Interaction of Cucurbiturils with Lipid Bilayers

Abstract

In this study cucurbit[7]uril (CB[7]) was loaded into preformed liposomes via a diffusion-controlled process to investigate the effect of CB[7] on the stability of the lipid membrane. The effect of CB[7] on liposome integrity was studied via calcein release, TGA, TEM, the size and charge of liposomes. In addition, the affinity of CB[7] towards cholesterol was determined. It was found that CB[7] has a Ka of 3×106 with cholesterol. Cholesterol was released from liposomes when the concentration of CB[7] is higher than 1.433 mM. Transmission Electron Microscope (TEM) images confirmed stable spherical intact liposomes that directly disrupted into either smaller micelles (5–10 nm) or aggregates upon CB[7] addition up to 0.2292 mM of CB[7]. Biocompatibility of CB[7] against human red blood cells (RBCs) was investigated and showed that 2.580 to 3.00 mM CB[7] concentrations caused a RBCs hemolysis percent of 56.88%.