Extracellular Vesicles and Biomaterial Design: New Therapies for Cardiac Repair

International audience; The use of extracellular vesicles (EVs) for cardiac regenerative medicine as an alternative to cell transplantation has been demonstrated. For clinical applications, new translational issues have emerged such as parental cell selection, large-scale production, characterization, and delivery. Two main delivery approaches of EVs for heart repair can be used: either direct myocardial delivery in patients requiring surgery, or intravenous (IV) infusion. To potentiate EV beneficial effects, direct myocardial EV administration can be optimized by controlled-release biomaterials, whereas EV engineering should allow IV-injected EVs to be directed more specifically to the heart. However, new challenges include possible changes in EV bioactivity because of their interactions with the biomaterial, as well as the complexities of EV engineering to improve organ-specific targeting.There is increasing evidence that extracellular vesicles (EVs) mediate the paracrine effects of stem cells. Although EVs have several attractive characteristics, they also raise issues related to delivery. For patients with cardiac disease that require a surgical procedure, direct intramyocardial (IM) administration of EVs is straightforward but its efficacy may be limited by fast wash-out, hence the interest of incorporating EVs into a controlled release polymer to optimize their residence time. For patients without surgical indication, the intravenous (IV) route is attractive because of its lack of invasiveness; however, whole-body distribution limits the fraction of EVs that reach the heart, hence the likely benefits of EV engineering to increase EV homing to the target tissue.