In vitro evaluation of ultrasound-assisted thrombolysis using targeted ultrasound contrast agents

The thrombus-targeted ultrasound contrast agent with tirofiban, a glycoprotein IIb/IIIa antagonist that can specifically bind to activated platelets in the thrombus, was designed to enhance both the image contrast and the cavitation effect. The targeting ability to thrombi was confirmed by microphotography and high frequency ultrasound (40MHz) images (3.34±0.30 dB enhancement). Our inertial cavitation induction system showed that the enhancement of percent weight loss was about 10%, and it was further examined by using a microscope. We conclude that the targeted microbubbles are applicable not only for molecular imaging of thrombus but also improving effectiveness of ultrasound-assisted thrombolysis.