Electronic Supplementary Information Interaction between GUVs and Catanionic Nanocontainers : a New insight into Spontaneous Membrane Fusion

The lipids used to prepare giant unilamellar vesicles were: L-α-phosphatidylcholine (Egg, Chicken) (Egg-PC), 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), 1-palmitoyl-2oleoyl-sn-glycero-3-phosphocholine (POPC), 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), phosphatidylserine (PS) cholesterol (all from Avanti Polar Lipids, Alabaster, Alabama, US). The lipids were stored in chloroform at -20°C. Experiments were performed at 20°C. At this temperature, POPC is in a fluid phase (ld), DPPC in a gel phase (so). Liquid ordered (lo) phase state was obtained by adding 30% of cholesterol in DPPC membrane. Coexisting phase states were obtained by adding given amounts of cholesterol in lipids. 20% or 30% of cholesterol in POPC membrane resulted in ld/lo phase state and 20% of cholesterol in DPPC membrane resulted in so/lo phase state.