Seed train intensification aims to generate ultra high-density cell cultures at optimal points during cell expansion using a robust cell retention device, such as the XCell ATF® Device, prior to the inoculation of the production bioreactor.
Traditional Seed Train
The purpose of a seed train is the generation of an adequate number of cells for the inoculation of a production bioreactor. The cells are usually run through many cultivation systems which become larger with each passage (e.g. T-flasks, roller bottles or shake flasks, small scale bioreactor systems and subsequently larger bioreactors). The production bioreactor (N stage) is inoculated out of the largest seed train scale.
Challenges
- 3-4 weeks to production bioreactor
- Multiple steps, some require open handling
- Seed variability creates scheduling risk and/or output variablity
8 steps
42 days to product
28 days to N
14 days in N stage
intensified seed Train
Intensified seed trains perform process intensification, using a cell retention device such as the XCell ATF® Device, at optimal points during cell expansion to attain the highest cell density inoculum for the production (N) bioreactor. Seed train intensification promotes flexibility and scalability, allowing small labs and global players alike to grow the exact amount of cell culture required, irrespective of whether they are needed for a clinical study, a new therapy or a personalized treatment.
Benefits
- Less time in production reactor
- More batches per year
- Shorter seed train times
- Reduced plant footprint
- Increased flexibility
- Reduced COGs
OPTION 1 | N-1 Intensification
Intensify cell growth in the step (N-1) prior to the production bioreactor (N). This process intensification is done by attaching a cell retention device to the N-1 bioreactor to attain high cell density and viability. This seeds the production bioreactor at a higher starting cell density and shortens the production bioreactor run time. This can dramatically increase the facility output without direct change to the core production process.
Variations are possible on this theme, depending on existing facility layouts, one common one being that one N-1 bioreactor might inoculate two production vessels.
8 steps
37 days to product
30 days to N
7 days in N stage
OPTION 2 | N-2 or earlier Intensification
Perform process intensification earlier in the workflow by attaching the XCell ATF® Device to the N-2 or earlier bioreactors. This can save as much as 1 week in the seed train and reduce or eliminate several bioreactors later in the workflow. This means less bioreactors to purchase, operate, clean, and validate - saving clean room floor space while mitigating risk.
6 steps
31 days to product
24 days to N
7 days in N stage
OPTION 3 | Large Volume High Density (LVHD) Frozen Process Intermediaries
De-couple cell bank and variable early cell culture expansion from manufacturing by producing and freezing intermediate cells. This ensures cells of high cell concentration and viability, and known volume, are provided to manufacturing every time. This process intensification option can be performed in a central facility and distributed globally, making scheduling vastly easier with inoculation occurring “on demand”.
5 steps and time not relevant
(performed outside production timeline)
OPTION 4 | Frozen Process Intermediaries with N-1 Intensification
Combine Frozen Process Intermediaries and N-1 or earlier intensification. This enables Manufacturing on Demand, and a truly flexible facility ready for batch or continuous operation.
- Significantly smaller footprint and less equipment
- Reduced CAPEX for equipment and cleanroom
- Fewer operational steps
- More repeatable output
- Faster turnaround of equipment and more batches per year
3 steps
13 days to product
6 days to N
7 days in N stage
Seed Train Intensification Technologies
Alternating Tangential Flow (ATF) Filtration
An award-winning technology, ATF allows the removal of spent media while keeping cells in culture. Applied using an XCell ATF® Device attached to a bioreactor, ATF minimizes cell shear and keeps cells in constant equilibrium with bioreactor contents. This results in faster cell growth at higher densities with higher productivity. Today, the XCell ATF® Device is the leading perfusion device for mAb and rProtein production.
Potent cell culture supplements
Repligen developed and manufactures cell culture supplements that provide the benefits of serum supplementation while maintaining an animal-free process.
Resources
Impact of N-1 Seed Train Intensification on Viral Vector Production
by Ly Truong, Riaj Mahamud, Benedict Kang, Keen Chung, Rene Gantier
Repligen Corporation
September 2022
Special Report on Continuous Bioprocessing: Upstream, Downstream, Ready for Prime Time?
by Angelo DePalma
BioProcess International, May 2016
Continuous Manufacturing: A Changing Processing Paradigm
By Randi Hernandez
BioPharm International, Apr 01, 2015
A Novel Seed-Train Process: Using High-Density Cell Banking, a Disposable Bioreactor, and Perfusion Technologies
by Benjamin Wright, Mike Bruninghaus, Mike Vrabel, Jason Walther, Neha Shah, Seul-A Bae, Timothy Johnson, Jin Yin, Weichang Zhou and Konstantin Konstantinov
BioProcess International, March 2015
Developing an Integrated Continuous Bioprocessing Platform: Interview with Konstantin Konstantinov
by Maribel Rios
BioProcess International, December 2012
A Brief History of Perfusion Biomanufacturing: How High-Concentration Cultures Will Characterize the Factory of the Future
by John Bonham-Carter and Jerry Shevitz
BioProcess International, October 2011