荧光/MRI双模态靶向成像诊疗试剂的制备

在聚乙二醇二胺(NH_2-PEG-NH_2)修饰的石墨烯量子点(GODs)表面以酰胺键偶联二乙基三胺五乙酸(DTPA)分子,之后将Gd~(3+)离子与其进行配合,得到了GODs-Gd(DTPA)复合纳米粒子,然后再通过酰胺键在GODs-Gd(DTPA)的表面修饰叶酸(FA)靶分子,最后进一步将阿霉素(DOX)通过π-π堆垛吸附在造影剂的表面,制备了FA/GODs-Gd(DTPA)/DOX荧光/MRI双模态靶向肺癌细胞成像诊疗试剂,通过透射电子显微镜、紫外可见吸收光谱、荧光光谱和激光共聚焦扫描显微镜等手段表征了其形貌、发光性能和靶向成像性能。MRI、激光共聚焦扫描显微镜和MTT等结果表明,相对于正常的HLF细胞,所制备的FA/GODs-Gd(DTPA)/DOX纳米粒子能够靶向检测FA受体高表达的肺癌H460细胞,并具有明显的抗肿瘤活性。

Synthesis of Fluorescence/MRI Dual Targeted Imaging Theranostics Reagent

Poly (ethylene glycol diamine) (NH₂-PEG-NH₂) modified graphene quantum dots (GODs) were conjugated with diethylenetriaminepentaacetic acid (DTPA) via an amide bond. Then the product further coordinated with Gd3+ ions, followed by the subsequent linkage of folic acid (FA) to form FA/GODs-Gd(DTPA). Next, an anticancer drug, doxorubicin (DOX), was loaded on the surface of FA/GODs-Gd(DTPA) to obtain the final fluorescence/MRI dual targeted imaging diagnostic reagents (FA/GODs-Gd(DTPA)/DOX) for lung cancer cells. The sample was characterized by transmission electron microscopy, UV-Vis absorption spectroscopy, fluorescence spectroscopy, laser confocal microscopy, and so on. Compared with normal HLF cells, the results of MRI, confocal laser scanning microscopy and MTT showed that the prepared FA/GODs-Gd(DTPA)/DOX could be targeted to detect lung cancer H460 cells, in which folate receptor was highly expressed, and also displayed significant anti-tumor activity.