Department of Biomedical Engineering and Division of Cardiovascular Medicine, University of Virginia, Charlottesville, VA 22903, USA.
Mol Imaging. 2011 Aug;10(4):238-47. doi: 10.2310/7290.2011.00002. Epub 2011 Apr 26.
Ultrasound-based molecular imaging employs targeted microbubbles to image vascular pathology. This approach also has the potential to monitor molecularly targeted microbubble-based drug delivery. We present an image-guided drug delivery technique that uses multiple pulses to translate, image, and cavitate microbubbles in real time. This technique can be applied to both imaging of pathology in large arteries (sizes and flow comparable to those in humans) and guiding localized drug delivery in blood vessels. The microbubble translation (or pushing) efficacy of this technique was compared in a variety of flow media: saline, viscous saline (4 cp), and bovine blood. It was observed that the performance of this approach was marginally better (by 6, 4, and 2 dB) in viscous saline than in bovine blood with varying levels of hematocrit (40%, 30%, and 10%). The drug delivery efficacy of this technique was evaluated by in vitro and ex vivo experiments. High-intensity pulses mediated fluorophore (DiI) deposition on endothelial cells (in vitro) without causing cell destruction. Ex vivo fluorophore delivery experiments conducted on swine carotids of 2 and 5 mm cross-section diameter demonstrated a high degree of correspondence in spatial localization of the fluorophore delivery between the ultrasound and composite fluorescence microscopy images of the arterial cross sections.
基于超声的分子成像采用靶向微泡来成像血管病理学。这种方法还有望用于监测基于分子靶向微泡的药物输送。我们提出了一种图像引导的药物输送技术，该技术使用多个脉冲实时平移、成像和空化微泡。该技术可应用于大血管中的病理学成像（与人类相似的大小和血流）以及血管内的局部药物输送。在各种流动介质（生理盐水、粘性生理盐水（4 cp）和牛血）中比较了该技术的微泡平移（或推动）效果。观察到，与不同红细胞压积（40%、30%和 10%）的牛血相比，该方法在粘性生理盐水中的性能略有提高（提高了 6、4 和 2 dB）。通过体外和体内实验评估了该技术的药物输送效果。高强度脉冲介导的荧光团（DiI）在不破坏细胞的情况下沉积在内皮细胞上（体外）。在 2 和 5 毫米横截面直径的猪颈动脉上进行的体外荧光团输送实验表明，超声和动脉横截面复合荧光显微镜图像之间的荧光团输送的空间定位具有高度的一致性。
