Bioprocess optimization for cell-based therapies is a resource heavy
activity. To reduce the associated cost and time, it is advantageous to
carry out process development in small volume systems, with the caveat
that such systems be predictive for process scaleup. The transport of
oxygen from the gas phase into the culture medium, characterized using
the volumetric mass transfer coefficient, kLa, has been
identified as a critical parameter for predictive process scaleup. In
both large- and small-scale bioreactors, kLa is
controlled via mixing, with the method employed dependent upon the size
of the reactor. However, existing microplate bioreactor platforms,
beneficial for their low working volumes and throughput and automation
capabilities, struggle to achieve desired kLa for
mammalian cell cultures. Here, we describe the development and testing
of a 96-well microplate with integrated Redbud Posts to provide mixing
and thus enhanced kLa. Mixing characteristics were
investigated, with actuating Redbud Posts shown (visually) to increase
convective transport while producing enhanced kLa,
providing means to mimic macroscale mammalian cell growth conditions at
the microscale. Improved cell growth rates with mixing was demonstrated
for two cell types, indicating the potential for this technology to play
a valuable role in early stage bioprocess development and optimization.