Graduate Institute of Biomedical Electronics and Bioinformatics, National Taiwan University, Taipei, Taiwan.
Ultrason Imaging. 2009 Oct;31(4):235-46. doi: 10.1177/016173460903100402.
A thrombus-targeted ultrasound contrast agent bound with tirofiban - a glycoprotein (GP) IIb/IIIa antagonist that can specifically bind to activated platelets in the thrombus - was designed to enhance both the image contrast and thrombolysis effect. In this study, we used 76 canine thrombi for investigation. The targeting ability to thrombi was confirmed by microphotography and high-frequency ultrasound (40 MHz) imaging. The effect of the targeted microbubbles on thrombolysis enhancement was investigated using an in vitro flow system: targeted and nontargeted microbubbles flowed through the clot for 30 seconds with a washing step; the microbubbles remained on the clot that were then cavitated by ultrasound (frequency = 1 MHz, MI = 1.2). The extent of thrombolysis was evaluated by weight reduction and histology analysis. The targeted microbubbles reduced the weight of thrombi by a factor of 1.7 times that of the nontargeted microbubbles. (clot weight reduction: 23.1 +/- 5.3% versus 13.6 +/- 4.9%, p < 0.01 between targeted and nontargeted group), and the signal enhancement was 3.34 +/- 0.30 dB (mean +/- SD, p < 0.01 compared to control). We conclude that targeted microbubbles are applicable not only for molecular imaging of thrombi but also for improving the effectiveness of ultrasound-assisted thrombolysis.
一种与替罗非班结合的靶向血栓的超声对比剂 - 一种糖蛋白（GP）IIb/IIIa 拮抗剂，可特异性结合血栓中的活化血小板 - 被设计用于增强图像对比和溶栓效果。在这项研究中，我们使用了 76 个犬血栓进行了研究。通过显微镜摄影和高频超声（40MHz）成像证实了对血栓的靶向能力。使用体外流动系统研究了靶向微泡对溶栓增强的作用：靶向和非靶向微泡在血栓中流动 30 秒，然后进行超声冲洗（频率=1MHz，MI=1.2）。通过重量减轻和组织学分析评估溶栓程度。靶向微泡使血栓的重量减轻了 1.7 倍，而非靶向微泡使血栓的重量减轻了 1.7 倍。（血栓重量减轻：23.1 +/- 5.3%比 13.6 +/- 4.9%，靶向组与非靶向组之间的差异有统计学意义（p < 0.01）），信号增强为 3.34 +/- 0.30dB（均值 +/- 标准差，与对照组相比差异有统计学意义（p < 0.01））。我们得出结论，靶向微泡不仅适用于血栓的分子成像，而且还可以提高超声辅助溶栓的效果。
