Atomistic Simulations of Functional Gold Nanoparticles Au144(Sr)60 Interacting with Membranes

Abstract

Gold nanoparticles (AuNps) are used in nanomedicine in, e.g., drug delivery and bio-imaging. However, it is regrettable that the understanding of nanoparticle properties in cellular surroundings is incompletely understood. Here, we have complemented our previous studies [1] by performing extensive atomistic molecular dynamics simulations of lipid membranes interacting with charged gold nanoparticles. We have elucidated the action of these nanoparticles on membranes characterized by lipid compositional asymmetry in the two leaflets, thereby unraveling the interactions of AuNPs with both the extracellular and the cytosolic sides of plasma membranes of eukaryotic cells. We have found that there is an appealing interplay between AuNps and the two membrane leaflets, where both the membrane leaflet composition and the charged nature of the nanoparticle (cationic vs. anionic) play a role. Here we discuss the resulting effects from both structural and dynamical points of view, and highlight the role of electrostatics in nanoparticle-membrane interactions.Figure 1Visualization of (a) anionic AuNP with the extracellular and (b) cationic AuNP with the cytosolic leaflet.View Large Image | View Hi-Res Image | Download PowerPoint Slide[1] E. Heikkila, et al. 2012. J. Phys. Chem. C 116: 9805-9815.