Seo Seung-Jun, Jeon Jae-Kun, Han Sung-Mi, Kim Jong-Ki
a Department of Biomedical Engineering and Radiology, School of Medicine , Catholic University of Daegu , Daegu City , South Korea.
b Department of Anatomy, School of Medicine , Catholic University of Daegu , Daegu City , South Korea.
Int J Radiat Biol. 2017 Nov;93(11):1239-1247. doi: 10.1080/09553002.2017.1361556. Epub 2017 Aug 16.
The Coulomb nanoradiator (CNR) effect produces the dose enhancement effects from high-Z nanoparticles under irradiation with a high-energy ion beam. To gain insight into the radiation dose and biological significance of the CNR effect, the enhancement of reactive oxygen species (ROS) production from iron oxide or gold NPs (IONs or AuNPs, respectively) in water was investigated using traversing proton beams.
The dependence of nanoradiator-enhanced ROS production on the atomic Z value and proton energy was investigated. Two biologically important ROS species were measured using fluorescent probes specific to •OH or [Formula: see text] in a series of water phantoms containing either AuNPs or IONs under irradiation with a 45- or 100-MeV proton beam.
The enhanced generation of hydroxyl radicals (•OH) and superoxide anions ([Formula: see text]) was determined to be caused by the dependence on the NP concentration and proton energy. The proton-induced Au or iron oxide nanoradiators exhibited different ROS enhancement rates depending on the proton energy, suggesting that the CNR radiation varied. The curve of the superoxide anion production from the Au-nanoradiator showed strong non-linearity, unlike the linear behavior observed for hydroxyl radical production and the X-ray photoelectric nanoradiator. In addition, the 45-MeV proton-induced Au nanoradiator exhibited an ROS enhancement ratio of 8.54/1.50 ([Formula: see text] / •OH), similar to that of the 100-KeV X-ray photoelectric Au nanoradiator (7.68/1.46).
The ROS-based detection of the CNR effect revealed its dependence on the proton beam energy, dose and atomic Z value and provided insight into the low-linear energy transfer (LET) CNR radiation, suggesting that these factors may influence the therapeutic efficacy via chemical reactivities, transport behaviors, and intracellular oxidative stress.
库仑纳米辐射器（CNR）效应在高能离子束辐照下会产生高Z值纳米颗粒的剂量增强效应。为深入了解CNR效应的辐射剂量及生物学意义，使用穿越质子束研究了水中氧化铁或金纳米颗粒（分别为IONs或AuNPs）产生活性氧（ROS）的增强情况。
研究了纳米辐射器增强的ROS产生对原子Z值和质子能量的依赖性。在一系列含有AuNPs或IONs的水模体中，使用针对•OH或[公式：见原文]的荧光探针，在45 MeV或100 MeV质子束辐照下测量了两种对生物学重要的ROS种类。
确定羟基自由基（•OH）和超氧阴离子（[公式：见原文]）的增强产生是由对NP浓度和质子能量的依赖性引起的。质子诱导的金或氧化铁纳米辐射器根据质子能量表现出不同的ROS增强率，表明CNR辐射有所不同。金纳米辐射器产生超氧阴离子的曲线显示出强烈的非线性，这与羟基自由基产生和X射线光电纳米辐射器所观察到的线性行为不同。此外，45 MeV质子诱导的金纳米辐射器表现出的ROS增强比为8.54/1.50（[公式：见原文] / •OH），与100 keV X射线光电金纳米辐射器的增强比（7.68/1.46）相似。
基于ROS对CNR效应的检测揭示了其对质子束能量、剂量和原子Z值的依赖性，并深入了解了低线性能量传递（LET）的CNR辐射，表明这些因素可能通过化学反应性、传输行为和细胞内氧化应激影响治疗效果。
