Content of the Growth Factors bFGF, IGF-1, VEGF, and PDGF-BB in Freshly Harvested Lipoaspirate after Centrifugation and Incubation

Abstract

BACKGROUND: In autologous fat transfer, several questions regarding basic biochemical properties of the transplant remain unanswered. Basic fibroblast growth factor (bFGF), insulin-like growth factor (IGF), vascular endothelial growth factor (VEGF), and platelet-derived growth factor (PDGF)-BB have been shown to improve transplantation results. However, no study regarding naturally occurring levels of growth factors in transplanted adipose tissue has yet been performed. In addition, there are no data as to whether intraoperative refinement eliminates or concentrates growth factors. METHODS: The authors investigated the content of bFGF, IGF, VEGF, and PDGF-BB in freshly aspirated adipose tissue and the presence of those factors in the various fractions after centrifugation by means of enzyme-linked immunosorbent assay readings. They also analyzed growth factor content after storage periods of 3 and 5 days and investigated the vitality of freshly centrifuged adipose tissue by staining with Hoechst 33342 and propidium iodide. RESULTS: The authors found significant quantities of bFGF, IGF-1, VEGF, and PDGF-BB (39.9, 113.8, 3.0, and 5.8 pg/mg, respectively) in the lipoaspirate harvested for transplantation. Separation by centrifugation and discarding of the infranatant and supernatant fluid means that most of the growth factors are left in the transplant. The growth factor content in the other fractions was significantly lower. Lipoaspirate can be cultured for several days, with the tissue remaining biologically active and producing significant growth factor levels. CONCLUSION: Knowledge of the naturally occurring range for these growth factor quantities will enable researchers and clinicians to make autologous fat transfer procedures more reliable and safe.