Self‐Assembled Triple‐Targeted Radiosensitizer Enhances Hypoxic Tumor Targeting and Radio‐Immunotherapy Efficacy

signal, enabling real-time tracking of tumor-specific delivery and hypoxia. Following low-dose X-ray irradiation (2 Gy), elevated NTR expression promotes further Cy-Ni-RGD NPs reduction, enhancing proteins labeling and causing DNA damage. Moreover, radiosensitization with A-Cy-Ni-RGD NPs triggers robust immunogenic cell death, stimulating antitumor immunity that inhibits tumor growth and metastasis, significantly prolonging survival in mice with orthotopic 4T1 tumors. This work underscores the potential of self-assembling, triple-targeted radiotheranostic agents for improving tumor targeting, imaging, and radiotherapy efficacy in hypoxic tumors.