Methacrylated gelatin microneedles loaded with cobalt-curcumin nanozymes promote diabetic wound healing by modulating oxidative stress and inflammatory microenvironment.

Diabetic wounds are characterized by persistent oxidative stress and chronic inflammation, which jointly impair tissue repair. Here, we developed cobalt-curcumin coordination nanoparticles (Co-Cur NPs)-loaded Methacrylated Gelatin (GelMA) microneedles (Co-Cur NPs@MN) for local diabetic wound treatment. Co-Cur NPs were prepared through coordination-driven assembly between cobalt ions and curcumin and encapsulated into photocrosslinked GelMA microneedles. The coordination-derived Co-Cur NPs modulated macrophage-associated inflammatory gene expression. In a streptozotocin (STZ)-induced diabetic rat wound model, Co-Cur NPs@MN accelerated wound closure compared with untreated wounds and topical Co-Cur NPs. Histological analyses showed enhanced granulation tissue formation and collagen deposition. Immunofluorescence further demonstrated a reduced interleukin-1β (IL-1β)-positive area and an increased interleukin-10 (IL-10)-positive area in treated wounds. These findings suggest that Co-Cur NPs@MN provides an effective local therapeutic strategy for diabetic wound repair by integrating nanozyme-mediated oxidative stress regulation with inflammatory microenvironment modulation.