Institute of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-based Functional Materials and Devices, Soochow University, Suzhou, Jiangsu, 215123, China.
Molecular Imaging Program at Stanford, Department of Radiology, Stanford University School of Medicine, 1201 Welch Road, Stanford, California, 94305-5484, USA.
Adv Mater. 2017 Aug;29(32). doi: 10.1002/adma.201700996. Epub 2017 Jun 23.
Radiation therapy (RT) including external beam radiotherapy (EBRT) and internal radioisotope therapy (RIT) has been widely used for clinical cancer treatment. However, owing to the low radiation absorption of tumors, high doses of ionizing radiations are often needed during RT, leading to severe damages to normal tissues adjacent to tumors. Meanwhile, the RT efficacies are limited by different mechanisms, among which the tumor hypoxia-associated radiation resistance is a well-known one, as there exists hypoxia inside most solid tumors while oxygen is essential to enhance radiation-induced DNA damages. With the development in nanotechnology, there have been great interests in using nanomedicine strategies to enhance radiation responses of tumors. Nanomaterials containing high-Z elements to absorb radiation rays (e.g. X-ray) can act as radio-sensitizers to deposit radiation energy within tumors and promote treatment efficacy. Nanoscale carriers are able to deliver therapeutic radioisotopes into tumors for internal RIT, or chemotherapeutic drugs for synergistically combined chemo-radiotherapy. As uncovered in recent studies, the tumor microenvironment could be modulated by various nanomedicine approaches to overcome hypoxia-associated radiation resistance. Herein, the authors will summarize the applications of nanomedicine for RT cancer treatment, and pay particular attention to the latest development of 'advanced materials' for enhanced cancer RT.
放射治疗（RT）包括外照射放疗（EBRT）和内放射性同位素治疗（RIT）已广泛用于临床癌症治疗。然而，由于肿瘤对辐射的吸收较低，在 RT 过程中通常需要使用高剂量的电离辐射，这会导致肿瘤附近的正常组织受到严重损伤。同时，RT 疗效受到不同机制的限制，其中肿瘤缺氧相关的辐射抗性是众所周知的，因为大多数实体肿瘤内部存在缺氧，而氧气对于增强辐射诱导的 DNA 损伤至关重要。随着纳米技术的发展，人们对利用纳米医学策略来增强肿瘤的辐射反应产生了浓厚的兴趣。含有高 Z 元素的纳米材料可以吸收射线（例如 X 射线），从而充当放射增敏剂，将辐射能量沉积在肿瘤内，并提高治疗效果。纳米级载体能够将治疗性放射性同位素递送到肿瘤内进行内部 RIT，或递送到肿瘤内进行协同联合化疗放疗的化疗药物。最近的研究表明，肿瘤微环境可以通过各种纳米医学方法进行调节，以克服与缺氧相关的辐射抗性。在此，作者将总结纳米医学在 RT 癌症治疗中的应用，并特别关注增强癌症 RT 的“先进材料”的最新进展。
