Polysaccharide-engineered mitochondria reprogram macrophages to resolve diabetic wound inflammation and promote...

Chronic diabetic wounds are characterized by persistent inflammation, defective resolution and impaired tissue regeneration, in which macrophage dysfunction and mitochondrial damage play central roles. Here, we developed a macrophage-targeted engineered mitochondrial transplantation system by coating adipose-derived stem cell (ADSC) mitochondria with triphenylphosphonium-modified konjac glucomannan (Mito-TPP-KGM). This design preserves mitochondrial membrane potential and ATP production while reducing ROS generation, and provides a mannose-rich corona for lectin receptor-related uptake. In RAW264.7 macrophages exposed to high glucose plus H₂O₂ or LPS, Mito-TPP-KGM is efficiently internalized, restores mitochondrial homeostasis, rebalances glycolysis and oxidative phosphorylation, and shifts inflammatory profiles toward a less inflammatory and more reparative phenotype. Engineered mitochondria also restore efferocytosis of apoptotic neutrophil-like cells and enhance the pro-angiogenic capacity of macrophage-conditioned media, thereby improving endothelial tube formation, migration and proliferation. Blocking experiments with mannan and anti-CD206/anti-DC-SIGN antibodies, together with species-specific mtDNA quantification, indicate that mannose-type lectin receptors contribute to the uptake and immunomodulatory effects of Mito-TPP-KGM. In a db/db mouse full-thickness wound model, local delivery of Mito-TPP-KGM promotes wound repair, improves histological healing, reduces oxidative damage, enhances angiogenesis, and modulates wound macrophage phenotype, leading to accelerated wound closure; these therapeutic benefits are partially attenuated by local CD206 blockade. Collectively, these findings demonstrate that polysaccharide-engineered mitochondria can reprogram diabetic wound macrophages via targeted mitochondrial transplantation, offering a promising immunometabolic strategy for chronic wound therapy.