Optical sensor enabled rocking T-flasks as novel upstream bioprocessing tools

Authors

  • Jose R. Vallejos,

    1. Center for Advanced Sensor Technology, Department of Chemical, Biochemical and Environmental Engineering, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250; telephone: 410-455-3415; fax: 410-455-1049
    Current affiliation:
    1. Martek Biosciences Corporation (a DSM Nutritional Lipids Division), Kingstree, SC.
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  • Martina Micheletti,

    1. The Advanced Centre for Biochemical Engineering, Department of Biochemical Engineering, University College London, Torrington Place, London, UK
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  • Kurt A. Brorson,

    1. Office of Biotechnology Products, Center for Drug Evaluation and Research, Food and Drug Administration, Silver Spring, Maryland
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  • Antonio R. Moreira,

    1. Center for Advanced Sensor Technology, Department of Chemical, Biochemical and Environmental Engineering, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250; telephone: 410-455-3415; fax: 410-455-1049
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  • Govind Rao

    Corresponding author
    1. Center for Advanced Sensor Technology, Department of Chemical, Biochemical and Environmental Engineering, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250; telephone: 410-455-3415; fax: 410-455-1049
    • Center for Advanced Sensor Technology, Department of Chemical, Biochemical and Environmental Engineering, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250; telephone: 410-455-3415; fax: 410-455-1049.
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Abstract

During the past decade, novel disposable cell culture vessels (generally referred to as Process Scouting Devices or PSDs) have become increasingly popular for laboratory scale studies and seed culture generation. However, the lack of engineering characterization and online monitoring tools for PSDs makes it difficult to elucidate their oxygen transfer capabilities. In this study, a mass transfer characterization (kLa) of sensor enabled static and rocking T-flasks is presented and compared with other non-instrumented PSDs such as CultiFlask 50®, spinner flasks, and SuperSpinner D 1000®. We have also developed a mass transfer empirical correlation that accounts for the contribution of convection and diffusion to the volumetric mass transfer coefficient (kLa) in rocking T-flasks. We also carried out a scale-down study at matched kLa between a rocking T75-flask and a 10 L (2 L filling volume) wave bioreactor (Cultibag®) and we observed similar DO and pH profiles as well as maximum cell density and protein titer. However, in this scale-down study, we also observed a negative correlation between cell growth and protein productivity between the rocking T-flask and the wave bioreactor. We hypothesize that this negative correlation can be due to hydrodynamic stress difference between the rocking T-flask and the Cultibag. As both cell culture devices share key similarities such as type of agitation (i.e., rocking), oxygen transfer capabilities (i.e., kLa) and disposability, we argue that rocking T-flasks can be readily integrated with wave bioreactors, making the transition from research-scale to manufacturing-scale a seamless process. Biotechnol. Bioeng. 2012;109: 2295–2305. © 2012 Wiley Periodicals, Inc.

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