Electrospun Hydrophobic Interaction Chromatography (HIC) Membranes for Protein Purification

Abstract

Responsive membranes for hydrophobic interaction chromatography have been fabricated by functionalizing poly(N-vinylcaprolactam) (PVCL) ligands on the substrate of electrospun regenerated cellulose nanofibers. Both static and dynamic binding capacities and product recovery were investigated using bovine serum albumin (BSA) and Immunoglobulin G (IgG) as model proteins. The effects of ligand chain length and chain density on static binding capacity were also studied. A static binding capacity of ~25 mg/mL of membrane volume (MV) can be achieved in optimal ligand grafting conditions. For dynamic binding studies, protein binding capacity increased with protein concentration from 0.1 to 1.0 g/L. Dynamic binding capacity increased from ~8 mg/mL MV at 0.1 g/L BSA to over 30 mg/mL at 1.0 g/L BSA. However, BSA recovery decreased as protein concentration increased from ~98% at 0.1 g/L BSA to 51% at 1 g/L BSA loading concentration. There is a clear trade-off between binding capacity and recovery rate. The electrospun substrate with thicker fibers and more open pore structures is superior to thinner fibrous membrane substrates.

Aggregate Removal by Responsive Electrospun Membrane based Hydrophobic Interaction Chromatography

“…Since the feed is pumped by convective flow through the membrane pores, pore diffusional resistances are minimized. Further membrane modules scale linearly unlike packed beds which are often difficult to scale up [22][23][24]. Numerous previous studies describe the use of membrane based HIC for protein purification [25][26][27][28][29][30][31].…”