Electrochemical corrosion behavior of orthopedic biomaterials in presence of human serum albumin

In this study, the effect of human serum albumin (HSA) in a concentration range of 0 to 4 g L^-1 in phosphate buffered saline (PBS) on the electrochemical corrosion behavior of AISI 316L, wrought Co-28Cr-6Mo and Ti-6Al-4 V was investigated by advanced electrochemical corrosion experiments such as cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The cyclic voltammetry results showed that the dissolution rate of iron from 316L and cobalt from Co-28Cr-6Mo alloy decreased in the presence of HSA. HSA also increased the oxidation of adsorbed hydrogen on Ti-6Al-4 V alloy by the external donation of hydrogen atoms. These results implied the formation of an adsorbed layer of protein on the oxide layer which was confirmed by the result of the EIS experiments. Furthermore, the increase of HSA concentration increased the surface coverage of HSA. The comparison of the BSA (bovine serum albumin) as an animal serum albumin with HSA showed that the surface coverage and the cathodic inhabitation of BSA were higher than HSA.