Renal clearable BiOI nanodots with M1 macrophage membrane coating for enhanced radiotherapy of hepatocellular carcinoma

Although radiotherapy has become indispensable for tumor treatment in recent years, the inevitable side effects of high-dose radiation on the normal tissue and deficiency of appropriate radiosensitizers without long-term body retention that do not cause potential toxicity limit further clinical applications to a certain extent. Herein, we rationally synthesized BiOI nanodots coated with M1 macrophage membrane (BiOI@M) by utilizing their coordination interaction. With two high-atomic-number elements and ultrasmall size, the prepared BiOI nanodots not only enhanced radiosensitivity by reactive oxygen species under X-ray irradiation in vitro, but also could be excreted quickly by kidneys. Meanwhile, the M1 macrophage membrane functioned as a highly desirable carrier with long-circulating and tumor-targeting capability. As a result, treatment with as-prepared BiOI@M could improve the therapeutic outcome of radiotherapy in a xenograft mouse model and reduce the potential toxicity of nanoparticles. Simultaneously, BiOI nanodots exhibited excellent CT imaging ability as contrast agents to visualize biodistribution in vivo and to monitor tumor growth. Therefore, our work demonstrated the preparation of a tumor targeting and renal clearable radiosensitizer and offered a potential approach to enhance the radiotherapy efficacy of hepatocellular carcinoma.