title: Grafting titanium nitride surfaces with sodium styrene sulfonate thin films.
abstract: The importance of titanium nitride lies in its high hardness and its remarkable resistance to wear and corrosion, which has led to its use as a coating for the heads of hip prostheses, dental implants and dental surgery tools. However, the usefulness of titanium nitride coatings for biomedical applications could be significantly enhanced by modifying their surface with a bioactive polymer film. The main focus of the present work was to graft a bioactive poly(sodium styrene sulfonate) (pNaSS) thin film from titanium nitride surfaces via a two-step procedure: first modifying the surface with 3-methacryloxypropyltrimethoxysilane (MPS) and then grafting the pNaSS film from the MPS modified titanium through free radical polymerization. X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were used after each step to characterize success and completeness of each reaction. The surface region of the titanium nitride prior to MPS functionalization and NaSS grafting contained a mixture of titanium nitride, oxy-nitride, oxide species as well as adventitious surface contaminants. After MPS functionalization, Si was detected by XPS, and characteristic MPS fragments were detected by ToF-SIMS. After NaSS grafting, Na and S were detected by XPS and characteristic NaSS fragments were detected by ToF-SIMS. The XPS determined thicknesses of the MPS and NaSS overlayers were ∼1.5 and ∼1.7 nm, respectively. The pNaSS film density was estimated by the toluidine blue colorimetric assay to be 260 ± 70 ng/cm(2).
authors.affiliation: National ESCA and Surface Analysis Center for Biomedical Problems, Departments of Chemical Engineering and Bioengineering, University of Washington, Seattle, Washington 98195-1653.
authors.forename: Gilad
authors.initials: G
authors.lastname: Zorn
authors.affiliation: Laboratory of Biomaterials and Specialty Polymers (LBPS/CSPBAT - UMR CNRS 7244), Institut Galilée, Université Paris 13 Sorbonne Paris Cité, 93430 Villetaneuse, France.
authors.forename: Véronique
authors.initials: V
authors.lastname: Migonney
authors.affiliation: National ESCA and Surface Analysis Center for Biomedical Problems, Departments of Chemical Engineering and Bioengineering, University of Washington, Seattle, Washington 98195-1653.
authors.forename: David G
authors.initials: DG
authors.lastname: Castner
mesh_terms: D055598:Chemical Phenomena; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D003124:Colorimetry; D006801:Humans; D056951:Photoelectron Spectroscopy; D011137:Polystyrenes / Q000737:chemistry*; D019736:Prostheses and Implants; D018629:Spectrometry, Mass, Secondary Ion; D014025:Titanium / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; D011137:Polystyrenes; C041500:titanium nitride; C003321:polystyrene sulfonic acid; D014025:Titanium