Xeno-Free Extraction, Culture, and Cryopreservation of Human Adipose-Derived Mesenchymal Stem Cells

Molecules of animal or bacterial origin, which pose a risk for zoonoses or immune rejection, are commonly used for extraction, culture, and cryopreservation of mesenchymal stem cells. There is no sequential and orderly protocol for producing human adipose-derived stem cells (hASCs) under xeno-free conditions. After standardizing a human platelet lysate (hPL) production protocol, four human adipose tissue samples were processed through explants with fetal bovine serum (FBS)-supplemented or hPL-supplemented media for extracting the adipose-derived stem cells. The cells were cultivated in cell culture medium + hPL (5%) or FBS (10%). The cellular replication rate, immunophenotype, and differentiation potential were evaluated at fourth passage. Cellular viability was evaluated before and after cryopreservation of the cells, with an hPL-based solution compared with an FBS-based solution. The explants cultured in hPL-supplemented media showed earlier and faster hASC proliferation than did those supplemented with FBS. Likewise, cells grown in hPL-supplemented media showed a greater proliferation rate, without losing the immunophenotype. Osteogenic differentiation of xeno-free hASC was higher than the hASC produced in standard conditions. However, adipogenic differentiation was reduced in xeno-free hASC. Finally, the cells cryopreserved in an hPL-based solution showed a higher cellular viability than the cells cryopreserved in an FBS-based. In conclusion, we have developed a complete xeno-free protocol for extracting, culturing, and cryopreserving hASCs that can be safely implemented in clinical studies.