New gluconamide-type cationic surfactants: Interactions with DNA and lipid membranes.

Abstract New linear cationic surfactants – 2-(alkyldimethylammonio)ethylgluconamide bromides, denoted as C n GAB, n  = 10, 12, 14 and 16 – were synthesized from natural resources and characterized with respect to their potential as gene-delivery agents in gene therapy applications. Interactions with plasmid DNA and with model membranes were studied both experimentally and theoretically. The compounds with n  = 12, 14 and 16 show exponentially increasing ability to fully condense DNA. C 16 GAB condenses DNA at 1:1 surfactant to nucleotide molar ratio. Furthermore, C n GABs interact with model membrane, slightly lowering the temperature of the main phase transition T m of the DPPC bilayer. C 10 GAB is found to interact only at the membrane surface. C 16 GAB reduces T m less than C 12 GAB and C 14 GAB, and forms domains in the bilayer at the surfactant/DPPC molar ratio of 0.1 and higher. The results suggest that C 16 GAB can be a promising candidate for building gene-delivery carrier systems.