Experimental study of the effect of adipose stromal vascular fraction cells with VEGF on the neovascularization of free fat transplantation

Abstract

To investigate the effect of adipose stromal vascular fraction cells (SVFs) with VEGF on the neovascularization of free fat transplantation. SVFs were obtained from subcutaneous fat and labelled with DiI. 0.3 ml autologous fat tissue was mixed with 0.2 ml cells: 1) autologous SVFs with VEGF (Group A); 2) autologous SVFs (Group B); 3) complete DMEM (Group C) And then the mixture was injected randomly under the back skin of 12 nude mice. The transplanted fat tissue in three groups was harvested at 2 months after implantation. Wet weight and diameter of fat grafts was measured. After HE and CD31 staining,blood vessel density, viable adipocytes and fibrous proliferation were observed. Trace of SVFs labeled by DiI in vivo could be detected by fluorescent microscope. The wet weight of fat grafts was (191.90 +/- 9.81) mg in group A, (177.01 +/- 10.50) mg in group B, and (92.05 +/- 8.30) mg in group C (P<0.01). The diameter of fat grafts was (0.49 +/- 0.24) cm in group A, (0.40 +/- 0.26) cm in group B, and (0.32 +/- 0.28) cm in group C (P<0.01). Histological analysis showed the blood vessel density was (14.58 +/- 2.06)/HPL in group A, (11.55 +/- 2.18)/HPL in group B, (7.87 +/- 1.55)/HPL in group C. Compared with group B and group C, group A had more adipose tissue with less fat necrosis and fibrosis and had significantly higher capillary density. The autologous adipose stromal vascular fraction cells with VEGF could improve the neovascularization of free fat significantly. It indicates a wide clinical application in the future.