Using liquid crystals to report molecular interactions between cationic antimicrobial peptides and lipid membranes

In this study, we develop a novel method for label-free and real-time imaging of molecular interactions between cationic antimicrobial peptides and lipid membranes using liquid crystals (LCs). The optical appearance of LCs changes from bright to dark after transferring phospholipids onto the aqueous/LC interface, representing an orientational transition of LCs from planar to homeotropic state. Bright domains are observed when an antimicrobial agent is in contact with the LC interface decorated with a lipid monolayer of negatively charged phospholipids, while, there is no change in the optical response when the antimicrobial agent is in contact with the LC interface decorated with neutral phospholipids. This approach holds great promise for studying membrane disruption or permeabilization caused by antimicrobial agents.