Investigation the Effect of Cholesterol on the Formation and Stability of the Liposomes using Coarse-Grained Molecular Dynamics Simulations

Liposomes or biological vesicles are formed from cholesterol, phospholipids, and water. Also, sometimes other biological and non-biological molecules imported in the structure of liposome. The stability of the liposomes in the treatment of diseases and drug delivery, it is vitally important and can be influenced by the composition of phospholipid. In addition, the presence or absence of cholesterol may also affect the stability of liposome. Also, the formation of liposomes is affected by the presence or absence of cholesterol. In this study, we are seeking to affect the presence or absence of cholesterol on the stability and the formation of the liposome. For this purpose, the molecular dynamics simulation method is used. Liposomes that they are simulated was of two types of liposomes type I and liposome type II. The formation analyzes including radial distribution function and solvent accessible surface area showed that each of liposomes created. The type I liposome created one nanodisc structure and type II liposome created two nanodisc structures. Also, energy analysis including total energy, van der Waals interaction energy, and electrostatic interaction energy showed that type I liposome is more stable. Because the cholesterol molecules are the presence of in this liposome structure, that ability to gives hydrogen bonding with side lipids and an increase of stability. In addition, hydrophobic interactions between cholesterol and phospholipids as well as distribution and proper orientation of these parts play a major stake in the stability of the structure.