Quantification of Lipid Corona Formation on Colloidal Nanoparticles from Lipid Vesicles

Formation of a protein corona around nano particles 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, zeta-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.