  It is now well accepted that cellular responses to materials in a biological
medium reflect greatly the adsorbed biomolecular layer, rather than the
material itself. Here, we study by molecular dynamic simulations the
competitive protein adsorption on a surface (Vroman effect), i.e. the
non-monotonic behavior of the amount of protein adsorbed on a surface in
contact with plasma as a function of contact time and plasma concentration. We
find a complex behavior, with regimes during which small and large proteins are
not necessarily competing between them, but are both competing with others in
solution. We show how the effect can be understood, controlled and inverted.
