Abstract

In the present study, polyethylenimine (PEI, 1800 Da) and liposome were combined in order to improve gene expression. A new gene delivery system (polycationic liposome) was developed by modification of liposomes with lipoploymers constructed from acrylate or bromoalkane derivatives. The polycationic liposome-plasmid DNA (pDNA) complexes were characterized for their size, zeta potential and ability for DNA condensation. Luciferase reporter gene was used for the determination of transfection efficiency in Neuro2A cells. While mean particle size of prepared vectors ranged from 75 to 520 nm, the zeta potential varied from 11-35 mV. Transfection activity of selected non-viral vectors was higher than that of PEI 1800 Da and PEI 25 KDa. The transfection activity of polycationic liposomes was reduced after replacement of bromoalkane derivatives by acrylates in the structure of lipopolymers. Furthermore, gene carriers described in this study showed low cytotoxicity. The results show that inclusion of hydrophobic PEI derivatives in liposome structure can improve the transfection efficiency but the lipopolymer structure determines the gene expression efficiency of vectors

Keywords: Lipopolymer, liposomes, non-viral gene delivery, polyethylenimine.