The ultimate goal of regenerative medicine is to overcome the failure of an organ, restoring its function and homeostasis. Mesenchymal stem cells (MSCs) are multipotent stem cells that can differentiate into a variety of cell types and represent one of the most well-investigated cell types for tissue regeneration. To explain tissue regeneration after the injection of MSCs in any injured organ, it was first hypothesized that MSCs would differentiate into the desired cell type to induce tissue regeneration. However, it was discovered a poor cell retention and survival in the injury site [1,2] resulting in unsatisafactory engraftment rates. With these considerations, the second mechanism proposed is related to the cell paracrine effect mediated, amongst others, by extracellular vesicles [3,4]. Extracellular vesislces are active players participating in homeostasis and disease which act as biological effectors in many physiological processes such as immune response, pregnancy, coagulation and cancer.
Recent discoveries demonstrate that extracellular vesicles generated by MSCs have protective and reparative properties to induce a regenerative effect in vivo in cardiovascular diseases, acute kidney injury, brain injury, liver injury, osteoarthrisis, bone regeneration, lung injury and cutaneous wound healing [5-12].
Extracellular vesicles as new therapeutic tools would allow to open a new era in cell therapy by mitigating the limitations and hurdles related to the administration of viable stem cells such as the risks of uncontrolled cell replication, differentiation or vascular occlusion. Additionally, extracellular vesicles benefit from leading advantages in terms of sterilization, storage and shelf-life compared to their cellular counterparts.