中文摘要：

目的：构建非RGD肽-超微超顺磁氧化铁（USPIO）分子探针,探讨其对人脐静脉内皮细胞（HUVEC）的靶向作用。方法：采用化学交联法将非RGD肽（命名为P1c）偶联于二巯基丁二酸（DMSA）修饰的USPIO,形成具有免疫活性的分子探针。采用细胞计数试剂盒（CCK-8）检测探针对HUVEC增殖的影响。USPIO标记的P1c肽作为实验组,USPIO为对照组,通过固相结合实验、普鲁士蓝染色分析其体外免疫学特性,采用1.5 T磁共振仪对探针与高表达整合素αvβ3的HUVEC进行体外细胞成像。结果：成功构建USPIO标记的P1c肽分子探针,其对HUVEC增殖无明显影响。固相结合实验及普鲁士蓝染色证实该探针能特异性与整合素αvβ3结合。体外MRI显示在同一铁质量浓度时,P1c-USPIO与HUVEC孵育后较USPIO组T2＊值明显缩短。结论：化学交联法可成功制备P1c肽USPIO分子探针,该分子探针具有良好免疫学活性,可特异性结合整合素αvβ3分子。

英文摘要：

Objective： To develop an ultrasmall superparamagnetic iron oxide（USPIO） based MR probe containing non RGD peptide（named P1c） and investigate its targeting effect on Human umbilical vein endothelial cells（HUVECs）.Methods： To prepare immunologically competent probe,P1c was conjugated with USPIO coated with meso-2,3-dimercaptosuccinic acid（DMSA）.Cell counting kit-8 assay was conducted to ascertain the probe’s effect on the HUVECs’ growth.The USPIO labeled P1c peptide was experimental group,and the USPIO was control group.The solid phase binding assay and Prussian blue staining were employed to evaluate the immunocompetence of P1c-USPIO.The probe’s cell MR imaging in vitro was performed using HUVECs with high integrin αvβ3 expression.Results： The P1c-USPIO was constructed.The probe had no effect on the growth of HUVECs.The solid phase binding assay and Prussian blue staining showed that the probe could bind with integrin αvβ3 on HUVECs with high specificity.MR cell imaging in vitro demonstrated that at the same mass concentration of iron the T2＊ value in P1c-USPIO group was much shorter than it in USPIO group.Conclusion： The molecular probe P1c-USPIO could be prepared successfully using chemical cross linking method.The P1c-USPIOs remained their immunocompetence.The probe could specifically bind with HUVECs.