Enhanced antibacterial and wound healing activities of microporous chitosan-Ag/ZnO composite dressing

Nano Ag/ZnO hybrid material has been considered to be a promising nanocomposites for biomedical application because it has enhanced antibacterial activity and low cytotoxicity. Here a sponge-like nano Ag/ZnO-loaded chitosan composite dressing was first synthesized via preparing a chitosan sponge by lyophilization process, followed by the incorporation of Ag/ZnO nanocomposites into chitosan sponge. The porosity, swelling, blood clotting and in vitro antibacterial activity against drug-sensitive and drug resistant pathogenic bacteria were evaluated. The results demonstrate that the prepared composite dressing shows high porosity and swelling as well as enhanced blood clotting and antibacterial activity. Cytocompatibility test evaluated in vitro illustrates the very low toxic nature of the composite dressing. Furthermore, the in vivo evaluation in mice reveals that the chitosan-Ag/ZnO composite dressing enhances the wound healing and promotes re-epithelialization and collagen deposition. These results strongly support the possibility of using this novel chitosan-AgZnO composite dressing for wound care application. (C) 2016 Elsevier Ltd. All rights reserved.