A recent study conducted at the University of Florida could transform the way we isolate stem cells, validating a method that takes only minutes and can be performed just about anywhere. Stem cells are “immature” cells that have the unique ability to develop into other cell types. For example, hematopoietic stem cells (HSCs) regenerate blood cells and mesenchymal stem cells (MSCs) regenerate cells of solid tissues. Because HSCs and MSCs are often used for clinical regenerative medicine, isolation techniques that are more efficient and simplified are needed. Dr. John Murray, Chief of the Division of Plastic Surgery at the University of Florida at Jacksonville, working with Dr. Andria Doty, Scientific Director at UF | ICBR Cytometry and others, used magnet activated cell sorting to enrich for Adipose-derived stem cells (ACSs), a type of MSC.
Magnet activated cell sorting uses antibodies against cell-surface proteins attached to paramagnetic immunobeads (PIBs). When added to a heterogenous population of cells, the antibodies bind selectively to cells that express the cell-surface protein, and the targeted cells/PIB complex can be pulled out of the mix by using a magnet. All the remaining unselected cells are washed away leaving a pellet of purified target cells. In this study PIBs containing antibodies to proteins expressed on the surface of ASCs were added to surgically obtained fresh human lipoaspirates and a hand-held magnet was used to capture the PIBs with the attached ASCs. Flow cytometry was used to detect the presence of the ASC-specific cell surface proteins CD90 and CD105, confirming the identity of the PIB-selected cells as ASCs. When grown in culture the isolated cells also showed differentiation characteristics diagnostic of ASCs. This study validates that functional ASCs may be isolated easily in the operating room from lipoaspirate in 20 minutes by magnetic enrichment. As both the harvest of adipose tissue by liposuction and this ASC enrichment technique do not require electricity, fresh primary therapeutic ASCs may be isolated in any point-of-care setting, even in developing countries, opening an avenue for easily obtaining fresh primary ASCs for therapeutic purposes. This method was described in the paper A New Ball for an Old Trick: Paramagnetic Cell Sorting of Human Mesenchymal Stem Cells from Adipose Tissue published in the Journal of Stem Cell Reports.