Long-Term Effects of Platelet-Rich Fibrin on Fat Graft Survival and Their Optimal Mixing Ratio

Abstract

Background Platelet-rich fibrin (PRF) can promote fat graft survival. But the reported mixing ratio of PRF and fat ranges from 1:25 to 1:2, lacking a clear standard for clinical application. Objectives Explore the long-term effects of PRF on the grafted fat, and their optimal mixing ratio. Methods Nude mice were randomly divided into a control group (receiving subcutaneous injection of fat granules) and 4 PRF groups (receiving subcutaneous injection of PRF and fat granules at a volume ratio of 1:5, 1:10, 1:15, and 1:20, respectively). The graft samples (n=12) were obtained in weeks 4, 8 and 12 to (1) calculate retention rates, (2) evaluate gene and protein expression of VEGF-A, PPAR-γ, COL1-A1, and BAX, (3) perform H&E, Masson’s trichrome, α-SMA, and periplipin-1 stainings, and (4) count the microvessels and viable adipocytes. Results Compared with the control group, PRF groups had higher retention rates, a higher gene/protein expression of VEGF-A, a lower gene/protein expression of COL1-A1 and BAX, less fibrosis, and more microvessels and viable adipocytes. Group 1:10 was superior than other groups in terms of retention rates and other evaluation indexes. The expression of PPAR-γ had no significant difference among groups. Conclusions PRF may not play a long-term effect on adipogenesis. But it can still promote fat graft survival through facilitating vascularization, regulating collagen production and inhibiting apoptosis. PRF can achieve the best promoting effect when the mixing ratio of PRF and fat is 1:10, which is recommended as the optimal ratio for clinical application.

Platelet-Rich Fibrin in Fat Grafts for Facial Lipofilling: A Randomized, Controlled Split-Face Clinical Trial

“…Based on a previous investigation, PRP may have a dose-dependent positive effect on fat grafts, and the concentration of PRP that appears to achieve the most favorable results ranges from 0.4 to 0.5 ml per ml of fat (1:2 ratio) ( 46 ). Other studies show that a higher concentration of PRP may induce unwanted cell differentiation resulting in counterproductive effects ( 47 , 48 ). However, the mixing ratio of PRF to fat was not established yet.…”