Shell-detachable micelles based on disulfide-linked block copolymer as potential carrier for intracellular drug delivery.

Aiming at development of a micellar nanoparticle system for intracellular drug release triggered by glutathione in tumor cells, a disulfide-linked biodegradable diblock copolymer of poly(epsilon-caprolactone) and poly(ethyl ethylene phosphate) was synthesized. It formed biocompatible micelles loaded with doxorubicin in aqueous solution but detached the shell material under glutathione stimulus, resulting in rapid drug release with destruction of micellar structure. These glutathione-sensitive micelles also rapidly released the drug molecules intracellularly and led to enhanced growth inhibition to A549 tumor cells, suggesting that this nanoparticle system may have potential for improving drug delivery efficacy.