In vitro investigation of ultra-pure Zn and its mini-tube as potential bioabsorbable stent material

In the study, the mechanical properties, degradation behavior and in vitro biocompatibility of an ultra-pure Zn and its mini-tube were evaluated with the high-pure Mg and its mini-tube as controls. Compared with high-pure Mg, ultra-pure Zn had close mechanical properties and cytotoxicity, but it indicated lower corrosion rate (0.011mm/y) than pure Mg in Hank's solution. Meanwhile, the hematolysis rate (1.00%) was lower than 5%, which means that Zn has no significant destructive effect on erythrocyte. Furthermore, compared with plate specimens, the tube specimens showed higher corrosion rate (Zn ~0.028 to 0.037mm/y and Mg ~0.61 to 0.73mm/y, respectively) and hemocompatibility (Zn ~1.19% and Mg ~9.50%, respectively). In conclusion, the ultra-pure Zn mini-tubes might be considered as a potential bioabsorbable stent material.