Cascade catalytic nanoplatform based on ions interference strategy for calcium overload therapy and ferroptosis.

Intracellular ions played prominent part in cell function and behavior. Disrupting intracellular ions homeostasis might switch ions signal from "regulating" to "destroying". Inspired by this, we introduced the ions interference strategy for tumor therapy. Herein, curcumin (CUR) and transferrin (Tf) co-loaded calcium peroxide nanoparticles (CaO2 NPs) were formulated. With tumor targeting ability, CaO2/Tf/CUR pinpointed tumor cells and then instantaneously decomposed in acidic lysosomes, concurrently accompanying with the release of Ca2+ and CUR, as well as the production of H2O2. Then H2O2 not only damaged structure of Tf to release Fe3+, but also was converted to hydroxyl radicals via ferric ions mediated Fenton reaction for ferroptosis. In addition, the released Ca2+ and CUR induced Ca2+ overload via exogenous and endogenous calcium ions accumulation, respectively, further activating mitochondria apoptosis signaling pathway for cell injury. Therefore, based on calcium and ferric ions interference strategy, the cascade catalytic CaO2/Tf/CUR offered synergistic combination of ferroptosis, Ca2+ overload therapy and chemotherapy, which held a great promise in cancer treatment.

Biomimetic Ca2+ nanogenerator based on ions interference strategy for tumour-specific therapy.

Intracellular Ca2+ ions as second messenger played key role in cell behaviour, which was often overlooked in traditional antitumor treatment. Disrupting Ca2+ ion homeostasis by Ca2+ overload might switch ions signal from 'regulating' to 'destroying'. Inspired by this, a biomimetic Ca2+ nanogenerator was constructed. Briefly, the curcumin (CUR) was loaded into mesoporous calcium carbonate nanoparticles (MCC NPs), and then coated with platelet (PLT) membrane. Upon reaching tumour cells by PLT membrane-mediated tumour targeting effect, PLT@MCC/CUR would instantaneously decompose in acidic lysosomes, concurrently accompanying with Ca2+ generation and CUR release. The CUR could further facilitate Ca2+ release from endoplasmic reticulum (ER) and inhibit Ca2+ efflux, aggravating Ca2+ overload to disrupt mitochondrial Ca2+ homeostasis for mitochondria apoptosis signalling pathway activation. Interestingly, such effect was ineffective in normal cells, realising the tumour-specific therapeutic therapy. Based on ions interference strategy, PLT@MCC/CUR herein offered synergistic combination of Ca2+ overload therapy and chemotherapy, which would pave the way towards more effective nanotherapeutics.