title: Chemical modification of metallic implant surfaces with biofunctional proteins (Part 2). Corrosion resistance of a chemically modified NiTi alloy.
abstract: The corrosion resistance of a NiTi alloy, chemically modified with a human plasma fibronectin (pFN) using an aminosilane and a glutaraldehyde, was examined by electrochemical techniques in a 0.9% NaCl solution and a cell culture medium containing serum. The role of serum proteins in influencing the passive behavior of the alloy was extensively studied by anodic polarization and X-ray photoelectron spectroscopy (XPS). The passive current density increased in the presence of serum proteins. The enhanced dissolution of the passive film appears to be a consequence of quick adsorption of the serum proteins and the subsequent formation of metal ion-protein complexes on the film surface. With the chemical modification, the corrosion rate was reduced by approximately 50% in both solutions due to a highly cross-linked siloxane network formed on the alloy surface. This network layer limited the diffusion of dissolved oxygen, metal ions, and biological molecules involved in the corrosion reactions.
authors.affiliation: Department of Dental Materials Sciences, Health Sciences University of Hokkaido, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Endo
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D003343:Corrosion; D003432:Cross-Linking Reagents / Q000737:chemistry; D003470:Culture Media / Q000737:chemistry; D003722:Dental Alloys / Q000737:chemistry*; D003775:Dental Polishing; D004563:Electrochemistry; D005353:Fibronectins / Q000737:chemistry; D006801:Humans; D009532:Nickel / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry; D011437:Propylamines; D019736:Prostheses and Implants; D011485:Protein Binding; D012821:Silanes / Q000737:chemistry; D012965:Sodium Chloride / Q000737:chemistry; D013057:Spectrum Analysis; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D003470:Culture Media; D003722:Dental Alloys; D005353:Fibronectins; D009942:Organometallic Compounds; D011437:Propylamines; D012821:Silanes; C040654:titanium nickelide; D012965:Sodium Chloride; D009532:Nickel; D014025:Titanium; C477625:amino-propyl-triethoxysilane