You Siheng Sean, Heffern Charles T R, Dai Yeling, Meron Mati, Henderson J Michael, Bu Wei, Xie Wenyi, Lee Ka Yee C, Lin Binhua
James Franck Institute, The University of Chicago , Chicago, Illinois 60637, United States.
Department of Chemistry, The University of Chicago , Chicago, Illinois 60637, United States.
J Phys Chem B. 2016 Sep 1;120(34):9132-41. doi: 10.1021/acs.jpcb.6b03734. Epub 2016 Aug 11.
Amphiphilic phospholipids and nanoparticles functionalized with hydrophobic capping ligands have been extensively investigated for their capacity to self-assemble into Langmuir monolayers at the air/water interface. However, understanding of composite films consisting of both nanoparticles and phospholipids, and by extension, the complex interactions arising between nanomaterials and biological membranes, remains limited. In this work, dodecanethiol-capped gold nanoparticles (Au-NPs) with an average core diameter of 6 nm were incorporated into 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) monolayers with surface densities ranging from 0.1 to 20% area coverage at a surface pressure of 30 mN/m. High resolution liquid surface X-ray scattering studies revealed a phase separation of the DPPC and Au-NP components of the composite film, as confirmed with atomic force microscopy after the film was transferred to a substrate. At low Au-NP content, the structural organization of the phase-separated film is best described as a DPPC film containing isolated islands of Au-NPs. However, increasing the Au-NP content beyond 5% area coverage transforms the structural organization of the composite film to a long-range interconnected network of Au-NP strands surrounding small seas of DPPC, where the density of the Au-NP network increases with increasing Au-NP content. The observed phase separation and structural organization of the phospholipid and nanoparticle components in these Langmuir monolayers are useful for understanding interactions of nanoparticles with biological membranes.
两亲性磷脂和用疏水性封端配体功能化的纳米颗粒因其在空气/水界面自组装成朗缪尔单层的能力而受到广泛研究。然而，对于由纳米颗粒和磷脂组成的复合膜，以及由此延伸出的纳米材料与生物膜之间产生的复杂相互作用的理解仍然有限。在这项工作中，将平均核心直径为6 nm的十二烷硫醇封端的金纳米颗粒（Au-NPs）掺入1,2-二棕榈酰-sn-甘油-3-磷酸胆碱（DPPC）单层中，在30 mN/m的表面压力下，表面密度范围为0.1%至20%面积覆盖率。高分辨率液体表面X射线散射研究揭示了复合膜中DPPC和Au-NP成分的相分离，在将膜转移到基底上后，原子力显微镜证实了这一点。在低Au-NP含量下，相分离膜的结构组织最好描述为含有孤立Au-NP岛的DPPC膜。然而，将Au-NP含量增加到超过5%面积覆盖率会将复合膜的结构组织转变为围绕小面积DPPC的Au-NP链的长程互连网络，其中Au-NP网络的密度随着Au-NP含量的增加而增加。在这些朗缪尔单层中观察到的磷脂和纳米颗粒成分的相分离和结构组织有助于理解纳米颗粒与生物膜的相互作用。
