OBJECTIVETo investigate the feasibility of using adipose tissue derived stem cells (ASCs) to promote neovascularization and survival rate of free fat transplantation.

METHODSASCs were isolated from aspirates from human liposuction and cultured in vitro. The cells were incubated in adipogenic, osteogenic, and chondrogenic medium for 2-4 weeks to induce adipogenesis, osteogenesis and chondrogenesis, respectively. ASCs were labelled by DiI. ASCs (A group), Insulin (B group), Medium (C group) were respectively mixed with free fat graft from aspirates. The mixtures were injected subcutaneously at the three random points on the back of eighteen 4- 6-week-old nude mice. Transplanted fat tissue was harvested after 6 months. The grafts were assessed by morphological observation, HE staining and immunohistochemistry.

RESULTSASCs can be easily harvested from liposuction aspirates and differentiate into adipogenic, osteogenic, chondrogenic lineages. The wet weight of transplanted fat tissue in ASCs group was (165.97 +/- 5.51) mg, significantly higher than that in the insulin group (93.42 +/- 5.12) mg and control group (67.64 +/- 5.09) mg (P = 0.000). The rate of fibrosis and steatonecrosis in ASCs group was( 152.2 +/- 9.8)/10HF, significantly lower than that in the Insulin group (743.9 +/- 20.4)/10HF and control group (892.2 +/- 16.5)/10HF (P = 0.000). DiI labelled ASCs were found between adipocytes and in the connective tissue in free transplanted fat tissue, and some of these cells were immunopositive for antihuman CD31 and FITC, suggesting differentiation into vascular endothelial cells.

CONCLUSIONSASCs can differentiate into vascular endothelial cells and contribute to angiogenesis in free transplanted fat tissue. ASCs can increase the survival rate and decrease the rate of fibrosis and steatonecrosis of free transplanted fat tissue. These findings suggest that ASCs-assisted transplantation may be an ideal cell therapy.