Skeletogenic capacity of human perivascular stem cells obtained via magnetic activated cell sorting.

Human perivascular stem/stromal cells (PSC) are a multipotent mesenchymal progenitor cell population defined by their perivascular residence. PSC are increasingly studied for their application in skeletal regenerative medicine. PSC from subcutaneous white adipose tissue are most commonly isolated via fluorescence activated cell sorting (FACS), and defined as a bipartite population of CD146+CD34-CD31-CD45- pericytes and CD34+CD146-CD31-CD45- adventitial cells. FACS poses several challenges for clinical translation, including requirements for facilities, equipment, and personnel. The purpose of this study is to identify if magnetic activated cell sorting (MACS) is a feasible method to derive PSC, and to determine if MACS-derived PSC are comparable to our previous experience with FACS-derived PSC. Briefly, CD146+ pericytes and CD34+ adventitial cells were enriched from human lipoaspirate using a multi-step column approach. Next, cell identity and purity were analyzed by flow cytometry. In vitro multilineage differentiation studies were performed with MACS-defined PSC subsets. Finally, in vivo application was performed in non-healing calvarial bone defects in Scid mice. Results showed that human CD146+ pericytes and CD34+ adventitial cells may be enriched by MACS, with defined purity, anticipated cell surface marker expression, and capacity for multilineage differentiation. In vivo, MACS derived PSC induce ossification of bone defects. These data document the feasibility of a magnetic activated cell sorting approach for the enrichment and application of perivascular stem/stromal cells in the field of tissue engineering and regenerative medicine.