Thermal, Morphological and Antibacterial Properties of Chitosan Grafted Silk Fibre Reinforced PVA Films

This study focuses on chemically modifying the surface of silk fibre using an anhydride and grafting the polysaccharide chitosan onto the fibre via an acyl bridge and thereby fabricate composite films of poly(vinyl alcohol) (PVA) reinforced with the grafted silk. Chitosan was grafted on to the silk fibre by forming an acyl bridge over the fibre surface. Acylation of the fibre was performed using succinic anhydride. Acylation provides an enhanced surface for grafting chitosan on silk, thus enhancing its antibacterial and anti fungal properties making it a potential candidate for biomedical applications. The chitosan grafted silk fibre was further finely incised into minute particles and then used for synthesizing the films. The films were fabricated by varying the weight ratios of grafted silk and PVA by film casting technique and further evaluated for thermal, morphological and biological properties. Thermal stability of the films improved on increasing the fibre concentration. Moreover, grafting of Chitosan onto silk was confirmed by IR and SEM. The presence of foreign particles firmly attached onto the surface of the fibre was revealed by SEM. Furthermore, the films were subjected to antimicrobial tests and showed significant activity against the bacterial strains S. aureus and E. coli. Fabrication of such biodegradable and biocompatible films may possibly be promising materials for wound healing applications. (C) 2018 Elsevier Ltd. All rights reserved.