Thiolated chitosan/glycosaminoglycans multilayered films : QCM-D study on the films formation and their biological properties (original) (raw)
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Layer by Layer Buildup of Polysaccharide Films: Physical Chemistry and Cellular Adhesion Aspects
Langmuir, 2004
The formation of polysaccharide films based on the alternate deposition of chitosan (CHI) and hyaluronan (HA) was investigated by several techniques. The multilayer buildup takes place in two stages: during the first stage, the surface is covered by isolated islets that grow and coalesce as the construction goes on. After several deposition steps, a continuous film is formed and the second stage of the buildup process takes place. The whole process is characterized by an exponential increase of the mass and thickness of the film with the number of deposition steps. This exponential growth mechanism is related to the ability of the polycation to diffuse "in" and "out" of the whole film at each deposition step. Using confocal laser microscopy and fluorescently labeled CHI, we show that such a diffusion behavior, already observed with poly(Llysine) as a polycation, is also found with CHI, a polycation presenting a large persistence length. We also analyze the effect of the molecular weight (MW) of the diffusing polyelectrolyte (CHI) on the buildup process and observe a faster growth for low MW chitosan. The influence of the salt concentration during buildup is also investigated. Whereas the CHI/HA films grow rapidly at high salt concentration (0.15 M NaCl) with the formation of a uniform film after only a few deposition steps, it is very difficult to build the film at 10 -4 M NaCl. In this latter case, the deposited mass increases linearly with the number of deposition steps and the first deposition stage, where the surface is covered by islets, lasts at least up to 50 bilayer deposition steps. However, even at these low salt concentrations and in the islet configuration, CHI chains seem to diffuse in and out of the CHI/HA complexes. The linear mass increase of the film with the number of deposition steps despite the CHI diffusion is explained by a partial redissolution of the CHI/HA complexes forming the film during different steps of the buildup process. Finally, the uniform films built at high salt concentrations were also found to be chondrocyte resistant and, more interestingly, bacterial resistant. Therefore, the (CHI/HA) films may be used as an antimicrobial coating.
Among the synthetic polymers, polyurethanes are one of the most important polymers applied in Tissue Engineering (TE). Their segmented block structure enables the control of different properties, such as, biocompatibility, blood compatibility, mechanical properties and also biodegradability. In this work, polyurethane membranes were obtained using the electrospinning apparatus. Fibroblasts cells were seeded on the membrane and the morphology, structure and cell adhesion and proliferation were studied using Scanning Electron Microscopy (SEM). Finally, the degradation behavior of the membranes was investigated by in vitro degradation studies. SEM results showed that the membrane presents high porosity, high surface area:volume ratio, it was observed a random fiber network. In vitro evaluation of fibroblasts cells showed that fibroblasts adhered and spread over the membrane surface and in vitro degradation study showed that the developed membrane can be considered a non-degradable polyurethane. This study supports further investigations of electrospun membranes as long-term devices for TE applications.
Sh.Adila et al 2013 Chitosan film
This study aims to evaluate the influence of solvent acids and glycerol as plasticizer on the antimicrobial and physical properties of chitosan films. Three types of acids were used in the same concentration, e.g. 1% acetic acid, 1% citric acid and 1% lactic acid whereas glycerol was fixed on 10% (w/w). In terms of barrier properties, chitosan film obtained by citric acid as solvent showed the lowest water vapour transmission rate (WVTR) followed by chitosan film prepared with lactic acid and acetic acid. Concerning mechanical properties, chitosan film prepared with acetic acid exhibited the highest tensile strength and the lowest percentage elongation. The expected result was obtained where plasticized chitosan films had higher percentage elongation than the unplasticized one. In this study, disc and well diffusion method were used against bacteria, yeast and fungi to characterize antimicrobial activity of the obtained films. When the disc diffusion method was used, all of chitosan films showed an inhibition activity against E. coli, B. cereus and S. aureus whereas no inhibition against Penicillium sp. and Candida sp except chitosan film prepared with acetic acid that showed inhibition against Candida sp. The same result was observed by using well diffusion method with the exception of chitosan solutions prepared with acetic acid solution where they also showed inhibition activity against Penicillium sp. and Candida sp.
Innovative Food Science & Emerging Technologies, 2015
This study was developed with the purpose to investigate the effect of polysaccharide/plasticiser concentration on the microstructure and molecular dynamics of polymeric film systems, using transmission electron microscope imaging (TEM) and nuclear magnetic resonance (NMR) techniques. Experiments were carried out in chitosan/glycerol films prepared with solutions of different composition. The films obtained after drying and equilibration were characterised in terms of composition, thickness and water activity.
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Novel Blend for Producing Porous Chitosan-Based Films Suitable for Biomedical Applications
Membranes
In this work, a chitosan-gelatin-ferulic acid blend was used in different ratios for preparing novel films that can be used in biomedical applications. Both acetic and formic acid were tested as solvents for the chitosan-gelatin-ferulic acid blend. Glycerol was tested as a plasticizer. The thickness, mechanical strength, static water contact angle and water uptake of the prepared films were determined. Also, the prepared films were characterized using different analysis techniques such as Fourier transform infrared spectroscopy (FT-IR) analysis, X-ray diffraction (XRD), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Acetic acid produced continuous compact surfaces that are not recommended for testing in biomedical applications. The plasticized chitosan-gelatin-ferulic acid blend, using formic acid solvent, produced novel hexagonal porous films with a pore size of around 10-14 µm. This blend is recommended for preparing films (scaffolds) for testing in biomedical applications as it has the advantage of a decreased thickness.
Functional properties of chitosan films modified by snail mucus extract
International Journal of Biological Macromolecules, 2019
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Journal of Materials Chemistry, 2012
Multilayered polyelectrolyte coatings comprising thiolated chitosan (TC) and glycosaminoglycans (GAGs), chondroitin sulphate and hyaluronic acid, were built using a layer-by-layer approach. The surface activity of these coatings for binding and inhibition of enzymes related to chronic inflammation, such as collagenase and myeloperoxidase, was assessed. The build-up of five bi-layers of TC/GAGs onto gold surfaces was monitored in situ by QCM-D. All experimental groups showed exponential growth of the coatings controlled by the degree of chitosan thiolation and the molecular weight of the GAGs. The degree of chitosan modification was also the key parameter influencing the enzyme activity: increasing the thiols content led to more efficient myeloperoxidase inhibition and was inversely proportional to the adsorption of collagenase. Enhanced fibroblast attachment and proliferation were observed when the multilayered polyelectrolyte constructs terminated with GAGs. The possibility to control either the activity of major wound enzymes by the thiolation degree of the coating or the cell adhesion and proliferation by proper selection of the ultimate layer makes these materials potentially useful in chronic wounds treatment and dermal tissue regeneration.
Novel biocompatible chitosan based multilayer films
2011
The formation of novel biocompatible multilayer films by the interactions between complementary polyelectrolytes, on planar surfaces, by layer-by-layer self-assembly, was studied. For this purpose, chitosan and two polyanions, poly(acrylic acid) and poly(2-acrylamido-2-methyl propanesulfonic acid co acrylic acid), were used. To get a direct image on the polyelectrolyte multilayers formation and properties, infrared spectroscopy, gravimetry and atomic force microscopy have been used. A special attention was paid to the responsiveness of the new biocomposite materials to the pH of the environment. Thanks to biocompatibility properties of CS and polyanions used in this study, these multilayer films may be potentially useful for biomedical and environmental protection applications.