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ABSTRACT Photoresponsive amphiphilic diblock poly(carbonate)s mPEG113-b-PMNC n with pendent o-nitrobenzyl ester group were synthesized through ring-opening polymerization (ROP) using 1,8-diazabi-cyclo[5.4.0]undec-7-ene (DBU) as catalyst and monomethoxy poly(ethylene glycol) (mPEG) as macroinitiator. In aqueous solution, the copolymers can self-assemble to spherical micelles with a PC core and a PEG shell. The critical micelle concentration (CMC), size, and morphology of the micelles were demonstrated by means of fluorescence spectroscopy, transmission electron microscopes (TEM), and dynamic light scattering (DLS). Under UV light irradiation, the amphiphilic copolymer micelles disassembled because of the photocleavage of o-NB ester, and the light-controlled release behaviors of payload Nile red were further proved. This study provides a convenient way to construct smart poly(carbonate)s nanocarriers for controlled drug release. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 2770-2780 [ABSTRACT FROM AUTHOR]

ABSTRACT In this article, a light and pH dual-sensitive block copolymer PEG- b-poly(MPC-Azo/DEA) was facilely prepared for the first time by azide-alkyne click chemistry between amphiphilic block copolymer bearing pendant alkynyl group poly(ethylene glycol)-poly(5-methyl-5-propargylxycarbonyl-1,3-dioxane-2-one) (PEG- b-poly(MPC)) and two azide-containing compounds azobenzene derivative (Azo-N3) and 2-azido-1-ethyl-diethylamine (DEA-N3). Light response of the polymeric nanoparticles benefits from the azobenzene segments and pH responsiveness is attributed to DEA moieties. The prepared copolymer could self-assemble into spherical micelle particles. The morphological changes of these particles in response to dual stimuli were investigated by UV/vis spectroscopy, dynamic light scattering (DLS), and transmission electron microscopy (TEM). Nile Red (NR) was utilized as probe, and fluorescence spectroscopy was served as an evidence for the enhanced release of cargos from polymeric nanoparticles under combined stimulation. Anticancer drug, DOX was loaded into the nanoparticles and the loaded-DOX could be released from these nanoparticles under dual stimuli. MTT assays further demonstrated that PEG- b-poly(MPC) and PEG- b-poly(MPC-Azo/DEA) were of biocompatibility and low toxicity against HepG2 cells as well as SMCC-7721 cells. More importantly, the prepared DOX-loaded nanoparticles exhibited good anticancer ability for the two cells. The synthesized light and pH dual-sensitive biodegradable polymeric nanoparticles were expected to be platforms for precisely controlled release of encapsulated molecules. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 1773-1783 [ABSTRACT FROM AUTHOR]

ABSTRACT A facile method for the construction of pH-responsive core crosslinked micelles (CCLMs) based on polycarbonate was developed. Biodegradable amphiphilic block copolymer monomethoxy poly(ethylene glycol)-b-Poly(AC) (mPEG-b-poly(AC)) with pendant acrylate group was synthesized by means of ring opening polymerization of acryloyl carbonate (AC). Then CCLMs were obtained via thiol-acrylate Michael addition reaction between the pendant acrylate group in the hydrophobic block and the crosslinker 1,6-hexanedithiol. DLS results showed that the CCLMs prepared from mPEG-b-poly(AC)25 were more stable than uncrosslinked micelles (UCLMs) upon dilution by 10-fold DMF. Model drug Coumarin 102 was then encapsulated into the micelles. The pH-responsive release of coumarin 102 from the CCLMs was demonstrated by fluorescence spectroscopy. The core crosslinked polycarbonate micelles have a potential as efficient intracellular smart drug delivery platforms. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44421. [ABSTRACT FROM AUTHOR]

ABSTRACT Light-responsive poly(carbonate)s PEG113- b-PMPC n-SP were synthesized via copper catalyzed azide-alkyne cycloaddition reaction between azide-modified spiropyran (SP-N3) and amphiphilic copolymer PEG113- b-PMPC n. PEG113- b-PMPC25-SP can self-assemble to biocompatible micelles with an average diameter of ∼96 nm and a critical aggregation concentration of 0.0148 mg mL−1. Under 365 nm UV light irradiation, the characteristic absorption intensity of merocyanine (MC) progressively increased and most of the micellar aggregations were disrupted within 10 min, suggesting the completion of the transformation of hydrophobic SP to hydrophilic MC. Subsequent exposuring the micelles to 620 nm visible light, spherical micelles aggregated again. The light-controlled release and re-encapsulation behaviors of coumarin 102-loaded micelles were further investigated by fluorescence spectroscopy. This study provides a convenient way to construct smart poly(carbonate)s nanocarriers for controlled release and re-encapsulation of hydrophobic drugs. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 750-760 [ABSTRACT FROM AUTHOR]