pH-Sensitive liposomes with embedded ampholytic derivatives of cholan-24-oic acid

Stimulus-sensitive liposomes have been prepared from zwitterionic dioleoylphosphocholine and ampholytic molecular switches with carboxylic anionic groups and the triazole or isobutylamino cationic ones attached to the opposite ends of the steroid core. When the pH of outer solution was altered from slightly alkaline to slightly acidic, the switches changed their orientation in the liposomal membrane, which induced temporal defects formation and the release of a drug model load. The low-toxic pH-sensitive isobutylamino derivative–dioleoylphosphocholine liposomes demonstrated fast cargo release.