(156c) The Effects of Membrane Surface Properties on the Clarification of Viral Capsids

While recombinant Adeno Associated Virus (AAV) is one of the most promising delivery systems for gene therapy treatments, only a few AAV-based therapeutics are currently FDA-approved. One of the significant challenges in the commercialization of these virus particle-based therapeutics is inefficient purification operations. The ratio of empty to full particles can be as high as 10:1. Naturally occurring empty particles potentially reduce the effectiveness of the therapy by competing for cell- mediated processes and serving as impurities that frequently lead to stronger immune responses. Current purification methods tend to be inefficient at removing empty and defective virus particles. Full, empty or defective virus particles display somewhat different hydrophobicity and isoelectric points (pIs). This difference arises partly from the effect of the encapsulated negatively-charged DNA on the overall particle charge. Here membrane surfaces of different properties are fabricated and investigated for the clarification of AAV lysate. The enrichment of full capsids over empty ones by membranes with different surface properties at different buffer and filtration conditions is determined. Moreover, the effects of surface properties on membrane performance in terms of throughput and AAV recovery are also investigated.