title: Thermoresponsive anionic copolymer brushes containing strong acid moieties for effective separation of basic biomolecules and proteins.
abstract: A thermoresponsive copolymer brush possessing the sulfonic acid group, poly(N-isopropylacrylamide (IPAAm)-co-2-acrylamido-2-methylpropanesulfonic acid (AMPS)-co-tert-butylacrylamide (tBAAm)), was grafted onto the surface of silica beads through surface-initiated atom transfer radical polymerization. Prepared copolymer and copolymer brushes on silica beads were characterized by observing the phase transition profile, CHNS elemental analysis, X-ray photoelectron spectroscopy, and gel permeation chromatography. The phase transition profile indicated that an appropriate AMPS composition for enabling thermally modulated property changes is 5 mol %, while excessive amounts of sulfonic acid groups prevented copolymer phase transition. Chromatographic elutions of catecholamine derivatives and basic proteins were observed, using the prepared copolymer brush-modified beads as chromatographic matrices, and the results suggest that the beads interact with these analytes through relatively strong electrostatic interactions. Thus, poly(IPAAm-co-AMPS-co-tBAAm) brush-modified beads will be useful for effective thermoresponsive chromatography matrices that separate basic biomolecules through strong electrostatic interactions.
authors.affiliation: Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University, TWIns , 8-1 Kawadacho, Shinjuku, Tokyo 162-8666, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Nagase
authors.forename: Jun
authors.initials: J
authors.lastname: Kobayashi
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kikuchi
authors.forename: Yoshikatsu
authors.initials: Y
authors.lastname: Akiyama
authors.forename: Hideko
authors.initials: H
authors.lastname: Kanazawa
authors.forename: Teruo
authors.initials: T
authors.lastname: Okano
mesh_terms: D000178:Acrylamides / Q000737:chemistry; D000838:Anions / Q000737:chemistry*; D002850:Chromatography, Gel / Q000379:methods; D044367:Phase Transition; D056951:Photoelectron Spectroscopy / Q000379:methods; D058105:Polymerization; D011108:Polymers / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D055672:Static Electricity; D013451:Sulfonic Acids / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature
chemical_list: D000178:Acrylamides; D000838:Anions; D011108:Polymers; D011506:Proteins; D013451:Sulfonic Acids; D012822:Silicon Dioxide; C067295:N-isopropylacrylamide; C115287:tert-butylacrylamide