title: Nanoparticles from polylactide and polyether block copolymers: formation, properties, encapsulation, and release of pyrene--fluorescent model of hydrophobic drug.
abstract: Polylactide-b-polyglycidol-b-poly(ethylene oxide) terpolymers and their derivatives with carboxyl and 4-(phenylazo)phenyl labels in polyglycidol blocks were used for formation of nanoparticles. Nanoparticles were produced by self assembly of terpolymer macromolecules in water above the critical aggregation concentration and by dialysis of terpolymer solutions in 1,4-dioxane against water. For terpolymers with 4-(phenylazo)phenyl labels critical aggregation concentrations increased after irradiation with UV light (300 < lambda < 400 nm) inducing conformational change of the label from trans- to cis-conformation. Diameters of nanoparticles obtained by self-assembly of macromolecules ranged from 20 to 44 nm. Dialysis yielded nanoparticles with bimodal diameter distribution. One fraction had diameters below 35 nm and diameters of the second fraction were in a range from 350 to 2300 nm, depending on terpolymer structure. Mixtures of terpolymers with poly(L,L-lactide) and poly(D,D-lactide) blocks yielded nanoparticles with diameters from 350 to 440 nm. Pyrene was incorporated into nanoparticles by partition between solution and nanoparticles or directly during particle formation by dialysis. Monitoring of pyrene release from nanoparticles suggests that a fraction of this compound was entrapped into the polylactide core whereas the remaining one was located in the polyether rich shell. The release from shells is faster for nanoparticles made from copolymers with carboxyl labels in polyglycidol blocks.
authors.affiliation: Center of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Lodz, Poland.
authors.forename: Stanislaw
authors.initials: S
authors.lastname: Slomkowski
authors.forename: Mariusz
authors.initials: M
authors.lastname: Gadzinowski
authors.forename: Stanislaw
authors.initials: S
authors.lastname: Sosnowski
authors.forename: Izabela
authors.initials: I
authors.lastname: Radomska-Galant
authors.forename: Andrea
authors.initials: A
authors.lastname: Pucci
authors.forename: Cinzia
authors.initials: C
authors.lastname: De Vita
authors.forename: Francesco
authors.initials: F
authors.lastname: Ciardelli
mesh_terms: D002214:Capsules / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D004058:Diffusion; D004337:Drug Carriers / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D007773:Lactates / Q000737:chemistry*; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D011721:Pyrenes / Q000008:administration & dosage / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D002214:Capsules; D004337:Drug Carriers; D007773:Lactates; D011108:Polymers; D011721:Pyrenes; C058523:polyethylene oxide-polylactic acid block copolymer; D011092:Polyethylene Glycols; C030984:pyrene