Computer modelling of the adsorption of proteins on solid surfaces under the influence of double layer and van der waals energy

Abstract

The study of protein interactions with surfaces is important in many branches of biomedical engineering. A computer model has been set up in order to aid the understanding and prediction of the likelihood of protein adsorption at a surface and of coagulation between two proteins. In this model, a protein is represented as a hard sphere, neglecting conformation changes which may occur during the adsorption process. The sphere is assumed to be in a medium whose properties are described by the ionic strength, the pH and the dielectric permittivity. It is considered to interact both with an infinite plane, representing the surface, and with another sphere, representing another protein. The model focuses on the total interaction energy between a protein and a surface and between two proteins. The energy is expressed according to the DLVO theory of colloidal stability, which assumes that the adsorption behaviour of proteins at a surface depends, first, on the van der Waals interactions energy and, second, on the electrostatic double layer interaction energy. The conditions under which adhesion is prevented correspond to the presence of local extremes of the energy function, whereas the conditions under which adhesion is likely to take place correspond to absence of local extremes.

Hollow Fibre Membrane Oscillations Against Fouling Process – a Numerical Study

“…The Debye length is equal to 2.5 nm (value computed for the ionic strength equal to 0.01 mol/dm 3 ). The particle and surface potential are set as control parameters and in our simulation vary between -25 mV and +25 mV as these values are reported in literature to be the limits of applicability of classical DLVO theory (Ruggiero et al, 1999;Senger et al, 1994). Equation (5) has been solved numerically for every particle by means of Verlet scheme.…”

“…This formula has been chosen as recommended for the interactions between two spheres at relatively small distances (Parsegian, 2006;Ruggiero et al, 1999;Senger et al, 1994).…”

Towards a Numerical Model of Bacterial Filtration in Fibrous Filters

“…if a collision results in bacterium deposition or not) and the re-entrainment rate. In most papers, the interactions between bacteria and solids are described with the DLVO/XDLVO model (Derjaguin and Landau, 1941;Ruggiero et al, 1999;Verwey and Overbeek, 1948). However, findings (obtained with the model) were repeatedly reported to have failed to agree with experimental data.…”

Computational Analysis of Displacement of Particles with Given Size on the Nonstationary Bulging Membrane as a Theoretical Model of Membrane Fouling

“…The double layer potential and force for the interaction between sphere and hemisphere have the same form as (3) and (4) with the particle radius R replaced by 2 1 2 1 R R R R + (Ruggiero et al, 1999). Fig.…”