State Research Center-Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, 123098 Moscow, Russia.
Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 119334 Moscow, Russia.
Int J Mol Sci. 2021 Jun 2;22(11):6030. doi: 10.3390/ijms22116030.
Nanoparticles (NPs) with a high atomic number () are promising radiosensitizers for cancer therapy. However, the dependence of their efficacy on irradiation conditions is still unclear. In the present work, 11 different metal and metal oxide NPs (from Cu ( = 29) to BiO ( = 83)) were studied in terms of their ability to enhance the absorbed dose in combination with 237 X-ray spectra generated at a 30-300 kVp voltage using various filtration systems and anode materials. Among the studied high- NP materials, gold was the absolute leader by a dose enhancement factor (DEF; up to 2.51), while HfO and TaO were the most versatile because of the largest high-DEF region in coordinates U (voltage) and E (effective energy). Several impacts of the X-ray spectral composition have been noted, as follows: (1) there are radiation sources that correspond to extremely low DEFs for all of the studied NPs, (2) NPs with a lower in some cases can equal or overcome by the DEF value the high- NPs, and (3) the change in the X-ray spectrum caused by a beam passing through the matter can significantly affect the DEF. All of these findings indicate the important role of carefully planning radiation exposure in the presence of high- NPs.
纳米粒子（NPs）具有较高的原子序数（），是很有前途的癌症治疗放射增敏剂。然而，它们的疗效对辐照条件的依赖性尚不清楚。在本工作中，研究了 11 种不同的金属和金属氧化物 NPs（原子序数从 Cu（=29）到 BiO（=83）），研究了它们在与 237 X 射线光谱联合使用时增强吸收剂量的能力，这些 X 射线光谱是在 30-300 kVp 电压下使用各种过滤系统和阳极材料产生的。在所研究的高原子序数 NP 材料中，金是绝对的领先者，剂量增强因子（DEF；高达 2.51），而 HfO 和 TaO 是最通用的，因为在 U（电压）和 E（有效能量）坐标中有最大的高 DEF 区域。注意到 X 射线光谱组成的几个影响，如下：（1）存在对应于所有研究的 NPs 极低 DEF 的辐射源，（2）在某些情况下，原子序数较低的 NPs 可以通过 DEF 值与高原子序数 NPs 相等或超过，（3）光束穿过物质引起的 X 射线光谱的变化会显著影响 DEF。所有这些发现都表明，在存在高原子序数 NPs 的情况下，仔细规划辐射暴露非常重要。
