Extracellular Vesicles: Immunomodulatory messengers in the context of tissue repair/regeneration

Inflammation is a complex and highly regulated biological process, crucial for a variety of functions in the human body, from host response against infectious agents to initiation of repair/regeneration of injured tissues. In the context of tissue repair, the action of different immune cell populations and their interplay with tissue specific cells, including stem cells, is still being uncovered. Extracellular Vesicles (EV) are small membrane vesicles secreted by cells in a controlled manner, which can act locally and systemically. The ability of EV to influence tissue repair and regeneration has been proposed as a physiologically intelligent and targeted strategy of cell communication. Herein, the role of EV in tissue repair is reviewed, summarising first their contribution to the regulation of immune cell function, and discussing the implications for the resolution of inflammation during repair. Next, the impact of EV on cell proliferation and differentiation, and on extracellular matrix remodelling, key aspects of the subsequent phases of tissue repair, is addressed. Finally, EV-based therapies are discussed, focusing on the application of naturally produced EV, and the use of EV as delivery vehicles.