Mesenchymal stem/stromal cell-derived extracellular vesicles have clinical potential

Within the last two decades mesenchymal stem/stromal cells (MSCs) emerged after hematopoietic stem cells as the second most investigated and applied somatic stem cell entity so far. MSCs mediate immunosuppressive as well as pro-regenerative activities. Against the initial assumption, MSCs may not primarily exert their therapeutic functions in a cellular but rather in a paracrine manner. Here, extracellular vesicles (EVs), such as exosomes and microvesicles, have been identified as major mediators of these paracrine effects. Meanwhile, MSC-EVs have been applied to an increasing amount of different animal models and were tested in a patient suffering from steroid-refractory acute graft-versus-host disease (acute GvHD) as well as in a patient cohort with chronic kidney disease. So far, the MSC-EV administration appears to be safe in humans and all tested animal models. Improvements were reported in all settings. Thus, MSC-EVs appear as promising novel therapeutic agents which might help to improve disease associated symptoms in millions of patients.