Hyperbranched poly (amine-ester)-poly (lactide-co-glycolide) copolymer and their nanoparticles as paclitaxel delivery system

A new hyperbranched poly (amine-ester)-poly (lactide-co-glycolide) copolymer (HPAE-co-PLGA) was synthesized by ring-opening polymerization of D, L-lactide (DLLA) glycolid and branched poly (amine-ester) (HPAE-OHs) with Sn(Oct)(2) as catalyst. The chemical structures of copolymers were determined by FT-IR, H-1-NMR(C-13 NMR), TGA and their molecular weights were determined by gel permeation chromatography (GPC). Paclitaxel-loaded copolymer nanoparticles were prepared by the nanoprecipitation method. Their physicochemical characteristics, e. g. morphology and nanoparticles size distribution were then evaluated by means of fluorescence spectroscopy, environmental scanning electron microscopy (ESEM), and dynamic light scattering (DLS). Paclitaxel-loaded nanoparticles assumed a spherical shape and have unimodal size distribution. It was found that the chemical composition of the nanoparticles was a key factor in controlling nanoparticles size, drug-loading content, and drug release behavior. As the molar ratio of DL-lactide/glycolide to HPAE increased, the nanoparticles size and drug-loading content increased, and the drug release rate decreased. The antitumor activity of the paclitaxel-loaded HPAE-co-PLGA nanoparticles against human liver cancer H7402 cells was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) method. The paclitaxel-loaded HPAE-co-PLGA nanoparticles showed comparable anticancer efficacy with the free drug. Copyright (C) 2010 John Wiley & Sons, Ltd.