Effects of simulated inflammation on the encapsulation performance of medical silicone rubber coating for implantable electronic devices

This study is the first to investigate the effects of inflammation on the encapsulation performance of silicone rubber. Simulated inflammatory solutions containing H 2 O 2 were prepared for electrochemical measurements and immersion testing of the samples. The hydrogen peroxide (H 2 O 2 ) released by human inflammatory reactions significantly affects the encapsulation performance of silicone rubber coatings and the corrosion behavior of metal interfaces. Research has shown that H 2 O 2 accelerates the penetration of corrosive media into the coating-metal interface, resulting in a decrease in the encapsulation performance of silicone rubber. Simultaneously, the strong oxidation of H 2 O 2 triggers the degradation of the molecular chain of silicone rubber, which is manifested as the side chain methyl group (-CH 3 ) breaking into methylene and Si-C bonds, and C=O, C-O bonds, and hydroxyl groups are generated, which eventually causes the coating surface to form a mesh crack, accelerating its deterioration. In addition, after H 2 O 2 penetrates the surface of T2 copper, it not only promotes the formation of copper oxides but also significantly enhances the cathodic reaction rate, thereby aggravating copper corrosion. The degree of corrosion increased with increasing H 2 O 2 concentration. This study reveals the coordinated damage mechanism of H 2 O 2 on silicone rubber coating and metal corrosion in the inflammatory microenvironment, providing a theoretical basis for the material optimization of implantable medical electronics.