Hydrodynamic phenomena in microcarrier cultures are investigated with regard to the development of improved reactor designs for large‐scale operations. New concepts and theoretical models that describe new data as well as previously published data are presented.

Continuous production of biologics, a growing trend in the biopharmaceutical industry, requires a reliable and efficient cell retention device that also maintains cell viability. Current filtration methods, such as tangential flow filtration using hollow-fiber membranes, suffer from membrane fouling, leading to significant reliability and productivity issues such as low cell viability, product retention, and an increased contamination risk associated with filter replacement. We introduce a novel cell retention device based on inertial sorting for perfusion culture of suspended mammalian cells. The device was characterized in terms of cell retention capacity, biocompatibility, scalability, and long-term reliability. This technology was demonstrated using a high concentration (>20 million cells/mL) perfusion culture of an IgG1-producing Chinese hamster ovary (CHO) cell line for 18–25 days. The device demonstrated reliable and clog-free cell retention, high IgG1 recovery (>99%) and cell viability (>97%). Lab-scale perfusion cultures (350 mL) were used to demonstrate the technology, which can be scaled-out with parallel devices to enable larger scale operation. The new cell retention device is thus ideal for rapid perfusion process development in a biomanufacturing workflow.

Hydrodynamic phenomena in microcarrier cultures are investigated with regard to the development of improved reactor designs for large-scale operations. New concepts and theoretical models that describe new data as well as previously published data are presented.

Results are presented which show how the microcarrier concentration affects the hydrodynamic environment in animal cell bioreactors. At low levels of agitation, no physical effects of microcarrier concentration were found. However, cell growth was strongly influenced by cell concentration. At high levels of agitation, a strong detrimental effect of microcarrier concentration was found. A new mechanism of hydrodynamic damage was identified which is second order in microcarrier concentration. The identification of this mechanism adds to the fundamental understanding of hydrodynamic phenomena in microcarrier bioreactors.

Removing nonviable cells from a cell suspension is crucial in biotechnology and biomanufacturing. Labelfree microfluidic cell separation devices based on dielectrophoresis, acoustophoresis, and deterministic lateral displacement are used to remove nonviable cells. However, their volumetric throughputs and test cell concentrations are generally too low to be useful in typical bioreactors in biomanufacturing. In this study, we demonstrate the efficient removal of small (<10 μm) nonviable cells from bioreactors while maintaining viable cells using inertial microfluidic cell sorting devices and characterize their performance. Despite the size overlap between viable and nonviable cell populations, the devices demonstrated 3.5-28.0% dead cell removal efficiency with 88.3-83.6% removal purity as well as 97.8-99.8% live cell retention efficiency at 4 million cells per mL with 80% viability. Cascaded and parallel configurations increased the cell concentration capacity (10 million cells per mL) and volumetric throughput (6-8 mL min −1). The system can be used for the removal of small nonviable cells from a cell suspension during continuous perfusion cell culture operations.