Evaluation of healing activity of PVA/chitosan hydrogels on deep second degree burn: pharmacological and toxicological tests.

Hydrogel based on poly(vinyl alcohol) containing 0.25% of chitosan was synthesized by gamma irradiation and evaluated as wound dressing material in a burn rat model. Histological analyses, Primary Irritation Index (P.I.I.) and Ocular Irritation Index (O.I.I.) were investigated. The comparative study showed that the wounds treated with PVA/chitosan hydrogel healed on the 9th day, while those treated with paraffin gauze dressing and cotton gauze healed on the 16th day. Histological analysis showed that new granulation tissue and epithelialization progressed better in wound treated with hydrogel PVA/chitosan. The determined values of P.I.I. and O.I.I. of the PVA/chitosan hydrogel were, respectively 0.5 and zero. These values indicate that the PVA/chitosan hydrogel can be considered as non-irritating to the skin.