Induced Mammary Epithelial Cell-Derived Extracellular Vesicles Promote the Repair of Skin Trauma

This study demonstrates that extracellular vesicles (EVs) derived from chemically induced mammary epithelial cells (CiMECs) significantly enhance skin wound repair when combined with a chitosan hydrogel, forming a composite system (CMECG). In a rat model, CMECG improved wound closure efficiency from 70% to 90% over 14 days, promoting fibroblast and mammary epithelial cell proliferation and migration, and enhancing collagen synthesis and remodeling. The therapeutic effects are attributed to miRNAs within CiMECs-EVs, which regulate cell proliferation, migration, angiogenesis, and inflammation through pathways like MAPK and PI3K-Akt. The study highlights CMECG as a promising strategy for clinical skin wound treatment, with optimal doses differing between in vitro (12.5 μg) and in vivo (200 μg) settings. Despite limitations such as a short follow-up period, the findings suggest potential for enhancing skin wound repair.