title: Thermoresponsive aggregation behavior of triterpene-poly(ethylene oxide) conjugates in water.
abstract: Bioconjugate amphiphiles comprising triterpene and poly(ethylene oxide) (PEO) were studied according to their thermoresponsive aggregation behavior (LCST) in water. Cholesteryl-PEO (CE) and betulinyl-PEO (BE) comprising <70 wt% PEO precipitated from water upon heating. CE, but not BE, solutions contained nanoscopic aggregates at room temperature causing different thermoprecipitation behaviors. Solutions containing 5 wt% solutions of BE with short PEO chains demonstrated dual thermoresponsive behavior, precipitating at high temperature and forming hydrogel at low temperature. A BE multiblock copolymer was found to form large aggregates, presumably vesicles, in water. Results suggest that the solution properties of triterpene-PEO amphiphiles can be controlled by the chemical composition and structure.
authors.affiliation: Max Planck Institute of Colloids and Interfaces, Department of Colloid Chemistry, Potsdam, Germany.
authors.forename: Junpeng
authors.initials: J
authors.lastname: Zhao
authors.forename: Jekaterina
authors.initials: J
authors.lastname: Jeromenok
authors.forename: Jens
authors.initials: J
authors.lastname: Weber
authors.forename: Helmut
authors.initials: H
authors.lastname: Schlaad
mesh_terms: D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D011092:Polyethylene Glycols / Q000737:chemistry*; D013696:Temperature; D014315:Triterpenes / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D014315:Triterpenes; D014867:Water; D011092:Polyethylene Glycols