['To test physicochemical and biological properties of PEG-poly(aspartate) [PEG-p(Asp)] block copolymer micelles entrapping doxorubicin hydrochloride (DOX) through ionic interaction.', 'PEG-p(Asp) was synthesized from 5\xa0kDa PEG and 20 Asp units. Carboxyl groups of p(Asp) were present as benzyl ester [PEG-p(Asp/Bz)], sodium salt [PEG-p(Asp/Na)] or free acid [PEG-p(Asp/H)]. Block copolymers and DOX were mixed at various ratios to prepare polymer micelles, which were subsequently characterized to determine particle size, drug loading and release patterns, and cytotoxicity against prostate (PC3 and DU145) and lung (A549) cancer cell lines.', 'PEG-p(Asp/Bz), Na- and H-micelles entrapped 1.1, 56.8 and 40.6\xa0wt.% of DOX, respectively. Na- and H-micelles (<100\xa0nm) showed time-dependent DOX release at pH 7.4, which was accelerated at pH 5.0. Na-micelles were most stable at pH 7.4, retaining 31.8% of initial DOX for 48\xa0h. Cytotoxicity of Na-micelles was 23.2% (A549), 28.5% (PC3) and 45.9% (DU145) more effective than free DOX.'] Do drug release patterns and cytotoxicity of PEG-poly ( aspartate ) block copolymer micelles in cancer cells?