Adsorption of Myoglobin and Corona Formation on Silica Nanoparticles

Abstract

The adsorption of proteins from aqueous medium leads to the formation of protein corona on nanoparticles. The formation of protein corona is governed by a complex interplay of protein−particle and protein−protein interactions, such as electrostatics, van der Waals, hydrophobic, hydrogen bonding, and solvation. The experimental parameters influencing these interactions, and thus governing the protein corona formation on nanoparticles, are currently poorly understood. This lack of understanding is due to the complexity in the surface charge distribution and anisotropic shape of the protein molecules. Here, we investigate the effect of pH and salinity on the characteristics of corona formed by myoglobin on silica nanoparticles. We experimentally measure and theoretically model the adsorption isotherms of myoglobin binding to silica nanoparticles. By combining adsorption studies with surface electrostatic mapping of myoglobin, we demonstrate that a monolayered hard corona is formed in low salinity dispersions, which transforms into a multilayered hard + soft corona upon the addition of salt. We attribute the observed changes in protein adsorption behavior with increasing pH and salinity to the change in electrostatic interactions and surface charge regulation effects. This study provides insights into the mechanism of protein adsorption and corona formation on nanoparticles, which would guide future studies on optimizing nanoparticle design for maximum functional benefits and minimum toxicity.

SARS-CoV-2 virion physicochemical characteristics pertinent to abiotic substrate attachment

“…Considering this and the fact that the spike protein molecules are oriented with the top part exposed to the bulk solution one can deduce that the effective zeta potential of the virion should be positive, which can enhance its affinity to model surfaces used in experiments such as mica,[ 29 ] and to typical fomite surfaces, for example silica, cellulose fibers, etc. [ [30] , [31] , [32] , [33] ], which are often negatively charged. On the other hand, the middle and lower parts of the protein are negatively charged, which ensure its stabilization and prevents cluster formation, as shown experimentally in Ref.…”

Structural Alterations of Antigens at the Material Interface: An Early Decision Toolbox Facilitating Safe-by-Design Nanovaccine Development

“…From all these data, it can be concluded that the conjugation efficiency of allergens with both candidate NPs is quite different. From previous reports, Alhydrogel ® adsorbs proteins dominantly through ligand exchange and by electrostatic interactions [ 29 ], whereas SiO 2 NPs adsorb proteins mainly by hydrophobic and electrostatic forces [ 30 , 31 ]. As both model allergens have a pI of around 5 (Bet v 1, 5.4; BM4, 5.6), they exhibit a negative net charge at pH 7.4 [ 32 ].…”

Solution NMR of Nanoparticles in Serum: Protein Competition Influences Binding Thermodynamics and Kinetics

“…Dynamic light scattering (DLS) is a non-invasive technique that relates the mean particle size to the timescale of fluctuations in light scattered from the nanoparticles. In protein-binding experiments, the formation of a protein corona will lead to an increase in the apparent hydrodynamic diameter (D H ) of the nanoparticles (Piella et al, 2017;Lee et al, 2020;McClain et al, 2020). When GB3 or FBS proteins saturate the AuNP surface, the D H observed by DLS increases from 18.3 ± 0.4 nm (bare AuNP) to 24.3 ± 0.1 and 34.3 ± 0.4 nm, respectively (Figure 1B).…”

“…Understanding this physiological response is predicated on the physical chemistry of proteinnanoparticle interactions, especially in the context of complex biological fluids. Multiple techniques exist to monitor thermodynamics and kinetics of binding for purified proteins on a uniform population of nanoparticles; however, this type of reductionist approach may not always work (Lacerda et al, 2010;Lee et al, 2020). Specifically, multiple studies have found that the binding affinity of an individual protein fails to predict its composition in the final protein corona formed in a mixture (Monopoli et al, 2011;Zhang et al, 2019).…”