Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan, Republic of China.
Phys Med Biol. 2010 Feb 21;55(4):931-45. doi: 10.1088/0031-9155/55/4/002. Epub 2010 Jan 20.
Biocompatible Au nanoparticles with surfaces modified by PEG (polyethylene glycol) were developed in view of possible applications for the enhancement of radiotherapy. Such nanoparticles exhibit preferential deposition at tumor sites due to the enhanced permeation and retention (EPR) effect. Here, we systematically studied their effects on EMT-6 and CT26 cell survival rates during irradiation for a dose up to 10 Gy with a commercial biological irradiator (E(average) = 73 keV), a Cu-Kalpha(1) x-ray source (8.048 keV), a monochromatized synchrotron source (6.5 keV), a radio-oncology linear accelerator (6 MeV) and a proton source (3 MeV). The percentage of surviving cells after irradiation was found to decrease by approximately 2-45% in the presence of PEG-Au nanoparticles ([Au] = 400, 500 or 1000 microM). The cell survival rates decreased as a function of the dose for all sources and nanoparticle concentrations. These results could open the way to more effective cancer irradiation therapies by using nanoparticles with optimized surface treatment. Difficulties in applying MTT assays were also brought to light, showing that this approach is not suitable for radiobiology.
为了增强放射疗法的应用，开发了表面经聚乙二醇（PEG）修饰的生物相容性金纳米粒子。由于增强的渗透和保留（EPR）效应，这些纳米粒子在肿瘤部位优先沉积。在这里，我们系统地研究了它们在 10 Gy 剂量下用商业生物辐照器（E(average) = 73 keV）、Cu-Kalpha(1) X 射线源（8.048 keV）、单色同步辐射源（6.5 keV）、放射肿瘤学直线加速器（6 MeV）和质子源（3 MeV）照射时对 EMT-6 和 CT26 细胞存活率的影响。在存在 PEG-Au 纳米粒子的情况下（[Au] = 400、500 或 1000 microM），辐照后存活细胞的百分比下降了约 2-45%。所有来源和纳米粒子浓度的细胞存活率都随剂量的增加而降低。这些结果为通过使用优化表面处理的纳米粒子进行更有效的癌症放射治疗开辟了道路。同时也揭示了 MTT 测定法应用的困难，表明该方法不适合放射生物学。
