Synergistic influence of topomimetic and chondroitin sulfate-based treatments on osteogenic potential of Ti-6Al-4V

International audienceWe combined topographical and chemical surface modifications of Ti-6Al-4V (TA6V) to improve its osteogenic potential. By acid-etching, we first generated topomimetic surface features resembling, in size and roughness, bone cavities left by osteoclasts. Next, we coated these surfaces with biomimetic Layer-by-Layer films (LbL), composed of chon-droitin sulfate A and poly-L-lysine that were mechanically tuned after a post-treatment with genipin. The structural impact of each surface processing step was thoroughly inspected. The desired nano/microrough topographies of TA6V were maintained upon LbL deposition. Whereas no significant promotion of adhesion and proliferation of MC3T3-E1 preosteoblasts were detected after independent or combined modifications of the topography and the chemical composition of the substrates, osteogenic maturation was promoted when both surface treatments were combined, as was evi-denced by significant long-term matrix mineralization. The results open promising route toward improved osseointegra-tion of titanium-based implants. V C 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 00B:000-000, 2016

Silver nanoparticle embedded copper oxide as an efficient core–shell for the catalytic reduction of 4-nitrophenol and antibacterial activity improvement

International audienc

Iron-loaded amine/thiol functionalized polyester fibers with high catalytic activities: a comparative study

International audienc

Hyaluronan‐based hydrogels as versatile tumor‐like models: Tunable ECM and stiffness with genipin‐crosslinking

International audienc

Mechano-chemical control of cell behaviour by elastomer templates coated with biomimetic Layer-by-Layer nanofilms

International audienceWithin the field of biomaterials, the control of cell-surface interactions is generally addressed through surface chemistry modification. In this respect, Layer-by-Layer (LbL) coatings constitute promising versatile tools. Most cells are mechanosensitive, therefore the stiffness of their microenvironment should also be considered as a crucial parameter when designing polymer-based biomaterials. Here, we report on the combination of mechanics and surface chemistry of LbL-treated polydimethylsiloxane substrates of tunable stiffness to control cell behaviour. Biomimetic LbL films consist of poly-L-lysine (PLL) and chondroitin-4-sulfate (CSA). Stiffness, surface chemistry, wettability and topography of bare and LbL-treated polydimethylsiloxane were analysed. We demonstrated that cells adhered and grew up on all the substrates with significant promotive effects of PLL-terminated films and stiffer substrates. Pre-osteoblasts differentiation was enhanced onto PLL-terminated films irrespective of stiffness and onto CSA-terminated films in a mechanical dependent manner. These results open outlooks within the field of bone tissue engineering, as they demonstrate that osteoconductive surfaces can be obtained by combining uncrosslinked biomimetic LbL films and the intrinsic mechanical properties of the substrates, that is, without any commonly used, potentially cytotoxic chemical crosslinking

Development of new multifunctional filter based nonwovens for organics pollutants reduction and detoxification: High catalytic and antibacterial activities

International audienc

Polyester-supported Chitosan-Poly(vinylidene fluoride)-Inorganic-Oxide-Nanoparticles Composites with Improved Flame Retardancy and Thermal Stability

International audiencePolyester (PET) was pre-activated by atmospheric air plasma and coated by various inorganic oxide nanoparticles (MOx) such as titanium dioxide (TiO2), zinc oxide (ZnO), and silicon oxide (SiO2), using poly(vinylidene fluoride) (PVDF) and chitosan (CT) as binders. The resulting PET-PVDF-MOx-CT composites were thermally compressed and then characterized by scanning electron microscopy, Fourier infrared spectroscopy, thermal gravimetric analysis, and flame retardancy (FR) ability tests. PET modifications resulted in more thermally stable and less harmful composites with weaker hazardous gas release. This was explained in terms of structure compaction that blocks pyrolysis gas emissions. CT incorporation was found to reduce the material susceptibility to oxidation. This judicious procedure also allowed improving flame retardancy ability, by lengthening the combustion delay and slowing the flame propagation. Chitosan also turned out to contribute to a possible synergy with the other polymers present in the synthesized materials. These results provide valuable data that allow understanding the FR phenomena and envisaging low-cost high FR materials from biodegradable raw materials

Preparation of a novel composite based polyester nonwovens with high mechanical resistance and wash fastness properties

International audienceIn this work, polyester fiber (PET) were functionalized by oxides (Ox) like titanium dioxide (TiO2), zinc oxide (ZnO) and silicon dioxide (SiO2), using polyvinylidene fluoride (PVDF) as binder to obtain a PET-PVDF-Ox material. Chitosan polymer (CT) was further grafted as coating layer to improve the surface compatibility, resulting in the PET-PVDF-Ox-CT composite. The obtained products were thermally pressed and fully characterized. The chemical coatings, physical and thermal properties were investigated. It was found that coated PET nonwoven is highly hydrophobic materials with good diffusion resistance. Incorporation of TiO2, ZnO and SiO2 resulted in the formation of strong cross-linked CT network, producing improved dripping resistance of PET nonwoven. In addition, the modification steps allowed increasing significantly the mechanical resistance. This was explained in terms of improved surface compatibly and interfacial bonding occurred in the matrix. Moreover, soil release tests confirmed the high durability against washing for PET-PVDF-Ox-CT composite. This work allowed developing a facile process for the fabrication of new composite based nonwovens with satisfactory durability and high mechanical resistance

functional agrowaste for CO2 capture

International audienceThis paper presents for the first time surface functionalization of cocoa shells (CS) through the covalent grafting of 3-aminopropyltriethoxysilane (APTES) followed by the substitution of poly(dimethylsiloxane) (PDMS) and in situ generation/insertion of cobalt nanoparticles (Co-NP). The immobilization and stability of APTES–PDMS on cocoa shell were confirmed by Fourier transform infrared spectroscopy and differential scanning calorimetry. Morphological analyses by scanning electron microscopy demonstrated that Co-NPs successfully grew on the surface of CS–APTES–PDMS. The CO2-adsorption capacity of these new materials was examined at ambient conditions. Both CS–APTES–PDMS and CS–APTES–PDMS–Co showed increased CO2 adsorption capacities as compared to unmodified cocoa shell. This enhancement was explained by the synergetic behavior of the silane derivate, PDMS grafting, and Co-NP incorporation for CO2 adsorption. This work represents a new step toward using cocoa shell as an excellent low-cost candidate for a variety of environmental applications such as CO2 storage at ambient temperature

Development of new composite fibers with excellent UV radiation protection

International audienceThis work reports the design and functionalization of new composite-based polyethylene terephthalate (PET) fibers with high anti UV radiation. Polyethylene terephthalate fibrous nonwovens were coated by materials oxides (MOx) like titanium dioxide (TiO2), zinc oxide (ZnO) and silicon dioxide (SiO2). Chitosan (CT) and polyvinylidene fluoride (PVDF) polymers were used to ensure the good surface compatibility of the resulting composite PET-PVDF-MOx-CT. These composites were fully characterized and the chemical coatings, surface modification, physical and thermal properties were investigated. Incorporation of materials oxides resulted in the formation of strong cross-linked chitosan network. The developed modification on PET nonwovens allows to highly reducing the UV radiation with an excellent blocking rate and a good UV protection factor (80.5–113.4). An outline mechanism is proposed for the UV protection. This was explained by the surface compatibly and the interfacial bonding occurred in the matrix. Regarding to the above results, the current work developed a facile process for the production of advanced materials based nonwovens with excellent UV blocking