Tumor-Specific Drug Release and Reactive Oxygen Species Generation for Cancer Chemo/Chemodynamic Combination Therapy.

The combination of chemotherapeutic drugs and reactive oxygen species (ROS) is a promising strategy to achieve improved anticancer effect. Herein, a nanomedicine (LaCIONPs) that can achieve tumor-specific chemotherapeutic drug release and ROS generation is developed for cancer chemo/chemodynamic combination therapy. The LaCIONPs are constructed by encapsulation of iron oxide nanoparticles (IONPs) and β-lapachone (La) in nanostructure assembled by hydrogen peroxide (HO)-responsive polyprodrug and pH-responsive polymer. Through the enhanced permeability and retention effect, the nanosized LaCIONPs can accumulate in tumor tissue. After the LaCIONPs are internalized by tumor cells, the structure of LaCIONPs is disintegrated in acidic intracellular environment, leading to rapid release of La and iron ions. Then the released La generates massive HO through tumor specific catalysis. On the one hand, HO further reacts with iron ions to produce highly toxic hydroxyl radicals for chemodynamic therapy. On the other hand, HO also activates the release of camptothecin from the polyprodrug for chemotherapy. The potent antitumor effect of the LaCIONPs is demonstrated by both in vitro and in vivo results. Therefore, the LaCIONP is a promising nanomedicine for tumor-specific chemo/chemodynamic combination therapy.