Figure 3.

A) Schematic depiction of a unit cell of MVL5/GMO–siRNA complexes in the double-gyroid (Ia3d) cubic phase, Q_II^{G, siRNA}, obtained for MVL5/GMO–siRNA complexes at 0.90 ≤ Φ_GMO ≤ 0.975. The surfaces were generated using the level-set equations⁴⁵ A lipid bilayer surface separates two independent, continuous water channels (blue and orange) containing the siRNA. For clarity, the bilayer is not shown in its entire thickness but represented by an imaginary surface (grey) corresponding to a thin layer in the membrane midplane as indicated in the enlarged inset. The majority of the membrane is comprised of GMO (red), with no more than 10 mol% of pentavalent cationic MVL5 (white, note the larger headgroup). B) Optical microscopy images of MVL5/GMO–siRNA complexes in the cubic phase region (Φ_GMO = 0.90) at charge ratio ρ = 1. Complexes were viewed in differential-interference-contrast mode (left), siRNA fluorescence mode (second panel) and lipid fluorescent mode (third panel). As evident from the merged image (right panel), lipids and siRNA are completely co-localized in the globular CL–siRNA lipid complexes.