Experimental Study On The Effect Of SVF-gel Assisted Coleman′s Fat Transplantation Promoting The Survival Of Fat Grafting With Large Volume In A Single-point

Objective: To observe the effect of single point fat transplantation with different injection quantity on the preservation rate of fat volume after transplantation,and to observe the histomorphological changes,so as to provide scientific basis for improving the survival rate of fat transplantation.Methods:(1)the adipose tissue of adult legs or lower abdomen was extracted by liposuction needle,SVF gel and Coleman fat were prepared,and the concentration of adipose stem cells in SVF gel was detected by flow cytometry;(2)108 male BALB / C nude mice were used to construct fat transplantation model.According to different single point fat injection quantity,they were randomly divided into control group(0.3ml injection group)and experimental group(0.6ml injection group,1.0ml injection group);each group was divided into the following four groups according to the different proportion of SVF gel and Coleman fat: A.Coleman fat group(Col group);B.SVF gel and Coleman fat 1:3(1svf Gel + 3col group);C.SVF gel and Coleman The ratio of fat was 1:1(1svf Gel + 1COL group),and D.(3)On the 3rd,7th,14 th,30th,60 th and 90 th day after the operation,drainage method and micro CT scanning were used to detect the change of the volume of fat grafts after fat transplantation,and he staining and immunohistochemistry were used to observe the angiogenesis,fat regeneration and fat transfer of fat grafts.Results: the total number of SVF cells was 5.7 × 10 ^ 5 / ml and 4.0 × 10 ^ 5 / ml by flow cytometry.On the 90 th day after transplantation,the general morphology of the0.6ml injection group was better than that of the control group,and the 1.0ml injection group was worse.On the 90 th day after transplantation,the preservation rate of 1 svfgel+ 3col in 0.6ml injection group was significantly higher than that in 0.3ml injection group(P = 0.0187).The score of 1svfgel + 3col group in 0.6ml injection group was lower than that of 1svfgel + 3col group in 0.3ml injection group(P = 0.044)Lipogenesis: on the 30 th day after surgery,most of the fat transplants in the Coleman group included perilipin negative areas and a large number of oil cysts.In SVF gel group,a large number of fat cells appeared in every field of fat graft,and in 1svfgel +3col group and 1svfgel + 1COL group,they were in the middle of the two groups.Angiogenesis: in the early postoperative period,the number of CD31 positive vessels in SVF gel group,1svfgel + 3col group and 1svfgel + 1COL group began to increase gradually on the 3rd day,reached the peak on the 14 th day,began to decline on the 30 th day,and maintained a relatively stable amount on the 30 th day.In Coleman group,the blood vessel density gradually increased 14 days later and maintained a low level.Graft source: on the 14 th day after fat transplantation,most of the HLA positive cells appeared in the intercellular space between mature fat cells,and presented a microvascular like lumen structure.However,in Coleman group,HLA was positive in a wide range;in 1svfgel + 3col and 1svfgel + 1COL groups,a small number of scattered mature fat cells with their nuclei overlapped HLA positive.Conclusion: in this study,we observed the influence of different injection amount of single point fat transplantation on the general view,survival rate and histomorphology of fat grafts after operation.We found that the SVF gel assisted Coleman fat transplantation in 0.6ml injection group can still maintain a certain preservation rate compared with 0.3ml injection group,and the 1svfgel + 3col group is the best,so the single point large volume injection method is feasible.