Mechanical properties of Ester- and Ether-DPhPC bilayers: a molecular dynamics study

Recently, a new liposomal drug delivery system has been proposed in which mechanosensitive ion channels are attached to superparamagnetic particles and used as nanovalves. However, in such system rise of temperature is inevitable which necessitates use of lipids with higher thermal and structural stability such as ether lipids. Hence, accurate measurement of their mechanical properties is essential. Herein, we examined the effect of the ether linkage on mechanical properties of ester- and ether-DPhPC lipid bilayers using all-atom molecular dynamics simulation. The value of area per lipid for the ester-DPhPC (80.8±0.1 (Å2)) is in agreement with experimental value (83.6±1.7 (Å2)). Moreover, although there are no experimental values available for the area per lipid of the ether-DPhPC, as anticipated, ether linkage decreased the area per lipid in the ether lipid bilayer. We used two approaches to calculate the area compressibility modulus both of which indicate a lower value for ester-DPhPC. These values are lower than those estimated in previous computational studies, but closer to the experimental values predicted for each monolayer.