Continuous perfusion culture of encapsulated hybridoma cells

Background: The production of Monoclonal antibodies (mAbs) is often performed in batch or fed-batch operations where low cell densities and low volumetric productivities are achieved. The main bottleneck of both processes is the short operating time with productive cells at maximum cell concentration. Results: The process studied in this work is based on a fluidized-bed bioreactor culture of encapsulated KB26.5 cells in a liquid core of calcium alginate microcapsules as a culture strategy to produce IgG₃. First, DMEM medium was modified in order to protect the microcapsules from degradation, and later, the optimal operating conditions were set. Under these conditions encapsulated KB26.5 cells reached cell densities of 1.05 × 10⁸cells mL^-1 or 9.8 × 10⁶ cells mL^-1 (referred to the inner capsule volume or total bioreactor volume, respectively), and a mAb volumetric productivity of 2.75 μg mL^-1 h^-1. Conclusions: The productivity of encapsulated KB26.5 cells in perfusion culture was enhanced significantly in comparison with batch and fed-batch processes. Continuous operation of the perfusion culture for periods longer than 35 days, represented a volumetric productivity about five-fold higher than conventional operations. However, the fluidized-bed also showed limitations such as low cell viability at high cell densities due to the mass transfer limitations of large molecules inside the microcapsules.