Protein interactions with corroding metal surfaces: comparison of Mg and Fe Victoria Wagener, Anne-Sophie Faltz, Manuela S. Killian, Patrik Schmuki and Sannakaisa Virtanen * Received 9th December 2014, Accepted 12th January 2015 DOI: 10.1039/c4fd00253a The influence of bovine serum albumin (BSA) on the electrochemical behaviour of pure Mg and Fe was studied in simulated body fluid (SBF), in view of the possible application of these materials as biodegradable metals. Results indicate a different trend for the BSA-effect on corrosion for the two metals: for Mg, a strong corrosion-inhibiting effect is observed in the presence of BSA in solution, especially for short-term exposure, whereas for Fe only a slight acceleration of corrosion is caused by the addition of BSA to the solution. For both metals, the protein-effect on the electrochemical behaviour shows a complex time-dependence. Surface analysis indicates that stronger BSA adsorption takes place on Mg than on Fe. Moreover, adsorption experiments with BSA and a second protein (lysozyme) were conducted. The results are discussed in view of electrostatic interactions between differently charged metal oxide/hydroxide surfaces and proteins. 1 Introduction Low-corrosion resistant metals to be used as biodegradable implant materials have been in the focus of intensive research activities in recent years, see e.g. review articles. 1–7 The seemingly simple idea is to exploit the inherent degradation of low-corrosion resistant metals and alloys in biomedical applications, where the device is only required for a certain time of healing and where permanent implants may lead to various long-term complications. Such applications could be for instance cardiovascular stenting or temporary bone healing devices. Due to the required mechanical properties of the materials used for these applications, metals instead of biodegradable polymers are in the focus of interest. A major part of the investigations on biodegradable metals have been carried out on Mg and its alloys; much less work has been dedicated to Fe based mate- rials. The current knowledge indicates that whereas many Mg alloys seem to show a too fast corrosion rate in biological environments, Fe based materials may Institute for Surface Science and Corrosion, University of Erlangen-Nuremberg, Martensstrasse 7 (WW4, LKO), 91058 Erlangen, Germany. E-mail: virtanen@ww.uni-erlangen.de; Fax: +499131-8527582; Tel: +499131- 8527577 This journal is © The Royal Society of Chemistry 2015 Faraday Discuss. , 2015, 180, 347–360 | 347 Faraday Discussions Cite this: Faraday Discuss. , 2015, 180, 347 PAPER Published on 23 April 2015. Downloaded by Universitat Erlangen Nurnberg on 24/01/2017 10:29:11. View Article Online View Journal | View Issue