Characterization and mechanical investigation of Ti–O2−x film prepared by plasma immersion ion implantation and deposition for cardiovascular stents surface modification

Up to date, materials for cardiovascular stents are still far from satisfactory because of high risk of biomaterials-associated restenosis and thrombosis. Extensive efforts have been made to improve the biocompatibility of the materials by various surface modification techniques. Ti–O2−x films prepared by plasma immersion ion implantation and deposition (PIII&D) have shown good blood compatibility. For clinical application, surface quality and mechanical durability of the Ti–O2−x film on stents are also of critical importance for the long-term serving. In this paper we present our research results on surface quality, mechanical investigation and characterization of Ti–O2−x films prepared using PIII&D on stent products provided by Boston Scientific SCIMED. Ti–O2−x films with mostly Rutile and little non-stoichiometric phases were obtained with smoothness of <3 nm RMS, largely homogeneity as well as good intergradient film/substrate interface. The Ti–O2−x films on stents products were sustained balloon-expansion of clinically-required extent without mechanical failure, showing highly potential feasibility for cardiovascular stents application.

► We prepared Ti–O2−x films of good quality by PIII&D successfully on stents product. ► The Ti–O2−x film shows good homogeneity and intergradient film/substrate interface. ► The Ti–O2−x films on stent sustain clinically-required expansion without failure. ► The films show good mechanical durability for cardiovascular stents application.