Wound dressing with sustained anti-microbial capability

To overcome current limitations in wound dressings for treating mustard-bur n induced septic wound injuries, a nonadherent wound dressing with sustaine d anti-microbial capability has been developed. The wound dressing consists of two layers: the upper layer is a carboxymethyl-chitin hydrogel material , while the lower layer is an anti-microbial impregnated biomaterial, The h ydrogel layer acts as a mechanical and microbial barrier, and is capable of absorbing wound exudate. In physiological fluid, the carboxymethylated-chi tin hydrogel swells considerably, imbibing up to 4 times its own weight of water and is also highly porous to water vapor. The moisture permeability o f the dressing prevents the accumulation of fluid in heavily exudating woun ds seen in second-degree burns. The lower layer, fabricated from chitosan a cetate foam, is impregnated with chlorhexidine gluconate. From the in vitro release studies, the loading concentration was optimized to deliver suffic ient anti-microbial drug into the wound area to sustain the anti-microbial activity for 24 h. The anti-microbial activity of the dressing against Pseu domonas aeruginosa and Staphylococcus aureus was tested using the Bauer-Kir by Disk Diffusion Test. (C) 2000 John Wiley & Sons, Inc.