Gas-forming poly(ethylene glycol)-b-poly(L-lactic acid) micelles

Abstract

In this study, a novel drug-carrying micelle composed of methoxy poly(ethylene glycol) (mPEG)-b-poly(L-lactic acid) (PLLA) with gas-forming carbonate linkage was fabricated. Here, the gas-forming carbonate linkage was formed by the chemical coupling of the terminal hydroxyl group of the PLLA block and benzyl chloroformate (BC). mPEG-b-PLLA-BC was self-organized in aqueous solution: the PEG block on the hydrophilic outer shell and the PLLA-BC block in the hydrophoboic innor core. The cleavage of carbonate linkage by hydrolysis and formation of carbon dioxide nanobubbles in the micellar core enabled an accelerated release of the encapsulated anticancer drug (doxorubicin: DOX) from the mPEG-b-PLLA-BC micelles. The amount of drug (DOX) released from the mPEG-b-PLLA-BC micelle was higher than that from the conventional mPEG-b-PLLA micelle, which allowed for increased in vitro toxicity against KB tumor cells. Copyright (c) 2013 John Wiley & Sons, Ltd.