Intelligent microneedle patch with cobalt-iron Prussian blue nanozymes for accelerating diabetic wound healing via heme biosynthesis-driven immunomodulation

released from ALA@CFP facilitated the transformation of 5-ALA to heme, significantly amplifying downstream heme oxygenase-1 (HO-1) activity and producing endogenous anti-inflammatory mediators, carbon monoxide and bilirubin. These molecules subsequently restructured the inflammatory wound microenvironment by instigating the polarization of macrophages from the M1-phenotype to the pro-repair M2-phenotype and upregulated the expression of anti-inflammatory factors, thereby fostering cell migration and angiogenesis. When embedded in a methacrylated gelatin/carboxymethyl chitosan hydrogel microneedle matrix, the system enables on-demand deep tissue delivery, achieving simultaneous antibacterial, anti-inflammatory, pro-angiogenic and regenerative effects in an infected diabetic mouse model. This study demonstrates a material-driven, metabolism-amplified strategy for intelligent wound repair, providing a promising platform for next-generation functional biomaterials.