On the structure and stability of novel cationic DPPC liposomes doped with gemini surfactants

A novel formulation of cationic liposomes was studied by mixing dipalmitoylphosphatidylcholine (DPPC) with tetradecyltrimethylammonium bromide gemini surfactants different alkane spacer groups lengths attached to their ammonium head-groups. The physicochemical characterization the obtained combining experimental results from differential scanning microcalorimetry (DSC) molecular dynamic simulations, in order understand structural configuration. An adapted Ising model used interpret terms cooperativity phase transitions. partition into lipid bilayer DPPC liposomes, and induced changes colloidal stability transition were analyzed detail. became positively charged upon surfactant partition, showing increased stability. Our show significant differences configuration between short long lengths. While shorter spacers allocate within both headgroups same layer, geminis longer unexpectedly intercalate membrane a particular zig-zag configuration, each headgroup located at side bilayer, altering coupling degree parameters membrane’s transition. extraordinary increase very low molar ratio possibility tune properties control de length opens new possibilities for liposomal formulations potential applications vaccines, drug/gene delivery or biosensing.