尾静脉注射方法考察Stearic-PEI/SPIO纳米基因载体的基因转染性能及磁共振可视化效果研究

The Effects of Tail Vein Injection on Gene Delivery and MR Imaging of Stearic-PEI/SPIO Nanovectors

实验应用硬脂酸-聚乙烯亚胺包裹超顺磁氧化铁(Superparamagnetic Iron Oxide,SPIO)装载目的基因构建可视化纳米复合物,进行BABL/c雌性小鼠体内磁共振成像实验、组织学检测,探讨其是否能够有效地介导体内基因表达以及产生磁共振成像(Magnetic Resonance Imaging,MRI)效果。MRI实验结果显示,对小鼠尾静脉注射复合物0.5小时后进行磁共振扫描,与注射生理盐水的对照组相比实验组T2加权信号明显降低,信号强度仅为对照组的35%;48小时后,实验组T2加权信号强度略有回升,但与对照组信号强度相比仍存在显著差异。组织学结果显示可视化基因纳米复合物能够穿过血管内皮细胞进入肝脏组织,并释放DNA在细胞内成功表达,但基因表达效果较差。综合MRI成像及组织检查实验结果可知,该纳米颗粒具有优良的MRI成像性能,但通过尾静脉注射方法基因转染效率较低。

A visible nanoparticle was constructed via recombination of stearic acid modified polyethyleneimine(stearic-PEI)and superparamagnetic iron oxide(SPIO) to combine with DNA. Then through tail vein injection, the stearic-PEI/SPIO/DNA nanoparticles were efficiently delivered to BABL/c female mice that were visualized by MRI(Magnetic Resonance Imaging)and confirmed by histology. The MRI results showed that the experimental group's T2 signal intensities significantly decrease at 0.5 h after injection, just 35% of that in the control group. Although the experimental group's T2 signal intensities slightly recovered at 48 h after injection, there were still obvious differences between the control group and experimental group. The histological staining showed that the visible gene deliver nanocomplexes could pass through vascular endothelial cell into liver tissues and release DNA into cells, but with low gene expression effect. From the foregoing results, the nanoparticles have excellent magnetic resonance imaging performance, but low gene transfection efficiency via tail vein injection.