中文摘要：

目的制备特异靶向易损斑块的超声微泡造影剂，并探讨其体外寻靶能力和超声成像性能。方法采用薄膜水化法和生物素－亲和素桥连法制备携E－选择素单克隆抗体（简称单抗）靶向脂质微泡造影剂，检测平均粒径、粒径分布及微泡抗体负载量，通过细胞计数试剂盒（CCK8）细胞增殖实验检测超声与微泡相互作用对细胞毒性的影响。设立靶向微泡组、游离抗体干预组和对照组，通过体外寻靶实验观察靶向脂质微泡与活化的bEnd.3小鼠血管内皮细胞特异性结合情况，评价其体外寻靶能力。检测不同时间点靶向脂质微泡的超声成像效果，评价其超声成像性能。采用两独立样本t检验和单因素方差分析处理数据。结果制得粒径均一的E－选择素单抗靶向脂质微泡造影剂，微泡和超声辐照对细胞活性无明显影响。体外细胞寻靶实验中，靶向微泡与活化的bEnd.3小鼠血管内皮细胞平均结合数量为（6.23±0.45）个，明显高于游离抗体干预组[（1.57±0.34）个]和对照组[（0.07±0.03）个；F＝291.43，P〈0.01]。靶向微泡超声成像性能检测实验中，靶向微泡与对照组微泡在同一时间点成像效果差异无统计学意义（均t〈0.51，均P〉0.05），成像性能稳定。结论成功制备的携E－选择素单抗靶向脂质微泡造影剂具备良好的体外寻靶能力和超声成像特性，有望作为超声分子探针对易损斑块进行早期诊断及预后评估。

英文摘要：

ObjectiveTo develop a vulnerable plaque targeting ultrasound contrast agent （UCA） and to evaluate its affinity and imaging performance in vitro.MethodsE-selectin receptor-targeting UCA, which conjugated with monoclonal antibody of E-selectin, was prepared with filming-rehydration method and biotin-avidin linkage. The size and distribution of UCA were measured with particle size analyzer, the connectivity condition of microbubbles with E-selectin antibody was also detected with fluorescence analysis. The cytotoxicity from microbubble and ultrasound irradiation was evaluated through cell counting kit-8 （CCK8） assay. The adhesion effect of UCA was assessed after co-incubated with activated mouse endothelial cells （bEnd.3） and compared with that of free antibody intervention group and control group. The imaging performance of UCA at different time points was observed on an ultrasound equipment with a high-frequency transducer. Two-sample t test and one-way analysis of variance were performed to analyze the data.ResultsE-selectin receptor-targeting UCA was successfully prepared. The cytotoxicity result with CCK8 assay demonstrated the favorable biocompatibility of UCA. The connection amount of UCA on activated bEnd.3 cells （（6.23±0.45） bubbles/cell） was significantly higher than that of the free antibody intervention group （（1.57±0.34） bubbles/cell） and control group （（0.07±0.03） bubbles/cell; F=291.43, P〈0.01）. The performance of in vitro ultrasonography at the same time points showed no obvious difference between targeting UCA and control UCA （all t〈0.51, all P〉0.05）.ConclusionsThe prepared E-selectin receptor-targeting UCA has favorable targeting and imaging capabilities. It might be a potentially ultrasound molecular imaging agent for early detection and prognosis evaluation of vulnerable plaque.