Experimental Study Of SVF-gel Reducing Capsular Contracture By Regulating Inflammatory Response

Objective: To investigate the influence of SVF-Gel on the Breast Augmentation capsule formation and contracture after transplantation around the prosthesis.Methods:(1)SVF-gel was prepared by mechanical micronization of lipoaspirates and identified by flow cytometry;(2)To establish capsular contracture model,silicone gel implants was placed under the submuscle of female SD rats at the age of 8W;(3)The infiltration degree of inflammatory cells and the thickness of the capsule were observed by HE method.(4)Obtain the arrangement of collagen in the capsule by Masson Trichrome Staining method;(5)CD31 immunohistochemical staining was used to observe the situation of vascular formation in the capsule tissue;The number and arrangement of myofibroblasts in the capsule were observed by α-SMA immunohistochemical staining.(6)The proportion of macrophages(M1/M2)at the early stage of implantation(0-7 days)was observed by immunofluorescence stainingResults:(1)SVF-gel prepared by mechanical micronization was composed of adipose tissue-derived stem cells(CD45-,CD31-,and CD34+),accounting for 9.78% of the total number of cells,endothelial progenitor cells(CD45-,CD31+,and CD34+)accounted for 18.5% of the total number of cells,and the remaining 71% were other cells.;(2)At 12 weeks,the Baker grade of the PBS group was level Ⅲ,while the SVF cell group and the SVF-gel Baker grade were both level II.(3)At 8 weeks,the capsule thickness of the SVF-gel group was 102.94±3.37 um,that of the SVF cell group was 141.45±6.21 um,and that of the PBS group was 251.79±4.66.The capsule thickness of the PBS group was thicker than that of the SVF cell group and the SVF-gel group,with statistical significance(p<0.05).At 12 weeks,the capsule thickness of the SVF-gel group was 124.68±6.31 um,that of the SVF cell group was 147.15±10.33 um,and that of the PBS group was 325.83±13.58 um.The thickness of the PBS group was thicker than that of the SVF cell group and the SVF-gel group,with statistical significance(p<0.05).(4)At 3 days,inflammatory cell infiltration appeared in advance in the SVF cell group and the SVF-Gel group;At 1 week,the number of inflammatory cell infiltration in the capsule of PBS group,SVF cell group and SVF-gel group was similar,and there was no statistical difference.At 12 weeks,the number of inflammatory cells in the PBS group was higher than that in the SVF group and the SVF-gel group,and the number was statistically significant(p<0.05).(5)M2 macrophages were observed in the SVF-gel group and the SVF group.(6)The number of collagen in SVF-gel group was lower than that in PBS group,and the difference was statistically significant(p<0.05).(7)The number of myofibroblasts in SVF-gel group was lower than that in SVF cell group and PBS group,and the difference was statistically significant(p<0.05).Conclusions: After SVF-gel was transplanted into the surrounding tissues of the silicone gel implants,it could advance and reduce the inflammatory response,promote the polarization of macrophages to M2 phenotype,inhibit fibrosis,thereby reducing the overall thickness and Baker grading of the capsule,affecting the formation and contracture process of the capsule after prosthesis implantation,and alleviating the contracture of the capsule.