Manganese Dioxide Nanozyme-Integrated Aligned Nanofibers Promote Diabetic Wound Repair through Growth Arrest-Specific Protein 6-Mediated Fibroblast-to-Macrophage Communication

Abstract

Chronic diabetic wounds remain difficult to treat because excessive reactive oxygen species (ROS), persistent inflammation, and impaired neovascularization collectively hinder tissue repair. Here, we present a bioinspired aligned electrospun nanofiber membrane composed of methacrylated gelatin and o-nitrobenzyl-modified gelatin and functionalized with manganese dioxide (MnO2) nanozymes to regulate the wound microenvironment. Upon hydration and brief ultraviolet irradiation, the membrane forms a conformable nanofibrous hydrogel that closely adapts to irregular wound beds. Among three MnO2 loadings, the formulation containing 180 μg/mL MnO2 was selected as the optimized formulation because it attenuated intracellular ROS while promoting fibroblast proliferation and migration and endothelial angiogenic activity. Mechanistic studies showed that the optimized hydrogel promoted fibroblast secretion of growth arrest-specific protein 6 (Gas6), which attenuated inflammatory macrophage responses and enhanced reparative macrophage responses. Gas6 knockdown weakened these effects, whereas recombinant Gas6 recapitulated them. Single-cell RNA sequencing identified treatment-associated changes in wound cell states and suggested Gas6-associated fibroblast-macrophage communication through computational ligand-receptor analysis. In streptozotocin-induced diabetic mice, the optimized hydrogel accelerated wound closure and enhanced vascularization, re-epithelialization, and collagen remodeling. These findings establish an aligned nanozyme-functionalized nanofibrous hydrogel that links redox regulation to Gas6-associated fibroblast-to-macrophage signaling for diabetic wound repair.