• • MG1655@PDA-NLG achieved >90% tumor growth inhibition in a CT26 colon tumor model under NIR irradiation, combining photothermal ablation and IDO-1 inhibition to overcome immunosuppression.
• • Engineered bacteria exhibited hypoxic tumor-targeting, accumulating in tumors within 12 h post intravenous injection and clearing from major organs by 72 h, with negligible hematological toxicity.
• • The photothermal effect induced immunogenic cell death (ICD), promoting dendritic cell maturation and enhancing CD4+ and CD8+ T cell infiltration, synergizing with tryptophan metabolism suppression.
• • Surface modification via in situ PDA polymerization preserved bacterial viability and bioactivity, enabling multifunctional integration for combined cancer immunotherapy.