Evaluation of corrosion behaviour of metals under cell culture environments

Accurate evaluation of the corrosion behaviour of metallic biomaterials is necessary for the reliability not only because dissolved metal ions may cause toxicity but also because the corrosion may accelerate wear and fatigue. Corrosion test is generally carried out in a saline solution, simulated body fluids and medium and so on. However, the in vitro corrosion behaviour does not always coincide with the in vivo behaviour observed in animal tests or in the human body. Understanding of the interaction between metallic materials and tissues (cells) is necessary to connect the results in vitro and in vivo. We then investigated the corrosion behaviour of metallic biomaterials under cell culture environments to elucidate the corrosion factor originating from the presence of cells (tissues). Here, the author explains the in vivo environment where metal surface is subjected and presents the results of electrochemical tests and the pH measurement under cell culture environments. It was revealed that the presence of cells causes the retardation of mass diffusion on the metal surface with cell bodies and extracellular matrices, and then it appears that quasi-crevice corrosion proceeds. Cell response to the anodic or cathodic polarization of metal substrate is also presented.