[Study on the survival rate of random flap using pre-injection of ADSCs]

Objective: To determine the effects of adipose-derived stem cells (ADSCs) on the survival rate of flaps by transplanting ADSCs into the experimental flaps pre-operatively. Methods: ADSCs were isolated from fresh human fat and cultured in vitro. Their morphological characters were observed, and flowcytometry and differentiation test and evaluation were conducted. A total of 40 BALB/c mice were divided into 5 groups randomly with each of 8 mice. 1 cm×4 cm random skin flap was designed on the mice back, ADSCs were injected in advance into subcutaneous tissues of 3 groups, the operation was performed on the 2^nd, 5^th and 7^th day after the ADSCs injection, meanwhile skin flap operation was conducted in the immediate injection group and control group. Survival condition of the skin flaps was observed and von willebrand factor (vWF) staining was used to detect the number of micro-vessels in the skin flap. The enzyme-linked immuno sorbent assay (ELISA) method was used to detect the concentration of vascular endothelial growth factor (VEGF) in the skin flap. Results: The immediate injection group had a significantly higher survival rate of skin flap than the pre-injection groups and the control group [(51.5±6.3)% vs (38.3±6.7)%, (21.0±2.9)%, (30.0±3.9)% and (34.5±4.2)%, all P<0.01]. The immediate injection group had a significantly higher number of micro-vessels in the skin flap than the pre-injection groups and the control group [(21.0±4.3) vs (17.5±3.9), (9.9±2.6), (13.9±2.6) and (16.1±3.3)/LPF, all P<0.01]. The laboratory results of the concentration of VEGF in skin flap kept a consistent tendency with the flap survival rate. Conclusion: Pre-injection with the ADSCs into the skin flap prevents the survival of the flap to a certain extend and does not show the function of promoting tissue angiogenesis.