Modeling of immunoglobulin uptake by N,N,N′,N′-ethylenediaminetetramethylenephosphonic acid-modified zirconia particles under static and dynamic conditions

Authors

Sabyasachi Sarkar, Department of Chemical and Biomolecular Engineering, University of Nebraska, 207 Othmer Hall, 820 North 16th Street, Lincoln, NE 68588, USA
Anuradha Subramanian, Department of chemical Engineering,University of Nebraska Lincoln.Follow

Date of this Version

5-24-2005

Comments

Published in Journal of Chromatography B 821:1 (July 5, 2005), pp. 81-87 doi 10.1016/j.jchromb.2005.04.002 Copyright © 2005 Elsevier B.V. Used by permission.

Abstract

A matrix developed from N,N,N′,N′-ethylenediaminetetramethylenephosphonic acid-modified zirconia beads (further referred to as r_PEZ); 25–38 μm in diameter and with a pore size of 22 ± 3 nm, was utilized for the separation of immunoglobulins (Igs). r_PEZ has been shown to bind to various Igs originating from a wide variety of species. To understand the mechanisms controlling the uptake of Igs by r_PEZ, static protein uptake experiments were carried out. The protein uptake profiles were further modeled with a kinetic rate constant model. Individual studies were undertaken for human immunoglobulin A, G and M (HIgA, HIgG and HIgM). The kinetic rate constant model indicated that HIgG binding to r_PEZ was more favorable than its disassociation. The equilibrium rate constants were found to decrease with increasing concentration. The effect of continuous loading in a packed bed system utilizing r_PEZ matrix was evaluated by carrying out frontal studies, using different feed concentrations and linear velocities. The breakthrough profiles obtained for the uptake of HIgG were modeled with the pore diffusion model. The model was found to best describe the breakthrough profiles obtained at a feed concentration of 2.0 mg of HIgG per milliliter. The NTU for the packed bed was found to be equal to 2.