Study on a novel non-virus triplex gene vectors composed of plasmid DNA

In order to study the feasibility and transfection mechanisms of a novel gene vector system composed of plasmid DNA-anti DNA antibody-cationic lipid (DAC) for non-virus site-specific gene therapy, stable DAC triplex nano-micelles were formed in PBS system through self-assembling of plasmid DNA, anti DNA antibody and cationic lipid. The mechanisms of cell uptake and entry with DAC were observed by fluorescent confocal microscopy. Transfection efficiency of DAC was estimated by using A10 cell in vitro with GFP-DNA (green fluorescent) triplex micelles. Cell culture studies revealed that DAC triplex micelles markedly increased the level of gene transferred to A10 cells, with more than 4-fold increase in transfection compared to DC group without anti DNA antibody and 11-fold increase compared to DA group without cationic lipid. Fluorescent DNA studies demonstrated greater cell uptake in vitro with DAC compared to the control formulations. Confocal microscopy studies confirmed nuclear entry in A10 cells with DAC, while formulations without anti-DNA antibody demonstrated no nuclear entry. It can be concluded that plasmid DNA-anti DNA antibody-cationic lipid (DAC) triplex micelle was a novel non-viral gene vector with high transfection efficiency and no cytotoxicity. It was hypothesized that DAC triplex micelles could enhance DNA delivery through mechanisms involving: increased levels of DNA incorporation into micelles due to antibody binding, enhanced plasmid DNA entry into nuclear due to the nuclear entry properties of anti-DNA antibody, and increased transfection efficiency via co-operation of anti-DNA antibody and cationic lipid. Gene delivery using DAC triplex micelles should be suitable for a wide array of single or multiple therapeutic gene strategies and for further successful gene therapy.