金纳米棒放射增强：解读蒙特卡洛剂量增强在几何、组成、涂层和定位中的作用

中文摘要 AI 辅助

纳米粒子放射增敏依赖于相互关联的纳米粒子性质，然而几何形状、元素组成、表面涂层和定位通常被分开研究，它们的综合生物学影响很少在一个框架内评估。基于博士研究中的TOPAS蒙特卡洛模拟，我们整合了四项关于金属纳米棒（主要是金纳米棒，AuNRs）的研究，在紧密关联的研究中考察了这些参数。研究结果表明，每个参数都能在特定的空间范围内产生影响。纳米棒几何形状主要改变数十纳米内发射的低能俄歇-迈特纳电子的能谱和分布。元素组成引起显著的近场剂量增强，该增强迅速衰减，在约1微米以外可忽略不计。表面涂层降低能量低于3.5 keV的二次电子通量，这些电子在表面约150纳米内被吸收，使物理剂量贡献降低1-7%。由于涂层主要去除低能电子，辐射分解产额通过电子能谱的偏移而改变，并非直接遵循剂量响应。在血管尺度上，增强剂量区域延伸至距血管壁约10微米处，这意味着纳米粒子定位决定了生物靶标相对于辐射源的位置。总的来说，没有任何单一设计参数能作为放射增敏的通用预测因子。将物理放射增强转化为生物学效应取决于靶标是否位于每个参数的有效范围内。此外，在光束约束需要的地方应用带电粒子平衡（CPE）校正，会显著改变计算得到的剂量增强比。因此，应明确报告记录距离和CPE校正值，以确保研究间的可比性。

英文摘要

Nanoparticle radiosensitization depends on interconnected NP properties, yet geometry, elemental composition, surface coating, and localization are typically studied separately, with their combined biological impact rarely assessed in one framework. Drawing on TOPAS Monte Carlo simulations from PhD research, we consolidated four investigations of metallic nanorods, mainly gold nanorods (AuNRs), examining these parameters across closely linked studies. The findings reveal that each parameter can influence over a distinct spatial range. Nanorod geometry primarily alters the spectrum and distribution of low-energy Auger-Meitner electrons emitted within tens of nanometers. Elemental composition induces significant near-field dose enhancement that rapidly attenuates and becomes negligible beyond roughly 1 um. Surface coatings reduce the fluence of secondary electrons below 3.5 keV, absorbed within about 150 nm of the surface, lowering physical dose contribution by 1-7%. Since coatings predominantly remove low-energy electrons, radiolytic yield changes through a shift in the electron energy spectrum, not directly following dose response. At the vascular scale, the enhanced dose region extends to approximately 10 um from the vessel wall, meaning NP localization determines where the biological target sits relative to radiation sources. Collectively, no single design parameter serves as a universal predictor of radiosensitization. Translating physical radioenhancement into biological effect depends on whether the target lies within each parameter's effective range. Furthermore, charged-particle equilibrium (CPE) correction, applied where beam confinement necessitated it, substantially alters calculated dose enhancement ratios. Consequently, scoring distance and CPE-corrected values should be explicitly reported to ensure comparability across studies.

发表机构

• Sunway University（双威大学）
• Physikalisch-Technische Bundesanstalt (PTB)（德国联邦物理技术研究院）
• The Miyan Research Institute, International University of Business Agriculture and Technology（国际商业农业科技大学米扬研究院）
• Korea University（高丽大学）
• Universiti Malaya（马来亚大学）
• University of Surrey（萨里大学）

机构由 AI 辅助整理，请以论文原文为准。