摘要
目的构建环RGD(Arg-Gly-Asp)多肽靶向微泡,评价其在高剪切应力下对体外和体内富血小板血栓的黏附效果。方法采用巯基-马来酰亚胺共价桥接法制备携环RGD多肽靶向微泡(Mb-cRGD)及同型对照微泡(Mb-CON),在平行板流动腔中测定二者靶向结合血小板的能力以及解离情况,在琼脂糖流动腔模型中观察二者对大鼠腹主动脉富血小板血栓的靶向显影效果。结果两种微泡粒径和浓度相近(P均>0.05);在3.60dyn/cm2剪切应力下,Mb-cRGD与血小板糖蛋白(GP)Ⅱb/Ⅲa的结合数目明显多于Mb-CON(P<0.05);采用封闭抗体cRGDfV封闭GPⅡb/Ⅲa后,两种微泡均不能与之有效黏附,两者比较差异无统计学意义(P>0.05);Mb-cRGD与GPⅡb/Ⅲa半数解离和完全解离所需剪切应力明显高于Mb-CON(P均<0.05);对体外及体内的富血小板血栓行超声检查,可见Mb-cRGD较Mb-CON对血栓显影更清晰(P均<0.05)。结论环RGD多肽靶向微泡黏附富血小板血栓牢固而持久,可作为一种新的超声分子探针用于动脉血栓成像。
Objective To synthesize microbubbles conjugated with cyclic RGD （Arg-Gly-Asp）, and to assess their adhesion efficiency to platelet-rich thrombus at high shear stress in vitro and in vivo. Methods Microbubbles conjugated with cyclic RGD （Mb-cRGD）or negative control peptides （Mh-CON） were prepared with thiol maleimide covalent coupling. A parallel plate flow chamber was used to measure the attachment of microbubbles to platelet as well as the detachment. Contrast-enhanced images of platelet-rich thrombi with Mb-cRGD and Mb-CON were observed in both the aga- rose flow chamber model and rat abdominal aortic thrombosis model. Results There was no significant difference between Mb-eRGD andMb-CON in both diameter and concentration （both P〉0.05）. At shear stress of 3.60 dyn/em2 , the number of Mb-cRGD binding to parallel plate coated with glyeoprotein （GP） II b/III a was obviously more than that of MB-CON （P d0.05）. When GP II b/III a was blocked with cRGDfV, no significant difference in attachment was noted （P〉0.05）. Shear stress at half-maximal and maximal dissociation of Mb-cRGD from GP II b/III a were significantly higher than Mb- CON （both P〈0.05）. The video intensity of thrombus imaging with Mb-cRGD was higher than with Mb CON in vitro and in vivo （both P〈0.05）. Conclusion Mb cRGD has persistent adhesion to platelet rich thrombus, which could be used as a novel ultrasound molecular probe to visualize arterial thromhi.
出处
《中国医学影像技术》
CSCD
北大核心
2013年第6期857-861,共5页
Chinese Journal of Medical Imaging Technology
基金
广东省科技计划项目(2010B031600093)
国家重大科研仪器设备研制专项(81227801)
国家自然科学基金(81101064)
