Nanobiotechnology Department, Faculty of Bioscience, Tarbiat Modares University, Tehran, Iran.
Nanobiotechnology Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran.
Sci Rep. 2020 Feb 4;10(1):1837. doi: 10.1038/s41598-020-58730-z.
Liposomes or biological vesicles can be created from cholesterol, phospholipid, and water. Their stability is affected by their phospholipid composition which can influence disease treatment and drug delivery efficacy. In this study, the effect of phospholipid type on the formation and stability of liposomes using coarse-grained molecular dynamics simulations is investigated. For this purpose, the simulation study of the DSPC (1,2-distearoyl-sn-glycero-3-phosphocholine) and DPSM (Egg sphingomyelin) lipids were considered. All simulations were carried out using the Gromacs software and Martini force field 2.2. Energy minimization (3000 steps) model, equilibrium at constant volume to adjust the temperature at 400 Kelvin and equilibrium at constant pressure to adjust the pressure, at atmospheric pressure (1 bar) have been validated. Microsecond simulations, as well as formation analysis including density, radial distribution function, and solvent accessible surface area, demonstrated spherical nanodisc structures for the DPSM and DSPC liposomes. The results revealed that due to the cylindrical geometric structure and small-size head group, the DSPC lipid maintained its perfectly spherical structure. However, the DPSM lipid showed a conical geometric structure with larger head group than other lipids, which allows the liposome to form a micelle structure. Although the DSPC and DPSM lipids used in the laboratory tests exhibit liposome and micelle behaviors, the simulation results revealed their nanodisc structures. Energy analysis including overall energy, Van der Waals interaction energy, and electrostatic interaction energy showed that DPSM liposome is more stable than DSPC liposome.
脂质体或生物囊泡可以由胆固醇、磷脂和水制成。它们的稳定性受磷脂组成的影响，而磷脂组成又会影响疾病的治疗和药物输送效果。在这项研究中，使用粗粒度分子动力学模拟研究了磷脂类型对脂质体形成和稳定性的影响。为此，考虑了 DSPC（1,2-二硬脂酰-sn-甘油-3-磷酸胆碱）和 DPSM（卵鞘磷脂）脂质的模拟研究。所有模拟均使用 Gromacs 软件和 Martini 力场 2.2 进行。已验证能量最小化（3000 步）模型、在 400 开尔文下恒定体积平衡以调整温度和在大气压（1 巴）下恒定压力平衡以调整压力。微秒模拟以及包括密度、径向分布函数和溶剂可及表面积的形成分析表明，DPSM 和 DSPC 脂质体形成了球形纳米盘结构。结果表明，由于圆柱形几何结构和较小的头部基团，DSPC 脂质保持了其完美的球形结构。然而，DPSM 脂质呈现出锥形几何结构，其头部基团比其他脂质更大，这使得脂质体能够形成胶束结构。尽管实验室测试中使用的 DSPC 和 DPSM 脂质表现出脂质体和胶束行为，但模拟结果揭示了它们的纳米盘结构。包括总能量、范德华相互作用能和静电相互作用能在内的能量分析表明，DPSM 脂质体比 DSPC 脂质体更稳定。
