A feasible method for the isolation of mesenchymal stem cells from menstrual blood and their exosomes.

BACKGROUND: Mesenchymal stem cells (MSCs) are currently the most promising candidates in regenerative medicine. Nonetheless, there are several limitations associated with the MSC tissue source such as infrequent and invasive bone marrow sampling methods. To overcome these limitations, we have procured MSCs from the menstrual blood (MenSCs) as a non-invasive source using a straightforward and cost-effective method. Moreover, we isolated MenSCs-derived exosomes as a safe and highly effective approach to exert the paracrine effects of MSCs.

METHODS: MSCs were isolated from menstrual blood through two different culture methods: ficoll-isolated mononuclear cells (MNCs) and whole blood culture. These cells were characterized by their plastic adherence, flow cytometry analysis of the surface markers and the differentiation potential. The exosomes were isolated from conditioned media using ultracentrifugation and characterized by different microscopy techniques, western blotting, and ELISA.

RESULTS: Both Methods resulted in the rapid isolation of cells with MSC properties. However, the cellular yield of the whole blood culture method was remarkably more than MNCs culture. MenSCs also produced a substantial amount of extracellular vesicles (EVs) possessed the minimum criteria for exosome definition.

CONCLUSION: The results suggest that direct culture of whole menstrual blood cells is a high throughput, straightforward and cost-effective method for MenSCs isolation using no special growth factors. Moreover, these cells are a good producer of exosome which can offer a cell-free therapy approach.