OS1-1-2 Molecular dynamics simulations of structural changes of lipid bilayer under ultrasound

Combined use of ultrasound and micro- or nano-sized bubbles can deliver macro molecules into biological cells. Here, we introduce molecular dynamics studies that we have conducted for past years to understand the molecular mechanisms about the molecular delivery into the cells. In the studies, we have used the lipid bilayer structure model, the common structure of all biological cell membranes, with unsteady and nonequilibrium molecular dynamics simulation techniques. The studies have revealed the structural changes of the bilayer and the water penetration to the bilayer induced by the impact of shockwave on the bilayer, and the formation of pore structure penetrating the bilayer after the loading of water molecules into the bilayer. Moreover, we present resent results about responses of the intact or pore-containing bilayers to stretch.