Application of nickel‑titanium (NiTi) alloys to medical implant devices is increasing due to their unique characteristics. However, many reports show adverse effects of corrosion of the alloys due to implantation in human body. To ensure good biocompatibility in the human body, fluorine-doped amorphous carbon (a-C:H:F) coating is a promising candidate. Generally, a-C:H:F coating shows poor adhesion on metallic alloys, so that silicon-incorporated interlayer is introduced between a-C:H:F and metallic alloys. However, this membrane design has a risk of delamination at the outermost interface (a-C:H:F//interlayer), and also there is a practical problem that coating time becomes long because the deposition process in multiple stages is required. Here we develop silicon and fluorine doped amorphous carbon (a-C:H:Si:F) film which exhibits high adhesion and excellent biocompatibility. One of the a-C:H:Si:F films “C2H2-doped”, which was deposited using a mixture of TMS, C2H2 and C3F8, showed higher adhesive strength than a-C:H:F with Si-interlayer and the same number of adhesive platelets and leukocytes as a-C:H:F. This result demonstrated that a single film with both adhesion of Si-interlayer and biocompatibility of a-C:H:F was fabricated. Furthermore, this a-C:H:Si:F coating can be anticipated as an effective film coating method in a practical point of view, because the film deposition is completed in one process.
ASJC Scopus subject areas
- 化学 (全般)