Fibrinogen Immobilization Behavior on a Planar Polyelectrolyte Brush

Abstract

We investigated human plasma fibrinogen (HPF) immobilization onto a planar sodium polystyrene sulfonate (NaPSS) brush in a protein aqueous solution. The saturated amount and time constant of the phenomenon were measured using time-resolved attenuated total reflection (ATR) UV absorption technique. The static and kinetic behavior were revealed to depend on the salt concentration in the protein solution. The results indicate that the immobilization is driven by the entropic effect and coulombic interaction, in contrast to previous reports for micellar PEB that the entropic effect is dominant. The immobilization mechanism identified in this work is independent of the molecular species and is applicable for any combination of protein and planar PEB with the same sign of charge in water, which is consistent with the nonspecific immobilization of proteins onto various PEB that has been reported to date.