Hindawi Publishing Corporation Bioinorganic Chemistry and Applications Volume 2012, Article ID 850390, 5 pages doi:10.1155/2012/850390 Research Article Analysis of the Release Characteristics of Cu-Treated Antimicrobial Implant Surfaces Using Atomic Absorption Spectrometry Carmen Zietz, 1 Andreas Fritsche, 1 Birgit Finke, 2 Vitezslav Stranak, 3 Maximilian Haenle, 1 Rainer Hippler, 3 Wolfram Mittelmeier, 1 and Rainer Bader 1 1 Biomechanics and Implant Technology Research Laboratory, Department of Orhtopeadics, University of Rostock, Doberaner Straβe 142, 18057 Rostock, Germany 2 Leibniz Institute for Plasma Science and Technology (INP e.V. Greifswald), Felix-Hausdorff-Straβe 2, 17489 Greifswald, Germany 3 Institute of Physics, Ernst-Moritz-Arndt University of Greifswald, Felix-Hausdorff-Straβe 6, 17487 Greifswald, Germany Correspondence should be addressed to Carmen Zietz, carmen.zietz@med.uni-rostock.de Received 1 September 2011; Accepted 24 October 2011 Academic Editor: Reinhard Paschke Copyright © 2012 Carmen Zietz et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. New developments of antimicrobial implant surfaces doped with copper (Cu) ions may minimize the risk of implant-associated infections. However, experimental evaluation of the Cu release is influenced by various test parameters. The aim of our study was to evaluate the Cu release characteristics in vitro according to the storage fluid and surface roughness. Plasma immersion ion implantation of Cu (Cu-PIII) and pulsed magnetron sputtering process of a titanium copper film (Ti-Cu) were applied to titanium alloy (Ti6Al4V) samples with different surface finishing of the implant material (polished, hydroxyapatite and corundum blasted). The samples were submersed into either double-distilled water, human serum, or cell culture medium. Subsequently, the Cu concentration in the supernatant was measured using atomic absorption spectrometry. The test fluid as well as the surface roughness can alter the Cu release significantly, whereby the highest Cu release was determined for samples with corundum-blasted surfaces stored in cell medium. 1. Introduction Total joint replacement (TJR) meets high quality and safety standards and has become a frequent surgical procedure in order to restore joint function [1]. However, implant revision remains a relevant problem in clinical use. Failure of TJR is mainly due to aseptic loosening caused by inflammatory reactions due to wear particles [2]. Postoperative implant- associated infections are rare but considered devastating complications after TJR. Although surgical techniques and environmental conditions during the surgical intervention have improved over the years, infections occur with a fre- quency of 0.5–2% with incisive consequences for the patients and medical costs [3]. Most implant-associated infections are caused by Staphylococcus aureus and Staphylococcus epidermidis [4, 5]. Immediately after implantation bacteria, and human host cells compete for the implant surface in the so-called “race for the surface” [6]. If bacteria adhere to the implant surface prior to human bone cells, biofilm formation might occur and osseous integration of the implant is precarious. In terms of biofilms, the treatment of implant-associated infec- tions can be further hindered by the thus increased bacterial resistance against antibiotics [7]. Novel developments of ion- based antimicrobial implant surfaces such as silver (Ag) [8] or copper (Cu) [9] might offer a possible solution to this problem. Various in vitro and in vivo studies confirm the antibacterial properties and cytocompatibility of Cu [10–13]. Other alternative antibacterial materials and agents are in development or already in use to prevent or treat implant- associated infections [14–18]. In vitro investigations of the antibacterial effects are usually performed on simplified samples and under simplified testing conditions, whereas in vivo tests are usually closer to the final application. In vitro conditions are often adjusted according to the respective test, that is, cell biological and microbiological tests are performed