(293a) Continuous Cell Production Using a Multiphase Bioreactor with Optimized Spiroid

Due to their broad applications in cell-based therapy and bioprocessing, bioreactors have become indispensable tools for cell culture. Various bioreactors are used to maintain well-controlled environments for cell growth, but oxygen transfer is a limiting factor. With the increase in single-use bioreactors, cell production and quality are limited. The advantages of continuous bioprocessing include sustained production and consistent product quality. Traditional bioreactors use impellers for enhancing cell production which causes increased shear stress. Hence, the goal is to enhance cell production and quality with low shear and continuous operation.

The focus of the current research is to enhance cell production using a low-shear continuous bioreactor with an internal spiroid providing enhanced mixing and oxygen transfer for improved cell viability. The spiroid is embedded in the cylindrical wall of the bioreactor to increase oxygen transfer to the liquid phase which fills two-thirds of the bioreactor. The bioreactor is a horizontal cylinder rotated on a roller bed. The rotation rate of the reactor can be adjusted to control the flow of gas and liquid in the spiroid. When the partially filled reactor is rotating, the spiroid picks up slugs of gas and liquid near the reactor exit and delivers them to the reactor entrance. Thus, the spiroid increases gas-liquid contact areas in the reactor to increase oxygen mass transfer. The bioreactor is fabricated by rapid prototyping and can be operated in either batch or continuous modes with inlet flows via rotary unions available to provide medium and oxygen and outlet flows for waste and in-line analysis. Saccharomyces cerevisiae was cultured in the reactor to validate the effect of the spiroid on cell growth. Cell growth was monitored at different operating conditions using a spectrophotometer. Results show that Saccharomyces cerevisiae could be cultured for more than 12 hours continuously at steady state. The reactor with spiroid produced higher concentration at high rotation rates and at low medium flow rates in both batch and continuous modes indicating the efficiency of the spiroid for enhanced production. With the results obtained from these experiments, the reactor was further modified and prototyped using 3D printing to optimize cell production for different cell lines. Growth curves were generated for these cell lines, and the biomass production increased. Computational fluid dynamic simulation models were generated for the cell lines and were in good agreement with the experimental results. These results were compared to published results and indicate that the reactor with a spiroid has a greater potential in increasing cell production.