title: Photoiniferter-based thermoresponsive graft architecture with albumin covalently fixed at growing graft chain end.
abstract: The aim of this study was to develop a novel surface graft architecture in which albumin is covalently fixed at the growing chain end of the hydrophilic polymers: poly(N, N-dimethylacylamide), PDMAM, and poly(N-isopropylacrylamide), PNIPAM. Photoiniferter-based surface-grafted polymers were prepared using either an albuminated iniferter or a nonalbuminated iniferter, both of which were derivatized on glass surfaces, and ultraviolet (UV)-light-irradiated in the presence of a DMAM or NIPAM monomer. Surface chemical composition analysis by X-ray photoelectron spectroscopy, contact angle measurement, immunostaining using fluorescence labeled antibody and the measurement of graft thickness, as determined from force-distance curves obtained in water at 25 degrees C and 37 degrees C by atomic force microscopy, evidenced that the thickness of graft layer increased with photoirradiation time and albumin molecules exist at growing chain ends. For PNIPAM-grafted surfaces, the interconversion between swollen and collapsed graft chains was observed below and above the lower critical solution temperature of PNIPAM. The potential application of a thermoresponsive graft with albumin covalently fixed at its growing chain end was discussed in terms of "active" nonfouling surface design based on the temperature-dependent switching of phase transition.
authors.affiliation: Division of Biomedical Engineering, Graduate School of Medicine, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. matsuda@med.kyushu-u.ac.jp
authors.forename: Takehisa
authors.initials: T
authors.lastname: Matsuda
authors.forename: Shoji
authors.initials: S
authors.lastname: Ohya
mesh_terms: D000180:Acrylic Resins; D001672:Biocompatible Materials; D011485:Protein Binding; D012710:Serum Albumin, Bovine; D012997:Solvents; D013499:Surface Properties; D013816:Thermodynamics; D023822:Tissue Engineering / Q000379:methods
chemical_list: D000180:Acrylic Resins; D001672:Biocompatible Materials; D012997:Solvents; C052970:poly-N-isopropylacrylamide; D012710:Serum Albumin, Bovine