Functional hydrogels promote chronic infectious wound healing by re-rousing macrophage M1 and inducing bacterial...

Traditional antibiotics are often ineffective against biofilm-associated infections, and biofilm-induced macrophage immune evasion directly halts the wound healing process. Disrupting biofilms and regulating macrophage immune functions are critical to improving wound healing. In this study, we synthesized g-C₃N₄ with peroxidase (POD) enzyme activity via thermal polymerization and copper alginate microspheres (CAM) via gas cutting. These were co-encapsulated into GelMA hydrogels to form a functionalized wound repair system (GelMA/CAM@g-C₃N₄) with both anti-biofilm and local immune microenvironment remodeling capabilities. In vitro, this system exhibited excellent biocompatibility and promoted endothelial cell migration, vascular formation, and CD31 expression. It also polarized macrophages toward the M1 phenotype, restoring their pro-inflammatory functions, upregulating inflammatory cytokines (IL-1, IL-6, TNF-α), and inhibiting Staphylococcus aureus and Escherichia coli. In vivo, the system suppressed S. aureus growth, promoted angiogenesis and collagen deposition, and reshaped the pathological microenvironment to achieve wound repair and regeneration. Conclusions: This system offers a new therapeutic strategy for chronic infectious wounds.