A versatile supramolecular nanoagent for three-pronged boosting chemodynamic therapy

Abstract

Chemodynamic therapy (CDT) utilizing toxic hydroxyl radicals (·OH) to kill cancer cells exhibits huge potentiality in antitumor treatment. However, inadequate acidity, insufficient hydrogen peroxide (H2O2) amount, and overexpressed reduced glutathione (GSH) inside cancer cells severely restrict the efficacy of CDT. Although numerous efforts have been made, fabricating a versatile CDT material for surmounting these obstacles simultaneously is still a great challenge, especially for supramolecular materials owing to lacking an active metal unit for the Fenton reaction. Here, we intriguingly proposed a powerful supramolecular nanoagent (GOx@GANPs) based on the host–guest interaction between pillar[6]arene and ferrocene for all-sided boosting CDT efficacy via in situ cascade reactions. GOx@GANPs could stimulate intracellular glucose conversion into H+ and H2O2 to optimize the in situ Fenton reaction conditions and continuously produce sufficient •OH. Meanwhile, consumption of the original intracellular GSH pool and inhibition of GSH regeneration were synchronously achieved through the GSH-responsive gambogic acid prodrug and cutting off adenosine triphosphate (ATP) supply for GSH resynthesis, respectively. This complete GSH exhausting characteristic of GOx@GANPs effectively suppressed •OH elimination, ultimately resulting in a superior CDT effect. Furthermore, GOx@GANPs also produced synergistic effects of starvation therapy, chemotherapy, and CDT, exhibiting low toxicity toward normal tissues. Thus, this work introduces a valuable way for optimizing and elevating CDT efficiency and synergistic treatment of tumors.