Systemic strategy for biocompatibility assessments of metallic biomaterials: Representativeness of cell culture medium

Corrosion tests of metallic materials for biomedical applications are generally carried out in highly simplified solutions and are often disapproved by direct or indirect cytotoxicity tests. Cell culture medium is then the better alternative to get robust biocompatibility assessments. The specific intrinsic reactivity of a Roswell Park Institute Medium cell culture medium (RPMI-1640) was studied here using a platinum electrode inside and outside a dedicated CO2 incubator. Electrochemical tests and surface analyses revealed that organic compounds of the RPMI-1610 are forming an organic adsorbed layer on the surface which is electrochemically active in a wide potential range. Precipitations of inorganic salts (calcium phosphate) are also promoted by organic species. The effect of the 5% content of CO2 in the incubator was also discussed, relative to the fact that carbonate and bicarbonate ions are involved in the charge transfer and mass transport processes. All these features were taken into account when performing biocompatibility tests for material design and selection. (C) 2018 Elsevier Ltd. All rights reserved.