, France and Department of Physics, Uppsala University, Box 530, S-751 21 Uppsala, Sweden; ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford Campus, Didcot, Oxfordshire, OX11 OQX, UK; Camurus AB, Ideon Science Park, Gamma Building, Sölvegatan 41, SE-22379 Lund, Sweden and Biomedical Science, Faculty of Health and Society, Malmö University, SE-20506, Malmö, Sweden; Division of Physical Chemistry, Lund University, P.O. Box 124, SE-22100 Lund, Sweden; Max IV Laboratory, Lund University, P.O. Box 118, SE-22100 Lund, Sweden; ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford Campus, Didcot, Oxfordshire, OX11 OQX, UK; Department of Physics, Uppsala University, Box 530, S-751 21 Uppsala, Sweden;Division of Physical Chemistry, Lund University, P.O. Box 124, SE-22100 Lund, Sweden

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.


No abstract for this day

Symposium organizers
Giovanni MARLETTAUniversity of Catania

Laboratory for Molecular Surfaces and Nanotechnology V.le A.Doria 6 Catania Italy

+39 95 7385130
Hai XUChina University of Petroleum

Centre for Bioengineering and Biotechnology 66 Changjiang West Road Huangdao Economic Development Zone Qingdao P.R. China

+86 532 86981318
Jian R. LUUniversity of Manchester

Biological Physics Lab, School of Physics and Astronomy Room 3.14, Schuster Building Oxford Road Manchester M13 9PL UK

+44 161 2003926
Nigel SLATERUniversity of Cambridge

Department of Chemical Engineering and Biotechnology Pembroke Street Cambridge CB2 3RA U.K.

+44 1223 762953
Tommy NYLANDERLund University

Physical Chemistry, Department of Chemistry PO Box 124 SE-221 00 Lund Sweden

+46 46 2228158