Institute for Human Science and Biomedical Engineering, National Institute of Advanced Industrial Science & Technology (AIST), Tsukuba, Ibaraki Japan.
Nanomedicine. 2011 Oct;7(5):604-14. doi: 10.1016/j.nano.2011.01.014. Epub 2011 Feb 17.
The radiosensitizing effect of 5-250 nm diameter Au nanoparticles (AuNPs) in water was investigated under irradiations of diagnostic x-ray and UV light. Enhanced generations of hydroxyl radical ((·)OH) and superoxide anion (O(2)(-)) were confirmed from their dependencies on the absorbed energy, ethanol concentration and AuNPs' concentration. Two kinds of fluorescent probes revealed that the reactive oxygen species (ROS) generation rate under x-ray irradiation was enhanced by factors of 1.46 for (·)OH and 7.68 for O(2)(-). Photo- and Auger electron charge transfer is possibly relevant to generation of O(2)(-) near the particle surface, whereas fluorescent x-rays are involved in generation of (·)OH in the secondary water radiolysis. Smaller diameter AuNPs with larger surface area showed a greater yield of ROS. An inverse proportion of ROS generation to the AuNPs' diameter suggests a catalytic function of AuNPs' surface for enhanced ROS generation.
研究了在诊断 X 射线和紫外光照射下，直径为 5-250nm 的金纳米粒子（AuNPs）在水中的增敏效应。通过依赖于吸收能量、乙醇浓度和 AuNPs 浓度，证实了增强的羟基自由基（(·)OH）和超氧阴离子（O(2)(-）的生成。两种荧光探针表明，X 射线照射下的活性氧（ROS）生成速率((·)OH 提高了 1.46 倍，O(2)(-)提高了 7.68 倍。光电子和俄歇电子电荷转移可能与粒子表面附近 O(2)(-)的生成有关，而荧光 X 射线则参与了二次水辐射分解中 (·)OH 的生成。具有较大表面积的较小直径 AuNPs 表现出更高的 ROS 生成率。ROS 生成与 AuNPs 直径呈反比，表明 AuNPs 表面具有增强 ROS 生成的催化作用。
