Biodegradable Amorphous Copper Iron Tellurite Promoting the Utilization of Fenton-Like Ions for Efficient Synergistic Cancer Theranostics

The major hurdles of chemodynamic therapy (CDT) are nondegradability and low-efficiency utilization of chemodynamic agents, and intracellular glutathione (GSH)-induced rapid scavenging of hydroxyl radicals (•OH). Here, a biodegradable a-CFT@IP6@BSA agent is reported for efficient cancer therapy by encapsulating amorphous copper iron tellurite nanoparticles (a-CFT NPs) into inositol hexaphosphate (IP6) and bovine serum albumin (BSA). The biggest merits of this agent are the GSH responsive degradation and amorphous structure, allowing the tumor-specific release of plenty of Cu⁺ ions and their high-efficiency utilization for •OH production via the Fenton-like reaction. Besides, the released Cu⁺ ions can deplete the intracellular GSH and thereby protect •OH from scavenging, greatly improving the CDT efficiency. Further, it is found that the a-CFT@IP6@BSA NP treatment down-regulates the levels of glutathione peroxidase 4 and BCL-2, indicating GSH depletion-associated ferroptosis and IP6-induced apoptotic death of cancer cells. Utilizing the T₁/T₂ dual-modal magnetic resonance imaging capability, the a-CFT@IP6@BSA NPs are demonstrated with excellent in vivo anticancer efficiency and have great potential for imaging-guided cancer treatment.