Injectable chitosan hydrogels tailored with antibacterial and antioxidant dual functions for regenerative wound healing

Herein, an injectable self-healing hydrogel with inherent antibacterial activity was fabricated based on the dynamic covalent bond formation between boronic acid and catechol groups in quaternized chitosan as building blocks in conjunct with the in-situ encapsulation of epigallocatechin-3-gallate (EGCG, a green tea derivative). Benefiting from the catechol groups and therapeutic effect of EGCG, the resulting natural-based injectable hydrogels showed excellent antibacterial and antioxidant dual functions in preventing bacterial infection and scavenging radicals. The hydrogels loaded with EGCG also exhibited good biocompatibility along with contact-active antibacterial activity via a "capture and kill" strategy. The dynamic covalent bonding enables shear-thinning delivery of the gels via syringe, followed by rapid self-healing. Additionally, the in vivo wound healing evaluation in a full-thickness skin defect model revealed the appreciable and regenerative wound healing performance of the hydrogels, demonstrating their great potential as novel wound dressings for wound management.