Investigative study of myofibroblasts and cytokines in peri-implant tissue of silicone breast expander by rt-PCR in a rat model.

The excessive collagen deposition around silicone breast implants followed by contracture and development of severe pain is a major clinical problem. This study was conducted to investigate the profibrotic and antifibrotic cytokines secreted by inflammatory cells and development of myofibroblasts at the tissue material interface around silicone breast expander and ultra-high-molecular-weight polyethylene (UHMWPE). Both materials were implanted in rats for 30, 90 and 180 days. Inflammatory cells and collagen deposition at the material-tissue interface were assessed with Haematoxylin-Eosin and Masson's Trichrome stain. Gene expression of TGFbeta, IL-1beta, IFNgamma, IL10 and alpha-SMA was quantitated by real-time (RT)-PCR in the peri-implant tissue. Results indicate a difference in collagen deposition and myofibroblast development around both materials with involvement of TGFbeta, IFNgamma and IL10. The results emphasise the need for further investigation into the molecular mechanisms of protomyofibroblast and myofibroblast formation around silicone implants, which would provide information on these target cells for inhibitory therapy in the clinical situation.