Isolation of adipose-derived stromal cells without enzymatic treatment: expansion, phenotypical, and functional characterization.

Stem cell therapy is a potential method for the treatment of numerous diseases. The most frequent cellular source is bone-marrow-derived mesenchymal stromal cells (BM-MSCs). Human adipose-derived stromal cells (ADSCs) share similar properties with BM-MSCs as they support hematopoiesis, modulate ongoing immune responses, and differentiate into cells of mesodermal origin. On the other hand, ADSCs have higher frequency in situ, higher availability, and very few ethical issues compared with BM-MSCs, giving them an advantage over BM-MSCs for clinical use. Most of the methods used to isolate ADSCs contain a collagenase digestion step, but the type of collagenase and time of sample digestion vary among studies and these differences could have an impact on the cell properties and thus in result comparison. To overcome this obstacle, we propose a new method to isolate ADSCs from lipoaspirate without collagenase digestion step. We compared ADSCs obtained with our method versus classical protocol using collagenase digestion. Cells obtained with our method are equivalent but they have a better long-term hematopoietic support than those obtained with classical method. Moreover, our method has an advantage over the classical one as it is easier, safer, faster, less expensive, and more consistent with good manufacturing practices to obtain large number of ADSCs ex vivo.