Nanoparticle-Membrane Interactions Studied with Lipid Bilayer Arrays

Abstract

Nanoparticles (NPs) have been explored for use in biomedical applications including gene and drug delivery, and recent studies have indicated that they are also cytotoxic and have significant interaction with lipid bilayer membranes. An understanding of the interactions between NPs and the cell membrane systems will help aid the design of NPs for beneficial applications and evaluate the cytotoxicity of environmental NPs. To study these interactions, we measured amine- and carboxyl-modified polystyrene NPs in arrays of 24-32 artificial lipid bilayers. The throughput possible with simultaneous electrical measurement of the bilayer arrays enabled study of NP/bilayer interactions while varying lipid composition, ionic strength, pH, voltage, and particle type. Our studies showed that amine-modified NPs interacted with bilayers whereas carboxyl-modified NPs did not. The interaction of the amine-modified NPs could be altered by changing the charge density on the bilayers, the ionic strength and pH.