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目的:制备二氧化硅包覆的金纳米团簇(silica-coated gold nanocluster,AuNC@SiO2),探讨以其为显像剂靶向胃癌MGC-803细胞荧光成像以及胃癌移植瘤模型中CT成像的双模式成像的可行性。方法:采用层层包硅法制备得到AuNC@SiO2,将其和肿瘤细胞标志物叶酸(folic acid,FA)偶联,MTT法检测偶联物AuNC@SiO2-FA对MCG-803细胞的毒性作用,激光共聚焦显微镜观察其靶向胃癌细胞荧光成像的可能性;以MG-803细胞皮下接种BALB/c裸鼠建立移植瘤模型,采用CT成像系统采集胃癌移植瘤内注射AuNC@SiO2前后的CT信号,探讨AuNC@SiO2在移植瘤模型中CT成像的可行性。结果:成功制备了形貌均一、分散性良好、具有良好荧光光学特性的AuNC@SiO2,AuNC@SiO2和AuNC@SiO2-FA在500 mg/ml时对胃癌MGC-803细胞和正常胃黏膜GES-1细胞的毒性均较低。在细胞学实验中,AuNC@SiO2-FA能够有效地靶向胃癌MGC-803细胞而非正常GES-1细胞,从而清晰地荧光成像;在裸鼠胃癌移植瘤模型中,肿瘤部位注射AuNC@SiO2后CT信号明显增强,HU值由注射前的129.16上升到383.32。结论:AuNC@SiO2能够用于荧光和CT双模式成像,AuNC@SiO2-FA能靶向胃癌细胞荧光成像。
OBJECTIVE: To prepare silica-coated gold nanoclusters (AuNC @ SiO2) and investigate the imaging of gastric cancer MGC-803 cells targeting CT imaging in gastric cancer xenografts Feasibility of dual mode imaging. Methods: AuNC @ SiO2 was prepared by the layer-by-layer silicon method and conjugated with the tumor cell marker folic acid (FA). The cytotoxicity of the AuNC @ SiO2-FA conjugate on MCG-803 cells was detected by MTT assay , Confocal laser scanning microscope was used to observe the possibility of targeting gastric cancer cells by fluorescence imaging. BALB / c nude mice were subcutaneously inoculated with MG-803 cells to establish a transplanted tumor model. The CT imaging system was used to collect CT before and after injection of AuNC @ SiO2 Signal to explore the feasibility of AuNC @ SiO2 CT imaging in xenograft models. RESULTS: AuNC @ SiO2, AuNC @ SiO2 and AuNC @ SiO2-FA with good morphology and good dispersity were successfully prepared for the treatment of gastric cancer MGC-803 cells and normal gastric mucosa GES- 1 cells are less toxic. In cytological experiments, AuNC @ SiO2-FA can effectively target gastric cancer MGC-803 cells but not normal GES-1 cells for clear fluorescence imaging. In the nude mice model of gastric cancer xenografts, AuNC @ SiO2 After the CT signal was significantly enhanced, HU value rose from 129.16 before injection to 383.32. CONCLUSIONS: AuNC @ SiO2 can be used for dual-mode fluorescence and CT imaging. AuNC @ SiO2-FA can target the fluorescence imaging of gastric cancer cells.