Mesenchymal stem cell-derived extracellular vesicles promote corneal wound repair

Abstract

Purpose: To investigate if topically applied mesenchymal stem cell (MSC)-derived extracellular vesicles (EVs) promote corneal wound repair.

Methods: EVs were isolated from media conditioned by human bone marrow-derived MSCs (n=4) using series of centrifugation, filtration (0.22μm) and ultracentrifugation. Transmission electron microscopy (TEM) was used to detect classical protein markers and size of EVs were determined using nanoparticle tracking analysis (NTA; NanoSight). Pro-healing effects of MSC-derived EV were examined in vitro by cell migration and scratch-wound-healing assays using human corneal epithelial (HCE) and endothelial (HCEC) cell lines. Moreover, angiogenesis was also studied using HUVEC cells on matrigel coating.

Results: Successful isolation of EVs was confirmed by immune-gold TEM showing expression of classical exosomal markers CD63 and TSG101 on their surface. NTA showed the average size of EVs ranged between 50-130nm. Significant increases in HCE and HCEC cell migration in both cell lines studied in the presence of MSC-EVs (<45%=HCEC; <93%=HCE) could be observed compared to PBS and EV-depleted media conditioned (dCM) by MSCs. Similarly, a significant increase in scratch-wound closure of the cells treated with EV was observed compared to PBS (<75%=HCEC; <80%=HCE) or dCM-treated cells. Interestingly, we also found increased capacity of angiogenesis in HUVEC cells when treated with MSC-derived EVs compared to PBS or dCM.

Conclusions: This study supports that MSC-derived EV show promising therapeutic potential and could be considered as an option for cell-free treatment in ocular surface disease.