Direct observations of ultrasound microbubble contrast agent interaction with the microvessel wall
Direct observations of ultrasound microbubble contrast agent interaction with the microvessel wall
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DOI：
10.1121/1.2747204
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发表时间：
2007-08-01
影响因子：
2.4
通讯作者：
Ferrara, Katherine W.
中科院分区：
文献类型：
--
作者：
Caskey, Charles F.;Stieger, Susanne M.;Ferrara, Katherine W.
世界各地的诊所已经进行了成千上万的对比超声研究。此外，这些检查中使用的微泡正在被广泛研究以递送药物和基因。在这里，第一次，这些微泡在小血管中的振荡被直接观察到，并显示出与以前的模型预测的和在大的流体体积内成像的基本不同。在中心频率为1MHz、峰值舒张压为0.8或2.0MPa的脉冲超声作用下，微泡被限制在大鼠盲肠小血管内时，微泡的扩张明显减少（P < 0.05）。顺应性血管内的微泡振荡模型，准确地预测小血管内的振荡和血管位移。由于小血管中振荡减少，需要由药剂融合或高机械指数产生的大的静止微泡直径以使药剂壳与内皮接触。此外，在不对称塌陷期间观察到与内皮的接触，而不是在扩张期间。这些结果将用于改进使用微泡的药物递送技术的设计。(C)2007年，美国声学学会。
Many thousands of contrast ultrasound studies have been conducted in clinics around the world. In addition, the microbubbles employed in these examinations are being widely investigated to deliver drugs and genes. Here, for the first time, the oscillation of these microbubbles in small vessels is directly observed and shown to be substantially different than that predicted by previous models and imaged within large fluid volumes. Using pulsed ultrasound with a center frequency of 1 MHz and peak rarefactional pressure of 0.8 or 2.0 MPa, microbubble expansion was significantly reduced when microbubbles were constrained within small vessels in the rat cecum (P < 0.05). A model for microbubble oscillation within compliant vessels is presented that accurately predicts oscillation and vessel displacement within small vessels. As a result of the decreased oscillation in small vessels, a large resting microbubble diameter resulting from agent fusion or a high mechanical index was required to bring the agent shell into contact with the endothelium. Also, contact with the endothelium was observed during asymmetrical collapse, not during expansion. These results will be used to improve the design of drug delivery techniques using microbubbles. (C) 2007 Acoustical Society of America.