疏水纳米颗粒对仿生膜流动性的影响: 尺寸效应

金属纳米颗粒与仿生膜的组装材料具有广阔的应用前景, 但纳米颗粒载入对仿生膜的物理性质的影响却存在争议. 在本文中, 我们合成了大于与小于膜厚度的疏水金纳米颗粒 (LPNs与SNPs), 系统地研究了粒子载入对膜流动性的影响. 通过荧光漂白恢复实验发现, LPNs与SNPs分别降低与提高磷脂的侧向扩散率. 基于荧光光谱实验与理论分析, 得到LPNs与SNPs分别通过空间位阻、改变磷脂有序度两种机制影响磷脂的侧向运动. 研究结果对构建功能性纳米颗粒磷脂组装体, 通过纳米材料调控仿生膜功能方面提供了参考.

Influence of Hydrophobic Nanoparticles on Fluidity of Biomembranes: Effect of Particle Size

Metal nanoparticles and biomembrane may assemble into perspective materials for biomedicine applications. However, the influence of the loading of the nanoparticles on the physical properties of biomembrane remains controversial. In this paper, we synthesized two types of hydrophobic gold nanoparticles with diameters larger and less than the lipid bilayer thickness (LPNs and SNPs), which were employed to study the influence of the loading of the particles on the fluidity of the membranes. It is found that LPNs and SNPs inhibit and promote the diffusion of phospholipids, respectively. Using the Laurdan fluorescence spectrum, it is discovered that LPNs have no significant impact on the packing order of lipids, while SNPs reduce the order. Therefore, the size of the particles loaded is an important parameter in determining the fluidity of membranes. Through theoretical analysis, it is found that SNPs promote the lateral diffusion of lipids by disturbing the packing order of the membranes, while LNPs decrease the lateral diffusion by steric hindrance. The results provide references for the designs of functional nanoparticle-lipid assemblies and the regulation of biomembrane functions by nanomaterials.