Corrosion protection and enhanced biocompatibility of biomedical Mg-Y-RE alloy coated with tin dioxide

Oxide films composed of mainly tin dioxide and a small amount of stannous oxide are sputter-deposited onto the biomedical Mg-Y-RE (WE) alloy to enhance the anticorrosion properties and biocompatibility. The film composition, thickness, water contact angle, corrosion resistance, protein adsorption, and initial cell behavior are evaluated. Compared to the control, the corrosion current density and charge transfer resistance of the coated WE alloy in simulated body fluids show a 345-fold decrease and increase of more than 3 orders of magnitude, respectively, thus indicating excellent protection rendered by the surface layer. Furthermore, the modified WE alloy shows enhanced attachment and spreading of MC3T3-E1 pre-osteoblasts resulting from more protein adsorption.