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.

中文翻译：

---

阴离子纳米粒子诱导的巨大单层囊泡的变形和渗透。

已经研究了大小为18 nm的阴离子磁铁矿纳米粒子（MNP）与带负电的巨型单层囊泡（GUV）的相互作用，该单囊泡由中性二油酰基磷脂酰胆碱（DOPC）和带负电的二醇酰基磷脂酰甘油（DOPG）脂质的混合物形成。已经发现，NPs引起球形GUV的变形。其他GUV对NP的反应在于其膜上出现孔。我们将静电的影响集中在带电膜与MNP的相互作用上。为了研究GUV的表面电荷对所考虑的过程的影响，我们将囊泡中DOPG的比例从0％更改为100％。我们检查了盐浓度在50-300 mM NaCl浓度范围内的影响。为了描述变形程度，引入了特殊的参数紧凑性。通过蔗糖的渗漏研究了GUVs膜中的孔形成。紧密度随时间增加，NPs浓度也增加。随着膜表面电荷密度的增加以及缓冲液中盐浓度的降低，变形的GUV的比例也随之增加。中性膜的致密性值是带电膜的致密性值的1.25倍。变形的GUV的比例在20分钟后变得恒定，但是随着NPs浓度的增加而增加。带电膜的随机孔形成时间少于中性膜。解释这些研究中获得的实验结果的物理机制。紧密度随时间增加，NPs浓度也增加。随着膜表面电荷密度的增加以及缓冲液中盐浓度的降低，变形的GUV的比例也随之增加。中性膜的致密性值是带电膜的致密性值的1.25倍。变形的GUV的比例在20分钟后变得恒定，但是随着NPs浓度的增加而增加。带电膜的随机孔形成时间少于中性膜。解释这些研究中获得的实验结果的物理机制。紧密度随时间增加，NPs浓度也增加。随着膜表面电荷密度的增加以及缓冲液中盐浓度的降低，变形的GUV的比例也随之增加。中性膜的致密性值是带电膜的致密性值的1.25倍。变形的GUV的比例在20分钟后变得恒定，但是随着NPs浓度的增加而增加。带电膜的随机孔形成时间少于中性膜。解释这些研究中获得的实验结果的物理机制。比收费的高25倍。变形的GUV的比例在20分钟后变得恒定，但是随着NPs浓度的增加而增加。带电膜的随机孔形成时间少于中性膜。解释这些研究中获得的实验结果的物理机制。比收费的高25倍。变形的GUV的比例在20分钟后变得恒定，但是随着NPs浓度的增加而增加。带电膜的随机孔形成时间少于中性膜。解释这些研究中获得的实验结果的物理机制。