Cholesterol tunes lipid bilayer interactions

In this study, we prepared SLBs on polystyrene colloids (CSLBs) and planar glass substrates with tunable cholesterol content. Using a fixed DPPC : DOPC molar ratio of 3 : 1 to promote the phase separation, we observed pronounced heterogeneity in CSLB diffusion near planar membranes. Notably, by profiling interbilayer interaction potentials, we found that cholesterol concentrations of ∼11 and ∼30 mol% significantly enhance bilayer adhesion-likely through membrane fusion intermediates. These findings highlight cholesterol's critical role in modulating interbilayer mechanics.