Scheme 1

Schematic representation shows that intracellular marriage of bicarbonate and Mn ions as “immune ion reactors” to regulate redox homeostasis and antitumor immune responses for synchronous enduring orthotopic cancer treatment. In the acidic environment, MnCO₃-ICG are decomposed to release ions (Mn²⁺, \({\text{HCO}}_{3}^{ - }\)) in situ that regulates intracellular redox homeostasis and antitumor immune responses. The self-supplying \({\text{HCO}}_{3}^{ - }\) escalates tumor oxidative stresses by catalyzing Mn-based Fenton-like reaction to efficiently generate hydroxyl radicals (·OH); the released ICG amplifies tumor oxidative stress by photothermal process; and Mn²⁺ ions as one of adjuvants enhance the immune response