A Biomimetic Multistage RNAi Platform Restores Mitochondrial Function in Diabetic Wounds via the ALKBH5-m⁶A-C2orf69 Axis

Diabetic wounds remain a major clinical challenge, largely due to vascular dysfunction. Here, we identified a previously unrecognized N⁶-methyladenosine (m⁶A)-dependent mechanism underlying endothelial injury in diabetic wounds. The m⁶A demethylase ALKBH5 was upregulated in diabetic wound endothelium, leading to reduced m⁶A modification within the coding sequence (CDS) of C2orf69 mRNA. Loss of m⁶A weakened IGF2BP2-mediated stabilization of C2orf69 transcripts, resulting in decreased C2orf69 expression, mitochondrial dysfunction, and impaired angiogenesis. To therapeutically target the ALKBH5-m⁶A-C2orf69 axis, we developed a biomimetic membrane-fusion nanovesicle system (siALK@L-Hyb) integrating arginine-rich lipopeptides (A-LPs), endothelial cell membranes, milk-derived extracellular vesicles (mEVs), and ALKBH5-specific siRNA. This platform enhanced tissue penetration, promoted endothelial uptake, and facilitated lysosomal escape, thereby achieving a sequential "Tissue-Cell-Organelle" intervention. The resulting efficient delivery of ALKBH5 siRNA restored mitochondrial function, improved angiogenesis, and significantly accelerated diabetic wound healing. Our work not only uncovers a novel m⁶A-regulated endothelial injury pathway in diabetic wounds, but also presents a versatile and translational nanoplatform for RNAi-based therapy.