Effect of ASC Injection in the Inflammatory Reaction in Silicone Implant Capsule: Animal Model

Background: Capsular contracture is a common complication affecting about 80% of patients who receive radiotherapy after breast reconstruction with silicone prostheses. This study examines the use of adipocyte stem cells (ASCs) to treat capsular contracture. Methods: Thirty rats were operated on to implant a minisilicone prosthesis in the dorsal region. The rats were divided into three groups: control (saline solution injection), radiotherapy (RDT), and RDT + ASC. After 3 months, the capsules were collected and submitted to histological analysis for inflammatory cell presence, vascular density, and collagen fibers, and gene expression of Tnf, Il1rap , Il10 , Cd68 , Mmp3 , and Mmp9 by qPCR. Results: In macroscopic analysis, the RTGO score showed a two-point reduction in RDT + ASC compared with the RDT ( P = 0.003). In histological analysis, ASC exhibited less than 50% of inflammatory cells compared with RDT ( P = 0.004), which was similar to control. This study demonstrated that Il1rap gene expression was identical in both RDT and RTD + ASC. Compared with control, treatment with ASC reduced Il1rap expression by 30%. Cd68 and Mmp3 expression levels were similar in both the control and RTD + ASC. Conclusion: This study suggests that ASC treatment decreases silicone prosthesis capsule inflammation.