Incorporation of Calix[6]Arene macrocycles and (pseudo)rotaxanes in bilayer membranes: Towards controllable artificial liposomal channels

The growing interest in the study of membrane-active ion (in particular, anion) transporters motivates the investigation of the mechanisms that underlie the transport process. The attention of the scientific community is largely due to the great importance of transmembrane ion transport phenomena in many diseases. In this paper we investigated the role of calix[6]arene-based pseudoro-taxanes and rotaxanes on transmembrane vehiculation of ions across the bilayer of liposomes composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC; diameter 100 nm). We evaluate the effect of these interlocked systems on the properties of the bilayer and on membrane permeability towards chloride and 5(6)-carboxyfluorescein. These findings may pave the way to the construction of new generations of pharmacological systems regulating the transport of Cl-.