Corrosion of clinical relevant components of metallic biomaterials. Influence on biocompatibility

Abstract

Despite the long-standing use of metallic biomaterials there are still unsolved problems in relation to ions release and its effect on the biological environment. Silver and copper are some of the metal components of clinical relevance because of the toxic effects of their cations. Thus, the study of corrosion of these metals is important in relation to their biocompatibility. Saline solutions have been employed in several research works as electrolyte media. However, the metal dissolution may be affected by the organic components of the biological media. Among them, proteins are readily adsorbed on several metals and may affect the corrosion rate. Electrochemical tests inDubelco´s Modified Eagle Medium (DMEM) are interesting because biocompatibility assays are frequently
made using DMEM with the addition of fetal bovine serum as a culture medium for osteoblast cells. The aim of this work is to compare the dissolution of silver and copper in several saline and organic media such as fetal bovine serum and DMEM.Potentiostatic
and potentiodynamic electrochemical techniques with different perturbation programs were applied. The concentration of metal ions was determined through atomic absorption spectrophotometry. Microscopic observations of the metal samples were also made. Results showed that the dissolution process in the saline media was mainly governed by the chloride concentration. However, voltamograms showed a strong effect of proteins on the dissolution process occurring in biological media. A significant inhibition of the cathodic process and alterations in the distribution and shape of the reduction peaks were observed, particularly in the case of
silver.