Recent Advances in the Functionalization of Aliphatic Polyesters by Ring-Opening Polymerization

Herein, we report a new drug-delivery system (DDS) that is comprised of a near-infrared (NIR)-light-sensitive gold-nanorod (GNR) core and a phase-changing poly(ε-caprolactone)-b-poly(ethylene glycol) polymer corona (GNR@PCL-b-PEG). The underlying mechanism of the drug-loading and triggered-release behaviors involves the entrapment of drug payloads among the PCL crystallites and a heat-induced phase change, respectively. A low premature release of the pre-loaded doxorubicin was observed in PBS buffer (pH 7.4) at 37 °C (<10% of the entire payload after 48 h). However, release could be activated within 30 min by conventional heating at 50 °C, above the Tm of the crystalline PCL domain (43.5 °C), with about 60% release over the subsequent 42 h at 37 °C. The NIR-induced heating of an aqueous suspension of GNR@PCL-b-PEG under NIR irradiation (802 nm) was investigated in terms of the irradiation period, power, and concentration-dependent heating behavior, as well as the NIR-induced shape-transformation of the GNR cores. Remotely NIR-triggered release was also explored upon NIR irradiation for 30 min and about 70% release was achieved in the following 42 h at 37 °C, with a mild warming (<4 °C) of the surroundings. The cytotoxicity of GNR@PCL-b-PEG against the mouse fibroblastic-like L929 cell-line was assessed by MTS assay and good compatibility was confirmed with a cell viability of over 90% after incubation for 72 h. The cellular uptake of GNR@PCL-b-PEG by melanoma MEL-5 cells was also confirmed, with an averaged uptake of 1250(±110) particles cell(-1) after incubation for 12 h (50 μg mL(-1)). This GNR@PCL-b-PEG DDS is aimed at addressing the different requirements for therapeutic treatments and is envisaged to provide new insights into DDS targeting for remotely triggered release by NIR activation.

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Regioselective Halogenation of Poly(lactide) by Free‐Radical Process

Beuille

Darcos

Coudane

et al. 2013

Macro Reaction Engineering

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International audienceModification of the biodegradable and renewable poly(lactide) (PLA) to provide functional aliphatic polyesters is highly desirable to meet application requirements. In this context, the objective of this work is to evaluate the possibility of using free-radical substitution as a simple and non-degrading method to yield the desired functional PLA. Halogenation of PLA is carried out in solution and various reaction conditions are evaluated. Halogenated PLAs are characterized by 1 H NMR spectroscopy and size exclu- sion chromatography (SEC) to evaluate the substitution ratios and to check the non-degrading character of the radical modification. Furthermore, reactions on model compounds as well as MALDI-TOF analyses are per- formed to elucidate the involved mechanism. The combined results prove the free-radical halogenation of PLA in solution to be regioselective with only the v-halogenated PLA being obtained without main-chain substitution

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Recent Advances in the Functionalization of Aliphatic Polyesters by Ring-Opening Polymerization

Cited by 3 publications

References 45 publications

Ring‐Opening Polymerization Strategies for Degradable Polyesters

Ring‐Opening Polymerization Strategies for Degradable Polyesters

Gold Nanorods with Phase‐Changing Polymer Corona for Remotely Near‐Infrared‐Triggered Drug Release

Regioselective Halogenation of Poly(lactide) by Free‐Radical Process

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