肝靶向性Gal-PEG—PEI纳米载体介导psiRNA转染HepG2细胞效率的检测

Transfection efficiency of galactosylated poly （ ethylene glycol ） -graft-polyethylenimine as hepato-cyte-targeting psiRNA carrier in HepG2 cells

目的检测肝细胞靶向性Gal—PEG—PEI纳米基因载体介导psiRNA转染HepG2细胞的效率。方法纳米粒径仪和透射电镜测定Gal—PEG—PEI／psiRNA复合物的粒径和形态，转染HepG2细胞，48h后用流式细胞仪测定转染效率。转染前加入1mg半乳糖观察其半乳糖竞争拮抗结果。结果Gal—PEG—PEI／psiRNA复合物的粒径随N／P的增大而减小，最小粒径为81．1nm；GaI—PEG—PEI载体的转染效率为（37．34±2．50）％，明显高于PEG—PEI、Lipofectamine^TM2000及裸psiRNA；加入竞争拮抗剂半乳糖后Gal－PEG—PEI的转染效率下降至3．60％。结论Gal—PEG—PEI纳米基因载体对HepG2细胞有较高的转染效率，具有良好的肝细胞靶向性。

Objective To evaluate transfection efficiency of galaetosylated poly （ ethylene glycol） - graft-polyethylenimine （Gal-PEG-PEI） as a non-viral gene cartier of hepatocyte-targeting plasmid siRNA （psiRNA） in HepG2 cells. Methods The characteristics of the Gal-PEG-PEI/psiRNA nanoparticles were measured by dynamic light scattering and transmission electron microscopy. The transfection experiments were performed with the Gal-PEG-PEI/psiRNA using GFP as the reporter gene in HepG2 cells, and the transfection efficiency was evaluated by flow cytometry after 48 h. The competition assay was carried out to confirm the uptake of Gal-PEG-PEI/psiRNA by ASGP-R in HepG2 cells by adding 1 mg galactose into the transfection media. Results The results indicated that the particle sizes were decreased with in- creasing charge ratios of Gal-PEG-PEI to psiRNA, and had a minimum value around 81.1 nm at the charge ratio of 20. The transfection efficiency of Gal-PEG-PEI was higher than that of PEG-PEI, LipofectamineTM 2000 or naked psiRNA in HepG2 cells. When galactose was added,the transfection efficiency of Gal-PEG- PEI was drastically decreased from 37.34% to 3.60%. Conclusion The Gal-PEG-PEI nanospheres display perfect hepatocyte-targeting ability and can be potentially used as a nonviral gene cartier in liver diease therapy.