Study of the adsorption mechanisms of Albumin on CoCrMo biomedical alloy by means of Electrochemical Impedance Spectroscopy

CoCrMo alloys have been widely employed in orthopaedic implants due to their high corrosion resistance, wear properties, hardness and biocompatibility in biological systems [1]. It has been suggested that the physicochemical and dielectric properties of the oxide film play an important role in determining implant biocompatibility [3]. It is well known that some proteins are adsorbed onto the surface of certain biomaterials modifying their surface characteristics. Recent studies showed that adsorption of Albumin takes place on the CoCrMo surfaces [3, 4]. Thus, the aim of this research is to determine the adsorption mechanisms of the Albumin on a CoCrMo alloy and the influence of temperature on those mechanisms. Adsorption of Albumin on the CoCrMo surface was studied by electrochemical techniques: Open Circuit Potential (OCP) measurements, Electrochemical Impedance Spectroscopy (EIS) and potentiodynamic curves (anodic and cathodic). Different Albumin concentrations were considered: 0, 5, 20, 50 and 500 mg/l in a NaCl solution (8 g/l). The electrochemical tests wer