We report the synthesis of a new series of Ketal Nucleoside Lipids (KNLs) featuring saturated hydrophobic double chains and either adenosine or uridine as nucleosides (KNLA and KNLU, respectively). Physicochemical studies (differential scanning calorimetry, small angle X ray scattering, transmission electronic microscopy, atomic force microscopy, Langmuir isotherm, infrared spectroscopy) show that the KNLs form hydrogels below the main phase transition temperature (Tm), whereas fluid lamellar phases are obtained above T-m. Mixing complementary KNLs affords a new stable Combined Supramolecular Systems (CSSs) due to complementary A-U recognition. Molecular modeling calculations of the bilayers in a fluid state exhibit a merging of the bilayers partially due to base-base interactions. (C) 2012 Elsevier Inc. All rights reserved.