Fat Extract Improves Random Pattern Skin Flap Survival in a Rat Model

Abstract Background Adipose tissue and its derivatives, including adipose-derived stem cells, stromal vascular fraction (SVF), and SVF-gel, have been utilized in the treatment of many ischemic disorders. However, the utilization of these products is limited in clinical applications by concerns related to the presence of cells in these derivatives. Objectives This study aimed to isolate a cell-free fat extract (FE) from fat tissue and to evaluate its proangiogenic ability in vitro as well as its protective effects on skin flap survival in vivo. Methods FE was isolated from human fat via a mechanical approach. The concentrations of several growth factors in the FE were determined by enzyme-linked immunosorbent assay. The proangiogenic ability of FE was evaluated utilizing assays of the proliferation, migration, and tube formation in human umbilical vein endothelial cells in vitro. The protective effects of FE on the survival of random pattern skin flaps were investigated by subcutaneous injection into rats. Results Enzyme-linked immunosorbent assay results revealed that FE contained proangiogenic growth factors that promoted proliferation, migration, and tube formation in human umbilical vein endothelial cells in vitro. In addition, FE reduced skin flap necrosis and increased survival, as demonstrated by macroscopic measurements and blood flow analysis. Histological analysis revealed that FE treatment increased the capillary density. Conclusions FE is a cell-free, easy-to-prepare, and growth-factor–enriched liquid derived from human adipose tissue that possesses proangiogenic activity and improves skin flap survival by accelerating blood vessel formation. FE may be potentially used for treating ischemic disorders.