Characterization and bioassays of extracellular vesicles extracted by tangential flow filtration

Aim: To evaluate the efficiency of tangential flow filtration (TFF) in improving the yield of human umbilical cord mesenchymal stem cell (hucMSC)-derived extracellular vesicles (EVs) while promoting cell regeneration under oxidative stress. Methods: HucMSC-EVs were extracted from supernatants by ultracentrifugation (UC-EVs) and TFF (TFF-EVs), followed by feature characterization and bioactivity assays. Results: The yield of TFF-EVs increased 18-times compared with that of UC-EVs. TFF-EVs displayed proliferation-promoting ability similar to that of UC-EVs in the damaged HaCaT cell model with ultraviolet radiation B (UVB) and H2O2. Furthermore, the antiapoptotic effects of TFF-EVs were improved, whereby the apoptosis rate exhibited a 3.7-fold decrease. Conclusion: HucMSC-EVs extracted by TFF show a higher yield and rejuvenate the damaged HaCaT cells induced by oxidative stress.Plain language summary The progresses in regenerative medicine will enable a perfect repair of burns. Stem cells release extracellular vesicles around injured tissues to improve its structural and functional repair. But the current methods for vesicles enrichment are not efficient enough to meet the needs of investigation. Here we isolated the vesicles from the stem cells supernatants by either traditional method or ultrafiltration. We found that the vesicles isolated with ultrafiltration method displayed a similar cell proliferation ability of that with the traditional one. The output of the vesicles or its anti-aging capability has increased 18- or 3.7-times respectively. Therefore, the scalable and effective isolation method described here may facilitate the successful medical translation of the vesicles for clinical use.