Flexible and micro porous chitinous nanocomposite bandages for wound dressing

Abstract

Current wound dressings have disadvantages such as less flexibility, poor mechanical strength, lack of porosity and a tendency to adhere onto the wound surface; in addition, a majority of the dressings lack antibacterial activity. To overcome these hassles, hydrogel-based wound dressings are designed to provide a moist environment which imparts cooling sensation, as well as act as a barrier to microbes. We have developed hydrogels by using and#945;-chitin, and#946;-chitin and chitosan. Using these hydrogels we developed flexible and microporous composite bandages by incorporating ZnO nanoparticles (nZnO) into it. The prepared nanocomposite bandages were characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometry (XRD), and scanning electron microscopy (SEM). In addition, swelling, degradation, blood clotting, antibacterial activity, antifungal activity, cytocompatibility, cell attachment on the material and cell infiltration into the composite bandages were evaluated. The nanocomposite bandage showed enhanced swelling, blood clotting, antifungal and antibacterial activity. Cytocompatibility of the composite bandages have been analyzed using normal human dermal fibroblast cells. Cell attachment and infiltration studies showed that cells were attached on to the nanocomposite bandages and penetrated into its interior. Furthermore, the in vivo evaluations of and#946;-chitin hydrogel/nZnO and chitosan hydrogel/nZnO composite bandages in Sprague-Dawley rats revealed that these nanocomposite bandages enhanced the wound healing and helped in faster re-epithelialization and collagen deposition. The wounds treated with the prepared composite bandages showed the development of intact epidermis and complete re-epithelial layer formation compared to the control wounds. The in vivo antibacterial evaluation proved the antibacterial potential of the prepared bandages by markedly reducing bacterial growth.