Use of modified superabsorbent polymer dressings for protease modulation in improved chronic wound care.

UNLABELLED:  With more than 6 million patients affected with them in the United States, chronic ulcers represent one of the greatest problems in wound care. High levels of corrosive proteases, particularly matrix metalloproteinases (MMPs), within the wound environment are thoughtto contribute to the persistence of these wounds through denaturation of connective tissue proteins crucial to healing progression. Therefore, there is considerable interest in protease modulation using wound dressings to promote healing in chronic wounds. Such modulation could be achieved by direct absorption of proteases, by depleting co- factors within the wound, or by release of protease inhibitors. METHOD: The aim of this study is to examine protease modulation of a range of dressings with different chemistries, particularly those having demonstrated efficacy in chronic wound healing. RESULTS: XTRASORB® HCS (dressing A) and XTRASORB® Foam (dressing B) were able to modulate proteases by both direct absorption of MMPs and depleting metal ion co-factors, and resulted in complete elimination of protease activity in the assay used. Duoderm® (dressing C) was able to modulate proteases by direct absorption only, and not by co-factor depletion. Promogran® (dressing D) was able to reduce MMP activity, but this was shown to be pH dependant, with any protease modulation being lost at neutral pH. Neither Allevyn® (dressing E) nor Vigilon® (dressing F) were able to modulate proteases by any mechanism. None of the protease modulating dressings acted through the release of protease inhibitors. CONCLUSION: Of the dressings studied, dressing A and dressing B were the most effective protease modulators due to their acting through 2 separate mechanisms. .