Restricted diffusion of molecules in porous affinity chromatography adsorbents

A restricted pore diffusion model is presented and employed as the principle theoretical tool to investigate salient characteristics of the permeability behavior of biologically active macromolecules in porous affinity chromatography media, when these large adsorbate molecules are adsorbed onto available vacant ligands immobilized therein. The contributions of steric hindrance at the entrance to the pores and frictional resistance within the pores to the overall restriction to pore diffusion, accompanied by the effects of pore size distribution, pore connectivity of the adsorbent, molecular dimension of adsorbate and ligand, and the fractional saturation of adsorption sites (ligands), are considered. Porous affinity matrices having dilute and high ligand concentrations are examined, and the permeability of the adsorbate in porous networks of connectivity nT is studied by means of effective medium approximation (EMA) numerical solutions. The detailed trends of the permeability of the adsorbate encountered in affinity adsorption systems of Porous Silica and Superose™ 6 with dilute and high ligand concentrations, are described and presented in numerous Tables. Results of this work may be of importance in studies involving the modeling, prediction of the dynamic behavior, design, and control of affinity chromatography (biospecific adsorption) adsorbents --Abstract, page iii