Transformation from Multi- to Single-lamellar Vesicle by Addition of a Cationic Lipid to 1,2-Dilauroyl-sn-glycero-3-phosphocholine Explored with SAXS and TEM

1,2-Dilauroyl-sn-glycero-3-phosphocholine (DLPC) is one of the major lipids constituting cellular membranes. When DLPC itself is dispersed in aqueous solutions, multilamellar vesicles are formed, although the cellular membranes are made of single bilayers. We found that the addition of a calix[4]arene derivative (CaL[4]C3) bearing four amine groups as the headgroup to the DLPC multilamellar vesicle induced the structural transformation to a single-lamellar vesicle, by use of small-angle X-ray scattering and electron microscopy, indicating that the highly condensed ionic groups of CaL[4]C3 are useful to control membrane morphology.