Understanding Biomolecules Diffusion for Continuous Vaccine Manufacturing

Increasing the availability of vaccines by reducing manufacturing costs is a key strategy to reduce global disease burden. Batch processing is a common method in vaccine manufacturing, but it could be improved by moving to continuous manufacturing, which has been shown to reduce capital and operating costs. One method to continuously purify viral vaccines is by using an aqueous two-phase system (ATPS), which is readily operated in continuous mode and is shown to recover up to 80% of infectious viruses. This system must be scaled up to an industrial setting, and to do so, the behavior of viral mass transport, which includes its diffusion, is key to understanding the system. For this study, we quantified porcine parvovirus and bovine serum albumin dynamics by measuring their diffusion in various compositions of polyethylene glycol – sodium citrate ATPS to measure their diffusion coefficients. The biomolecules were tagged with a fluorescent dye, and the rate of diffusion in the bulk phases of ATPS was observed in a microchannel. Image analysis using a Python code determined the diffusion coefficient of each molecule. These values will be critical to determining optimal mixing to achieve maximum recoveries in industrial vaccine manufacturing.