Fat Extract Improves Random Pattern Skin Flap Survival in a Rat Model

Abstract

Backgrounds: Adipose tissue, as well as their derivatives, including adipose derived stem cells, stromal vascular fraction (SVF), and SVF-gel, have been used in the treatment of many ischemic disorders but limited by cell-related concerns in clinical application. The aim of this study is to isolate a cell-free fat extract (FE) from fat tissue, and evaluate its proangiogenic ability in vitro as well as its protective effects on skin flap survival in vivo. Methods: FE was isolated from hunam fat via mechanical approach. The levels of various growth factors in the FE were measured by the enzyme-linkedimmunosorbent assay (ELISA). The proangiogenic ability of FE was evaluated on cell proliferation, migration and tube formation of human umbilical vein endothelial cells (HUVECs) in vitro. The protective effects on survival of random pattern skin flap were investigated in rats by subcutaneous injection of FE. Findings: The ELISA results revealed that the FE contain high levels of proangiogenic growth factors and FE promoted the proliferation, migration and tube formation of HUVECs in vitro. In addition, FE reduced the necrosis of skin flap and enhanced the their survival, which were demonstrated by macroscopic measurement and blood flow analysis. Histological analysis revealed that capillary densities were enhanced by FE treatment. Interpretation: FE is a cell-free, easy-to-prepare and growth factors-enriched liquid derived from human adipose tissue, which possesses proangiogenic activity and improves skin flap survival by accelerating blood vessel formation. It could be potentially used for treating ischemic disorders. Funding: This work was supported by the National Natural Science Foundation of China (81771993), the National Key Research and Development Program of China (2016YFC1101400), and the Natural Science Foundation of Shanghai (16ZR1419800). Declaration of Interest: The authors declare that they have no conflicts of interest. Ethical Approval: The study was approved by the Ethics Committee of Shanghai Jiaotong University School of Medicine, Shanghai, China.