Harvest of superficial layers of fat with a microcannula and isolation of adipose tissue-derived stromal and vascular cells.

BACKGROUND Adipose tissue is a source of stromal and vascular cells suitable for regenerative medical applications. Cell recovery depends on several factors, including the characteristics of the cannula used to harvest tissue. OBJECTIVES The authors assess whether aspiration of superficial layers of adipose tissue performed with a microcannula, rather than a standard cannula, allows for improved isolation of stromal and vascular cells, and they evaluate the angiogenic potential of the isolated cells in vitro and in vivo. METHODS Adipose-derived stromal and stem cells (ADSC) were collected from the lipoaspirate of the abdomen and hip regions of 6 healthy female donors. For adipose tissue harvest, several options were compared: (1) a rounded-tip cannula with a length of 170 mm, a diameter of 3 mm, and a single elliptic suction port on the side near its distal end (port diameter: 3 × 9 mm) or (2) a rounded-tip infiltration cannula with a length of 170 mm, a diameter of 2 mm, and 5 round ports placed spirally along the sides of the distal cannula shaft (each port diameter: 1 mm) (Shipper Medical Technologies Corporation, Centennial, Colorado). Isolated cells were characterized for (1) expression of the endothelial specific marker CD31 by immunohistochemical and cytofluorimetric analyses and (2) tubular-like structure formation using a 3-dimensional angiogenesis assay on Matrigel. Human ADSC were transduced to express firefly luciferase as a marker suitable for bioluminescent tracking and transplantation studies into immunosuppressed mice were performed. RESULTS ADSC yield was determined to be significantly higher in samples collected with the microcannula (P = .04). Moreover, isolated cells acquired typical endothelial-like morphology in vitro, formed capillary-like structures, and expressed the distinctive endothelial cell marker CD31. Cells implanted into immunosuppressed mice persisted for several weeks in areas undergoing neovascularization. CONCLUSIONS These results suggest that aspiration of adipose tissue with a microcannula can be a minimally invasive method to obtain clinically relevant numbers of stromal and vascular cells useful for autologous transplant procedures and for promoting tissue regeneration and neovascularization.