Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
Med Phys. 2009 Oct;36(10):4664-71. doi: 10.1118/1.3215536.
Gold nanoparticles can be engineered to target cancerous cells and at the same time designed to absorb specific wavelengths of light. Consequently, with the presence of optically tunable gold nanoparticles such as gold nanoshells, light can be effectively converted to heat via photothermal effect well enough to raise the temperature of medium surrounding gold nanoshells for thermal ablation or hyperthermia treatments of cancers. In this study, the authors proposed a new computational method to estimate thermal response of gold nanoshells embedded in a tissue-like medium when illuminated by a near-infrared (NIR) laser. Specifically, the light transport theory with diffusion approximation was initially applied to model the temperature rise within a medium without gold nanoshells as a result of the dissipation of the NIR laser power throughout the medium. After then, the heat generated by individual gold nanoshells due to photothermal effect was calculated and combined with the results for the medium without gold nanoshells to estimate the global elevation of temperature within the gold nanoshell-laden medium. The current computational model was tested for its validity using two different phantom examples, one of which was similar to a previously reported phantom experiment. The test demonstrated the capability of the current model in terms of producing qualitatively reasonable results, while it also revealed a number of potential differences in the assumptions for the current model and previous experiment. After an adjustment in the model parameters to properly take into account such differences, the computational results and the experimental data matched reasonably well within the average percentage difference of 10%.
金纳米粒子可以被设计成靶向癌细胞，同时被设计成吸收特定波长的光。因此，在存在光可调谐金纳米粒子（如金纳米壳）的情况下，光可以通过光热效应有效地转化为热，足以将金纳米壳周围介质的温度升高，从而进行癌症的热消融或热疗。在这项研究中，作者提出了一种新的计算方法来估计近红外（NIR）激光照射下嵌入组织样介质中的金纳米壳的热响应。具体来说，首先应用带有扩散近似的光传输理论来模拟由于 NIR 激光功率在整个介质中耗散而导致的无金纳米壳介质内的温升。然后，计算由于光热效应而单个金纳米壳产生的热量，并将其与无金纳米壳介质的结果结合起来，以估计金纳米壳填充介质内的整体温升。当前的计算模型通过两个不同的体模示例进行了有效性测试，其中一个与之前报道的体模实验相似。该测试证明了当前模型在产生定性合理结果方面的能力，同时也揭示了当前模型和之前实验在假设方面的一些潜在差异。在对模型参数进行调整以适当考虑这些差异之后，计算结果与实验数据在平均百分比差异为 10%的范围内匹配得相当好。
