(184s) Diffusion of Viral Vectors Informs Continuous Manufacturing with Aqueous Two-Phase Extraction

Continuous biomanufacturing is just around the corner but many traditional unit operations are struggling to adapt quickly. That is why we recently developed a multi-step continuous purification platform for viral vectors using aqueous two-phase systems (ATPS). Recoveries of up to 80% of infectious titer, multiple log removal of host cell protein, and consistent performance among enveloped and non-enveloped viruses make it a robust tool for vaccine or gene therapy manufacturing. An economic analysis of our ATPS-based process shows a 90% reduction in capital costs and 50% lower operating cost compared to traditional chromatography-based manufacturing. During this development, a strong dependence on mass transport related to mixing and settling was observed. To speed optimization for new viral vectors, parameters describing this separation process are needed. In this work, diffusion coefficients in each aqueous phase and mass flux across the ATPS interface are measured for protein and virus to determine the contributions of diffusion during the separation. A Y-channel microdevice allows capture of real-time diffusion using fluorescently labeled particles and comparison with calculated models in COMSOL Multiphysics software is used to identify transport parameters. These results will inform scale up of ATPS purification steps as we continue toward demonstrating fully continuous end-to-end viral vector manufacturing.