微泡超声爆破助溶血栓机制的离体研究

目的用荧光分子探针标记脂膜超声微泡,荧光显微镜下观察并追踪荧光微泡在超声作用下于血栓表面及内部分布情况,为超声联合微泡对体外血栓的助溶机制提供病理学依据。方法将染料标记于脂膜微泡,结合发射频率1MHz、输出声功率1.0W/cm2治疗超声用于离体溶栓实验。实验分为单纯微泡组和超声联合微泡两组,称量血栓失重量比较两组溶栓率,荧光显微镜观察两组血栓表面及内部的荧光分布强度及密度,最后血栓标本进行HE染色后光镜观察。结果单纯微泡组和超声联合微泡组的溶栓率分别为(21.73±2.78)%、(29.51±5.17)%,组间比较差异有统计学意义(P<0.01)。荧光显微镜下单纯微泡组血栓表面呈明亮荧光带,内部仅见几个细小荧光颗粒;超声联合微泡组血栓周边形成更为明亮宽大的荧光带,内部有较为密集的荧光颗粒分布。光镜下超声联合微泡组血栓表面见微孔和撕裂,内部可见不规则的裂隙,而单纯微泡组血栓无此改变。结论脂膜微泡在治疗超声连续爆破作用下有渗入血栓内部的倾向,这可能更有助于超声发挥助溶效应。

Mechanism of microbubbles augmented sonothrombolysis: a preliminary in vitro study

Objective To explore the mechanism of lipid microbubbles (MB) enhanced sonothrombolysis in vitro using therapeutic ultrasound (US,1 MHz).Methods Lipid-coated MB was fluorescently labeled by 3,3'-dioctadecyloxacarbocyanine.The clots were divided into the simple MB group and the US+MB group,the dissolution rates of clots were calculated to evaluate the thrombolysis efficacy.The distribution of fluorescent spots in clots was visually assessed and compared between the two groups under fluorescence microscope.Results There were significant differences between the dissolution rates of US+MB group and the simple MB group ( 29.51% vs 21.73 %, P < 0.01 ).Much more fluorescence spots were found in the US+MB group than that in the simple MB group.Minor pores and clefts were often found in the clots of the US+MB group under biological microscope but not seen in the simple MB group.Conclusions Much more cavitated MB bursting in the clots in sonication might explain the mechanism of MB accelerates sonothrombolysis.