MRI观察金磁微粒结合抗podoplanin抗体体外标记淋巴管内皮细胞

MRI observation on lymphatic endothelial cell labeled by GoldMag and anti-podoplanin antibody in vitro

目的制备淋巴管内皮细胞(LEC)靶向分子探针(GoldMag-pod),探讨GoldMag-pod对LEC的体外标记情况及其在MR检查中对信号强度的影响。方法将金磁微粒(GoldMag)与抗podoplanin抗体通过"一步法"耦联,制备GoldMag-pod,以分光光度计检测GoldMag的抗体耦联效率,ELISA法检测抗体与GoldMag结合前、后的免疫活性,免疫荧光染色、普鲁士蓝染色检测GoldMag-pod对LEC的标记情况。用不同浓度GoldMag-pod标记LEC后,观察GRET2*WI信号强度的改变。结果 GoldMag与抗podoplanin抗体通过"一步法"耦联成功,GoldMag的抗体耦联效率为52.94%,抗podoplanin抗体与GoldMag结合后其免疫活力降低为结合前的42.05%;GoldMag-pod标记后的LEC发出特异性绿色荧光,标记阳性率随GoldMag-pod浓度的增高而增高。GoldMag-pod标记后的LEC悬液的GRE T2*WI信号强度明显降低。结论 GoldMag与抗podoplanin抗体耦联制备的分子探针GoldMag-pod具有较高免疫活性,能特异性标记LEC,产生MR靶向增强作用。

Objective To synthesize molecular probe（GoldMag-pod） which can label lymphatic endothelial cell（LEC）,and to investigate the labeling efficiency and MRI enhancement of the molecular probe in vitro.Methods GoldMag-pod was synthesized by using single-step coupling process of GoldMag and anti-podoplanin antibody.The coupling efficiency（CE） of GoldMag was determined with UV-Vis spectroscopy.ELISA was performed to evaluate the influence of GoldMag on antibody immunoactivity.The LEC label status of GoldMag-pod was observed with immunofluorescence and Prussian blue staining.After labeling by a range of different concentrations of GoldMag-pod,the variation of GRE T2＊WI signal intensity of the solutions of LEC was investigated.Results GoldMag-pod was successfully synthesized,and the CE of GoldMag was 52.94%.The immunoactivity of GoldMag-pod was 42.05% of original antibody.LEC showed green fluorescence after immunofluorescence staining,and the results of Prussian blue staining showed that the positive label rate of LEC increased as the concentration of GoldMag-pod raised up.After labeled by GoldMag-pod,GRE T2＊WI signal intensity of LEC solution decreased significantly.Conclusion The molecular probe GoldMag-pod coupled by GoldMag and anti-podoplanin antibody has relative high immunoactivity,which can specifically label LEC and result in targeted enhancement of MR imaging.