过程参数对PLLA-PEG-PLLA微泡造影剂的性质影响

The Influence of the Process Parameters to the Character of PLLA-PEG-PLLA Micro-bubbles Used as Ultrasound Contrast Agent

研究双乳化过程参数对PLLA-PEG-PLLA(聚乳酸-聚乙二醇-聚乳酸)共聚物微泡造影剂形貌、粒径分布及二次谐波性质的影响。改变制备的过程参数,用双乳化法制备空心微泡;使用光学显微镜和扫描电镜观察微泡的形貌;用百胜DU8彩色多普勒超声诊断仪2～5MHz的探头在体外测试微泡的二次谐波特性。得到一系列在生理盐水中分散性很好的空心微泡,在低MI(机械指数)下有不同的二次谐波信号增强的造影剂。油相中材料的浓度、内水相体积、外水相中PVA的浓度对微泡的二次谐波性质具有较大影响,油相中材料的浓度还极大的影响微泡的粒径及其分布。樟脑和碳酸铵的加入对微泡的形貌和声学性质有显著影响。

The purpose of this study is to investigate the influence of parameters in the double emulsion process upon the morphology, size distribution and see-harmonic character of PLLA-PEG-PLLA copolymer micro-bubbles. Micro- bubbles were prepared by using double emulsion technique and changing the technologic parameters in double emulsion process. Light microscope and scanning electron microscopy were applied to observe the nanoparticles morphology. The sec-harmonic character of micro-bubbles was tested by using Color Doppler Uhrasonoscope（ESAOTE DU8）. A series of hollow micro-bubbles that could be easily re-dispersed in water were obtained. The bubbles showed a great enhancement of see-harmonic signal at low MI （mechanical index）. The concentration of material in oil, the volume of inner water and the concentration of PVA in external water had influences upon see-harmonic character of the bubbles. The concentration of material in oil also affected the size distribution of micro-bubbles significantly. The addition of camphor and ammonium carbonate also showed influences upon the morphology and see-harmonic character of the bubbles significantly.