Synthesis and Potential Cytotoxicity Evaluation of Carboxymethyl Chitosan Hydrogels (original) (raw)
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Synthesis of Chitosan and Carboxymethyl Chitosan Hydrogels by Electron Beam Irradiation
Progress on Chemistry and Application of Chitin and its Derivatives, 2016
Solutions of chitosan (CS) and carboxymethyl chitosan (CMCS) were subjected to irradiation by electron beam in presence of a crosslinking agent (poly(ethylene glycol) diacrylate-PEGDA) in order to produce carboxymethyl chitosan-and chitosan-based hydrogels. PEGDA macromonomer itself undergoes simultaneous polymerization and crosslinking either in neutral water or in acidic medium. Acidic solutions of chitosan of 0.5, 1 and 2% can be effectively crosslinked with PEGDA to form a gel. Although CMCS undergoes radiation-initiated crosslinking only at high concentration in water (over 10%), the presence of PEGDA in solution facilitated hydrogel formation even at lower concentration of CMCS. Formation of CS and CMCS hydrogels required irradiation doses lower than those needed for sterilization, i.e. 25 kGy, in some cases even as low as 200 Gy. Sol-gel analysis revealed relatively high gel fraction of obtained hydrogels, up to 80%, and good swelling ability. Both parameters can be easily controlled by composition of the initial solution and irradiation dose. Possible mechanisms of crosslinking reactions were proposed, involving addition of the polysaccharide macroradicals to a terminal double bond of PEGDA.
Chitosan-containing hydrogel wound dressings prepared by radiation technique
Radiation Physics and Chemistry, 2017
The aim of the study was to develop an antimicrobial hydrogel wound dressing by means of radiation-initiated crosslinking of hydrophilic polymers, i.e. by well-established technology comprising gel manufacturing and its sterilization in one process. The approach included admixture of chitosan of relatively low molecular weight dissolved in lactic acid (LA) into the initial regular components of the conventional hydrogel dressing based on poly(N-vinyl pyrrolidone) (PVP) and agar. Molecular weight of chitosan was regulated by radiationinitiated degradation in the range of 39-132 kg mol-1. Optimum total concentration of LA in the resultant hydrogel dressing was evaluated as 0.05 mol dm-3 , that is ca. 0.5 %. Presence of LA in the system influenced essential radiation and technological parameters of hydrogel manufacturing. The setting temperature of the pre-hydrogel mixture, resulting from agar ability to congeal, was reduced with LA concentration, yet remained significantly above the room temperature. 0.5 % of chitosan was effectively dissolved in aqueous solution of lactic acid due to its pH (lower than 5.5). Radiation parameters of PVP crosslinking in the presence of LA, as determined with generalized Charlesby-Pinner equation, were reflected in slight reduction of the maximum gel fraction and increase in gelation dose and in the factor comparing yields of scission to crosslinking. Nevertheless, essentially physical characteristics of the hydrogel was not affected, except for somewhat increased water uptake capacity, what in turn improves functionality of the dressing as extensive exudate for the wound can be efficiently absorbed. Preliminary microbiological studies showed antimicrobial character of the chitosan-containing hydrogel towards Gram-positive bacterial strain.
We report on the successful preparation of wet dressings hydrogels based on Chitosan-Poly(N-Vinyl-Pyrrolidone)-Poly(ethylene glycol)-Poly(acrylic acid) and Poly(ethylene oxide) by e-beam cross-linking in weakly acidic media, to be used for rapid healing and pain release of infected skin wounds. The structure and compositions of hydrogels investigated according to sol-gel and swelling studies, network parameters, as well as FTIR and XPS analyses showed the efficient interaction of the hydrogel components upon irradiation, maintaining the bonding environment while the cross-linking degree increasing with the irradiation dose and the formation of a structure with the mesh size in the range 11-67 nm. Hydrogels with gel fraction above 85% and the best-swelling properties in different pH solutions were obtained for hydrogels produced with 15 kGy. The hydrogels are stable in the simulated physiological condition of an infected wound and show appropriate moisture retention capability and th...
Journal of Functional Biomaterials
Herein, three different recipes of multi-component hydrogels were synthesized by e-beam irradiation. These hydrogels were obtained from aqueous polymer mixtures in which different proportions of bovine collagen gel, sodium carboxymethylcellulose (CMC), poly(vinylpyrrolidone), chitosan, and poly(ethylene oxide) were used. The cross-linking reaction was carried out exclusively by e-beam cross-linking at 25 kGy, a dose of irradiation sufficient both to complete the cross-linking reaction and effective for hydrogel sterilization. The hydrogels developed in this study were tested in terms of physical and chemical stability, mechanical, structural, morphological, and biological properties. They are transparent, maintain their structure, are non-adhesive when handling, and most importantly, especially from the application point of view, have an elastic structure. Likewise, these hydrogels possessed different swelling degrees and expressed rheological behavior characteristic of soft solids ...
Hydrogels of polysaccharide derivatives crosslinked with irradiation at paste-like condition
Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, 2003
Polysaccharides such as cellulose, starch, chitin/chitosan and their water-soluble derivatives have been known as degradable type polymers under action of ionizing radiation. Recently, we found that water-soluble polysaccharides derivatives such as carboxymethylcellulose (CMC), carboxymethylstarch (CMS) and carboxymethylchitin (CMCT), carboxymethylchitosan (CMCTS) lead to radiation crosslinking at high concentrated aqueous solution (more than 10%, paste-like state). It was proved that the crosslinking was remarkably affected by their concentration. It was assumed that radiation formation of hydrogels of these polysaccharides derivatives were mainly due to the mobility of side chains. Side-chains radicals were formed mostly via indirect effects, by the abstraction of H atoms by the intermediate products of water radiolysis. Some important characteristics of these novel hydrogels were also investigated. These hydrogels exhibited good swelling in water and possess satisfying biodegradability. In addition, the antibacterial activity against E. coli was also found in CMCTS hydrogel.
Asian Journal of Chemical Sciences
Hydrogel which can swell rapidly and retain large volumes of water in their swollen structure have shown a significant contribution for wound healing. More recently, hydrogel synthesized by radiation polymerization and grafting have been reported which did not require any crosslinking agent. In this study, Crosslinked Poly ethylene oxide (PEO) / N, N-dimethylacrylamide (DMA) hydrogel containing chitosan for wound dressing has been prepared by gamma radiation technique. Chitosan solutions with different concentration (0.5-1.5%,10%) have been blended with 5% aqueous solution of Poly ethylene oxide, N, N-dimethylacrylamide and irradiated at the doses 5-20 kGy by gamma rays. The copolymers were characterized by Fourier transform infra-red spectroscopy and their physical chemical properties of hydrogels were evaluated in terms of gel fraction, swelling ratio, elongation at break and mechanical properties (tensile Strength). It was found that under maximum condition of incorporation 1% ch...
Radiation synthesis and characterization of nanosilver/gelatin/carboxymethyl chitosan hydrogel
Radiation Physics and Chemistry, 2012
A series of antibacterial hydrogels were fabricated from an aqueous solution of AgNO 3 , gelatin and carboxymethyl chitosan (CM-chitosan) by radiation-induced reduction and crosslinking at ambient temperature. The nanosilver particles were in situ synthesized accompanying with the formation of gelatin/CM-chitosan hydrogel. Transmission Electron Microscope and UV-vis analysis have verified the formation and homogeneous distribution of nanosilver particles in the hydrogel matrix. The nanosilver/ gelatin/CM-chitosan hydrogels possessed interconnected porous structure, had a compressive modulus of 44 to 56 kPa, and could absorb 62 to 108 times of deionized water to its dry weight. Furthermore, the hydrogels were found to have sound antibacterial effect on Escherichia coli (E. coli), and their antibacterial ability could be significantly enhanced by the increasing of AgNO 3 content. The comprehensive results of this study suggest that nanosilver/gelatin/CM-chitosan hydrogels have potential as an antibacterial wound dressing.
Philippine Journal of Science
Carboxymethyl κ-carrageenan (CMKC), with different degrees of substitution (DSs), were gamma-irradiated in viscous or paste solutions. Successfully synthezised chemically crosslinked hydrogels showed dependence on the DS, concentration, and radiation dose. The highest gel fraction was 76% exhibited by CMkC-3s hydrogel with a DS of 1.58. The hydrogels showed different swelling degrees in water and saline. Swelling behavior vs. time, in both solvents, corresponded to 2nd-order kinetics. The CMkC-3s at 20% concentration irradiated at 15 kGy had the highest water absorption of 334 g water/g dry gel. Selected hydrogels were evaluated for applications as wound dressing, as water retainer in sandy soil, and as metal adsorbent. As a wound dressing, CMkC-2s and CMkC-3s hydrogels exhibited considerable tensile strengths, abilities to absorb pseudo extracellular fluid, and extractables with pH/conductivity conducive for healing promotion. Also, the CMkC-3s hydrogel had no cytotoxic potential b...
Biological activity of radiation-induced collagen–polyvinylpyrrolidone–PEG hydrogels
Materials Letters, 2018
The synthesis of novel degradable hydrogels, with designable structures and good biocompatibility, produces attractive materials for use in connective tissue regeneration applications. However, the way in which human fibroblast cells respond to terpolymer hydrogels such as collagen-polyvinylpyrrolidonepolyethylene glycol (C-PVP-PEG) remains largely unknown. The aim of this study was to synthesize a gamma-radiation-induced C-PVP-PEG hydrogel and to evaluate its structure, morphology and cell viability in fibroblasts. Fourier transform infrared spectroscopy showed shifting of amide I to higher frequencies, as evidence of crosslinking produced by the radiation. The morphology of the hydrogel varied with the ratio of the polymers. We show a proposal for the mechanism of the hydrogel synthesis. The in vitro assessment of the hydrogels suggested that at 50 kGy, the presence of collagen decreased the cell viability for all samples, except for C-PVP. However, when PEG and PVP were added to the collagen, the cell's viability increased with respect to the irradiated collagen sample.