title: Biofunctionalization of a "clickable" organic layer photochemically grafted on titanium substrates.
abstract: We have developed a general method combining photochemical grafting and copper-catalyzed click chemistry for biofunctionalization of titanium substrates. The UV-activated grafting of an α,ω-alkenyne onto TiO(2)/Ti substrates provided a "clickable" thin film platform. The selective attachment of the vinyl end of the molecule to the surface was achieved by masking the alkynyl end with a trimethylgermanyl (TMG) protecting group. Subsequently, various oligo(ethylene glycol) (OEG) derivatives terminated with an azido group were attached to the TMG-alkynyl modified titanium surface via a one-pot deprotection/click reaction. The films were characterized by X-ray photoelectron spectroscopy (XPS), contact angle goniometry, ellipsometry, and atomic force microscopy (AFM). We showed that the titanium surface presenting click-immobilized OEG substantially suppressed the nonspecific attachment of protein and cells as compared to the unmodified titanium substrate. Furthermore, glycine-arginine-glycine-aspartate (GRGD), a cell adhesion peptide, was coimmobilized with OEG on the platform. We demonstrated that the resultant GRGD-presenting thin film on Ti substrates can promote the specific adhesion and spreading of AsPC-1 cells.
authors.affiliation: Department of Chemistry, University of Houston, Houston, Texas 77204, USA.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Meirong
authors.initials: M
authors.lastname: Zhao
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Kai
authors.initials: K
authors.lastname: Liu
authors.forename: Chengzhi
authors.initials: C
authors.lastname: Cai
mesh_terms: D002448:Cell Adhesion; D002460:Cell Line; D057930:Click Chemistry; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis*; D006801:Humans; D055668:Photochemical Processes; D023822:Tissue Engineering / Q000379:methods*; D014025:Titanium / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; D014025:Titanium