Mesenchymal Stem Cell-Derived Exosomal miRNAs in Skin Repair and Rejuvenation

Skin aging and wound healing are the result of intricate and interconnected processes involving chronic inflammation, oxidative stress, cellular senescence and extracellular matrix degradation. Mesenchymal stem cell (MSC)-derived exosomes are rich in bioactive components, particularly microRNAs (miRNAs), which play a crucial role in regulating gene expression and key signaling pathways critical for maintaining skin homeostasis. This article reviews the current evidence regarding the roles of MSC-derived exosomal miRNAs (MSC-Exo-miRNAs) in cutaneous repair and rejuvenation. Specific exosomal miRNAs are analyzed for their ability to modulate inflammatory responses, promote fibroblast proliferation and collagen synthesis, enhance angiogenesis, and facilitate keratinocyte migration and re-epithelialization. Their roles in regulating key signaling pathways are discussed in the context of skin regeneration and aging, including nuclear factor-κB (NF-κB), PI3K/Akt, TGF-β/Smad, Wnt/β-catenin, and nuclear factor erythroid 2-related factor 2 (Nrf2). Additionally, emerging engineering strategies aimed at optimizing miRNA cargo loading, improving delivery efficiency, and advancing clinical translation are highlighted. Overall, MSC-Exo-miRNAs represent a promising cell-free therapeutic strategy for skin repair and rejuvenation; however, further mechanistic investigations and rigorous clinical studies are necessary to fully realize their translational potential.