IEEE Trans Nanobioscience. 2019 Oct;18(4):661-668. doi: 10.1109/TNB.2019.2937327. Epub 2019 Aug 26.
High intensity focused ultrasound (HIFU) has gained increasing attention as a noninvasive therapeutic method for wide range of biomedical applications from drug delivery to cancer treatment. However, high level of ultrasonic power required for efficient HIFU treatment can cause adverse effects such as damage to surrounding healthy tissues and skin burns. One of the strategies to improve the therapeutic mechanism of HIFU is to use ultrasound absorption agents during the treatment. The objectives of current study are to investigate the feasibility of adopting gold nanoparticles (AuNPs) as ultrasound absorption agents to enhance the HIFU thermal ablation when the NPs were injected locally to the focal region; and to examine the dose effects of AuNPs on both heating and cooling mechanisms of HIFU. To this end, we conducted an experimental study on tissue-mimicking phantoms where AuNPs were injected to the focal region under the guidance of ultrasound imaging. A set of thermal parameters including temperature, specific absorption rate of acoustic energy, and cooling rate were measured to monitor the mechanism of AuNPs-mediated HIFU. The results suggest that both heating and cooling rates of HIFU procedure could be greatly improved by injecting AuNPs, which demonstrates the feasibility of using AuNPs to reduce the level of ultrasonic power from extracorporeal source for HIFU treatment.
高强度聚焦超声（HIFU）作为一种无创治疗方法，在药物输送到癌症治疗等广泛的生物医学应用中受到越来越多的关注。然而，为了实现高效的 HIFU 治疗，需要高强度的超声功率，这可能会对周围健康组织和皮肤造成不良影响。改善 HIFU 治疗机制的策略之一是在治疗过程中使用超声吸收剂。目前这项研究的目的是探讨在将纳米颗粒注射到焦点区域的情况下，采用金纳米颗粒（AuNPs）作为超声吸收剂来增强 HIFU 热消融的可行性；并研究 AuNPs 对 HIFU 加热和冷却机制的剂量效应。为此，我们在组织模拟体中进行了一项实验研究，在超声成像的引导下将 AuNPs 注射到焦点区域。测量了一组热参数，包括温度、声能比吸收率和冷却速率，以监测 AuNPs 介导的 HIFU 机制。结果表明，注射 AuNPs 可以大大提高 HIFU 程序的加热和冷却速率，这表明可以使用 AuNPs 来降低从体外源用于 HIFU 治疗的超声功率水平。
