靶向多功能纳米造影剂对肝癌细胞MRI显像和基因传输的研究

摘要

目的：观察叶酸靶向化聚乙烯亚胺包被的超顺磁性四氧化三铁（Fa-PEI-SPIO）转染Hep3B肝癌细胞的显像效果和基因传输效果。方法 Fa-PEI-SPIO纳米造影剂复合增强型绿色荧光蛋白（EGFP）真核表达质粒后转染肝癌Hep3B细胞。通过激光共聚焦实验检测纳米造影剂的靶向传输效率；通过MRI扫描检测纳米造影剂的显影效果；通过流式细胞术检测纳米造影剂的基因传输效率。结果激光共聚焦实验观察发现Fa-PEI-SPIO/EGFP纳米造影剂可以高效携带荧光分子进入肝癌细胞，转染后细胞中在细胞核的蓝色荧光周围出现大量纳米复合物的绿色荧光。MRI T2扫描观察发现靶向化纳米造影剂中携带的SPIO发挥了良好的显影效果，转染后肝癌细胞的T2信号明显降低。流式细胞术检测发现，靶向化纳米造影剂明显提高了EGFP真核表达质粒在细胞中的表达效率，表达效率高达（97.72 ± 8.23）﹪。结论多功能纳米造影剂Fa-PEI-SPIO可高效负载MRI和荧光造影剂实现对肝癌细胞的高效率敏感显像，并可同时实现目的基因的传输。%Objective  To study the feasibility of using folate targeted PEI coated SPIO(Fa-PEI-SPIO)to transfect into Hep3B hepatoma cells for MR imaging and the gene transfect effect on hepatocellular carcinoma cells. Methods Fa-PEI-SPIO was transfected into Hep3B cells after combined with EGFP plasmid. The efficiency of the targeted delivery of the contrast agent was detected by confocal laser scanning confocal microscopy. Contrast effect of nano contrast agent was evaluated in the MRI scan. Gene transfer efficiency of nano contrast agent was evaluated using flow cytometry. ResultsConfocal experiment showed that Fa-PEI-SPIO/EGFP nano contrast agent can efficiently carry fluorescent molecules into cells, resulting in a large number of green fluorescent nanocomposites around the nucleus of the blue fluorescence. T2 weighted images showed that Fa-PEI-SPIO/EGFP played a good contrast effect, the T2 signal of HCC cells decreased. Flow cytometry showed that Fa-PEI-SPIO/EGFP increased the expression efficiency of EGFP, and the expression efficiency increased to(97.72 ± 8.23)﹪. ConclusionFa-PEI-SPIO has the potential of efficiently loading MRI and fluorescent contrast agent to achieve high efficiency and sensitive imaging of liver cancer cells, and can simultaneously achieve the purpose of gene transfer.