Red-light-triggered microenvironment-responsive sustained carbon monoxide release for enhanced tumor therapy

a Fenton reaction, further promoting sustained CO release under dark conditions in the second stage. Light irradiation acts as a gating mechanism to achieve precise and sustained CO release. This CO delivery platform can be efficiently internalized by 4T1 tumor cells and, upon 630 nm light irradiation, releases CO intracellularly to induce ferroptosis. By synergistically disrupting mitochondrial function, it exhibits effective antitumor activity in 4T1 tumor-bearing mice.