Cithrol, a commercially available type of monoolein was a gift from Croda Chemicals (Goole, UK) and 3,7,11,15-tetramethyl-1,2,3-hexadecanetriol (Phytantriol, PHYT) was purchased from Adina Cosmetics Ingredients (Kent, UK). Cithrol and PHYT had a purity of < 96 % and >98.3 % respectively while the rest of the lipids had a purity of >99% and were used without further purification. MO:DOPS and MO:DOPS:CHOL mixtures were prepared by mixing the appropriate amounts of dry lipids and co-dissolving them in chloroform. The chloroform solutions were dried using a stream of N2 gas and the dry lipid films were left under vacuum overnight to remove any residual solvent.