AUTHOR=Ã…berg Christoffer , Jansen Alwin TITLE=Zeroth order model for the nanoparticle biomolecular corona JOURNAL=Frontiers in Nanotechnology VOLUME=Volume 7 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/nanotechnology/articles/10.3389/fnano.2025.1537076 DOI=10.3389/fnano.2025.1537076 ISSN=2673-3013 ABSTRACT=When nano-sized objects are introduced into biological systems they almost inevitably will be exposed to a compositionally complex fluid environment. It is a general observation that nanoparticles in such environments rapidly get covered by a biomolecular corona composed of proteins, lipids, and sugars that adsorb to the particle surface. While this phenomenon has been extensively studied from an experimental point of view, and to some extent also theoretically and computationally, we still lack a solid theoretical framework. Here we investigate the kinetics of corona formation, particle-to-particle variability in corona composition, and the spatial vicinity of different biomolecules in the corona. We do so under the assumptions that biomolecular adsorption occurs randomly, that adsorption is irreversible, and that there are no biomolecule-biomolecule interactions. We derive analytical formulae but also illustrate their outcomes using for experiments reasonable parameters. Overall, our results, derived under simplifying assumptions, are intended as useful reference points against which both experimental and more realistic computational and theoretical studies can be compared.