title: TiO2-coated CoCrMo: improving the osteogenic differentiation and adhesion of mesenchymal stem cells in vitro.
abstract: The current gold standard material for orthopedic applications is titanium (Ti), however, other materials such as cobalt-chromium-molybdenum (CoCrMo) are often preferred due to their wear resistance and mechanical strength. This study investigates if the bioactivity of CoCrMo can be enhanced by coating the surface with titanium oxide (TiO2 ) by atmospheric pressure chemical vapor deposition (CVD), thereby replicating the surface oxide layer found on Ti. CoCrMo, TiO2-coated CoCrMo (CCMT) and Ti substrates were used for this study. Cellular f-actin distribution was shown to be noticeably different between cells on CCMT and CoCrMo after 24 h in osteogenic culture, with cells on CCMT exhibiting greater spread with developed protrusions. Osteogenic differentiation was shown to be enhanced on CCMT compared to CoCrMo, with increased calcium ion content per cell (p < 0.05), greater hydroxyapatite nodule formation (p < 0.05) and reduced type I collagen deposition per cell (p < 0.05). The expression of the focal adhesion protein vinculin was shown to be marginally greater on CCMT compared to CoCrMo, whereas AFM results indicated that CCMT required more force to remove a single cell from the substrate surface compared to CoCrMo (p < 0.0001). These data suggest that CVD TiO2 coatings may have the potential to increase the biocompatibility of CoCrMo implantable devices.
authors.affiliation: Biomaterials and Tissue Engineering, University College London, Eastman Dental Institute, London, WC1X 8LD, United Kingdom.
authors.forename: Niall
authors.initials: N
authors.lastname: Logan
authors.forename: Anas
authors.initials: A
authors.lastname: Sherif
authors.forename: Alison J
authors.initials: AJ
authors.lastname: Cross
authors.forename: Simon N
authors.initials: SN
authors.lastname: Collins
authors.forename: Alison
authors.initials: A
authors.lastname: Traynor
authors.forename: Laurent
authors.initials: L
authors.lastname: Bozec
authors.forename: Ivan P
authors.initials: IP
authors.lastname: Parkin
authors.forename: Peter
authors.initials: P
authors.lastname: Brett
mesh_terms: D002113:Calcification, Physiologic / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects*; D002478:Cells, Cultured; D020099:Coated Materials, Biocompatible / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism*; D010012:Osteogenesis / Q000187:drug effects*; D014025:Titanium / Q000737:chemistry / Q000494:pharmacology; D014800:Vitallium / Q000737:chemistry / Q000494:pharmacology
chemical_list: D020099:Coated Materials, Biocompatible; D014800:Vitallium; C009495:titanium dioxide; D014025:Titanium
keywords: AFM; cobalt alloy; mesenchymal stem cells; osteogenesis; titanium oxide