Untersuchung der Vitalität und der Expressionsmuster wachstums- und angiogenesefördernder Faktoren in Zentrifugationsfraktionen von Liposuktionspräparaten

BACKGROUND: Standard protocols for autologous fat transfer involve centrifugation of the lipoaspirate for better separation. But the effect of the centrifugal forces on cell viability and possible induction of apoptosis is discussed controversially in current literature. In addition to this, 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, but there is still no data on the content of those in lipoaspirate used for lipofilling.METHODS: We have examined the viability of adipocytes in lipoaspirates after centrifugation by 8 different accelerations up to 20.000xg immediately after the respective centrifugation as well as after 4 days of cultivation by staining with Hoechst 33342 and propidium iodide. 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 was measured by means of enzyme-linked immunosorbent assay readings. Growth factor content was also analyzed after storage periods of 3 and 5 days.RESULTS: No significant alterations in the viability of differently centrifuged adipocytes were found. There are significantly interindividual varying quantities of bFGF, IGF-1, VEGF, and PDGF-BB 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: Our results show that centrifugation, as a part of the protocol of lipofilling, has no effect on the survival rate of isolated adipocytes in the purified fat. In contrast, lipoaspirates centrifuged with higher accelerations seem to be better cleansed of oil. The knowledge of the naturally occurring range for these growth factor quantities is a plausible explanation for the volume reduction often found after lipofilling procedures