Improved biodegradability of zinc and its alloys by sandblasting treatment

Abstract Zinc (Zn) and its alloys have been considered as potential materials for osteosynthesis implants. Nonetheless, the relatively slow degradation rates within bone environments impede their further application. Herein, sandblasting surface treatment with two Al2O3 particle sizes (125 μm and 250 μm) was employed to accelerate the degradation rates of Zn and two Zn alloys, a Zn 4Ag and a Zn-2Ag-1.8Au-0.2V (wt%). The degradation processes of Zn and Zn alloys were significantly increased after sandblasting treatment mainly due to the increased surface roughness and embedded Al2O3 particles in the surfaces. However, an increase of sandblasting particle size from 125 μm to 250 μm did not affect the degradation rates. Moreover, the mean relative metabolic activities of Saos-2 osteoblasts below 70% were observed for alloys treated with 250 μm Al2O3 particles, indicating apparent cytotoxic effects. The results showed that the size of the sandblasting particles had no direct effect on the degradation rate but on the cytotoxicity. Therefore, sandblasting treatment with appropriate particles might be a promising surface modification to accelerate the biodegradability of Zn and its alloys.