Parylene-N a Better Candidate for Medical Substrate Coating than Parylene-C

摘要

The biomaterial - tissue interface plays a key role in implant success. The advantage of using parylene-C a class VI FDA approved polymer for implants is well known. Parylene-N and parylene-C thin films deposited via polymer vapor deposition (PVD) on Si (111) were investigated by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The surface of parylene - C is smooth, while for parylene - N bundles of fibrils are clearly observed by SEM. XRD showed that parylene-N is more packed than parylene-C thus should withstand better to moisture. The kinetics of the two is different; parylene-C has a greater deposition rate than parylene-N but the last one has a greater penetration to small crevices than parylene-C. Therefore we hypothesize that parylene-N could be more suitable as protective coating for medical instruments (not for implantable devices though) than parylene-C.