Research paper Simultaneous analysis of multiple serum proteins adhering to the surface of medical grade polydimethylsiloxane elastomers Aleksandar Backovic a, ⁎ , Dolores Wolfram b , Barbara Del-Frari b , Hildegunde Piza b , Lukas A. Huber c , Georg Wick a a Division for Experimental Pathophysiology and Immunology, Biocenter, Innsbruck Medical University, Fritz-Pregl Str. 3/4; A-6020 Innsbruck, Austria b Department of Plastic and Reconstructive Surgery, Innsbruck Medical University, Anichstr. 35, A-6020 Innsbruck, Austria c Division of Cell Biology, Biocenter, Innsbruck Medical University, Fritz-Pregl str. 3, A-6020 Innsbruck, Austria Received 19 February 2007; received in revised form 24 July 2007; accepted 29 August 2007 Available online 19 September 2007 Abstract Although polydimethylsiloxane (PDMS, silicone) elastomers are presumed to be chemically inert and of negligible toxicity, they induce a prompt acute inflammatory response with subsequent fibrotic reactions. Since local inflammatory and fibrotic side effects are associated with the proteinaceous film on the surface of silicone implants, the process of protein adherence to silicone is of practical medical relevance, and interesting from theoretical, clinical and biotechnological perspectives. It is hypothesized that the systemic side effects resembling rheumatoid and other connective tissue diseases may be triggered by local immunological changes, but this functional relationship has yet to be defined. Because the proteinaceous film on the surface of silicone has been identified as a key player in the activation of host defense mechanisms, we propose a test system based on a proteomics screen to simultaneously identify proteins adsorbed from serum to the surface of silicone. Herein, we describe protein adsorption kinetics on the surface of silicone implants, correlate the adhesion properties of serum proteins with the occurrence of adverse reactions to silicone, and successfully discriminate their signature on the silicone surface in a blinded study of patients suffering from fibrotic reactions (as determined by Baker scale) to silicone implants. © 2007 Elsevier B.V. All rights reserved. Keywords: Polydimethylsiloxane; Protein adsorption; Fibronectin; Silicone implants; Biocompatibility; In vitro test 1. Introduction Polydimethylsiloxane elastomers are used for the production of numerous active and passive implantation devices that are in direct, and sometimes prolonged, contact with human tissues. Routine medical practice during the last decades has endorsed silicone as the most widely used implant material despite the occurrence of intermittent local and systemic adverse immunological effects. Local side effects generally include formation of Journal of Immunological Methods 328 (2007) 118 – 127 www.elsevier.com/locate/jim ⁎ Corresponding author. Tel.: +43 512 9003 70966; fax: +43 512 9003 73960. E-mail addresses: Aleksandar.Backovic@i-med.ac.at (A. Backovic), Dolores.Wolfram@i-med.ac.at (D. Wolfram), Barbara.Del-Frari@uibk.ac.at (B. Del-Frari), Hildegunde.Piza@uibk.ac.at (H. Piza), Lukas.A.Huber@i-med.ac.at (L.A. Huber), Georg.Wick@i-med.ac.at (G. Wick). 0022-1759/$ - see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.jim.2007.08.016