Cationic liposomes-polyallylamine-plasmid nanocomplexes for gene delivery

Abstract

The aim of the present study was to prepare, characterise and evaluate the transfection efficiency of ternary complexes (lipopolyplexes) composed of cationic liposome, polyallylamine (PAA), plasmid DNA (pDNA). PAA was reacted with a varying amount of a linker, 6-bromohexanoic acid (6-bromo-HA), to prepare a series of modified polymers. Lipopolyplexes consisting of cationic liposome, PAA (or modified PAA), pDNA were prepared. The nanoparticles, so formed, were characterised by their size and zeta potential and were subsequently evaluated for their cytotoxicity and transfection ability on Neuro2A cells. Mean size of prepared complexes ranged from 170 to 280 nm. All lipopolylexes showed a positive zeta potential. Highest transfection efficiency was for lipopolyplex containing PAA 15 kDa-modified polymer and liposome at C/P ratio of 0.5. High molecular weight PAA was more toxic than PAA 15 kDa for Neuro2A cells especially in higher C/P ratio. The results indicate that using the hydrophobic modified PAA in the structure of lipopolyplexes is an effective strategy for improving transfection efficiency.