Biomimetic nano-chelate diethyldithiocarbamate Cu/Fe for enhanced metalloimmunity and ferroptosis activation in glioma therapy

Ferroptosis has emerged as a promising therapeutic approach for glioma. However, its efficacy is often compromised by the activated GPX4-reduced glutathione (GSH) system and the poor brain delivery efficiency of ferroptosis inducers. Therefore, suppression of the GPX4-GSH axis to induce the accumulation of lipid peroxides becomes an essential strategy to augment ferroptosis. In this study, we present a metalloimmunological strategy to target the GPX4-GSH axis by inhibiting the cystine/glutamate antiporter system (system Xc−) and glutathione synthesis. To achieve this, we developed a complex of diethyldithiocarbamate (DDC) chelated with copper and ferrous ions (DDC/Cu-Fe) to trigger T-cell immune responses in the tumor microenvironment, as well as to inhibit tumor-associated macrophages, thereby alleviating immunosuppression. To enhance brain delivery, the DDC/Cu-Fe complex was encapsulated into a hybrid albumin and lactoferrin nanoparticle (Alb/LF NP), targeting the nutrient transporters (e.g., LRP-1 and SPARC) overexpressed in the blood-brain barrier (BBB) and glioma cells. The Alb/LF NP effectively promoted the brain accumulation of DDC/Cu-Fe, synergistically induced ferroptosis in glioma cells and activated anticancer immunity, thereby prolonging the survival of glioma-bearing mice. The nanoformulation of DDC/Cu-Fe provides a promising strategy that combines ferroptosis and metalloimmunology for glioma treatment.