title: Control of nanobiointerfaces generated from well-defined biomimetic polymer brushes for protein and cell manipulations.
abstract: To better understand protein/material and cell/material interactions at the submolecular level, well-defined polymer brushes consisting of poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) on silicon wafers were prepared by atom transfer radical polymerization (ATRP). Silicon wafers were treated with 3-(2-bromoisobutyryl)propyl dimethylchlorosilane (BDCS) to form a monolayer that acts as initiators for ATRP. Silicon-supported BDCS monolayers were soaked in a methanol/water mixture solution containing Cu(I)Br, bipyridine, and a sacrificial initiator. After MPC was added to the solution, ATRP was carried out for 18 h. The molecular weight and thickness of the PMPC brush layer on the silicon surface increased with an increase in the polymerization time. The dense polymer brushes were obtained by the "grafting from" system. By selective decomposition of the BDCS monolayer by UV light-irradiation, the PMPC brush region and the sizes were well controlled, resulting in fabricating micropatterns of the PMPC brushes. When the thickness of the PMPC brush layer was greater than 5.5 +/- 1.0 nm (3 h polymerization), serum protein adsorption and fibroblast adhesion were effectively reduced, i.e., proteins and cells could recognize such thin polymer brushes on the surface. In addition, the density of the adherent cells on the patterned PMPC brush surface could be controlled by changing the size of the pattern.
authors.affiliation: Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, 2-3-10 Kanda-surugadai, Chiyoda-ku, Tokyo 101-0062, Japan.
authors.forename: Ryoko
authors.initials: R
authors.lastname: Iwata
authors.forename: Piyawan
authors.initials: P
authors.lastname: Suk-In
authors.forename: Vipavee P
authors.initials: VP
authors.lastname: Hoven
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takahara
authors.forename: Kazunari
authors.initials: K
authors.lastname: Akiyoshi
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Iwasaki
mesh_terms: D000327:Adsorption; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D002448:Cell Adhesion; D002460:Cell Line; D004577:Electron Probe Microanalysis; D046911:Macromolecular Substances; D051379:Mice; D018625:Microscopy, Atomic Force; D008856:Microscopy, Fluorescence; D008956:Models, Chemical; D036103:Nanotechnology / Q000379:methods*; D011108:Polymers / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors; D014466:Ultraviolet Rays; D014867:Water
chemical_list: D001672:Biocompatible Materials; D046911:Macromolecular Substances; D011108:Polymers; D011506:Proteins; D014867:Water; D012825:Silicon