Chiral pH-Sensitive cyclobutane β-amino acid-based cationic amphiphiles: Possible candidates for use in gene therapy

Publication date: Available online 16 October 2019Source: Journal of Molecular LiquidsAuthor(s): Bernat Pi-Boleda, Mireia Bouzas, Nerea Gaztelumendi, Ona Illa, Carme Nogués, Vicenç Branchadell, Ramon Pons, Rosa M. OrtuñoAbstractChiral cis/trans diastereomeric cationic amphiphiles 8 and 9 have been synthesized and studied. They are based on β-amino acids and contain C12- and C16-alkyl chains, respectively, as hydrophobic tails while the polar head consists of an ammonium cation linked to a cyclobutane ring. Their physicochemical properties, such as the cmc (critical micellar concentration), the pKa, the ratio of cationic versus non-ionic species, and the surface tension are strongly dependent on the pH of the medium. At the same time the aggregation state influences on the apparent pKa values of the aggregates, with release of protons at the cmc whose values, as well as those of the adsorption effectiveness, account for their efficient surfactant behavior. A tail-length effect is manifest because surfactant cmc of compounds with a C16-alkyl chain are smaller than the C12-ones, although not as small as expected. On the other hand, while for C12-surfactants the role of the stereochemistry on the physicochemical parameters is patent, it is not very clear for C16-surfactants. The stereochemistry also determines the predominant mode of self-assembly since the trend for cis-isomers is to form micelles or vesicles while trans-isomers preferably form fibers. CD spectroscopy confir...
Source: Journal of Molecular Liquids - Category: Molecular Biology Source Type: research