Extracellular vesicles in regenerative medicine

Regenerative medicine is a multidisciplinary field aimed at developing methods, molecular agents, and (nano)materials to regrow, repair, or replace damaged, malfunctioning or missing tissues. Current approaches include and combine use of stem cells, tissue engineering based on functional biodegradable scaffolds, and cell-free strategies, with stem cells and their progenitors playing the main role. However, it is now recognized that the therapeutic efficacy of stem cells largely depends on paracrine-secreted soluble factors and extracellular vesicles (EVs). Preclinical and clinical studies indicate that EVs can exert immunomodulatory and regenerative action, thus efficiently recapitulating the therapeutic effects of stem cells. On the other hand, EVs are uncapable of self-replication agents and can be nonimmunogenic, thus offering remarkable advantages and safety over stem cells for therapeutic translation. This chapter, after an introduction of EV biological and physicochemical properties, will present and discuss advances in EV-based regenerative medicine.