摘要
目的构建携Sialyl Lewisx和抗ICAM-1单抗双配体和同型对照单配体靶向超声微泡,体外对比评价其靶向黏附性能。方法采用"亲和素-生物素"桥接法构建携Sialyl Lewisx与抗ICAM-1单抗双配体(MB-D)、携Sialyl Lewisx(MB-S)和携抗ICAM-1单抗(MB-I)三种靶向超声微泡,以流式细胞术定量分析其配体结合率,并利用平行板流动腔分别在0.5、2.0和4.0dyn/cm2三种剪切应力下的不同时间点观察微泡的结合及解离情况。结果 MB-D、MB-S和MB-I的配体结合率均达85%以上,各组间无统计学差异(P>0.05)。在三种剪切应力下,MB-D和MB-S集中于前3~5min高效结合,在5min后两者的结合率均呈平台状态,而MB-I全程结合率(1~6min)均呈低水平状态;MB-D的平均结合率和全程结合数目均明显高于MB-S和MB-I(P<0.05),而半数解离剪切应力则按MB-I、MB-D和MB-S顺序依次递减(P<0.05)。结论相同条件下,MB-S表现为早期快速、不稳定的黏附,MB-I为缓慢、牢固的结合,而MB-D呈早期高效、相对牢固的结合。MB-D有可能用于高流速的动脉超声分子成像。
Objective To synthesize dual-targeted microbubbles carrying both Sialyl Lewis^x and anti-ICAM-1 monoclonal antibodies,and to assess their binding capability to targets in vitro. Methods Dual-targeted (via both targeting ligands) microbubbles (MB-D) selectin-targeted (via Sialyl Lewis^x) microbubbles (MB-S) and ICAM-1-targeted (via anti-ICAM-1 monoclonal antibodies) microbubbles (MB-I) were prepared with attaching the ligands to the biotinylated lipid-microbubbles via multi-step avidin biotin bridging chemistry. The binding rate of ligands in microbubbles was measured with quantitative flow cytometry. A parallel plate flow chamber was used to determine the targeting efficiency of the microbubbles at various shear stress (0.5,2.0 and 4.0 dyn/cm2) over 6 min. And microbubbles detachments were tested by ramping up the shear stress at 30 s intervals. Results All of the ligand-binding rates in MB-D,MB-S and MB-I were more than 85% (P〈0.05). In all flow conditions,the adhesive numbers of MB-D and MB-S to the targets increased rapidly in the first 3—5 min,followed by a plateau,while the adhesive number of MB-I increased very low in the whole course. The adhesive number and mean adhesive rate of MB-D were obviously greater than those of MB-S and MB-I (P〈0.05). Half-maximal detachment decreased gradually in MB-I,MB-D and MB-S by turns (P〈0.05). Conclusion In the same condition,MB-S has a rapid and instability binding capability in the early stage,MB-I has a slow and firm binding capability. MB-D has a rapid and firm binding capability to the specific targets. MB-D can be used to achieve ultrasound molecular imaging in high-shear floor.
出处
《中国医学影像技术》
CSCD
北大核心
2010年第7期1209-1213,共5页
Chinese Journal of Medical Imaging Technology
基金
国家863计划项目(2006AA02Z478)
国家自然科学基金(30870722)