The growing use of nanotechnology has led to increased interest in understanding the molecular-level interactions of nanoparticles in environmental matrices. Natural organic matter (NOM) can form an �environmental corona� around the nanoparticle and impact nanoparticle hydrodynamic and electrokinetic properties, but the effects on subsequent biological interactions are poorly understood. We have conducted studies aimed at understanding how nanoparticles functionalized with different surface ligands interact with NOM and how the presence of NOM impacts nanoparticles interaction with solid-supported lipid bilayers (SLBs), a model for cellular membranes. We characterize the interaction of NPs with supported lipid bilayers in real time in the presence and absence of NOM using quartz crystal microbalance with dissipation monitoring.  NOM-induced changes in hydrodynamic size were measured using dynamic light scattering, and changes in charge were investigated using laser Doppler microelectrophoresis. Our studies show the presence of NOM decreases the attachment of positively charged diamond nanoparticles to SLBs composed of zwitterionic phospholipids or mixtures of zwitterionic and negatively charged phospholipids. Contrary to initial expectations based on simple electrostatics, we observe that positively charged nanoparticles bind to a larger extent to a purely zwitterionic bilayer compared to a mixed bilayer in which zwitterionic molecules are mixed with negatively charged molecules. Our results show that nanoparticle interactions with SLBs involve a complex interplay of interactions. We will discuss these and other studies aimed at elucidating the molecular-level interactions of nanoparticles with SLBs.

Influence of natural organic matter on the interaction of functionalized nanoparticles with supported lipid bilayers

248th National Meeting (2014)

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