A thermo-sensitive PLGA-PEG-PLGA hydrogel for sustained release of docetaxel

The aim of this study was to investigate the suitability of poly-(D,L-lactic acid-co-glycolic acid) (PLGA)-polyethylene glycol (PEG)-PLGA triblock copolymer as a matrix material for a sustained-release system for docetaxel (DTX). The copolymers were synthesized by ring-opening polymerization reaction and characterized by H-1-NMR and gel permeation chromatography. The DTX-loaded formulations were prepared, characterized. And the antitumor efficacy and the pharmacokinetics of DTX-loaded copolymer on A-549 lung tumor-bearing BALB/cA mice were investigated. The results showed that DTX-loaded copolymer highly increased the solubility of DTX by more than 3000-fold. And copolymer concentration as well as drug loading level exerted appreciable influence on the drug release behavior. Further, the pharmacokinetic test showed that DTX-loaded copolymer could be with the sustained-release nature for over 3 weeks, which correlated well with the in vitro release. Additionally, one intratumoral injection of the thermosensitive hydrogel containing DTX was comparable to three intravenous injections of DTX injection in inhibiting the tumor growth in A-549 lung tumor-bearing BALB/cA mice with a less toxic manner. PLGA-PEG-PLGA could thus provide a promising alternate locally delivered vehicle for DTX to achieve prolonged exposure having greater efficacy in inhibiting tumor growth with lower toxicity.