Computational and experimental characterizations of silver nanoparticle-apolipoprotein biocorona.

With the advancement of nanotoxicology and nanomedicine, it has been realized that nanoparticles (NPs) interact readily with biomolecular species and other chemical and organic matter to result in biocorona formation. The field of the environmental health and safety of nanotechnology, or NanoEHS, is currently lacking significant molecular-resolution data, and we set out to characterize biocorona formation through electron microscopy imaging and circular dichroism spectroscopy that inspired a novel approach for molecular dynamics (MD) simulations of protein-NP interactions. In our present study, we developed a novel GPU-optimized coarse-grained MD simulation methodology for the study of biocorona formation, a first in the field. Specifically, we performed MD simulations of a spherical, negatively charged citrate-covered silver nanoparticle (AgNP) interacting with 15 apolipoproteins. At low ion concentrations, we observed the formation of an AgNP-apolipoprotein biocorona. Consistent with the circular dichroism (CD) spectra, we observed a decrease in α-helices coupled with an increase in β-sheets in apolipoprotein upon biocorona formation.