A hierarchical hydrogel dressing with continuous biochemical gradient for immunoregulation, nerve repair and angiogenesis of refractory diabetes wounds

The healing of diabetic wounds poses a significant healthcare burden due to persistent inflammation, M1 macrophage aggregation, and high glucose levels in the microenvironment. Previous studies have demonstrated that immunomodulatory hydrogel dressings can facilitate diabetic wound healing. However, current immunomodulatory hydrogels require costly and complex treatments such as cell therapy and cytokines. Herein, a hierarchical hydrogel dressing with continuous biochemical gradient based on glycyrrhizic acid (GA) was constructed to modulate immunomodulatory processes in diabetic wounds. The hydrogels present many desirable features, such as tunable mechanical properties, broad antibacterial ability, outstanding conductive, transparent, and self-adhesive properties. The resultant hydrogel can promote diabetic wound healing by preventing bacterial infection, promoting macrophage polarization, improving the inflammatory microenvironment, and inducing angiogenesis and neurogenesis. Furthermore, electrical stimulation (ES) can further promote the healing of chronic diabetic wounds, providing valuable guidance for relevant clinical practice.