Cyclization and unsaturation rather than isomerisation of side chains govern the selective antibacterial activity of cationic-amphiphilic polymers.

Membrane-active agents represent a promising alternative to overcome antibiotic resistance. Here, we report cationic-amphiphilic polymers with variations in the side chain architecture such as cyclization, isomerization and unsaturation that resulted in potent antibacterial activity and low mammalian cell toxicity with a membrane-active mode of action.