Chitin nanofibrils/chitosan glycolate composites as wound medicaments

Highly crystalline chitin nanofibrils were isolated from crustacean chitin and characterized by X-ray diffraction and FT-infrared spectrometry. A novel formulation including chitin nanofibrils, chitosan glycolate, and chlorhexidine was manufactured in three presentations: spray, gel, and gauze. The latter included non-woven dibutyryl chitin as a biocompatible support. The products were tested in murine wound models, with phytostimuline-medicated wounds as controls, in two series of experiments, one of which included a concomitant laser treatment capable to activate cells. The gauze consistently induced better epithelial differentiation and keratinization, and better reorganization of the basal lamina. The angiogenetic response induced by the gauze was indicative of satisfactory vascular trophism irrespective of the laser treatment. Immunohistochemical observations showed that the actin cytoskeleton of dermal and epidermal cells was well formed. The gauze was used to treat 75 patients hospitalized for a variety of traumatic wounds with good results in all cases. A single dressing could be kept on site for at least four days, and the healing took place within periods of time similar to those reported for traditional dressings under comparable conditions; in no case secondary infections developed. In conclusion, the spray could be used as a first-aid tool on bleeding abrasions; the gel enhanced physiological repair and was recommended for areas with thin epidermal layers, and the gauze was found to be superior to other dressings insofar as no scar remained. A laser treatment could optionally be applied. The biochemical significance of the chitin/chitosan products was found to accompany their commercial viability in terms of time of healing and clinical labor costs. (c) 2007 Elsevier Ltd. All rights reserved.