Stability of and inflammatory response to silicon coated with a fluoroalkyl self-assembled monolayer in the central nervous system.

Abstract

A self-assembled monolayer (SAM) of fluoroalkyl silane (FAS) (CF(3)(CF(2))(5)(CH(2))(2)SiCl(3)) was deposited on the surface of silicon wafers, aiming to enhance its stability and to reduce the inflammatory response in the central nervous system. Following implantation of the FAS SAM coated silicon in rat brains, the FAS SAM coating failed to reduce the inflammatory response of silicon, because it could not prevent the corrosion of the underlying silicon. The corrosion was hindered for the initial 10 days by the FAS SAM coating, but there was nearly no difference when compared to the uncoated silicon when the implantation periods were extended to 28 and 90 days. The FAS SAM coating was completely removed within 28 and 90 days. Meanwhile, on all the extracted uncoated and FAS SAM coated silicon wafers, there were proteinaceous substances deposited on the surfaces, and the amount of the deposits increased with exposure time.