The production of clinical-grade human pluripotent stem cells (hPSCs) requires advanced manufacturing strategies. Vertical-Wheel Bioreactor Scale-Up has emerged as a promising solution to meet the high cell demands of regenerative medicine. Traditionally, engineers relied on volume-averaged metrics to transition from small to large vessels. However, recent research reveals that these metrics may be insufficient. Instead, the study highlights the critical role of tracking individual cell aggregate trajectories to optimize growth and viability.

Improving Vertical-Wheel Bioreactor Scale-Up with EDR Tracking

Researchers conducted 3D turbulent flow simulations to compare 100 mL and 500 mL bioreactors. They discovered that the energy dissipation rate (EDR) experienced by cell aggregates significantly impacts aggregation efficiency and total expansion fold ratios. Interestingly, shear stress had a minimal effect on hPSC proliferation under the tested conditions. Therefore, focusing on trajectory-based EDR exposures provides a more reliable foundation for Vertical-Wheel Bioreactor Scale-Up than traditional volume-averaged EDR.

Furthermore, the study indicates that aggregate size and agitation rates must be carefully modulated. By shifting the focus to Lagrangian-based exposures, manufacturers can better predict how cell aggregates will behave in larger environments. This approach ensures more consistent yields and higher quality for clinical applications. Consequently, these findings offer a clearer roadmap for industrializing stem cell therapies.

Frequently Asked Questions

What is the benefit of trajectory-based EDR in hPSC culture?

Trajectory-based EDR accounts for the actual history of forces an aggregate experiences as it moves through the bioreactor. This provides a more accurate prediction of cell growth and aggregation than simple averages.

Does shear stress always affect stem cell expansion?

While shear stress is a concern in many bioprocesses, this study found it did not significantly impact hPSC aggregation or proliferation in vertical-wheel bioreactors under the specific conditions analyzed.

Disclaimer: This content is for informational and educational purposes only and does not constitute medical advice or professional bioprocessing recommendations. Refer to the latest local and national guidelines for clinical practice.

References

1. Bauer JES et al. Scaling-Up Vertical-Wheel Bioreactors Based on Cell Aggregate Exposure to Shear Stress and Energy Dissipation Rate. Ann Biomed Eng. 2026 Apr 14. doi: 10.1007/s10439-026-04091-z. PMID: 41979868.

2. Kropp C, Massai D, Zweigerdt R. Progress and Challenges in Large-Scale Expansion of Human Pluripotent Stem Cells. Process. 2017; 5(1):17.

3. Nienow AW. Hydrodynamics of Stirred-Tank Bioreactors. Adv Biochem Eng Biotechnol. 2006; 101:1-31.