Investigation of the temperature effect on the properties of biological nanomembranes with different concentrations of cholesterol using molecular dynamics simulation

The cell membrane is the outermost boundary of the cell, and its role is to protect the cell. Drugs must first pass through the membrane to enter the cell; therefore, investigating the properties of the bilayer membrane is of great importance and can provide important information regarding drug delivery processes. In this study, the effect of increasing temperature on the properties of bilayer membranes with 0 %, 10 %, 30 %, and 50 % cholesterol was investigated using molecular dynamics simulation. Moreover, the phase transition temperature of the lipid bilayer was selected based on the percentages of cholesterol. The results indicated that with increasing temperature, the membrane changed from gel phase to fluid phase. Moreover, a rise in temperature led to an increase in the area per lipid and a decrease in the order parameter, the reason for which was the increase in the kinetic energy of the molecules. The fluid phase membrane, which is at a higher temperature, had a higher diffusion coefficient than the gel phase membrane. The increase in the temperature caused the membrane with 0 % cholesterol to experience a 24 % decrease in the order parameter, while the structural properties of the membrane with 50 % cholesterol are almost constant with increasing temperature, indicating the rigidity of the membrane. With the increase in cholesterol concentration from 0 % to 50 %, the time for pore formation under the electric field increased from 0.26 ns to 8.46 ns. These results will be helpful in the development of drug delivery and therapeutic processes.