Preparation, characterization and evaluation of glycerol plasticized chitosan/PVA blends for burn wounds.

Chitosan like natural polymers have been widely used in burn wound management. Novel low molecular weight chitosan-PVA soft membranes have been studied for antibacterial and wound healing properties. The effectiveness of antibacterial activity was carried against bacterial pathogens while wound healing nature of chitosan was conducted in second degree burns on rabbits as model animal. Rabbits were divided into three groups; control untreated, treated with commercial Fusidic acid (Fu-A) cream and chitosan-PVA membranes. Low molecular weight chitosan showed significant antibacterial property towards bacterial pathogens. Wound healing experiments on second degree burn exhibited chitosan as significant wound healing agent for wound dressings. In morphological studies, normal growth of epidermis was observed and chitosan exhibited more effective for wound healing. Morphological studies also showed that chitosan wound dressings accelerated the granule and fibrous connective tissues formation. Physical characteristics of chitosan-PVA membranes were evaluated by water uptake capacity, SEM analysis, mechanical and water barrier studies.

Chitosan: A potential biopolymer for wound management.

It has been seen that slow healing and non-healing wounds conditions are treatable but still challenging to humans. Wound dressing usually seeks for biocompatible and biodegradable recipe. Natural polysaccharides like chitosan have been examined for its antimicrobial and healing properties on the basis of its variation in molecular weight and degree of deacetylation. Chitosan adopts some vital characteristics for treatment of various kinds of wounds which include its bonding nature, antifungal, bactericidal and permeability to oxygen. Chitosan therefore has been modified into various forms for the treatment of wounds and burns. The purpose of this review article is to understand the exploitation of chitosan and its derivatives as wound dressings. This article will also provide a concise insight on the properties of chitosan necessary for skin healing and regeneration, particularly highlighting the emerging role of chitosan films as next generation skin substitutes for the treatment of full thickness wounds.

Bioactivity of Variant Molecular Weight Chitosan Against Drug-Resistant Bacteria Isolated from Human Wounds.

Chitosan available from crab shells is usually of high molecular weight which may result in reduced efficiency for its antibacterial activity. One of the techniques for improving chitosan antibacterial efficiency is reducing its molecular weight. The irradiation of chitosan by gamma radiations is considered to be one of the most effective and widely used methods for improving its antibacterial activity. Chitosan obtained from crab shells was irradiated with gamma radiations at different doses, and effects on chitosan were analyzed by molecular weight determination and Fourier Transform Infrared spectroscopy. Unirradiated and irradiated chitosans were studied for their antibacterial properties against bacterial pathogens, that is, Pseudomonas aeruginosa (SS29), Escherichia coli (SS2, SS9), Proteus mirabilis (SS77), and Staphylococcus aureus (LM15). Studies have shown that irradiation has significantly developed and improved the antibacterial activity of crab shell chitosan. A correlation was found between bacterial metabolites and antibacterial activity by the analysis for 4-hydroxy-2-alkylquinolines and related metabolites of P. aeruginosa (SS29) in the absence and presence of chitosan by liquid chromatography mass spectrometer, exhibiting the suppression of these virulence factors due to chitosan. Antibacterial efficiency of chitosan was found to be molecular weight dependent and applied concentration of the chitosan. The findings suggest on the use of low-molecular weight chitosan as antibacterial agent in pharmaceutical preparations.

Characterization and potential applications of gamma irradiated chitosan and its blends with poly(vinyl alcohol).

Naturally available chitosan (CHI), of high molecular weight, results in reduced efficiency of these polymers for antibacterial activity. In this regard, irradiation is a widely used method for achieving reduction in molecular weight of polymers, which may improve some of its characteristics. Chitosan was extracted from crab shells and degraded by gamma radiations. Effect of radiation dose on chitosan was analyzed by Fourier transform infrared (FTIR) spectroscopy. Furthermore, the irradiated chitosan was blended with poly(vinyl alcohol) (PVA) and crosslinked with tetraethylorthosilicate (TEOS) into membranes. The membranes were found to be smooth, transparent and macroporous in structure, exhibiting high tensile strength (TS: 27-47 MPa) and elongation at break (EB: 292.6-407.3%). The effect of molecular weight of chitosan and chitosan blends on antibacterial activity was determined. Irradiated low molecular weight chitosan and membranes showed strong antibacterial activity against Escherichia coli and Bacillus subtilis.