title: Preparation and characterization of self-assembled nanoparticles formed by poly(ethylene oxide)-block-poly(epsilon-caprolactone) copolymers with long poly(epsilon-caprolactone) blocks in aqueous solutions.
abstract: Aqueous solutions of self-assembled nanoparticles formed by biocompatible diblock copolymers of poly(epsilon-caprolactone)-block-poly(ethylene oxide) (PCL-PEO) with the same molar mass of the PEO block (5000 g mol-1) and three different molar masses of the PCL block (5000, 13 000, and 32 000 g mol-1) have been prepared by a fast mixing the copolymer solution in a mild selective solvent, tetrahydrofuran (THF)/water, with an excess of water, that is, by quenching the reversible micellization equilibrium, and a subsequent removal of THF by dialysis of the water-rich solution against water. The prepared nanoparticles have been characterized by static and dynamic light scattering and atomic force microscopy imaging. It was found that stable monodisperse nanoparticles are formed only if the initial mixed solvent contained 90 vol % THF. The results show that the prepared nanoparticles are spherical vesicles with relatively thick hydrophobic walls, that is, spherical core/shell nanoparticles with the hollow core filled with the solvent.
authors.affiliation: Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University in Prague, Albertov 2030, 128 40 Prague 2, Czech Republic.
authors.forename: Radek
authors.initials: R
authors.lastname: Sachl
authors.forename: Mariusz
authors.initials: M
authors.lastname: Uchman
authors.forename: Pavel
authors.initials: P
authors.lastname: Matĕjícek
authors.forename: Karel
authors.initials: K
authors.lastname: Procházka
authors.forename: Miroslav
authors.initials: M
authors.lastname: Stĕpánek
authors.forename: Milena
authors.initials: M
authors.lastname: Spírková
mesh_terms: D004337:Drug Carriers; D005663:Furans / Q000737:chemistry; D008027:Light; D008823:Micelles; D018625:Microscopy, Atomic Force; D015233:Models, Statistical; D053758:Nanoparticles / Q000737:chemistry*; D011091:Polyesters / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D012542:Scattering, Radiation; D012995:Solubility; D012997:Solvents / Q000737:chemistry; D014867:Water / Q000737:chemistry*
chemical_list: D004337:Drug Carriers; D005663:Furans; D008823:Micelles; D011091:Polyesters; D011108:Polymers; D012997:Solvents; D014867:Water; C016240:polycaprolactone; C018674:tetrahydrofuran; D011092:Polyethylene Glycols