Localized corrosion and cytotoxic effect of ASTM F745 in culture médium

RICARDO W. GREGORUTTI; JE GRAU; PARISI J.; CASTROGIOVANNI, D.; CECILIA I. ELSNER

Darmstadt

Congreso; Materials Science and Engineering; 2018

DGM

AbstractAustenitic stainless steels (specification ASTM F138/139/745 are widely used for loadbearing partial and total joint replacements, and post trauma reconstructive surgeries. Thesebiomaterials contain Cr and Ni, which would cause different systemic-toxic reactionsduring the time that the device is implanted in the body. In particular, Ni is known asallergenic agent and has some carcinogenic potential.To evaluate this behaviour, samples of ASTM 745 have been subjected to localizedcorrosion assays by cyclic polarization tests, using a cell culture medium (CCM) as anelectrolyte. The CCM allow simulating in a more approximate way the conditions of thehuman body. In the present work, DMEM high glucose containing inorganic salts,vitamins, proteins, and supplemented with 10% inactivated fetal calf serum, 100 IU/mLpenicillin and 100 g/mL streptomycin sulfate, was used as CCM. The aim was to releaseCr and Ni ions to evaluate their possible cytotoxic effects.Cytotoxicity was evaluates by Neutral red and MTT assays, using UMR-106 cell line. Thebioassays were performed by triplicate and eight measurements were done in each case.The mean values from the 24 determinations were compared to negative and positivecontrols. The negative control is the culture medium not exposed to any toxic agent, whilethe positive control consists of the culture medium with a toxic agent (0.01% phenol) thatcauses a decrease in cell viability. The data were statistically analyzed by Student?s t-test,considering a critical p-value < 0.05. For p ≥ 0.05, the null hypothesis is valid and forp < 0.05, the null hypothesis is refused.The obtained electrochemical results are shown in Figure 1. The fast current increaseobserved at potentials close to 0.800 V/Ref could be ascribed to the onset of localizedcorrosion. After that, the stainless steel showed high repassivation capacity, since thereverse scan ended at 0.600 V/Ref, with a short hysteresis loop.