title: Preparation of thermoresponsive anionic copolymer brush surfaces for separating basic biomolecules.
abstract: Poly(N-isopropylacrylamide-co-acrylic acid-co-N-tert-butylacrylamide) (poly(IPAAm-co-AAc-co-tBAAm) brush grafted silica beads were prepared through a surface-initiated atom transfer radical polymerization (ATRP) with CuCl/CuCl(2)/Me(6)TREN catalytic system in 2-propanol at 25 degrees C for 4 h. The prepared beads were characterized by chromatographic analysis. Basic analytes, catecholamine derivatives, and angiotensin peptides could be separated by a short column length containing the beads because of its high densely grafted copolymer structure. Chromatograms for catecholamine derivatives were obtained with high resolution peaks due to their electrostatic and hydrophobic interactions to the densely grafted anionic copolymers on the beads. Effective separation of angiotensin peptides was performed near the lower critical solution temperature of copolymers, because the total electrostatic and hydrophobic interactions between the copolymer and the analytes become strong at the temperature. These results indicated that the copolymer brush grafted surfaces prepared by ATRP was an effective tool for separating basic biomolecules by modulating the electrostatic and hydrophobic 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: Masahiko
authors.initials: M
authors.lastname: Annaka
authors.forename: Teruo
authors.initials: T
authors.lastname: Okano
mesh_terms: D000809:Angiotensins / Q000737:chemistry*; D002395:Catecholamines / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D010446:Peptide Fragments / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D011109:Polymethacrylic Acids / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature
chemical_list: D000809:Angiotensins; D002395:Catecholamines; D010446:Peptide Fragments; D011108:Polymers; D011109:Polymethacrylic Acids; D012822:Silicon Dioxide