Preparation and characterization of ?chitin whisker - reinforced [beta]-chitin nanocomposite films for wound healing application

Abstract

Chitin-based nanocomposite films, chitin films incorporated with various contents of chitin whisker, were prepared by solution casting technique. To facilitate chitin dissolution in formic acid, chitin gel was firstly prepared by dissolving chitin in concentrated sodium hydroxide solution and then dialyzing alkaline chitin solution against distilled water until neutral. Chitin gel, obtained as precipitate in dialysis bag, was easily dissolved in formic acid and clear chitin solution was obtained. Chitin whisker, prepared from acid hydrolysis of chitin, was dispersed in chitin solution before casting. Chitin whisker contents in the nanocomposite films were varied form 0 to 2% (w/v). The chitin film was transparent whereas the nanocomposite films became more translucent as the chitin whisker contents increased. By the addition of chitin whisker, the nanocomposite films had higher thermal stability and better mechanical properties than those of chitin film. The maximum tensile strength was obtained for the nanocomposite films with 1% (w/v) whisker content. The biodegradability of the nanocomposite films was investigated by using lysozyme. The percentage of weight loss after enzymatic hydrolysis for seven days decreased wthi increasing of chitin whisker contents. Oxygen permeability of films reduced as the increase in chitin whisker content. The cytotoxicity of the nanocomposite films was determined by indirect method using MTT assay and L929 cultured. The nanocomposite films were non-toxic with L929 mouse fibroblasts.