A novel property of gold nanoparticles: Free radical generation under microwave irradiation.
A novel property of gold nanoparticles: Free radical generation under microwave irradiation.
复制标题
金纳米颗粒的一个新特性：微波照射下自由基的产生。
DOI：
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
E. Parsai
中科院分区：
文献类型：
--
作者：
N. Paudel;D. Shvydka;E. Parsai
目的
金纳米粒子（GNP）是微波热疗的有效介质。与电磁场的相互作用、大的表面与体积比以及纳米颗粒（NP）的尺寸量化可以导致超出纯加热效应的增加的细胞杀伤。本研究的目的是探讨自由基产生的可能性GNP在水介质中，当他们暴露于微波场。
方法
用电子顺磁共振（EPR）/电子自旋共振光谱仪扫描在20 ppm GNP胶体悬浮液中具有500 mM 5，5-二甲基-1-吡咯啉N-氧化物（DMPO）的许多样品，以产生和检测自由基。来自光谱仪的固定频率（9.68 GHz）微波用于生成和检测自由基。用光谱仪作为强度的一阶导数获得的EPR光谱被双重积分以获得自由基信号强度。通过施加不同水平的微波功率（12.5，49.7，和125 mW），同时保持所有其他扫描参数相同的自由基强度的功率依赖性进行了研究。比较了在相同功率水平下获得的初始和最终扫描的自由基信号强度。
结果
发现由于GNP-DMPO胶体样品暴露于微波场而产生羟基自由基（OH）信号。在12.5 mW微波功率下持续2.8 min所产生的OH-2信号的强度接近于从暴露于1.5戈伊电离辐射剂量的水-DMPO样品获得的OH-2信号的强度。对于重复扫描，对于在初始和最终扫描之间施加的较高功率水平，在最终扫描中观察到较高的OH-2强度。对于初始和最终扫描之间的较短时间间隔，最终强度也较高。
结论
我们的研究结果首次表明，GNP在水介质中产生OH自由基时，他们暴露于微波场。如果通过适当定位NP，可以在细胞的脱氧核糖核酸附近产生OH自由基，则NP辅助的微波热疗可以通过升高的温度和自由基的产生来产生细胞杀伤。
PURPOSE
Gold nanoparticles (GNPs) are known to be effective mediators in microwave hyperthermia. Interaction with an electromagnetic field, large surface to volume ratio, and size quantization of nanoparticles (NPs) can lead to increased cell killing beyond pure heating effects. The purpose of this study is to explore the possibility of free radical generation by GNPs in aqueous media when they are exposed to a microwave field.
METHODS
A number of samples with 500 mM 5,5-dimethyl-1-pyrroline N-oxide (DMPO) in 20 ppm GNP colloidal suspensions were scanned with an electron paramagnetic resonance (EPR)/electron spin resonance spectrometer to generate and detect free radicals. A fixed (9.68 GHz) frequency microwave from the spectrometer has served for both generation and detection of radicals. EPR spectra obtained as first derivatives of intensity with the spectrometer were double integrated to get the free radical signal intensities. Power dependence of radical intensity was studied by applying various levels of microwave power (12.5, 49.7, and 125 mW) while keeping all other scan parameters the same. Free radical signal intensities from initial and final scans, acquired at the same power levels, were compared.
RESULTS
Hydroxyl radical (OH⋅) signal was found to be generated due to the exposure of GNP-DMPO colloidal samples to a microwave field. Intensity of OH⋅ signal thus generated at 12.5 mW microwave power for 2.8 min was close to the intensity of OH⋅ signal obtained from a water-DMPO sample exposed to 1.5 Gy ionizing radiation dose. For repeated scans, higher OH⋅ intensities were observed in the final scan for higher power levels applied between the initial and the final scans. Final intensities were higher also for a shorter time interval between the initial and the final scans.
CONCLUSIONS
Our results observed for the first time demonstrate that GNPs generate OH⋅ radicals in aqueous media when they are exposed to a microwave field. If OH⋅ radicals can be generated close to deoxyribonucleic acid of cells by proper localization of NPs, NP-aided microwave hyperthermia can yield cell killing via both elevated temperature and free radical generation.
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DOI：
--
发表时间：
--
期刊：
Environmental Science and Pollution Research International
影响因子：
--
作者：
P. Wust;B. Hildebrandt;G. Sreenivasa;B. Rau;J. Gellermann;H. Riess;R. Felix;P. Schlag
通讯作者：
P. Wust;B. Hildebrandt;G. Sreenivasa;B. Rau;J. Gellermann;H. Riess;R. Felix;P. Schlag
影响因子：
3.5
作者：
Hainfeld, JF;Slatkin, DN;Smilowitz, HM
通讯作者：
Smilowitz, HM
影响因子：
17.1
作者：
Sano, Kohei;Nakajima, Takahito;Choyke, Peter L.;Kobayashi, Hisataka
通讯作者：
Kobayashi, Hisataka
影响因子：
16.1
作者：
Cherukuri, Paul;Glazer, Evan S.;Curleya, Steven A.
通讯作者：
Curleya, Steven A.