Lipid membranes form the interface between living cells and their environment. Nanoparticle (NP) uptake into cells requires attachment to and penetration of lipid bilayers, and NP interaction with lipid membranes may initiate signaling cascades or membrane disruption leading to adverse biological outcomes. At present, only limited molecular scale information is available on the interactions of NPs with cellular membranes that influence their attachment to and internalization by cells. As a first step toward deeper molecular scale understanding of NP uptake by and effects on cell membranes we investigated NP interaction with model phospholipid membranes. We examined the influence of NP charge, solution conditions, and bilayer composition on NP attachment, changes in membrane order, and membrane disruption. Gold nanoparticles were synthesized and functionalized with organic ligands (e.g., mercaptopropionic acid) or polymer wrapped (e.g., poly(allylamine hydrochloride), or poly(acrylic acid)). Supported lipid bilayers composed of single and binary mixtures of phospholipids were formed on solid substrates. We employed a suite of techniques to investigate NP interaction with the supported lipid bilayers including quartz crystal microbalance with dissipation, sum frequency generation spectroscopy (SFG), and optical waveguide lightmode spectroscopy. Inclusion of phospholipids into the lipid bilayer with head groups bearing charge opposite that of the NPs promoted attachment. SFG spectroscopy allowed us to observed structural changes of the lipids within the bilayer induced by interaction with NPs.

Interactions of functionalized-gold nanoparticles with supported lipid bilayers

246th National Meeting (2013)

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