title: Reverse thermal gelation of PAF-PLX-PAF block copolymer aqueous solution.
abstract: The aqueous solution of poly(L-Ala-co-L-Phe)-poly(propylene glycol)-poly(ethylene glycol)-poly(propylene glycol)-poly(L-Ala-co-L-Phe) block copolymers (PAF-PLX-PAF) in a concentration range of 6.0-10.0 wt % underwent sol-to-gel transition as the temperature increased from 10 to 50 degrees C. Circular dichroism spectra, hydrophobic dye solubilization, dynamic light scattering, and transmission electron microscopy image of the polymer suggest that the polymers form micelles in water, where the hydrophilic (PLX) blocks form a shell and the hydrophobic (PAF) blocks form a core of the micelle. Circular dichroism, FTIR, and (13)C NMR spectra suggest that sol-to-gel transition accompanies partial strengthening of the beta-sheet structure of PAF and a decrease in molecular motion of the PLX. The sol-to-gel transition temperature could be controlled by varying the molecular weight of PAF and PLX blocks, the ratio of Ala to Phe, and the corresponding secondary structure of the polypeptide.
authors.affiliation: Department of Chemistry and Nano Science, Ewha Womans University, Daehyun-Dong, Seodaemun-Ku, Seoul, 120-750, Korea.
authors.forename: Eun Hae
authors.initials: EH
authors.lastname: Kim
authors.forename: Min Kyung
authors.initials: MK
authors.lastname: Joo
authors.forename: Kyung Hyun
authors.initials: KH
authors.lastname: Bahk
authors.forename: Min Hee
authors.initials: MH
authors.lastname: Park
authors.forename: Bo
authors.initials: B
authors.lastname: Chi
authors.forename: Young Mi
authors.initials: YM
authors.lastname: Lee
authors.forename: Byeongmoon
authors.initials: B
authors.lastname: Jeong
mesh_terms: D005782:Gels / Q000737:chemistry*; D008823:Micelles; D008968:Molecular Conformation; D010455:Peptides; D011092:Polyethylene Glycols; D011108:Polymers / Q000737:chemistry*; D011409:Propylene Glycols; D012996:Solutions; D044366:Transition Temperature; D014867:Water
chemical_list: D005782:Gels; D008823:Micelles; D010455:Peptides; D011108:Polymers; D011409:Propylene Glycols; D012996:Solutions; D014867:Water; D011092:Polyethylene Glycols