Pulmonary gene delivery of hybrid vector, lipopolyplex containing N-lauroylsarcosine, via the systemic route

We newly prepared lipopolyplexes containing N-lauroylsarcosine (LS) as a hybrid vector for pulmonary gene delivery via the systemic route. Lipopolyplexes were composed of polyethylenimine (PEI), N-[1-(2,3-dioleyloxy)propyl]-N,N,N-trimethlylammonium chloride (DOTMA), LS, and plasmid DNA (pDNA). The particle size of lipopolyplex of PEI, DOTMA, and pDNA (lipopolyplex 2P-2D) was not largely changed by the addition of LS, although the addition of LS decreased the high zeta potential. Lipopolyplexes containing LS with low zeta potential showed little aggregation with erythrocytes and low cytotoxicity. In HepG2 cells, lipopolyplexes containing LS showed high transgene efficiency comparable to lipopolyplex 2P-2D. After intravenous injection of the complexes into mice, lipopolyplexes containing LS showed high transgene efficiency, comparable to lipopolyplex 2P-2D. In particular, lipopolyplexes containing LS showed extremely high transgene efficiency in the lung. As a result of the analysis to identify optimum formulations, we discovered that LS contributed to the high transgene efficiency in the lung as 76.7% of the contribution index. These results suggest that lipopolyplexes containing LS are safe and useful gene delivery vectors with lung directivity.