Ki67, HSP70 and TUNEL for the specification of testing of silicone breast implants in vivo

This investigation of capsular tissue adjacent to silicone breast implants concerns the long-term tissue response to the implant environment. Fifty-three silicone breast implants have been analyzed at the time of explantation. The implant duration ranged from 2 months to 153 months. The reason for explantation was capsular contracture (57%), dissatisfaction with the effect (11%), local inflammation (6%), implant rupture (4%) and exchange of tissue expanders (21%). The cell turnover within the interface of the silicone device and the fibrous capsule was detected by specific antibodies against Ki67 for cell proliferation, by TUNEL for apoptosis, and by DNA strand breaks and heat shock protein 70 (HSP70) for cell stress. We found a negative correlation between the expression of HSP 70 and the capsular thickness (p < 0.043) and decreased levels in specimens obtained from Baker IV implant capsules. Ki67, and TUNEL were significantly positive (p < 0.001 for both) and HSP 70 were significantly negative (p < 0.001) with signs of inflammation. Both Ki67 and TUNEL indicated decreasing values over time. Ki67 and TUNEL showed no correlation with clinical signs of implant failure, such as the Baker score. The expression of HSP70, on the other hand, was connected with structural changes of the implant capsule, in terms of capsular thickness and the Baker score.