Experimental study on the effects of cross-linked hyaluronic acid on the survival of microfat grafting
Objective To investigate the effects of cross-linked hyaluronic acid(CLHA)on the survival of micro-fat grafting.Methods Seventy-two eight-week-old SPF fe-male BALB/c nude mice weighting 22-24 g were divided into two parts,of these,24 were used only to determine the metabolism of customized CLHA,and 48 were used only to study the effect of CLHA on survival after microfat grafting.Twenty-four nude mice were divided into groups A,B,C,and D according to the random number table method,with 6 mice in each group;0.3 ml customized CLHA was injected subcuta-neously into the back of nude mice,all nude mice in groups A,B.C,and D were necropsied at 1,2.4.and 12 weeks postop-eratively,and the remaining volume of customized CLHA was determined and HE staining were determined.Forty-eight nude mice were divided into the experimental group and the control group according to the random number table method,with 24 mice in each group.The experimental group received a mixture of 0.3 ml customized CLHA and 0.3 ml human mi-crofat subcutaneously in the back,while the control group received only 0.3 ml of human microfat.Six nude mice were necropsied at 1,2,4,and 12 weeks postoperatively in each group,and fat tissue volume retention,histologic scores,Per-ilipin-1(+)live adipocytes percentage,CD31(+)vessels number,and vascular endothelial growth factor(VEGF)optical density values,and effective volume retention were compared between the two groups.Results Over time,the visual and measured volume of the transplanted customized CLHA gradually decreased,and customized CLHA was no longer visible in group D.In group A,a large number of pale blue-purple customized CLHA were distributed in the tissue interstitium;in group B,fibrosis and inflammatory cell infiltration were seen in the interstitium,and customized CLHA were scattered;in group C,the interstitium of the tissues were loosened and widened,the interstitial fibrosis was intensified,and the infiltration of inflammatory cells was increased,and the area of customized CLHA was reduced;in group D,no customized CLHA were seen in the field of view,and the subcutaneous structure of the injection site was similar to that of the normal subcutaneous structure.The experimental group had the most neovascularization at 4 weeks postoperatively,whereas it decreased at 12 weeks postoperatively compared with the previous period;and the overall neovascularization of the grafts in the control group was more evenly distributed at all time points.At 1,2,4,and 12 weeks postoperatively,the volume retention rate in the ex-perimental group was lower than that in the control group(P＜0.05).In the experimental group,more inflammatory cell infil-tration and extracellular matrix deposition were seen among the adipocytes of the grafts,and neovascularization was mainly concentrated in the periphery of the grafts;in the control group,the adipocytes were predominantly structurally intact,and inflammatory cell infiltration and extracellular matrix deposition were less.At 1,2,4,and 12 weeks postoperatively,the adipocyte integrity scores of the experimental group were lower than those of the control group,and the fibrosis regions and inflammation cell infiltration scores were higher than those of the control group(P＜0.05);at 1,4,and 12 weeks postopera-tively,the necrosis regions scores of the experimental group were higher than those of the control group(P＜0.05);at 2,4,and 12 weeks postoperatively,the oil sac/void scores of the experimental group were lower than those of the control group(P＜0.05).The live adipocytes in the experimental group were smaller and less regular in shape in the early stage,but the adipocytes increased significantly in volume and tended to be more rounded in shape at 2 weeks postoperatively;in the con-trol group,the morphologic homogeneity of the live adipocytes was poorer at all time points and there was no obvious tenden-cy for the volume to increase.At 1 and 2 weeks postoperatively,Perilipin-1(+)live adipocytes percentage in the experimen-tal group was lower than that in the control group(P＜0.05);at 4 and 12 weeks postoperatively,Perilipin-1(+)live adipocytes percentage in the experimental group was higher than that in the control group(P＜0.05).At 1,2,4 and 12 weeks postoperatively,the effective volume retention rate of the experimental group was lower than that of the control group(P＜0.05).At 1 and 2 weeks postoperatively,neovascularization in the experimental group was mainly concentrated at the edges of the grafts and gradually grew into the interior over time;in the control group,the distribution of vasculature was consis-tently more holistic and homogeneous.At 1 week postoperatively,CD31(+)vasculature number in the experimental group was lower than that in the control group(P＜0.05);at 2,4.and 12 weeks postoperatively,CD31(+)vasculature number in the experimental group was higher than that in the control group(P＜0.05).At 1,2,4,and 12 weeks postoperatively,the VEGF optical density value of the experimental group was higher than that of the control group(P＜0.05).Conclusion The pres-ence of CLHA is detrimental to the long-term survival of microfat grafting,and it is recommended to wait until the local CLHA has been completely metabolized or pre-solubilized with hyaluronidase before granular fat grafting is performed in the clinic.
万方数据
维普
