放射治疗（RT）因其无创性和广泛的适应性而在肿瘤治疗中发挥着重要作用。近年来，人们发现放射治疗可以诱导抗肿瘤免疫反应，引起了科学家和临床医生的广泛关注。在这篇综述中，我们重点介绍了纳米生物材料在放射治疗激活免疫治疗中应用的最新进展。我们首先讨论不同放射增敏纳米生物材料与免疫检查点抑制剂的组合，以增强肿瘤免疫反应并提高放疗疗效。随后，引入了各种纳米生物材料支持的肿瘤氧合策略，以缓解缺氧的肿瘤环境并放大免疫调节作用。在纳米疫苗和佐剂的帮助下，放射治疗可以刷新宿主的免疫系统。此外，电离辐射响应纳米生物材料可提高先天免疫介导的抗肿瘤免疫力。最后，我们总结了免疫调节纳米生物材料的快速发展，并讨论了肿瘤放射免疫治疗纳米生物材料发展的关键挑战。了解纳米生物材料辅助放射免疫治疗将最大限度地发挥临床放射治疗和免疫治疗的益处，并促进新的联合治疗方式的开发。© 2023。作者。

Radiotherapy (RT) plays an important role in tumor therapy due to its noninvasiveness and wide adaptation. In recent years, radiation therapy has been discovered to induce an anti-tumor immune response, which arouses widespread concern among scientists and clinicians. In this review, we highlight recent advances in the applications of nano-biomaterials for radiotherapy-activated immunotherapy. We first discuss the combination of different radiosensitizing nano-biomaterials and immune checkpoint inhibitors to enhance tumor immune response and improve radiotherapy efficacy. Subsequently, various nano-biomaterials-enabled tumor oxygenation strategies are introduced to alleviate the hypoxic tumor environment and amplify the immunomodulatory effect. With the aid of nano-vaccines and adjuvants, radiotherapy refreshes the host's immune system. Additionally, ionizing radiation responsive nano-biomaterials raise innate immunity-mediated anti-tumor immunity. At last, we summarize the rapid development of immune modulatable nano-biomaterials and discuss the key challenge in the development of nano-biomaterials for tumor radio-immunotherapy. Understanding the nano-biomaterials-assisted radio-immunotherapy will maximize the benefits of clinical radiotherapy and immunotherapy and facilitate the development of new combinational therapy modality.© 2023. The Author(s).