纳米级超声造影剂制备及成像的实验研究

Characteristics and ultrasonic imaging of a nano-scale ultrasound-enhanced contrast

目的探讨纯度较高的纳米级超声微泡造影剂的理化性质及体内成像效果。方法机械振荡法与低速离心法结合制备纳米级微泡，观察微泡形态，检测其平均粒径，并观察其增强正常兔肝显影的情况，并与微米级微泡造影剂进行比较。结果光镜以及透射电镜观察，微泡呈圆形，分布均匀，无聚集现象。Zeta SIZIER 3000测定微泡粒径均值为623．4nm，微泡表面电位均值1．3mV。注射纳米级造影剂于新西兰大白兔体内能持续增强肝的显像效果，与微米级造影剂对比无明显差异。结论纳米级的微泡造影剂大小合理，分布均匀，显像效果强，为下一步研制小型化靶向造影剂奠定了基础。

Objective To investigate characteristics and ultrasonic imaging of the nano-scale ultrasound-enhanced contrast in vivo. Methods Nano-scale microbubbles were prepared by machine vibration and low speed centrifugation. The surface morphology and average size distribution of microbuble were measured. The contrast-enhanced effect of the nano-scale microhubbles in the normal rabbit liver was observed,and compared with micro-scale microbubbles. Results The nano-scale microbubbles had a good shape and uniform distribution by light microscope and transmission electron microscope, with average diameter of 623.4 nm and surface electric potential of 1.3 mV. The contrast imaging study in vivo showed the nano-seale microbubbles could significantly enhance ultrasonic imaging of rabbit livers, which had no obvious difference with micro-scale microhuhhles. Conclusions The nano scale ultrasound contrast agent is stable and effective for the enhancement of ultrasound imaging, which is based on development of miniaturizing targeting ultrasound contrast agent.