Model lipid bilayers mimic non-specific interactions of gold nanoparticles with macrophage plasma membranes.

Understanding the interaction between nanomaterials and biological interfaces is a key unmet goal that still hampers clinical translation of nanomedicine. Here we investigate and compare non-specific interaction of gold nanoparticles (AuNPs) with synthetic lipid and wild type macrophage membranes. A comprehensive data set was generated by systematically varying the structural and physicochemical properties of the AuNPs (size, shape, charge, surface functionalization) and of the synthetic membranes (composition, fluidity, bending properties and surface charge), which allowed to unveil the matching conditions for the interaction of the AuNPs with macrophage plasma membranes in vitro. This effort directly proved for the first time that synthetic bilayers can be set to mimic and predict with high fidelity key aspects of nanoparticle interaction with macrophage eukaryotic plasma membranes. It then allowed to model the experimental observations according to classical interface thermodynamics and in turn determine the paramount role played by non-specific contributions, primarily electrostatic, Van der Waals and bending energy, in driving nanoparticle-plasma membrane interactions.