title: Hydrophobically modified biodegradable poly(ethylene glycol) copolymers that form temperature-responsive Nanogels.
abstract: Biodegradable copolymers consisting of a hydrophilic poly[l-aspartic acid-alt-poly(ethylene glycol)] (poly(l-Asp-alt-PEG)) backbone and hydrophobic capryl units as side chains were synthesized. The amphiphilic copolymer was found to form nanosized hydrogel particles (nanogels) of approximately 15 nm in size by self-assembly at 20 degrees C in aqueous media, and the nanogel solutions displayed phase-transition in response to temperature. The transition of the nanogel solution was reversible and tunable in the range from 19 to 55 degrees C by variation of the amounts of capryl units introduced and the solution concentration. The nanogels were gradually degraded within days in a phosphate buffer solution (PBS) at 37 degrees C. Temperature-responsive biodegradable nanogel systems consisting of biocompatible PEG may have potential utility for high biocompatibility temperature-responsive nanodevices such as microreactor systems, molecular-chaperones, and drug delivery vehicles.
authors.affiliation: Department of Chemistry and Materials Engineering, Faculty of Chemistry, Materials and Bioengineering and High Technology Research Center, Kansai University, Suita, Osaka 564-8680, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Nagahama
authors.forename: Mihoko
authors.initials: M
authors.lastname: Hashizume
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Ouchi
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ohya
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D001673:Biodegradation, Environmental; D004337:Drug Carriers / Q000737:chemistry; D016503:Drug Delivery Systems; D005782:Gels / Q000737:chemistry*; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry; D008956:Models, Chemical; D000080385:Nanogels; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry*; D011094:Polyethyleneimine / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D012996:Solutions; D013696:Temperature
chemical_list: D001672:Biocompatible Materials; D004337:Drug Carriers; D005782:Gels; D000080385:Nanogels; D011108:Polymers; D012996:Solutions; C413692:polyethylene glycol polyethyleneimine nanogel; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D011092:Polyethylene Glycols; D011094:Polyethyleneimine