Effect of Polyethylenimine Content on Liposome/Polyethylenimine Complexes-Mediated Gene Delivery

摘要

Cationic liposome(Lipo) and polyethylenimine(PEI) are widely applied for nonviral gene transfection.In this study,in order to combine the favorable properties of Lipo and PEI systems for gene delivery,Lipo/PEI complexes with different contents of PEI(5%,10%,20% and 40% relative to phosphatidyl choline in reaction system) were prepared.The physicochemical properties of Lipo/PEI complexes,as well as the influences of PEI content on the storage stability,cytotoxicity and transfection efficiency were investigated.The transmission electron microscopy(TEM) images showed that Lipo/PEI complexes had smaller size compared to pure Lipo.The zeta potential values decreased with the increasing content of PEI.After storaged for 3 months at 4 ℃,obvious aggregation was observed when the addition of PEI content was up to 20%.In vitro cytotoxicity assay showed that Lipo/PEI complexes had decreased cytotoxicity over pure PEI,while the cytotoxicity was enhanced as the PEI content increased.Importantly,the luciferase activity assay and confocal microscope observation revealed that Lipo/PEI complexes prepared with the lowest amount of PEI(Lipo/PEI-5%)possessed the highest transfection efficiency.Thus,these results suggest that feeding the appropriate content of PEI in Lipo/PEI complexes allows them to be excellent vehicle for gene delivery.