The characterization of cationic fusogenic liposomes mediated antisense oligonucleotides into HeLa cells

Antisense oligonucleotides (ODNs) are potential therapeutic agents, but their development is still limited due to poor cellular uptake and high degradation rate in biological media. To resolve these problems, we propose to attach the Sendai virus to cationic liposomes. Cationic-fusogenic liposomes (CFLs) were prepared by reverse-phase evaporation and fused with the Sendai virus. The mean diameter was about 186 nm, determined by photon correlation laser light scattering method. The cytotoxicity of CFLs and the ODN loading efficiency depended on the +/- charge ratio. The fluorescence intensity in cytoplasm was enhanced with the increasing of DC-Chol content and +/- charge ratio. We also investigated the mechanism of cellular uptake using temperature shifts and lysosomotropic agent. The results indicated that the vector was introduced into the cells, not via endocytosis but membrane fusion. The preliminary experiment showed that CFLs are a promising formulation for ODN delivery with high levels of transfection and minimal cytotoxicity.