Modeling adsorption of colloids and proteins

Recent developments in the modeling of particle and protein adsorption kinetics on solid surfaces are discussed. Emphasis is focused on the coarse-grained methods, where protein molecules are treated as particles having a regular shape (spheres, spheroids) or a system of spherical beads of various sizes. Using such approaches hydrodynamic radii and diffusion coefficients of protein molecules are calculated in an exact way using the linear Stokes equation. Additionally, the surface blocking functions and jamming coverages for such molecule shapes are determined using the random sequential adsorption simulations. Theoretical results obtained in this way for various molecule shapes, including the bead models of fibrinogen are discussed. Knowing the jamming coverage and blocking functions one can formulate boundary conditions for bulk transport equations. Solutions of these equations for the convection and diffusion-controlled transport are presented. These theoretical predictions proved adequate for interpreting experimental data obtained for fibrinogen using AFM, ellipsometry and fluorescence methods. It is, therefore, concluded that these coarse grained approaches combined with solutions of the continuity equation can be efficiently used for quantitatively predicting protein adsorption kinetics for the time scale met under practical situations.