In vitro and in vivo biocompatibility of an Ag-bearing Zr-based bulk metallic glass for potential medical use

Abstract

A bulk metallic glass (BMG), Zr46(Cu4.5/5.5Ag1/5.5)46Al8 (ZrCuAlAg), has been prepared and systematically evaluated in terms of microstructure, corrosion resistance, wear resistance, cytotoxicity, and in vivo implantation, aiming at exploring its use as a novel biomedical material. For comparison, the above-mentioned tests were also performed on Zr51.9Cu23.3Ni10.5Al14.3, Zr51Ti5Ni10Cu25Al9, and Ti40Zr25Ni12Cu3Be20 BMGs, pure Ti and Ti–6Al–4V alloys. ZrCuAlAg BMG exhibits better corrosion resistance in both NaCl and Hank's solutions than other materials. The cell culture tests indicate that the BMGs exhibit a cytotoxicity of Grades 0–1, identical with pure Ti and Ti–6Al–4V alloys. Cell morphological analysis shows that the cells were flattened and well spread out on the surfaces of the BMGs, demonstrating their good cell compatibility. Animal tests proved that the ZrCuAlAg BMG implant performed as well as Ti–6Al–4V, without any obvious inflammation reaction at the implantation sites. The excellent biocompatibility of ZrCuAlAg BMG can be attributed to its amorphous structure-related high corrosion resistance as well as its unique composition, i.e. free of toxic Ni and Be, and containing biocompatible Ag element. It suggests that the Ag-bearing ZrCuAlAg BMG with excellent biocompatibility is promising for biomedical applications.