Reduction-sensitive degradable micellar nanoparticles as smart and intuitive delivery systems for cancer chemotherapy.

INTRODUCTION: Biodegradable micellar nanoparticles are one of the most promising platforms for targeted cancer chemotherapy. In particular, reduction-sensitive micellar nanoparticles that actively deliver and release drugs into cancer cells have recently appeared as an advanced drug release system. The in vitro and in vivo studies have pointed out that reduction-sensitive micellar drug formulations afford significantly enhanced antitumor activity as compared with 'traditional' reduction-insensitive counterparts. AREAS COVERED: This review provides an overview of recent advances in reduction-sensitive degradable micellar nanoparticles for triggered anticancer drug delivery. The design and preparation of reduction-sensitive micellar nanoparticles, redox-triggered in vitro and intracellular drug release, in vitro as well as in vivo antitumor performances of drug-loaded nanoparticles are discussed. EXPERT OPINION: Reduction-sensitive degradable micellar nanoparticles with unique advantages of high stability against hydrolytic degradation, fast response to intracellular reducing environment and triggered drug release right in the cytosol and cell nucleus have demonstrated a tremendous potential in targeted and active intracellular delivery of potent and poorly soluble anticancer drugs. These intracellular-activatable fast drug releasing nanosystems may eventually be developed as 'drug bomb' for effective treatment of various tumors including multidrug-resistant tumors.