Characterization of black carbon and silica nanoparticle interactions with human plasma proteins

The tiny particles of atmospheric ultrafine particles (PM0.1) will rapidly bind with large amounts of proteins to form a protein corona when entering human blood. However, PM0.1 is a highly heterogeneous mixture. Do different insoluble particles in PM0.1 have different adsorption behaviors for proteins? In this work, we investigated the adsorption of plasma proteins on black carbon nanoparticles (BC NPs) and silica nanoparticles (SiO2 NPs) which represented the airborne particles from different sources. It was found that the BC NPs and SiO2 NPs adsorbed plasma proteins to form protein coronas, thereby changing the hydrated particle size and the surface charge of these two NPs. The composition of the protein coronas had some commonalities but also differences. The interactions between the NPs and the corona proteins were mainly dependent on the abundance of proteins in the plasma. Four main proteins (human serum albumin, fibrinogen, apolipoprotein A-I, and immunoglobulin G) were adopted to investigate the effects on the protein secondary structure induced by the NPs. The results concluded that electrostatic interactions might play a key role in adsorption-induced structural changes. The findings of this research highlighted that there were differences in the protein corona formed by different insoluble particles in PM. There is an urgent need to understand the impact of particle variability on the overall toxicity assessment of PM.