Stem cell-derived extracellular vesicles: a functional immunomodulator for cell-free therapy of autoimmune diseases

Patients with autoimmune diseases (AIDs) seldom receive efficient clinical management and timely therapy.Although certain immunomodulatory drugs or biologics currently in use have been shown to decelerate AID progression, potential complications and the extended treatment duration affect the prognosis and living quality of patients.Extracellular vesicles (EVs) have attracted significant interest as a cell-free therapeutic approach with reduced side effects. Research has indicated that stem cell-derived EVs (SC-EVs) can modulate the immune response by suppressing hyper-immunity and inflammation. Of note, SC-EVs are anticipated to serve as a potential alternative to traditional cell therapy. The present review explores the effects of different isolation methods on the quality and quantity of EVs derived from various sample sources. It also discusses the mechanisms through which SC-EVs can be used for AID treatment. In addition, the paper summarises the classic preclinical findings of SC-EVs in AID in recent years.Finally, the potential challenges of SC-EVs before receiving approval for clinical application have been elucidated, thereby offering novel insights for future studies on SC-EVs in AIDs.