| Background:Autologous adipose tissue transplantation for soft-tissue augmentation is commonly used in plastic and reconstructive surgery nowadays. It differed from synthetic prothesis or the allograft, the risk of immune rejection in autologous lipotransfer is null. The autologous adipose tissue transplantation has been verified from a block of fat tissue transplantation to lipoaspirate transplantation. However, adipocyte’s apoptosis, calcification, fibrils accompanies with the graft absorption during long time follow up happens frequently.Some studies suggest the reason of absorption is lacked of sufficient blood supply after transplantation. By studying the mechanism of adipose tissue transplantation, the lack of vascular structures and stromal vascular fraction cells(SVF) including adipose derived stem cells(ASCs) in the grafted adipose tissue compared with the normal adipose tissue has been found. With plenty of studies depict positive results, the prompt of using adipose stromal cells to prevent apoptosis and other untoward effects could be one way to solve the problem. And attempts to supplement SVF in adipose tissue transplantation called cell assisted lipotransfer(CAL) got a improve, but the result still not contentment. Insufficient cell concentration may be the reason. Different cell concentration may have effect on the survival of transplantation. It is worthwhile to increase the cell concentration in graft tissue in order to make a further improvement.So far, as we know, the ASCs perform an important role in adipose transplantation by continuously self renew and secreting growth factors. However, just like the other mesenchymal stem cells losing their pluripotency and proliferation capabilities during ageing, ASCs are inevitably ageing too. Umbilical cord mesenchymal stem cells(UCMSCs) have greater expansion capability, also could differentiate into many cell types, have stronger proliferation capability, and well tolerated by the immune system. Suggesting that UC-MSCs are a primitive stromal cell population with therapeutic potential.ASCs enhance adipose tissue survival after transplantation, mostly because the improved vascularization. Endothelial cells(ECs) are indispensable in vascular formation, a recent study depicts that ECs from mouse could reassemble vascular network after transplantation rapidly. So it is necessary to study the endothelial cells’ effect on adipose tissue transplantation.we designed a preliminary study on discovering the concentration of the cells’ effects on the survival rate, and on supplementing umbilical cord mesenchymal stem cell(UCMSCs) and endothelial cell(ECs) to the adipose tissue transplantation, and in order to find a guidance for the optimal cell strategy in lipotransfer.Objects:1. Study the effects of cell concentration to survival of adipose tissue transplantation,2. Study the effect of supplement umbilical cord mesenchymal cells of adipose tissue transplantation.3. Compare the difference between ASCs and UCMSCs effect on adipose tissue transplantation, investigate the mechanism of ASCs and UCMSCs’ contribution of vascularization.4. Study the effect of endothelial cells on adipose tissue transplantation, the concentration of endothelial cells of survival, and try to detect the mechanism of these procedures.Methods:1. Supplement the ASCs at different concentration to adipose tissue transplantation. Harvest the transplant tissue at 1 week, 1 month, 2 months after surgery, measure the weight of the drafted tissue, HE staining to analysis the absorption,cysts, fibrosis within the tissue, and real-time PCR to detect Peroxisome proliferator-activated receptor gamma(PPAR-γ), vascular endothelial growth factor(VEGF) gene expression.2. Supplement UCMSCs to fat transplant, Harvest the transplant tissue at 1week, 1month, 2months after surgery, measure the weight of the drafted tissue, HE staining to analysis the absorption,cysts, fibrosis within the tissue, and real-time PCR to detect PPAR-γ,VEGF gene expression.3. Transplant adipose tissue with UCMSCs and ASCs, harvest the transplanted tissue at 1 week,1 month and 2 months after transplantation, measure the weight of the grafted tissues, analysis the vascular formation using immunofluorescence staining of tissue sections, real-time PCR analysis of the VEGF, PPAR-γand interleukin-8(IL-8) gene expression between these groups. Compare the growth factors IL-8,interleukin-6(IL-6), tumor necrosis factor-α(TNF-α), VEGF, hepatocyte growth factor(HGF) secreted by UCMSCs and ASCs by ELISA analysis.4. Isolate endothelial cells from SVF using the MACS microbead, then characterize the cells as endothelial cells. Co-transplant the endothelial cells at different concentration, analysis the weight, vascular density, and angiogenesis gene expression after 1 week, 1 month, 2 months post-operation, so as to clarify ECs’ role in vascularization, and determine the effects of cell concentration to adipose transplant survival.Results:1. Increase ASCs concentration could improve graft survival, increase VEGF and PPAR-γ gene expression at 1.month and 2 months post-transplantation, and the results are statistically different 2 months post-transplantation.2. Based on the pure fat control, UCMSCs could help increase the graft tissue weigtht and VEGF to a certain degree, though there are no statistical difference at 1week, 1 month and.2 months post-transplantation.3.Compared with UCMSCs, ASCs performed better in assisting adipose transplantation by increasing the graft tissue weight, vascular diameter, and VEGF, PPAR- γ,IL-8 gene expression, the differences are statistical significant. And ASCs secreting more IL-6, IL-8, TNF-α, VEGF, HGF.4. The cells isolated from adipose tissue was capable to express endothelial markers, up-take acetylated low-density lipoprotein, labeled with 1,1￠-dioctadecyl-3,3,3￠,3￠ tetramethylindocarbocyanineperchlorate(Ac-Dil-LDL), and form tube structures in Matrigel. ECs could improve the adipose tissue survival by the increase the weight of graft tissue, vascular density, angiogenesis gene expression level, and the higher cell concentration brings an enhanced result. The 4x106/0.5ml concentration ECs showing a little promotion effect on tissue augmentation after 2 months observation.Conclusions:1. Increasing the cell concentration could improve the adipose tissue survival by higher graft tissue weight, and more VEGF gene expression in the grafted tissue.2. UCMSCs could not capable to increase vascularization and adipogenesis or decrease the absorption of the graft fat significantly, it’s still doubt to application UCMSCs in adipose tissue transplantation.3. ASCs could help the vessel formation, secrete growth factors to enhance vascularization and prone to adipogenesis, is quite suit for assist adipose transplantation. UCMSCs have less characters mentioned above, and not as suitable as ASCs in assisting adipose tissue transplantation.4. ECs could increase survival rate of adipose tissue transplantation statistically significantly by direct form vascular networks, it could be a choice to assist lipotransfer. And the graft weight, vessel density and VEGF gene expression are concentration dependent to the cell concentration. |
PDF Full Text Request