Comparison of production methods for mesenchymal stem cell-derived small extracellular vesicles and evaluation of their effects on retinal pigment epithelium

The properties of extracellular vesicles depend on characteristics of the origin of cells. This study aimed to comprehensively evaluate a protocol for production of bone marrow mesenchymal stem cell-derived small extracellular vesicles (BM-MSC-sEVs) and investigate their effects on hydrogen peroxide (H₂O₂) induced cell damage to spontaneously arising retinal pigment epithelium (ARPE-19). We found that cell morphology and proliferative capacities of BM-MSCs obtained in α-MEM were higher than those cultured in DMEM, although not statistically significant. The particle yields were statistically higher when isolated by tangential flow filtration (TFF) than by ultracentrifugation (UC). Toxicity of BM-MSC-sEVs and therapeutic effects upon damaged ARPE-19 were assessed. They were found to be noncytotoxic, and to enhance ARPE-19 cell proliferation. While viability of ARPE-19 cells after H₂O₂ exposure was 37.86 ± 0.61%, application of sEVs (50 µg/mL) onto these cells for 24 h before or after H₂O₂ exposure increased viabilities to 54.60 ± 3.59% and 52.68 ± 0.49%, respectively. Flow cytometry showed significant reduction of total apoptotic cells. In conclusion, isolation of sEVs by TFF was the more effective method. Derived sEVs demonstrated capabilities as a potential therapeutic agent for retinal diseases.