治疗辐射能下金纳米颗粒的微剂量学和放射生物学效应。

Microdosimetric and radiobiological effects of gold nanoparticles at therapeutic radiation energies.

机构信息

Department of Physics and Astronomy, The University of Texas at San Antonio, San Antonio, TX, USA.

Department of Radiation Oncology, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.

出版信息

Int J Radiat Biol. 2023;99(2):308-317. doi: 10.1080/09553002.2022.2087931. Epub 2022 Jun 21.

DOI:10.1080/09553002.2022.2087931

PMID:35709481

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC10089366/

Abstract

PURPOSE

The purpose of this study was to quantify the microscopic dose distribution surrounding gold nanoparticles (GNPs) irradiated at therapeutic energies and to measure the changes in cell survival in vitro caused by this dose enhancement.

METHODS

The dose distributions from secondary electrons surrounding a single gold nanosphere and single gold nanocube of equal volume were both simulated using MCNP6. Dose enhancement factors (DEFs) in the 1 μm volume surrounding a GNP were calculated and compared between a nanosphere and nanocube and between 6 and 18 MV energies. This microscopic effect was explored further by experimentally measuring the cell survival of C-33a cervical cancer cells irradiated at 18 MV with varying doses of energy and concentrations of GNPs. Survival of cells receiving no irradiation, a 3 Gy dose, and a 6 Gy dose of 18 MV energy were determined for each concentration of GNPs.

RESULTS

It was observed that the dose from electrons surrounding the gold nanocube surpasses that of a gold nanosphere up to a distance of 1.1 μm by 18.5% for the 18 MV energy spectrum and by 23.1% for the 6 MV spectrum. DEFs ranging from ∼2 to 8 were found, with the maximum DEF resulting from the case of the gold nanocube irradiated at 6 MV energy. Experimentally, for irradiation at 18 MV, incubating cells with 6 nM (0.10% gold by mass) GNPs produces an average 6.7% decrease in cell survival, and incubating cells with 9 nM (0.15% gold by mass) GNPs produces an average 14.6% decrease in cell survival, as compared to cells incubated and irradiated without GNPs.

CONCLUSION

We have successfully demonstrated the potential radiation dose enhancing effects in vitro and microdosimetrically from gold nanoparticles.

摘要

目的

本研究旨在量化金纳米粒子（GNPs）在治疗能下照射时的微观剂量分布，并测量这种剂量增强对体外细胞存活的影响。

方法

使用 MCNP6 模拟了单个金纳米球和等体积的单个金纳米立方体周围的次级电子剂量分布。计算了 GNPs 周围 1μm 体积的剂量增强因子（DEF），并比较了纳米球和纳米立方体之间以及 6 和 18MV 能量之间的 DEF。通过实验测量在 18MV 下照射时不同能量剂量和 GNPs 浓度下的 C-33a 宫颈癌细胞的存活率，进一步探索了这种微观效应。对于每个 GNPs 浓度，测量了未接受照射、3Gy 剂量和 18MV 能量 6Gy 剂量的细胞存活率。

结果

观察到，对于 18MV 能谱，金纳米立方体周围的电子剂量在 1.1μm 距离内超过金纳米球的剂量，超过了 18.5%；对于 6MV 能谱，超过了 23.1%。发现的 DEF 范围从 2 到 8，最大值来自于在 6MV 能量下照射的金纳米立方体的情况。在实验中，对于 18MV 的照射，孵育含有 6nM（质量为 0.10%金）GNPs 的细胞会导致细胞存活率平均降低 6.7%，孵育含有 9nM（质量为 0.15%金）GNPs 的细胞会导致细胞存活率平均降低 14.6%，与未孵育和未照射 GNPs 的细胞相比。