Mesenchymal Stromal Cell-Derived Extracellular Vesicles in Tissue Repair: Applications and Mechanisms

Abstract

Mesenchymal stromal/stem cell-derived extracellular vesicles (MSC-EVs), including preparations frequently described as exosomes, are being investigated as cell-free candidates for tissue repair. These lipid-bilayer-delimited particles carry proteins, lipids, and nucleic acids that may modulate immune responses, cell survival, angiogenesis, proliferation, migration, and extracellular-matrix remodeling in experimental systems. This review summarizes the biological characteristics of MSC-EVs, commonly used separation methods, proposed mechanisms of action, and preclinical applications in peripheral nerve repair, bone regeneration, and cutaneous wound healing. It also considers major barriers to translation, including inconsistent nomenclature and characterization, variable yield, purity, composition, and potency, limited tissue retention and targeting, and the absence of broadly standardized, scalable manufacturing processes. Future studies should use rigorous EV characterization, mechanism-linked potency assays, reproducible production protocols, and appropriately designed preclinical and clinical studies to establish the safety and efficacy of MSC-EV-based interventions.