Self-healing, adhesive, antibacterial, and biocompatible hydrogel dressings using sialic acid substituted chitosan and oxidized pullulan with incorporation of epigallocatechin gallate

Abstract

The development of innovative therapeutic strategies is highly desired for wound regeneration. In this study, sialic acid substituted chitosan (CS-SA) was reacted with oxidized pullulan (OPL) via Schiff base links to obtain functional CS-SA/OPL hydrogels, into which the polyphenol epigallocatechin gallate (EGCG) was in situ incorporated. The prepared hydrogels exhibited interconnected porous structure and good water absorption ability (over 37 g/g). Furthermore, the CS-SA/OPL hydrogels performed excellent self-healing and adhesive properties. With the incorporation of EGCG, the antibacterial effects against E. coli and S. aureus, as well as antioxidative activity, were significantly improved. In addition, in vitro L-929 cell experiments confirmed that cell viability and cell immigration could be significantly improved with the incorporation of EGCG in CS-SA/OPL hydrogels. Based on the above results, hydrogels possess a promising potential as wound dressings in wound healing applications.