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目的:探讨RGD肽介导的MR分子探针在体外结直肠癌细胞的MRI显像及对其生物学行为的影响方法:利用纳米技术构建靶向RGD荧光纳米MR探针,利用荧光倒置相差显微镜观察该探针与LOVO细胞结合情况;体外磁共振成像(MRI)显像;利用细胞克隆实验测其增殖活性;流式细胞术检测其细胞周期、凋亡。结果:荧光相差显微镜示该RGD肽介导的MR分子探针能特异性与LOVO细胞结合;体外MRI成像示靶向RGD组T_1信号强度高于非靶向组及对照组(P<0.05);该探针作用24h后的LOVO细胞增殖活性降低,细胞分裂周期发生变化,阻滞在S+G_2M期的细胞比例上升,细胞凋亡率与其他两组相比有显著增加(P<0.05)结论:该RGD肽介导的MR分子探针能与结直肠癌LOVO细胞靶向结合,能增强MRI的显像效果,并对肿瘤细胞具有一定的抑制作用
OBJECTIVE: To investigate the MRI imaging of RGD-peptide-mediated MR molecular probes in vitro and its effect on the biological behavior of colorectal cancer cells.Methods: Targeted RGD-fluorescent nano-MR probes were constructed by using nanotechnology and the fluorescence inverted phase contrast microscopy The binding of the probe to LOVO cells was observed. MRI imaging was performed in vitro. Cell proliferation was measured by cell clone assay. Cell cycle and apoptosis were detected by flow cytometry. Results: Fluorescence phase contrast microscopy showed that the RGD peptide-mediated MR probe could specifically bind to LOVO cells. In vitro MRI imaging showed that signal intensity of T_1 in RGD group was higher than that in non-target group and control group (P <0.05). After 24 hours, the activity of LOVO cells decreased, the cell division cycle changed, and the percentage of cells arrested in S + G_2M phase increased. The apoptosis rate of LOVO cells increased significantly compared with the other two groups (P <0.05). Conclusion : The RGD peptide-mediated MR probe can be targeted to LOVO cells in colorectal cancer, which can enhance MRI imaging and inhibit the tumor cells