title: The dependence of radiation enhancement effect on the concentration of gold nanoparticles exposed to low- and high-LET radiations.
abstract: We examined the dependence of hydroxyl radical production on the concentration of 15 nm citrate-capped AuNPs and dose using coumarin-3-carboxylic acid in phosphate buffered saline (PBS), and investigated the radiosensitisation of different concentration AuNPs on human cervix carcinoma HeLa cells through clonogenic survival assay for X-rays and carbon ions. The enhancement factor of AuNPs for hydroxyl radical production reached a maximum 3.66 for X-rays at the concentration of 0.1 μg/mL while the maximum was 5.52 for carbon ions in presence of 1.0 μg/mL AuNPs in PBS. At 50% survival level, the sensitizer enhancement ratios of X-rays and carbon ions varied from 1.14 to 2.88 and from 1.27 to 1.44, respectively, when cells were co-cultured with 1.5-15.0 μg/mL AuNPs. Our data indicate AuNPs showed radiosensitisation in terms of hydroxyl radical production and cell killing for low- and high-LET radiations. The concentration of AuNPs in PBS and cells played an important role in radiosensitizing effect. Based on the fact-the AuNPs in PBS could improve the production of hydroxyl radical and no accumulation of cells in the G2/M phase was observed, we deduce that the increment of hydroxyl radical production with AuNPs provided a mechanism for radiosensitisation.
authors: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: liuyan@impcas.ac.cn.
authors: Yan
authors: Y
authors: Liu
authors: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: liuxi@impcas.ac.cn.
authors: Xi
authors: X
authors: Liu
authors: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000, China. Electronic address: jinxd@impcas.ac.cn.
authors: Xiaodong
authors: X
authors: Jin
authors: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: hepengbo@impcas.ac.cn.
authors: Pengbo
authors: P
authors: He
authors: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: zhengxg@impcas.ac.cn.
authors: Xiaogang
authors: X
authors: Zheng
authors: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000, China. Electronic address: daizhongying@impcas.ac.cn.
authors: Zhongying
authors: Z
authors: Dai
authors: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: yefei@impcas.ac.cn.
authors: Fei
authors: F
authors: Ye
authors: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000, China. Electronic address: zhaoting@impcas.ac.cn.
authors: Ting
authors: T
authors: Zhao
authors: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000, China. Electronic address: chenwq7315@impcas.ac.cn.
authors: Weiqiang
authors: W
authors: Chen
authors: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China; Key Laboratory of Heavy Ion Radiation Biology and Medicine of Chinese Academy of Sciences, Lanzhou 730000, China. Electronic address: liqiang@impcas.ac.cn.
authors: Qiang
authors: Q
authors: Li
mesh_terms: D002453:Cell Cycle / Q000187:drug effects / Q000528:radiation effects; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D002951:Citrates / Q000737:chemistry; D003374:Coumarins / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D004705:Endocytosis / Q000187:drug effects / Q000528:radiation effects; D006046:Gold / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D006367:HeLa Cells; D063193:Heavy Ion Radiotherapy; D006801:Humans; D017665:Hydroxyl Radical / Q000378:metabolism; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D018499:Linear Energy Transfer; D053768:Metal Nanoparticles; D011836:Radiation Tolerance / Q000187:drug effects*; D011838:Radiation-Sensitizing Agents / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D014965:X-Rays
chemical_list: D002951:Citrates; D003374:Coumarins; D011838:Radiation-Sensitizing Agents; D017665:Hydroxyl Radical; D006046:Gold; C104227:coumarin-3-carboxylic acid
keywords: Gold nanoparticles; Low- and high-LET radiations; Radiation enhancement effect; Sensitizer enhancement ratio