title: Thermogelling poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) disulfide multiblock copolymer as a thiol-sensitive degradable polymer.
abstract: We report a reverse thermogelling poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) disulfide multiblock copolymer as a thiol-sensitive biodegradable polymer. The poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) aqueous solutions studied in this research underwent sol-gel-sol or sol-gel-sol-gel transition depending on the molecular weight and concentration of the polymer, whereas the corresponding disulfide multiblock copolymer aqueous solutions underwent sol-gel transition as the temperature increased in a range of 0-60 degrees C. The hydrophobic dye solubilization and dynamic light scattering of the polymer aqueous solution suggest that the poly(ethylene oxide-b-propylene oxide-b-ethylene oxide)s undergo unimer (3 nm) to micelle (12 nm) transition, whereas the disulfide multiblock copolymers undergo unimer (6 nm) to aggregated polymer (600 nm) transition as the temperature increases. The gel duration increased from 6 h (poly(ethylene oxide-b-propylene oxide-b-ethylene oxide)) to more than 12 days (the corresponding disulfide multiblock copolymer) in phosphate buffer saline, and the gel duration of the latter depended on the glutathione concentration of the medium. The model drug, paclitaxel, was released from the in-situ-formed poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) disulfide multiblock copolymer gel in a glutathione concentration-sensitive manner.
authors.affiliation: Department of Chemistry, Division of Nano Sciences, Ewha Womans University, Daehyun-Dong,Seodaemun-Ku, Seoul, 120-750, Korea.
authors.forename: Kyung Hwa
authors.initials: KH
authors.lastname: Sun
authors.forename: Youn Soo
authors.initials: YS
authors.lastname: Sohn
authors.forename: Byeongmoon
authors.initials: B
authors.lastname: Jeong
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D001709:Biotechnology / Q000379:methods*; D002845:Chromatography; D004396:Coloring Agents / Q000494:pharmacology; D004220:Disulfides / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D005782:Gels / Q000737:chemistry; D005978:Glutathione / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008422:Materials Testing; D011095:Polyethylenes / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D011126:Polypropylenes / Q000737:chemistry*; D012542:Scattering, Radiation; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013696:Temperature
chemical_list: D001672:Biocompatible Materials; D004396:Coloring Agents; D004220:Disulfides; D005782:Gels; D011095:Polyethylenes; D011108:Polymers; D011126:Polypropylenes; D013438:Sulfhydryl Compounds; C078661:UCON 50-HB-5100; D005978:Glutathione