Department of Physics, Bangladesh University of Engineering and Technology, Dhaka, 1000, Bangladesh.
Department of Physics, Bangladesh University of Engineering and Technology, Dhaka, 1000, Bangladesh.
Chem Phys Lipids. 2020 Aug;230:104916. doi: 10.1016/j.chemphyslip.2020.104916. Epub 2020 May 12.
The interaction of anionic magnetite nanoparticles (MNPs) of size 18 nm with negatively charged giant unilamellar vesicles (GUVs) formed from a mixture of neutral dioleoylphosphatidylcholine (DOPC) and negatively charged dioleoylphosphatidylglycerol (DOPG) lipids has been investigated. It has been obtained that NPs induces the deformation of spherical GUVs. The reaction of other GUVs on NPs consists in the appearance of pores in their membranes. We focused the effect of electrostatics on the interaction of charged membranes with MNPs. To study the influence of the surface charge of GUVs on the processes under consideration, we varied the fraction of DOPG in the vesicles from 0 to 100%. We examined the influence of salt concentration in the range of 50-300 mM NaCl concentration. To describe the degree of deformation, a special parameter compactness was introduced. The pore formation in the membranes of GUVs was investigated by the leakage of sucrose. The compactness increases with time and also NPs concentration. The fraction of deformed GUVs increases with the increase of surface charge density of membranes as well as the decrease of salt concentration in buffer. The value of compactness for neutral membrane is 1.25 times higher than that of charged ones. The fraction of deformed GUVs become constant after 20 min, however it increases with NPs concentration. The time taken for stochastic pore formation is less for charged membrane than neutral one. The physical mechanism explaining the experimental results obtained in these investigations.
已经研究了尺寸为 18nm 的带负电荷的磁铁矿纳米粒子（MNPs）与由中性二油酰基磷脂酰胆碱（DOPC）和带负电荷的二油酰基磷脂酰甘油（DOPG）脂质组成的带负电荷的巨大单层囊泡（GUVs）之间的相互作用。已经得到 NPs 诱导球形 GUVs 的变形。其他 GUVs 对 NPs 的反应是在它们的膜上出现孔。我们专注于静电对带电膜与 MNPs 相互作用的影响。为了研究 GUVs 的表面电荷对所考虑过程的影响，我们将囊泡中 DOPG 的分数从 0 变化到 100%。我们检查了盐浓度在 50-300mM NaCl 浓度范围内的影响。为了描述变形程度，引入了一个特殊参数紧密度。通过蔗糖泄漏研究了 GUVs 膜中的孔形成。紧密度随时间和 NPs 浓度的增加而增加。变形 GUVs 的分数随膜表面电荷密度的增加以及缓冲液中盐浓度的降低而增加。中性膜的紧密度值比带电膜高 1.25 倍。变形 GUVs 的分数在 20 分钟后保持不变，但随着 NPs 浓度的增加而增加。随机孔形成所需的时间对于带电膜比中性膜更短。解释这些研究中获得的实验结果的物理机制。
