| The research and development of ultrasound contrast microbubbles and the corresponding diagnostic techniques dates back several decades.However quite limited clinical contrast agents are currently available. The size of conventional types of contrast agents are within 1 to 8μm. Microbubbles of this scale will be promptly removed by the liver and thus cannot be adopted by vascular endothelial cells into the surrounding tissue space.However, the nano-bubble, due to its unique nature, can overcome the above problem. In the targeting imaging studies, apolipoprotein ApoA-I has been applied to the atherosclerotic plaque imaging studies. In imaging methods, the magnetic resonance imaging, the isotope radioactive imaging, the optical imaging and other techniques have already been adopted, but not the ultrasound imaging so far. Thus my research is focused on nano-bubble contrast agents and the targeting contrast effect. On the one hand, through the comparison of imaging effect and time duration between nano-bubbles and SonoVue microbubbles, which are clinically applied, I came to the conclusion that nano-bubbles have much longer imaging time than SonoVue micro-bubbles, but no obvious enhanced imaging effect. On the other hand, by optimizing the cDNA cloning of apolipoprotein ApoA-I and providing ApoA-I prepared with nano-bubbles, we find the following striking fact. Though the nano-bubble fails to bring significant effect to the contrast-enhanced plaque in vivo studies, it can increase the average capability of nano-bubbles to bind macrophages in vitro studies. This suggests that the nano-bubble has the potential of becoming the ultrasound contrast agent in targeting atherosclerotic plaque. |
