Host: The Society of Chemical Engineers, Japan
We report a novel method to prepare nano scale vesicles with high encapsulation efficiency of target nucleotides. First, DNA was extracted from an aqueous solution into a cationic reverse micellar solution consisting of dimethyldistearylammonium bromide (2C18AB). Secondly, small amount of the reverse micellar solution containing DNA was dropped into an aqueous surfactant solution to form the outer-layer of vesicles. We mainly employed polyoxyethylene (20) sorbitan monolaurate (Tween 20) or cetyltrimethylammonium bromide (CTAB) as an outer-layer surfactant. Salt concentration of the aqueous solution affects the solubility of the organic solution droplets into the aqueous surfactant solution. At high NaCl concentration, over 60 % of extracted DNA was re-dispersed in the aqueous solution, while DNA was hardly dispersed in the solution without NaCl. Characterization of the resulting surfactant-DNA complexes was carried out by dynamic light scattering (DLS), and which showed that the average diameters were between 200-300 nm. This technique facilitates high encapsulation efficiency of DNA molecules into liposome, and the resultant lipid-DNA complex is nano-scale gene vector.
