Boosting Reactive Oxygen Species Generation with a Dual-Catalytic Nanomedicine for Enhanced Tumor Nanocatalytic Therapy.

Generating lethal reactive oxygen species (ROS) within tumors by nanocatalytic medicines is an advanced strategy for tumor-specific therapy in recent years. Nevertheless, the low yield of ROS restrains its therapeutic efficiency. Herein, a dual-catalytic nanomedicine based on tumor microenvironment (TME)-responsive liposomal nanosystem co-delivering CuO2 and dihydroartemisinin (DHA) (LIPSe@CuO2&DHA) is developed to boost ROS generation against tumor. The liposomal nanosystem can degrade in the ROS-overexpressed TME and liberate CuO2 and DHA to initiate Cu-based dual-catalytic ROS generation. Serving as generators of H2O2 and Cu2+, CuO2 can self-produce plenty of toxic hydroxyl radicals via Fenton-like reaction in the acidic TME. Meanwhile, the released Cu2+ can catalyze DHA to generate cytotoxic C-centered radicals. Together, the self-supplied H2O2 and Cu-based dual-catalytic reaction greatly increase the intratumoral level of lethal ROS. Importantly, Cu2+ can decrease the GSH-mediated scavenging effect on the produced ROS via a redox reaction and undergo a Cu2+-to-Cu+ conversion to enhance the Fenton-like reaction, further guaranteeing the high efficiency of ROS generation. Resultantly, LIPSe@CuO2&DHA induces remarkable cancer cell death and tumor growth inhibition, which may present a promising nanocatalytic medicine for cancer therapy.

Multichannel Ca2+ Generator for Synergistic Tumor Therapy via Intracellular Ca2+ Overload and Chemotherapy.

Ca2+ overload has attracted an increasing attention due to its benefit of precise cancer therapy, but its efficacy is limited by the strong Ca2+ excretion of cancer cells. Moreover, monotherapy of Ca2+ overload usually fails to treat tumors satisfactorily. Herein, we develop a multifunctional nanosystem that could induce Ca2+ overload by multipathway and simultaneously produce chemotherapy for synergistic tumor therapy. The nanosystem (CaMSN@CUR) is prepared by synthesizing a Ca-doped mesoporous silica nanoparticle (CaMSN) followed by loading the anticancer drug curcumin (CUR). CaMSN serves as the basis Ca2+ generator to induce Ca2+ overload directly in the intracellular environment by acid-triggered Ca2+ release, while CUR could not only exhibit chemotherapy but also facilitate Ca2+ release from the endoplasmic reticulum to the cytoplasm and inhibit Ca2+ efflux out of cells to further enhance Ca2+ overload. The in vitro and in vivo results show that CaMSN@CUR could exhibit a remarkable cytotoxicity against 4T1 cells and significantly inhibit tumor growth in 4T1 tumor-bearing mice via the synergy of Ca2+ overload and CUR-mediated chemotherapy. It is expected that the designed CaMSN@CUR has a great potential for effective tumor therapy.