Mitochondrial transfer via ADSC-EVs reprograms glucose/glutamine metabolism to restore TCA cycle-driven M2 polarization in diabetic wounds

Chronic diabetic wounds are trapped in a persistent inflammatory state, largely due to macrophage failure to transition from pro-inflammatory (M1) to pro-reparative (M2) phenotypes. Here, we show that adipose-derived stem cell extracellular vesicles (ADSC-EVs) deliver functional mitochondria into diabetic wound macrophages, thereby restoring tricarboxylic acid (TCA) cycle-driven M2 polarization. Mechanistically, ADSC-EV-mediated mitochondrial transfer reactivates pyruvate dehydrogenase ( PDH ) and pyruvate carboxylase ( PC ), increases TCA cycle flux, and suggests enhanced glutamine anaplerosis, as evidenced by ¹³C-glucose isotope tracing. This metabolic rewiring restores oxidative phosphorylation (OXPHOS), elevates oxygen consumption rate (OCR) and suppresses glycolysis. Consequently, ADSC-EV treatment reduces M1 macrophages and increases M2 macrophages, lowers pro-inflammatory cytokines ( IL-1β , TNF-α , IL-6 , MCP1 , p < 0.0001), and upregulates IL-10 in vitro , p < 0.0001). In a diabetic mouse wound model, a single course of ADSC-EVs accelerates wound closure at day 14 ( p < 0.05), enhances re-epithelialization and collagen deposition, and reduces local oxidative stress and inflammation. Mitochondria‑depleted Rho-ADSC-EVs show markedly diminished effects, confirming that functional mitochondrial transfer is the primary driver. Our findings establish ADSC-EV-mediated mitochondrial transfer as a central metabolic reprogramming strategy that breaks the inflammatory lock in diabetic wounds and promotes healing.