Improvement of the survival of autologous free-fat transplants in rats using vascular endothelial growth factor 165-transfected bone mesenchymal stem cells.

BACKGROUND: Autologous free-fat transplantation is limited by fat absorption and fibrosis due to fat necrosis. In this study, we explored the feasibility of using bone mesenchymal stem cells (BMSCs) transfected by vascular endothelial growth factor (VEGF) 165 gene to improve the survival of transplanted fat tissues in a rat model.

METHODS: Bone mesenchymal stem cells with (group A) and without (group B) VEGF165 gene transfection were each mixed with free transplanted fat tissue; then, they were injected subcutaneously at sites on the backs of 36 Sprague-Dawley rats. A control group (group C) was established by using low-glucose Dulbecco modified Eagle medium. The transplants from groups A, B, and C were gathered respectively at 30, 90, and 180 days after transplantation. Transplanted tissue volume and histology were evaluated, and revascularization was quantified by counting the number of capillaries.

RESULTS: The survival rate of the A group was significantly higher than that of the B group (P < 0.05), which was significantly higher than that of the C group (P < 0.05). Histologic analysis revealed that both groups A and B had significantly less fat necrosis and fibrosis (P < 0.05). Group A had significantly higher capillary density than the other 2 groups (P < 0.05), and its chloromethyl-1-1'-dioctadecyl-3,3,3', 3'-tetramethylindocarbocyanineperchlorate-labeled BMSCs were also von Willebrand factor positive.

CONCLUSIONS: When transfected by the VEGF165 gene, the BMSCs of a rat can better promote the regeneration of capillaries, which can improve the survival rate of transplanted free-fat tissue. This experiment combined correlative theory and techniques of stem cell research, genetic technology, and autologous free-fat transplantation. It may provide a new way to improve the survival of tissue undergoing autologous free-fat transplantation.