Polydopamine modified multifunctional carboxymethyl chitosan/pectin hydrogel loaded with recombinant human epidermal growth factor for diabetic wound healing.

The development of a multifunctional wound dressing that can adapt to the shape of wounds and provide controlled drug release is crucial for diabetic patients. This study developed a carboxymethyl chitosan-based hydrogel dressing with enhanced mechanical properties and tissue adherence that were achieved by incorporating pectin (PE) and polydopamine (PDA) and loading the hydrogel with recombinant human epidermal growth factor (rhEGF). This EGF@PDA-CMCS-PE hydrogel demonstrated robust tissue adhesion, enhanced mechanical properties, and superior water retention and vapor permeability. It also exhibited significant antioxidant capacity. The results showed that EGF@PDA-CMCS-PE could effectively scavenge 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate)， (1,1-diphenyl-2-picrylhydrazyl), and superoxide anions and increase superoxide dismutase and catalase levels in vivo. In vitro cytotoxicity and antibacterial assays showed good biocompatibility and antimicrobial properties. The sustained release of EGF by the hydrogel was confirmed, with a gradual release profile over 120 h. In vivo studies in diabetic mice showed that the hydrogel significantly accelerated wound healing, with a wound contraction rate of 97.84% by day 14. Histopathological analysis revealed that the hydrogel promoted fibroblast proliferation, neovascularization, and orderly connective tissue formation, leading to a more uniform and compact wound-healing process. Thus, EGF@PDA-CMCS-PE hydrogel presents a promising tool for managing chronic diabetic wounds, offering a valuable strategy for future clinical applications.