Viable cell density as an indicator for dynamic feeding strategy in fed-batch and perfusion CHO cell culture.

The general approach to industrial production of monoclonal antibodies is fed-batch culture using Chinese Hamster Ovary (CHO) cells. Perfusion culture is also attracting attention as a next-generation culture method. In these culture methods, optimization of amino acid and glucose concentration in the culture medium is essential, and influences cell proliferation, viability, productivity, and monoclonal antibody quality. Further, the maintenance of optimal nutrient levels - by avoiding both depletion and accumulation - is crucial. This study aimed to develop a dynamic feeding strategy based on specific indicators to maintain optimal amino acid and glucose concentrations. Multivariate correlation analysis confirmed a strong relationship between nutrient consumption and viable cell density (VCD). Regression analysis was used to establish a regression model to estimate amino acid and glucose consumption based on VCD. Using this model, the nutrient composition of feed media for both fed-batch and perfusion cultures was adjusted, and a dynamic feeding strategy guided by VCD was evaluated. The observed nutrient concentration trends closely matched the model's predictions, confirming that VCD is a reliable indicator for implementing dynamic feeding. In both fed-batch and perfusion cultures, the VCD-guided dynamic feeding strategy enables the maintenance of multiple amino acids and glucose at target concentrations.