WEB Influence of protein adsorption on the corrosion of FeMn alloys in physiological environments
Bioresorbable metallic implants provide desired functional properties for a certain time range and degrade safely within the body after their use phase. Iron based alloys have increasingly been considered for the development of biodegradable implants because of their mechanical properties. However, the degradation rate of pure iron is insufficient. Alloying iron with manganese is a way to increase the degradation rate. Another approach is the alloying of noble metals like silver, which act as local cathode to promote the corrosion.
When implant materials are exposed to blood, they are immediately coated with serum protein layers. This adsorption of proteins has an influence on the corrosion and biocompatibility. In this work, the corrosion properties of FeMn alloys and pure iron are investigated by potentiodynamic polarization and electrochemical impedance spectra in simulated body fluid (SBF) as physiological electrolyte containing different proteins. Bovine serum albumin (BSA) and hen egg white lysozyme (LYZ) are investigated as model proteins. Surface characterization by atomic force microscopy (AFM), Raman spectroscopy and FT-IR spectroscopy enables the correlation of alloy and surface film composition with the corrosion behavior.