Measurement of ultrasound-enhanced diffusion coefficient of nanoparticles in an agarose hydrogel
Measurement of ultrasound-enhanced diffusion coefficient of nanoparticles in an agarose hydrogel
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DOI：
10.1121/1.5083828
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发表时间：
2018-12-01
影响因子：
2.4
通讯作者：
Wu, Junru
中科院分区：
文献类型：
--
作者：
Ma, Dong;Marshall, Jeffrey S.;Wu, Junru
实验研究了超声对纳米颗粒在琼脂糖水凝胶中扩散的影响。琼脂糖水凝胶通常用作生物膜和某些生物组织（如肌肉和脑组织）的模拟剂。最近的实验表明，中等强度的超声波激发可以显著增强纳米颗粒在水凝胶中的扩散。当前研究的目的是获得超声对纳米颗粒扩散的影响的详细测量，并将其与没有声激励的分子扩散进行比较。实验采用1 MHz超声波，纳米颗粒直径分别为20和100 nm，采用荧光成像技术测量颗粒浓度分布。在超声暴露下，实验得出了水凝胶内声扩散系数和声流速度的估计。声流速度的实测值约为0.1 μ m/s，与理论计算结果吻合较好。结果表明，20 nm颗粒的声扩散系数比分子扩散系数大74%，100 nm颗粒的声扩散系数比分子扩散系数大133%。(C) 2018年美国声学学会。
An experimental study has been performed to measure the effect of ultrasound on nanoparticle diffusion in an agarose hydrogel. Agarose hydrogel is often used as a simulant for biofilms and certain biological tissues, such as muscle and brain tissue. The work was motivated by recent experiments indicating that ultrasonic excitation of moderate intensity can significantly enhance nanoparticle diffusion in a hydrogel. The objective of the current study was to obtain detailed measurements of the effect of ultrasound on nanoparticle diffusion in comparison to the molecular diffusion in the absence of acoustic excitation. Experiments were conducted with 1 MHz ultrasound waves and nanoparticle diameters of 20 and 100 nm, using fluorescent imaging to measure particle concentration distribution. Under ultrasound exposure, the experiments yield estimates for both acoustic diffusion coefficients as well as acoustic streaming velocity within the hydrogel. Measured values of acoustic streaming velocity were on the order of 0.1 mu m/s, which agree well with a theoretical estimate. Measured values of the acoustic diffusion coefficient were found to be 74% larger than the molecular diffusion coefficient of the nanoparticles for 20 nm particles and 133% larger than the molecular diffusion coefficient for 100 nm particles. (C) 2018 Acoustical Society of America.