Preparation and and evaluation of Bletilla striata polysaccharide/carboxymethyl chitosan/Carbomer 940 hydrogel for wound healing

This study aims at developing an effective, safe and economic hydrogel, with wound healing ability, by making use of polysaccharides. Bletilla striata polysaccharide (Bsp) and the bioactive natural polymers, carboxymethyl chitosan (CMC), were physically blended with Carbomer 940 (CBM940) in order to promote gel-forming and improve water retention. FT-IR displayed hydrogen bonding between CBM940 and CMC played a role in physical gel formation. XRD showed broad and weak intensity peak of Bsp/CMC/CBM940 hydrogel. SEM, rheological measurement and water loss test revealed that the best hydrogel with optimum characteristics in relation to porous structure, elastic property and water retention could be obtained by mixing Bsp, CMC and CBM940 in a ratio of 4:1:1. In vitro studies proved that the Bsp/CMC/CBM940 hydrogel possessed blood compatibility. M293T cells viability was over 85% via MTT assay which revealed non-cytotoxicity. Hydroxyl radical scavenging property highly improved while Bsp combined with CMC. The full-thickness wound experiment illustrated 71.64 6.64% and 83.80 5.56% wound healing rates for Bsp4:CMC1:CBM9401 hydrogel on Day 7 and Day 14, respectively, which showed no significant differences (p> 0.05) in comparison to the positive control. Histological observation expressed epithelization, dense collagen fiber and neovascular formation in hydrogel group on Day 14. Bsp/CMC/CBM940 hydrogel can, hence, serve as an attractive candidate for healing wounds. (C) 2019 Published by Elsevier B.V.