一种新型高分子聚合材料微泡超声造影剂的制备与体外显影实验

Production of a novel high molecular polymer ultrasound contrast agents and in vitro experiment

目的探索应用人工合成高分子聚合材料制备微泡超声造影剂的方法并观察其体外显影效果。方法采用人工合成高分子聚合物乳酸/羟基乙酸共聚物(PLGA)作为成膜材料,通过双乳化法首先制备包裹水滴的PLGA微球,再通过真空冷冻干燥使微球内的水分升华,形成空隙,然后在冷冻干燥室内缓慢冲入氟烷气体,从而制备内含氟烷气体的PLGA微泡超声造影剂高聚显。将一定浓度的高聚显溶液水囊与脱汽水水囊在体外进行超声显影实验,观察其显影效果。结果光镜和扫描电镜观察,采用该法制备的高聚显微泡造影剂呈球形,形态规则,大小均匀,表面光滑;高聚显冻干粉复溶后分散度好;激光测径仪检测其粒径分布窄,平均粒径大小与制备过程中声振仪的设置相关;体外显影效果好。结论采用该方法制备的PLGA微泡超声造影剂高聚显具有大小均匀、显影效果好、抗压性强等特点,同时由于其外壳材料能在体内生物降解,对人体无毒副作用,因而具有广阔的应用前景。

Objective To explore a way to produce a novel high molecular polymer ultrasound contrast agents, and to explore its effect of enhancing ultrasound imaging in vitro experiment. Methods Poly lactic-co-glycolic acid（PLGA） and polyvinyl alcohol（PVA）, biodegradable high molecular polymers were used in producing a ultrasound contrast agent. The double emulsion technique was required to produce PLGA microshpheres with water inside. After lyophilizing, the water in the microspheres came off and small microbubbles were left inside the microspheres. By exchanging the air with perfluorcarbon gas, a novel high molecular polymer ultrasound contrast agent, GAOJUXIAN, was produced. Scanning electron microscope and light microscope were used to examine the surface morphology of GAOJUXIAN. Then two degassed water tanks with or without GAOJUXIAN were observed by ultrasound imaging. Results Scanning electron microscope and light microscope studies of GAOJUXIAN indicated that the agent appeared uniformly spherical microbubbles with smooth surface. The size distribution analysis by using lazer particle size analyzer showed their diameters were between 0.5 μm and 4 μm and their size distribution was tight. In vitro experiment showed that they can enhance the ultrasound imaging greatly. Conclusions The high molecular polymer ultrasound contrast agents produced by our method had many good characters, such as small and tight size distribution, good ultrasound imaging enhancement, etc. At the same time, because they are biodegradable and harmless, they are well suited for future applications.