载吲哚菁绿超声微泡造影剂活体近红外荧光显像兔淋巴结

目的制备载吲哚菁绿的聚乳酸羟基乙酸（ICG-PLGA）超声微泡造影剂并检测其特性,观察以之进行活体近红外荧光显像兔淋巴结的效果。方法用双乳化法制备ICG-PLGA超声微泡造影剂,行光镜、扫描电镜、粒径检测检查,观察其形态及大小;用分光光度法绘制吲哚菁绿的标准曲线,计算造影剂中吲哚菁绿的载药量和包封率。对3只正常大白兔经足垫注射该造影剂,观察活体近红外荧光显像兔腘窝淋巴结的效果。结果 ICG-PLGA超声微泡造影剂为淡绿色乳液,光镜和电镜下形态规则,表面光滑,大小均匀;活体近红外荧光成像能清晰显示兔腘窝淋巴结。结论 ICG-PLGA超声微泡造影剂具备荧光成像的特征,具有高敏感性,可作为荧光成像的示踪剂。

Near-infrared fluorescence imaging of rabbit lymph nodes with indocyanine green-loaded ultrasound microbubbles contrast agents

Objective To prepare a poly-lactide-co-glycolic acid (PLGA) polymer ultrasound contrast agent loading indocyanine green (ICG), and to observe its effect on rabbit lymph nodes with near-infrared fluorescence imaging. Methods ICG-PLGA ultrasound contrast agent was made by double emulsion methods. The morphology and potential of it were examined by using light microscope, electron microscope scanning and Malvern potential tests. ICG content standard curve was drawn by spectrophotometer. The ICG content and encapsulation were calculated. Three normal rabbits were subcutaneous injected by the foot pad with contrast agents, then the effect of near-infrared fluorescence imaging of the popliteal fossa lymph node was observed. Results ICG-PLGA ultrasound contrast agent was light green emulsion. Light and electron microscopy showed regular shape, smooth surface and uniform size, while near-infrared fluorescence imaging showed the whole lymph node clearly, and contrast agent filled the entire lymph node. Conclusion ICG-PLGA ultrasound contrast agent has basic fluorescent characteristic and high sensitivity. And it is potential to be a fluorescent probe.