title: Temperature-modulated adsorption of poly(N-isopropylacrylamide)-grafted ferritin on solid substrate.
abstract: Ferritin grafted with temperature-responsive poly(N-isopropylacrylamide) (PIPAAm-ferritin) was synthesized by a coupling reaction using PIPAAm and ferritin for obtaining stimuli-responsive biomaterials. The hydrodynamic diameter of PIPAAm-ferritins in aqueous solution increased at 37 °C at a higher protein concentration (>0.2mg/mL) because of the intermolecular aggregation through the hydrophobic interaction of PIPAAm chains. On the other hand, PIPAAm-ferritins at a lower concentration (<0.2mg/mL) were unable to increase their size even at 37 °C. The adsorption kinetics of PIPAAm-ferritins on hydrophobically modified Si substrate were evaluated with a quartz crystal microbalance in 10 mmol/L Bis-Tris/HCl buffer (pH 5.8) with and without poly(oxyethylene) sorbitan monolaurate (TWEEN 20) (0.05 wt%) as a surfactant. Although the adsorption of PIPAAm-ferritins on hydrophobic Si substrate at 25 °C in the buffer with TWEEN 20 was hardly observed, PIPAAm-ferritins were considerably adsorbed on the substrate at 37 °C, indicating that the hydrophobic interaction between the substrate and PIPAAm grafts on the ferritins after the destruction of the hydrophobic interaction between the protein and the substrate by TWEEN 20.
authors.affiliation: Institute of Advanced Biomedical Engineering and Science, Tokyo Women's Medical University (TWIns), 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Kumashiro
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Ikezoe
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Hayashi
authors.forename: Youichi
authors.initials: Y
authors.lastname: Okabayashi
authors.forename: Kaoru
authors.initials: K
authors.lastname: Tamada
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yamato
authors.forename: Teruo
authors.initials: T
authors.lastname: Okano
authors.forename: Masahiko
authors.initials: M
authors.lastname: Hara
mesh_terms: D000178:Acrylamides / Q000737:chemistry*; D000180:Acrylic Resins; D000327:Adsorption; D005293:Ferritins / Q000737:chemistry*; D057446:Hydrodynamics; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D010316:Particle Size; D011108:Polymers / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature
chemical_list: D000178:Acrylamides; D000180:Acrylic Resins; D011108:Polymers; C052970:poly-N-isopropylacrylamide; D005293:Ferritins; D012825:Silicon