超高剂量率照射后水分子的辐射化学效应研究

Radiation chemistry effects on water molecules after ultra-high dose rate irradiation

目的对比分析超高剂量率(FLASH)照射和常规剂量率照射后水分子电离的辐射化学效应。方法以超纯水为研究对象,分别实施常规照射和FLASH照射,采用电子顺磁共振法检测均相阶段的羟基自由基生成量,荧光探针法分析扩散期过氧化氢(H_(2)O_(2))产量。构建脂质体常规照射和FLASH照射模型,分析水分子辐射化学效应诱发脂质过氧化情况。结果照射可诱导水分子电离发生化学反应。其中,均相阶段,FLASH照射产生羟基自由基的水平与常规照射无明显差异(P>0.05)。扩散期,FLASH照射产生H_(2)O_(2)的水平明显低于常规照射(t=0.49-12.81,P<0.05)。构建脂质体模型证实,常规照射通过水分子辐射化学效应诱导脂质氧化应激较FLASH照射显著(t=0.31-11.73,P<0.05)。结论FLASH照射后水分子的辐射化学效应明显弱于常规照射,这可能是FLASH效应的机制之一。

ObjectiveTo compare the radiation chemistry effects on water molecules after ultra-high dose rate(FLASH)and conventional irradiation.MethodsBoth FLASH and conventional irradiation were applied to ultrapure water,with the hydroxyl radical yield in the homogeneous phase detected using electron paramagnetic resonance(EPR)and the hydrogen peroxide(H_(2)O_(2))yield in the diffusion phase analyzed uuxing fluorescence probe.The liposome model was then established to investigate the radiation chemistry effect of FLASH and conventional irradiation in inducing lipid peroxidation.ResultsRadiation chemistry reactions were observed in water molecules after irradiation.In the homogeneous phase,the yield of free radicals using FLASH irradiation is similar to those from conventional irradiation(P>0.05).In the diffusion phase,the amount of H_(2)O_(2) produced by FLASH irradiation was significantly lower than those from conventional irradiation(t=0.49-12.81,P<0.05).The liposome model confirmed that conventional irradiation could significantly induce lipid peroxidation through the radiation chemistry effect in water molecules as compared with FLASH irradiation(t=0.31-11.73,P<0.05).ConclusionsThe radiation chemistry effect in water molecules after FLASH irradiation was significantly lower than that from conventional irradiation.This could be one of the mechanisms of FLASH effect.