Search results for "Chitosan"
showing 10 items of 195 documents
Structure and thermal properties of a chitosan coated polyethylene bilayer film
2012
The thermal and the structural properties of chitosan coated polyethylene (PE) films were studied. The coating process did not significantly influence the thermal stability and the PE surface structure and/or composition of the polyolefin. Dehydration temperature of chitosan films reflected the strength of water/acetic acid/chitosan chains interactions. Glycerol, used as a plasticizer, formed new hydrophilic centres in the film matrix. Moreover it was better integrated in the CSEGLY than in CSAGLY network. Besides, the addition of a plasticizer in the chitosan films decreased the film degradation temperature. There were two main steps for the PE chitosan coated films degradation. The first …
In vitrouptake of lysozyme-loaded liposomes coated with chitosan biopolymer as model immunoadjuvants
2009
Chitosan binds to negatively charged soy lecithin liposomes by an electrostatic interaction driven by its cationic amino group. This interaction allows developing stable coated vesicles suitable as a targeted carrier and controlled release system for drugs and vaccines. In this work, we studied the effect of chitosan-coated liposomes on the uptake and antigen presentation of hen egg-white lysozyme (HEL) in Peyer's patches peritoneal macrophages isolated from mice. Chitosan-coated liposomes were characterized according to size, zeta potential, and antigen-loading and release properties. Results showed an increase in the positive net charge and size of the liposomes as the concentration of ch…
Endothelialization of chitosan porous conduits via immobilization of a recombinant fibronectin fragment (rhFNIII7–10)
2013
Abstract The present study aimed to develop a pre-endothelialized chitosan (CH) porous hollowed scaffold for application in spinal cord regenerative therapies. CH conduits with different degrees of acetylation (DA; 4% and 15%) were prepared, characterized (microstructure, porosity and water uptake) and functionalized with a recombinant fragment of human fibronectin (rhFNIII 7–10 ). Immobilized rhFNIII 7–10 was characterized in terms of amount ( 125 I-radiolabelling), exposure of cell-binding domains (immunofluorescence) and ability to mediate endothelial cell (EC) adhesion and cytoskeletal rearrangement. Functionalized conduits revealed a linear increase in immobilized rhFNIII 7–10 with rhF…
Comparison between the effect of adding microhydroxyapatite and chitosan on surface roughness and Microhardness of resin modified and conventional gl…
2019
Background This study aimed to compare the effect of chitosan (CH) and hydroxyapatite (HP) on the surface roughness and microhardness of a conventional glass ionomer cement (CGIC) and a resin modified glass ionomer cement (RMGIC). Material and Methods 60 disk-shaped specimens (2mm x 6mm) were prepared in 6 groups; group I: CGIC, group II: RMGIC, group III: CGIC + 15% volume CH solution in liquid, group IV: CGIC +10% weight micro-HP in powder, group V: RMGIC + 15% volume CH, group VI: RMGIC + 10% weight micro-HP. After storage in deionized water at room temperature for 24 hours, the surface roughness and microhardness of the specimens were measured using a surface profilometer and Vickers mi…
Biomimetic chitosan-mediated synthesis in heterogeneous phase of bulk and mesoporous silica nanoparticles
2009
Both bulk and mesoporous silica nanoparticles can be obtained in the form of granular aggregates using chitosan flakes as additive under very soft biomimetic reaction conditions. Puchol Estors, Victoria, Victoria.Puchol@uv.es ; El Haskouri, Jamal, Jamal.Haskouri@uv.es ; Latorre Saborit, Julio, Julio.Latorre@uv.es ; Beltran Porter, Aurelio, Aurelio.Beltran@uv.es ; Beltran Porter, Daniel, Daniel.Beltran@uv.es ; Amoros del Toro, Pedro Jose, Pedro.Amoros@uv.es
Chitosan-based smart hybrid materials: a physico-chemical perspective.
2020
Chitosan is one of the most studied cationic polysaccharides. Due to its unique characteristics of being water soluble, biocompatible, biodegradable, and non-toxic, this macromolecule is highly attractive for a broad range of applications. In addition, its complex behavior and the number of ways it interacts with different components in a system result in an astonishing variety of chitosan-based materials. Herein, we present recent advances in the field of chitosan-based materials from a physico-chemical perspective, with focus on aqueous mixtures with oppositely charged colloids, chitosan-based thin films, and nanocomposite systems. In this review, we focus our attention on the physico-che…
Kinetics and isotherm of fibronectin adsorption to three-dimensional porous chitosan scaffolds explored by125I-radiolabelling
2013
In this study, 125I-radiolabelling was explored to follow the kinetics and isotherm of fibronectin (FN) adsorption to porous polymeric scaffolds, as well as to assess the elution and exchangeability of pre-adsorbed FN following incubation in serum-containing culture medium. Chitosan (CH) porous scaffolds with two different degrees of acetylation (DA 4% and 15%) were incubated in FN solutions with concentrations ranging from 5 to 50 µg/mL. The kinetic and isotherm of FN adsorption to CH were successfully followed using 125I-FN as a tracer molecule. While on DA 4% the levels of adsorbed FN increased linearly with FN solution concentration, on DA 15% a saturation plateau was attained, and FN a…
Dependence of the Optical Constant Parameters of p-Toluene Sulfonic Acid-Doped Polyaniline and Its Composites on Dispersion Solvents
2020
The optical constants of Para-Toluene sulfonic acid-doped polyaniline (PANI), PANIchitosan composites, PANI-reduced graphene-oxide composites and a ternary composite comprising of PANI, chitosan and reduced graphene-oxide dispersed in diluted p-toluene sulfonic acid (PTSA) solution and N-Methyl-2-Pyrrolidone (NMP) solvent have been evaluated and compared. The optical constant values were extracted from the absorbance spectra of thin layers of the respective samples. The potential utilization of the materials as the active sensing materials of surface plasmon resonance biosensors has also been assessed in terms of the estimated value of the penetration depth through a dielectric medium. The …
Effect of relative humidity on carvacrol release and permeation properties of chitosan based films and coating
2014
International audience; The influence of water vapour conditions on mass transport and barrier properties of chitosan based films and coatings were studied in relation to surface and structural properties. Water contact angles, material swelling, polymer degradation temperature, barrier properties (PO2, PCO2, WVP) and aroma diffusion coefficients were determined. The solvent nature and the presence of carvacrol influenced the surface and structural properties and then the barrier performance of activated chitosan films. Increasing RH from 0% to 100% led to a significant increase in material swelling. The plasticization effect of water was more pronounced at high humid environment, while at …
Surface, mechanical and barrier properties of bio-based composite films based on chitosan and whey protein
2014
Mono-component and composite bilayer and blend films composed of chitosan and whey protein were made. Colour, microstructure, water contact angles, swelling, water vapour sorption, barrier properties (oxygen, water vapour), water vapour diffusion coefficients and mechanical properties were determined. The influence of water vapour on barrier properties was studied in relation to the surface and structural properties. Mono-component and bilayer films were transparent with a homogeneous surface. Contrarily, blend films were translucent. Bilayer films had significantly lower water vapour permeability in comparison to mono-component and blend films. In all bilayer films, the air side (chitosan)…