Secondary feed filtration and storage conditions influence trace element availability and process performance at...

Area of Science:

• Biotechnology
• Bioprocess Engineering
• Cell Culture Technology

Background:

• Consistent performance of Chinese Hamster Ovary (CHO) cell cultures during process scale-up is crucial for biopharmaceutical manufacturing.
• Subtle changes in operational parameters, such as feed media handling, can significantly impact cell culture outcomes.
• Previous scale-up efforts have encountered challenges in maintaining cell viability and productivity.

Purpose of the Study:

• To investigate the impact of feed media filtration and storage on CHO cell culture performance during process scale-up.
• To identify the root cause of reduced titer and viable cell density observed at a 2000 L scale.
• To establish strategies for restoring and maintaining consistent cell culture performance during scale-up.

Main Methods:

• Comparative analysis of CHO cell culture performance at different scales (bench vs. 2000 L).
• Root cause analysis including trace element analysis of feed media.
• Evaluation of feed media storage conditions (temperature) and filtration steps (secondary sterile filtration).
• Implementation of process modifications (eliminating secondary filtration, optimizing storage).

Main Results:

• A 70% reduction in titer and a 25% decrease in peak viable cell density (VCD) were observed at the 2000 L scale.
• Trace element analysis revealed significant loss of copper (Cu2+) in feed media at the 2000 L scale.
• Copper loss was attributed to precipitation during storage and removal by secondary sterile filtration, leading to increased lactate accumulation.
• Optimizing feed media storage (2-8°C) and eliminating secondary filtration restored process performance at the 2000 L scale.

Conclusions:

• Feed media filtration and storage conditions critically influence micronutrient stability and availability, impacting CHO cell metabolism and productivity.
• Secondary sterile filtration, while intended for microbial control, can inadvertently alter feed composition and negatively affect cell culture outcomes.
• Thorough evaluation of feed media stability, filtration, and storage strategies is essential for ensuring consistent bioreactor performance across manufacturing scales.