Cell-specific ferroptosis targeting tumors while sparing immune cells

Ferroptosis serves as a pivotal mechanism in diverse clinical chemotherapeutics and physiological processes, profoundly impacting tumor metabolism and the tumor microenvironment. Recently, the immunosuppression induced by ferroptosis has raised major concerns regarding tumor recurrence upon ferroptosis-based antitumor therapies. However, due to the lack of cell specificity, the antitumor and immunosuppressive effects in ferroptosis are inherently intertwined. Herein, we address the conflicting challenges between immunosuppression and antitumor efficacy in ferroptosis-based therapy by enabling cell-specific ferroptosis, thereby targeting tumors while sparing immune cells. By employing a specially designed nanoagent, i.e., ferrous selenide half-shell-covered gold, we induce notable upregulation of glutathione peroxidase 4 (GPX4) and downregulation of prostaglandin E2, leading to an increase in CD⁴⁺ and CD⁸⁺ T cell populations and intense antitumor immune responses. Despite the elevated level of GPX4, significant tumor cell ferroptosis is achieved, which is further promoted by the agent's photothermal and photocatalytic effects. Consequently, long-term immunological memory is established, yielding a long-lasting and recurrence-free antitumor efficacy spanning at least 200 days post-treatment. This work unlocks an avenue to balance immunosuppression reversal with tumor inhibition in ferroptosis-based therapies, providing promising prospects for antitumor therapies facing immunological hurdles in the tumor microenvironment.