Development and characterization of chitosan membranes for wound dressing and drug controlled release / Desenvolvimento e caracterização de membranas de quitosana para recobrimento de feridas e liberação controlada de farmacos

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

Skin wounds treatment (burns, ulcers, surgical and diabetes wounds) is a world-wide problem that has been widely argued and studied due to the healing process complications, such as infections, septicemia and death. The skin is the interface of the human organism with the external environment and when this barrier is wounded, microorganism infections, as well as the loss of fluids and dehydration are possible consequences. Therefore, a wound dressing must be used to protect the wound from microorganisms invasion and loss of fluids, besides substituting functions of the lost skin. Commercially available wound dressings are mainly based on collagen. However, because of the high cost of this raw material, the search for new materiais for wound dressings has been continuous. Chitosan is a biopolymer derived from chitin, the most abundant polysaccharide found in nature after cellulose, found mainly in insects and crustaceans exoskeletons. Beyond biocompatible and biodegradable, chitosan also presents interesting biological properties, such as bactericidal, fungicidal, hemostatic, immune-adjuvant and anti-tumor activities. The process of chitosan production is economic and environmentally viable; since it uses fishing industry by-products a~ raw material. Thus, pure chitosan price is about 20 times cheaper than collagen one. For these reasons, chitosan has been widely studied and employed in the treatment of wounds like film, membrane, porous màtrix, gel and solution. Moreover, plasticizers cross linkers and other polymers are also used in association with chitosan to improve the obtained material properties. In this present work, chitosan membranes for wound dressing had been developed and characterized. The use of D-sorbitol as plasticizer and hexamethylene diisocyanate as cross-linker also was investigated. Moreover, chitosan based drug release systems based was developed and the releases of gentamicin and silver sulfadiazine were ín vítro evaluated. D-sorbitol revealed a good plasticizer for chitosan membranes: it improved mechanical properties and increased water vapor permeability. Moreover, it did not show direct and indirect cytotoxicity. Hexamethylene diisocyanate was previous/y blocked with sodium bisulfite to protect reactive groups and to increase chitosan cross linking reaction yield. Cross linked membranes had not shown cytotoxicity and had revealed to be efficient systems for controlled release of gentamicin and silver sulfadiazine

ASSUNTO(S)

membranas (tecnologia) tecnologia de liberação controlada controlled release chitosan wound dressing cicatrização de feridas membranes quitosana

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