Controlled drug release system based on cyclodextrin-conjugated poly(lactic acid)-b-poly(ethylene glycol) micelles

Cyclodextrin-conjugated poly(lactic acid)-b-poly(ethylene glycol) (beta-CD-PLA-mPEG), a well-defined amphiphilic copolymer, was synthesized by controlled ring-open copolymerization and click coupling reaction, in order to obtain a biocompatible drug delivery system with controlled release profiles. The beta-CD-PLA-mPEG copolymer could self-assemble in aqueous solution to form micelles with a mean particle size of 173.4 nm, which will decrease to 159.2 nm after loaded with a kind of hydrophobic drug (indomethacin, IND). The IND-loaded beta-CD-PLA-mPEG micelles show spherical shape within the nano-size scale under TEM imaging. Compared with that formed by PLA-mPEG, the micelles formed by beta-CD-PLA-mPEG copolymer present higher drug loading efficiency and controlled release profile of IND, especially in the control of its initial burst release. Meanwhile, beta-CD-PLA-mPEG copolymer exhibits low toxicity to cells. The micelles formed by beta-CD-PLA-mPEG copolymer could be a promising controlled release system for various hydrophobic drugs. (c) 2013 Elsevier B.V. All rights reserved.