Cellular defense system-destroying nanoparticles as a platform for enhanced chemotherapy against drug-resistant cancer.

Cellular defense system represented by glutathione (GSH) greatly weakens the outcomes of cancer therapy by antioxidation and detoxification. GSH depletion has been proved to be an effective way to enhance the efficacy of reactive oxygen species (ROS)-based therapies and chemotherapy. However, the existing strategies of GSH depletion still face the problems of unclear biosafety and high complexity of multicomponent co-delivery. In this study, we developed a GSH-depleting carrier platform based on disulfide-bridged mesoporous organosilica nanoparticles (MONs) to destroy the cellular defense system for cancer therapy. Responding to the high level of GSH in cancer cells, the disulfide bonds in the framework of MONs could be broken and consumed substantial GSH at the same time. Moreover, this process also promoted the degradation of MONs. In order to evaluate the effect of this platform in cancer therapy, chemotherapeutic drug cisplatin was loaded into MONs (Pt@MONs) to treat drug-resistant non-small cell lung cancer. In vitro and in vivo results indicated that Pt@MONs efficiently triggered GSH depletion, promoted platinum-DNA adduct formation, and induced cell apoptosis, resulting in significant tumor growth inhibition without marked toxicity. Taken together, the cellular defense system-destroying nanoparticles provide a promising platform for enhanced cancer therapy.