ABSTRACT Gold nanoparticles (AuNPs) and gold nanoclusters (AuNCs) are gaining interest in medical diagnosis and therapy as they are bio-compatible and are easy to functionalize. Their interaction with radiofrequency (RF) field for hyperthermia treatment is ambiguous and needs further investigation. A systematic study of the absorption of capacitive RF field by AuNPs and AuNCs dispersed in phosphate-buffered saline (PBS) is reported here in tissue mimicking phantom. The stability of AuNPs and AuNCs dispersed in PBS was confirmed for a range of pH and temperature expected during RF hyperthermia treatment. Colloidal gold solutions with AuNPs (10 nm) and AuNCs (2 nm), and control, i.e. PBS without nanogold, were loaded individually in 3 ml wells in a tissue phantom. Phantom heating was carried out using 27 MHz short-wave diathermy equipment at 200 and 400 W for control and colloidal gold solutions. Experiments were conducted for colloidal gold at varying gold concentrations (10–100 µg/ml). Temperature rise measured in the phantom wells did not show dependence on the concentration and size of the AuNPs. Furthermore, temperature rise recorded in the control was comparable with the measurements recorded in both nanogold suspensions (2, 10 nm). Dielectric property measurements of control and colloidal gold showed <3% difference in electrical conductivity between the control and colloidal gold for both nanoparticle sizes. From the measurements, it is concluded that AuNPs and AuNCs do not enhance the absorption of RF-capacitive field and power absorption observed in the biological medium is due to the ions present in the medium.

中文翻译：

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金纳米粒子和纳米团簇在生物介质中对射频场的吸收研究

摘要 金纳米粒子 (AuNPs) 和金纳米团簇 (AuNCs) 具有生物相容性且易于功能化，因此在医学诊断和治疗中越来越受到关注。它们与用于热疗的射频 (RF) 场的相互作用不明确，需要进一步研究。本文报道了在组织模拟体模中分散在磷酸盐缓冲盐水 (PBS) 中的 AuNPs 和 AuNCs 对电容性射频场吸收的系统研究。AuNPs 和 AuNCs 分散在 PBS 中的稳定性在 RF 热疗期间预期的一系列 pH 值和温度下得到证实。将含有AuNPs (10 nm) 和AuNCs (2 nm) 的胶体金溶液和对照（即不含纳米金的PBS）分别装入组织模型中的3 ml 孔中。体模加热是使用 27 MHz 短波透热设备在 200 和 400 W 下进行的，用于控制和胶体金溶液。对不同金浓度 (10–100 µg/ml) 的胶体金进行了实验。在幻影井中测量的温升没有显示出对 AuNP 的浓度和大小的依赖性。此外，对照中记录的温升与两种纳米金悬浮液 (2, 10 nm) 中记录的测量值相当。对照和胶体金的介电性质测量表明，对照和胶体金之间的两种纳米颗粒的电导率差异小于 3%。从测量结果来看，