In order to test an encapsulation method of short fragmented DNA (~ 20-300 bp), we study the solubilisation in 150 mM solution of NaCl of a cubic phase formed by glycerol monooleate (GMO) with negatively charged dioleoylphosphatidylglycerol (DOPG) up to the level of unilamellar vesicles and, subsequently, the restoration of the cubic phase using Ca 2+ cations. We performed small angle X-ray and neutron scattering (SAXS and SANS) to follow structural changes in DOPG/GMO mixtures induced by increasing DOPG content. The cubic phase (Pn3m space group) is preserved up to ~ 11 mol% of DOPG in DOPG/GMO. Above 20 mol%, the SANS curves are typical of unilamellar vesicles. The thickness of the DOPG/GMO lipid bilayer (d L) decreases slightly with increasing fraction of DOPG. The addition of 15 mM of CaCl 2 solution shields the electrostatic repulsions of DOPG molecules, increases slightly d L and restores the cubic structures in the mixtures up to ~ 37 mol% of DOPG. Zeta potential shows negative surface charge. The analysis of the data provides the radius of the water nano-channels of the formed non-lamellar structures. We discuss their dimensions with respect to DNA binding. In addition, Ca 2+ mediates DNA-DOPG/GMO binding. The formed hexagonal phase, H II , binds less of DNA in comparison with cubic phases (~ 6 wt% and ~ 20 wt% of the total amount, respectively). The studied system can be utilized as anionic Q II delivery vector for genetic material.