title: pH-Sensitive micelles with cross-linked cores formed from polyaspartamide derivatives for drug delivery.
abstract: A series of polyaspartamide derivatives were synthesized by grafting O-(2-aminoethyl)-O'-methylpoly(ethylene glycol) 5000 (MPEG), 1-(3-aminopropyl) imidazole (API), and cinnamate onto polysuccinimide (PSI) with the respective degrees of substitution adjusted by the feed molar ratio. The chemical structure of the prepared polymer was confirmed using FT-IR and (1)H NMR spectroscopy. A new pH-sensitive polymeric micelle based on the synthesized polymer was prepared and characterized, and its pH-sensitive properties were characterized by the measurement of light transmittance and particle sizes at varying pH values. pH-dependent aggregation and deaggregation behavior was clearly observed in the polymer aqueous dispersion system. Photo-cross-linking of the cinnamate branches cross-linked the core of the micelles. The core cross-linked micelles showed high stability over a wider pH range and displayed obvious pH-dependent swelling-shrinking behavior instead of micelle-unimer transition behavior. This micelle system overcame the drawback of the facile disintegration of normal polymeric micelles and showed obvious delayed paclitaxel release in in vitro drug delivery experiments.
authors.affiliation: Department of Chemical Engineering, Theranostic Macromolecules Research Center, Sungkyunkwan University, Suwon, Kyunggi 440-746, Korea.
authors.forename: Wang
authors.initials: W
authors.lastname: Lin
authors.forename: Dukjoon
authors.initials: D
authors.lastname: Kim
mesh_terms: D003432:Cross-Linking Reagents / Q000138:chemical synthesis* / Q000737:chemistry; D016503:Drug Delivery Systems; D006863:Hydrogen-Ion Concentration; D008823:Micelles; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D003432:Cross-Linking Reagents; D008823:Micelles; D010455:Peptides; C017645:polyaspartate