ORIGINAL PAPER Staphylococcus aureus adhesion to standard micro-rough and electropolished implant materials Llinos G. Harris Æ D. Osian Meredith Æ Lukas Eschbach Æ R. Geoff Richards Received: 1 November 2005 / Accepted: 29 March 2006 / Published online: 1 February 2007 Ó Springer Science+Business Media, LLC 2007 Abstract Implant-associated infections can cause serious complications including osteomyelitis and soft tissue damage, and are a great problem due to the emergence of antibiotic resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA). In some cases, antibiotic-loaded beads which release the antibiotic locally have been used, however such systems may lead to the development of antibiotic- resistant bacteria, as seen with gentamicin-loaded beads. Hence modifying the actual metal implant surface to inhibit or reduce initial bacterial adhesion may be an alternative option. This study describes the visualisation and quantification of S. aureus adhering to standard micro-rough ‘commercially pure’ titanium (TS) and Ti-6Al-7Nb (NS) surfaces, electropolished titanium (TE) and Ti-6Al-7Nb (NE) surfaces, and standard electropolished stainless steel (SS). Qualita- tive and quantitative results of S. aureus on the different surfaces correlated with each other, and showed significantly more live bacteria on NS than on the other surfaces, whilst there was no significant difference between the amount of bacteria on TS, TE, NE and SS surfaces. The results showed a significant decrease in the amount of bacteria adhering to the NE compared to standard NS surfaces. Such an observa- tion suggests that the NS surface encouraged S. aureus adhesion, and could lead to higher infection rates in vivo. Hence electropolishing Ti-6Al-7Nb surfaces could be advantageous in osteosynthesis areas in minimising bacterial adhesion and lowering the rate of infection. Introduction Osteosynthesis implant surfaces are generally designed to encourage soft and hard tissue adherence, eventu- ally leading to tissue integration and osseointegration. Soft tissue infections and osteomyelitis are serious complications associated with implants, particularly open fracture injuries [1]. The ability of S. aureus in adhering to the extracellular matrix (ECM) and plasma proteins deposited on biomaterials, eventually forming biofilms, are significant factors in the pathogenesis of implant-associated infections [2–4] Titanium, titanium alloys and stainless steel are commonly used for osteosynthesis implants, and the differences between stainless steel and titanium, and their biocompatibility are well documented [5–7]. Stainless steel implants are associated with significantly greater infection rates than standard titanium implants [5, 8]. A possible explanation for this is the fact that soft tissue adheres firmly to titanium implant surfaces [7, 9], whilst stainless steel implants encourage the formation of a fibrous capsule, enclosing a non-vascu- larised liquid filled void [9, 10]. In theory, bacteria can spread and multiply freely in this space, particularly as L. G. Harris Á D. O. Meredith Á R. G. Richards AO Research Institute, AO Foundation, Clavadelerstrasse 8, 7270 Davos, Switzerland L. G. Harris (&) School of Medicine, University of Wales Swansea, Margam Building, Singleton Park, Swansea SA2 8PP, UK e-mail: llinosharris@yahoo.co.uk L. Eschbach Dr. h. c. Robert Mathys Stiftung, Bischmattstrasse 12, 2544 Bettlach, Switzerland J Mater Sci: Mater Med (2007) 18:1151–1156 DOI 10.1007/s10856-007-0143-0 123