(369d) Functionalized Electrospun Fibrous Membranes for Bioreactor Harvesting

The bioreactor harvesting operations sometimes known as ‘mid-stream’ operations involve a combination of unit operations. Combinations of centrifugation, depth filtration and tangential-flow filtration (TFF) are often used to remove the cells, cell debris, and other impurities. While TFF is very amenable to continuous operation, membrane fouling is a major concern. Recombinant proteins are typically excreted to the medium by cultured cells whereas most virus particles are enclosed in the cells which requires cell lysis during production. As a result, large amounts of cell debris, host cell protein (HCP) and DNA are present in viral vector feedstock making bioreactor harvesting process significantly more challenging. Electrospun fibrous membranes generally have a more open structure and can be tailored to have a large pore size and high porosity. Here regenerated cellulose (RC) electrospun membranes have been fabricated for viral vector harvesting. The effects of fabrication conditions including polymer concentration, voltage applied, distance between needle and collecting plate as well as needle size on the properties of fabricated membrane and subsequently on adeno-associated virus (AAV) particle harvesting are investigated. Critical flux, throughput, impurity removal, turbidity reduction and product yield of electrospun fibrous membranes for AAV harvesting are determined. The effects of surface functionalization with tertiary and quarternary amines on AAV clarification are also investigated.