NIR Image-Guided Multimodal Nanotherapy Synergizing Photothermal, NO Gas, and Ferroptosis Enhances Immunogenic Cell Death in Triple-Negative Breast Cancer

• The photothermal-sensitive bioreactor, ASNP NPs, enabled a three-way treatment model, including photothermal therapy, NO gas therapy, and ferroptosis, which demonstrated a synergistic therapeutic effect in cancer treatment. • ASNP NPs promoted the release of damage-associated molecular patterns and reprogrammed the tumor immune microenvironment to establish more effective tumoricidal immunity. • ASNP NPs significantly inhibited tumor growth in a 4T1 tumor-bearing mouse model and prevented local tumor recurrence. • ASNP NPs demonstrated a photothermal effect and the ability of NO and ·OH production in fresh human breast cancer tissue, indicating its potential for clinical translation. Immunogenic cell death (ICD), which relies on the release of damage-associated molecular patterns (DAMPs), is able to induce a powerful immune response and improve the antitumor treatment efficacy. Unfortunately, traditional ICD inducers are limited by insufficient release of DAMPs, greatly diminishing their antitumor effects. Here, a multifunctional bioreactor (ASNP NPs) was developed to effectively activate ICD by increasing the release of DAMPs. Specifically, photothermal agent (aza-BODIPY-4C8) and sodium nitroprusside (SNP) were encapsulated into thermally sensitive liposomes to obtain the photothermal-sensitive ASNP NPs. Under irradiation with near-infrared light, ASNP NPs generated heat and released SNP. SNP reacted with glutathione (GSH) to produce NO and Fe 2+ . Fe 2+ further reacted with H 2 O 2 to generate hydroxyl radical (·OH). This further promoted ferroptosis in tumor cells. Together, the photothermal, NO gas, and ferroptosis multimodal therapy by ASNP NPs effectively promoted the release of DAMPs. Importantly, the enhanced ICD effect induced by ASNP NPs reprogrammed the tumor immune microenvironment to establish more effective tumoricidal immunity. This synergistic treatment strategy significantly inhibited tumor growth in a 4T1 tumor-bearing mouse model. Furthermore, the photothermal effect and NO and ·OH production induced by ASNP NPs was observed in fresh human breast cancer tissues, indicating its potential for clinical translation.