Fabrication of Multimodal Anion Exchange Membrane for Chromatographic Purification of Full Adeno‐Associated Viral Capsids

Abstract A multi‐modal anion exchange ligand 2‐methyl‐phenylimidazole has been successfully functionalized on highly porous electrospun regenerated cellulose membrane substrate for the separation of full and empty adeno‐associated viral (AAV) capsids. The functionalized membrane has an average pore size of 0.5 µm and exhibits both charge and hydrophobic functionality. The ligand is able to distinguish the subtle physio‐chemical differences between the full and empty viral capsids. The multi‐modal anion exchange membrane is able to separate the full capsids from affinity‐captured mammalian AAV2 using both gradient and two‐step elution methods with superior performance. A full capsid recovery of 72.9% at 85.3% purity with gradient elution, or 70.3% recovery at 92.2% purity with two‐step elution can be achieved at significantly higher viral capsid loading of ≈0.5‐1.3 × 10 14 particles mL −1 of membrane volume compared to previous studies. Moreover, AAV2 capsids demonstrate similar transduction efficiency before and after the purification with the functionalized membrane.