title: Protein adsorption to surface chemistry and crystal structure modification of titanium surfaces.
abstract: OBJECTIVE
  To observe the early adsorption of extracellular matrix and blood plasma proteins to magnesium-incorporated titanium oxide surfaces, which has shown superior bone response in animal models.
  
  
  METHODS
  Commercially pure titanium discs were blasted with titanium dioxide (TiO2) particles (control), and for the test group, TiO2 blasted discs were further processed with a micro-arc oxidation method (test). Surface morphology was investigated by scanning electron microscopy, surface topography by optic interferometry, characterization by X-ray photoelectron spectroscopy (XPS), and by X-ray diffraction (XRD) analysis. The adsorption of 3 different proteins (fibronectin, albumin, and collagen type I) was investigated by an immunoblotting technique.
  
  
  RESULTS
  The test surface showed a porous structure, whereas the control surface showed a typical TiO2 blasted structure. XPS data revealed magnesium-incorporation to the anodic oxide film of the surface. There was no difference in surface roughness between the control and test surfaces. For the protein adsorption test, the amount of albumin was significantly higher on the control surface whereas the amount of fibronectin was significantly higher on the test surface. Although there was no significant difference, the test surface had a tendency to adsorb more collagen type I.
  
  
  CONCLUSIONS
  The magnesium-incorporated anodized surface showed significantly higher fibronectin adsorption and lower albumin adsorption than the blasted surface. These results may be one of the reasons for the excellent bone response previously observed in animal studies.
authors.affiliation: Department of Prosthodontics, Faculty of Odontology, Malmö University Malmö Sweden. ; Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, Göteborg University Göteborg Sweden.
authors.forename: Ryo
authors.initials: R
authors.lastname: Jimbo
authors.affiliation: Clinical Research Center, Örebro University Hosptial Örebro Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Ivarsson
authors.affiliation: Clinical Research Center, Örebro University Hosptial Örebro Sweden.
authors.forename: Anita
authors.initials: A
authors.lastname: Koskela
authors.affiliation: Department of Biomaterials, Institute of Clinical Sciences, Sahlgrenska Academy, Göteborg University Göteborg Sweden. ; Institute for Clinical Dental Research, Korea University Seoul South Korea.
authors.forename: Young-Taeg
authors.initials: YT
authors.lastname: Sul
authors.affiliation: Department of Clinical Medicine, School of Health and Medical Sciences, Örebro University Örebro Sweden.
authors.forename: Carina B
authors.initials: CB
authors.lastname: Johansson
keywords: albumins; collagen type I.; fibronectins; immunoblotting; magnesium; titanium dioxide