Fabrication and characterization of a cellulose monolith-like particle for virus purification

Monolith-like particles (MLP) are a new base bead architecture optimized for industrial chromatographic downstream processing of very large targets such as whole viral particles (5–300 nm diameter). They have been designed with large pore size though-channels to facilitate access of large diameter targets to the intraparticle chromatographic surface. Herein we describe a novel MLP bead architecture that have been fabricated and characterized for virus purification. This is the first study to demonstrate cellulose-based MLP beads applied for bioseparation of viral particles. The MLP was produced from cellulose acetate by a combined concept of thermally induced phase separation and oil-in-water emulsification. Hydrolyzation, cross-linking, and surface modification with dextran sulfate were carried out for pseudo-affinity chromatographic applications. Scanning electric microscopy analysis showed the presence of large pores that penetrated from the outer surface to within the intraparticle structure. Mercury intrusion porosimetry analysis estimated the mode pore radius to be 1.5 µm. For influenza A virus purification, the MLP surface modified with dextran sulfate exhibited significant higher dynamic binding capacity compared with commercial resins, Cellufine Sulfate and Capto DeVirS. These results demonstrate that viral particles can access the intraparticle surface within these novel large through-pore MLP beads. The novel MLP base architecture described in this study will be a useful support matrix for giant biomolecule and whole viral particle purification.