A real-time oxygen uptake rate monitoring approach suitable for the antibody production process

Abstract

Significant progress has been achieved in large-scale mammalian cell culture technology for biotherapeutics manufacturing over the past decades, necessitating the Process Analytical Technology (PAT) for the real-time measurement of critical quality attributes and the guidance for precise process control to ensure productivity, quality, and consistency. The Oxygen Uptake Rate (OUR) serves as a crucial indicator for characterizing the energy metabolism of mammalian cells, offering insights into cellular state and metabolism dynamics. However, current cellular OUR monitoring in antibody production depends mainly on costly gas analyzers or periodic manual sampling. Here, we introduce a novel method for in-line monitoring of cellular OUR in bioreactors based on the stationary liquid phase balance (SLPB) theory, which extends its applicability to diverse aeration and foam conditions without additional equipment or labor expenditures. We modeled the kLa of the aerated stirred bioreactor, assessed the influence of foam on liquid surfaces induced by gas sparging on oxygen transfer, and processed raw OUR data using a sliding filter. The established method was applied to monitoring the real-time OUR of Chinese Hamster Ovary (CHO) cell cultures for antibody production, demonstrating its excellent accuracy, sensitivity and readability. Aligned with the Quality by Design (QbD) concept, this real-time OUR estimation enables rapid detection of metabolic changes, revealing cellular physiology and facilitating precise feedback control in biotherapeutics manufacturing.