title: Distribution of functionalized gold nanoparticles between water and lipid bilayers as model cell membranes.
abstract: Lipid bilayers are biomembranes common to cellular life and constitute a continuous barrier between cells and their environment. Understanding the interaction of nanoparticles with lipid bilayers is an important step toward predicting subsequent biological effects. In this study, we assessed the affinity of functionalized gold nanoparticles (Au NPs) with sizes from 5 to 100 nm to lipid bilayers by determining the Au NP distribution between aqueous electrolytes and lipid bilayers. The Au NP distribution to lipid bilayers reached an apparent steady state in 24 h with smaller Au NPs distributing onto lipid bilayers more rapidly than larger ones. Au NPs distributed to lipid bilayers to a larger extent at lower pH. Tannic acid-functionalized Au NPs exhibited greater distribution to lipid bilayers than polyvinylpyrrolidone-functionalized Au NPs of the same size. Across the various Au NP sizes, we measure the lipid bilayer-water distribution coefficient (K(lipw) = C(lip)/C(w)) as 450 L/kg lipid, which is independent of dosimetric units. This work suggests that the nanoparticle-cell membrane interaction is dependent on solution chemistry and nanoparticle surface functionality. The K(lipw) value may be used to predict the affinity of spherical Au NPs across a certain size range toward lipid membranes.
authors.affiliation: Mechanical Engineering, Chemical Engineering, University of Washington, Seattle, Washington 98195-2600, United States. whou4@asu.edu
authors.forename: Wen-Che
authors.initials: WC
authors.lastname: Hou
authors.forename: Babak Yaghoubi
authors.initials: BY
authors.lastname: Moghadam
authors.forename: Charlie
authors.initials: C
authors.lastname: Corredor
authors.forename: Paul
authors.initials: P
authors.lastname: Westerhoff
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Posner
mesh_terms: D000327:Adsorption; D002462:Cell Membrane / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008051:Lipid Bilayers / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D010316:Particle Size; D011205:Povidone; D013057:Spectrum Analysis; D013634:Tannins; D014867:Water / Q000737:chemistry
chemical_list: D008051:Lipid Bilayers; D013634:Tannins; D014867:Water; D006046:Gold; D011205:Povidone