Quantification of Lipid Corona Formation on Colloidal Nanoparticles from Lipid Vesicles.

Formation of a protein corona around nanoparticles when immersed into biological fluids is well-known; less studied is the formation of lipid coronas around nanoparticles. In many cases, the identity of a nanoparticle-acquired corona determines nanoparticle fate within a biological system and its interactions with cells and organisms. This work systematically explores the impact of nanoparticle surface chemistry and lipid character on the formation of lipid coronas for 3 different nanoparticle surface chemistries (2 cationic, 1 anionic) on 14 nm gold nanoparticles exposed to a series of lipid vesicles of 4 different compositions. Qualitative (plasmon band shifting, ζ-potential analysis, dynamic light scattering on the part of the nanoparticles) and quantitative (lipid liquid chromatography/mass spectrometry) methods are developed with a "pull-down" scheme to assess the degree of lipid corona formation in these systems. In general, cationic nanoparticles extract 60-95% of the lipids available in vesicles under the described experimental conditions, while anionic nanoparticles extract almost none. While electrostatics apparently dominate the lipid-nanoparticle interactions, primary amine polymer surfaces extract more lipids than quaternary ammonium surfaces. Free cationic species can act as lipid-binding competitors in solution.