Preparation and Properties of Zn-Cu Alloy for Potential Stent Material

Among degradable metal cardiac stent materials, zinc has great biocompatibility and corrosion properties, which make it become the most potential stent material. However, the mechanical properties of zinc cannot meet the performance requirements of stent material which severely limit its application. In this paper, Zn-xCu (x = 1, 2 and 3 wt.%) alloys were prepared, and their mechanical properties, corrosion properties and biocompatibility were studied. Tensile testing showed the tensile strength and hardness of Zn-xCu alloys both increased with the addition of copper, but the elongation decreased at first and then upturned. Since the formation of galvanic cell, the corrosion rates of Zn-xCu alloys increased. The main corrosion mechanism of Zn-xCu alloy was pitting corrosion, and the corrosion products mainly included ZnO and Zn(OH)2. The cytotoxicity evaluation showed that Cu2+ and Zn2+ would contribute to cell proliferation, while the concentrations of them reached a suitable range like the concentration of soaking solution of Zn-3Cu alloy was 25%. However, it would inhibit proliferation, while the concentrations of Zn2+ and Cu2+ were too large. In general, Zn-3Cu alloy had the best comprehensive properties.