Quantitative Modeling of Fibrinogen Adsorption on Different Biomaterials

Abstract

Adsorption processes of biological macromolecules on solid surfaces, e.g. on implant materials, are of scientific, medical and technological interest. The adsorption process of the blood plasma protein fibrinogen from aqueous solutions on biomaterial surfaces is simulated by solving the diffusion equation in one dimension in combination with a two dimensional cellular automaton model. The adsorption/desorption kinetics of fibrinogen on different metallic biomaterials is tracked until a dynamic equilibrium is reached. In addition to mass transfer towards the surface, adsorption of fibrinogen molecules and surface diffusion of single fibrinogen molecules and clusters the algorithm also accounts for the desorption of single molecules. By varying the desorption behavior in the simulation calculation, the equilibrium surface coverage changes in the range of 0.2–0.85, implying more flexible and higher surface coverage than previous models. The influences of surface properties of the biomaterials and of the initial concentration of fibrinogen on the adsorption process are quantified. Experimental results from the literature on fibrinogen adsorption kinetics are compared with our simulation results and illustrate good quantitative agreement that is only achievable using desorption as essential model component.