title: Staphylococcal biofilm growth on smooth and porous titanium coatings for biomedical applications.
abstract: Implant-related infections are a serious complication in prosthetic surgery, substantially jeopardizing implant fixation. As porous coatings for improved osseointegration typically present an increased surface roughness, their resulting large surface area (sometimes increasing with over 700% compared to an ideal plane) renders the implant extremely susceptible to bacterial colonization and subsequent biofilm formation. Therefore, there is particular interest in orthopaedic implantology to engineer surfaces that combine both the ability to improve osseointegration and at the same time reduce the infection risk. As part of this orthopaedic coating development, the interest of in vitro studies on the interaction between implant surfaces and bacteria/biofilms is growing. In this study, the in vitro staphylococcal adhesion and biofilm formation on newly developed porous pure Ti coatings with 50% porosity and pore sizes up to 50 μm is compared to various dense and porous Ti or Ti-6Al-4V reference surfaces. Multiple linear regression analysis indicates that surface roughness and hydrophobicity are the main determinants for bacterial adherence. Accordingly, the novel coatings display a significant reduction of up to five times less bacterial surface colonization when compared to a commercial state-of-the-art vacuum plasma sprayed coating. However, the results also show that a further expansion of the porosity with over 15% and/or the pore size up to 150 μm is correlated to a significant increase in the roughness parameters resulting in an ascent of bacterial attachment. Chemically modifying the Ti surface in order to improve its hydrophilicity, while preserving the average roughness, is found to strongly decrease bacteria quantities, indicating the importance of surface functionalization to reduce the infection risk of porous coatings.
authors: Department of Metallurgy and Materials Engineering (MTM), KU Leuven, B-3001, Heverlee, Belgium.
authors: Annabel
authors: A
authors: Braem
authors: Lieve
authors: L
authors: Van Mellaert
authors: Tina
authors: T
authors: Mattheys
authors: Dorien
authors: D
authors: Hofmans
authors: Evelien
authors: E
authors: De Waelheyns
authors: Liesbet
authors: L
authors: Geris
authors: Jozef
authors: J
authors: Anné
authors: Jan
authors: J
authors: Schrooten
authors: Jef
authors: J
authors: Vleugels
mesh_terms: D018441:Biofilms / Q000254:growth & development*; D016062:Porosity; D013211:Staphylococcus aureus / Q000502:physiology*; D013212:Staphylococcus epidermidis / Q000502:physiology*; D014025:Titanium / Q000737:chemistry*; D017155:Wettability
chemical_list: D014025:Titanium
keywords: Staphylococci; biofilm formation; porous Ti coating; roughness; surface properties