Perfusion Seed Culture for High-Density Fed-Batch Bioproduction
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Solution Overview
Problem
Traditional batch or fed-batch production processes in bioreactor systems struggle to achieve high viable cell densities in the N-1 seed train stage, leading to inefficient production durations and reduced volumetric productivity.
Innovation Solution
Implement nutrient supplementation and/or waste product removal, combined with a perfusion cell culture process in the N-1 seed train bioreactor, to attain high viable cell densities, enabling higher seeding densities in the production bioreactor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional batch or fed-batch production processes are used, then the production process is simple to operate, but the volumetric productivity is low and production duration is extended
Solution Approach 1:
The invention applies preliminary action by conducting intensive cell growth in the N-1 seed train stage before production, achieving high viable cell densities (≥25×10^6 cells/ml) in advance. This allows the production bioreactor to start with high seeding densities, immediately entering the productive stationary phase without a prolonged unproductive growth phase, thereby increasing volumetric productivity and reducing production duration.
Solution Approach 2:
The invention changes key process parameters by implementing perfusion culture in the N-1 stage with specific perfusion rates (0.01-0.2 nL/cell/day) and controlling metabolic waste accumulation. This parameter change enables sustained high cell densities and improves cell health, leading to faster productivity onset in the production stage.
2Quantity of substance
If traditional batch or fed-batch N-1 seed train cultures are used, then the process is easy to manufacture, but high viable cell densities cannot be sustained
Solution Approach 1:
The invention uses perfusion culture as an intermediary process between traditional batch culture and production. The perfusion system acts as a mediator that enables sustained high viable cell densities by continuously removing metabolic waste and supplementing nutrients, bridging the gap between simple batch culture and the requirement for high cell densities without excessive manufacturing complexity.
Solution Approach 2:
The invention applies continuity of useful action through perfusion culture in the N-1 stage, where nutrients are continuously supplied and metabolic waste is continuously removed. This continuous action sustains high viable cell densities and maintains cell health throughout the seed train phase, enabling the achievement of ≥25×10^6 cells/ml without the limitations of discrete batch feeding.
3Productivity
If the growth phase is shifted to the N-1 seed train stage, then production bioreactor utilization improves, but achieving high viable cell densities in N-1 becomes difficult
Solution Approach 1:
The invention implements feedback control by monitoring cell density, metabolic waste levels, and nutrient consumption in the N-1 perfusion culture. This feedback enables dynamic adjustment of perfusion rates and feed composition to maintain optimal conditions for achieving and sustaining high viable cell densities, ensuring reliable production bioreactor utilization.
Solution Approach 2:
The invention changes physical and chemical parameters of the N-1 culture by implementing controlled perfusion at specific rates (0.01-0.2 nL/cell/day) and adjusting media composition. These parameter changes create optimal conditions for sustained high cell densities, making the shift of growth phase to N-1 stage reliable and reproducible.
Data Source
AI summary
Methods of improving the efficiency of production of a protein product of interest in mammalian cell culture are presented. In particular, the methods result in an increase in the quantity of a protein product produced, or decreases protein product production time in a manufacturing-scale bioreactor cell culture. The disclosed methods comprise: (a) culturing the N-1 bioreactor culture to high viable cell densities; and (b) seeding the production bioreactor culture at high viable cell seeding densities.