Natural Killer (NK) cells are a powerful component of the innate immune system with the ability to eliminate tumor and virus-infected cells without prior sensitization. Their unique biological properties make them highly attractive for off-the-shelf cell therapies.

At the IBD Group, we develop advanced, scalable, and automated bioprocesses for NK cell manufacturing, combining biological understanding with engineering-driven process design.

From Biology to Bioprocess Engineering

NK cells act via:

• Direct cytotoxicity (perforin, granzymes, FasL/TRAIL)
• Immune modulation via cytokine release 

Current Limitations in NK Cell Manufacturing

Despite their potential, NK cell therapies are still limited by:

• Poor process standardization
• Lack of scalable production strategies
• Insufficient understanding of functionality during expansion 

Today’s NK production processes are often:

• Manual and poorly automated
• Based on undefined process parameters
• Dependent on complex and variable media
• Expensive and difficult to scale 

A lack of holistic understanding prevents Quality-by-Design (QbD) implementation and robust process control.

Our Approach: Data-Driven NK Bioprocess Development

We follow a systematic, engineering-driven workflow:

1. Definition of critical quality attributes (CQAs)
2. Identification of critical process parameters (CPPs)
3. Medium and process optimization
4. Scale-up using CFD simulations
5. Process monitoring via PAT tools
6. Data-driven modeling and automation 

This approach enables a fully integrated NK cell production process.

Key Innovations

• Dynamic control of cytotoxicity
  Cytotoxicity is a time-dependent quality attribute and can be fully recovered within 2  days, enabling optimized harvest strategies.
• Lactate-driven process understanding
  Identification of lactate as a critical parameter affecting cytotoxicity and growth
• Integrated recovery and control strategies
  Implementation of recovery phases and soft sensor-based monitoring for real-time process control.
• High-yield, intensified processes
  Production of >2 × 10⁹ cells within 5 days with reduced serum requirements and improved functionality.
• Perfusion based fully automated processes with in-line control: Alternating-tangential flow perfusion yields significantly higher cell counts of high quality. The process is controlled automatically by in-line real time lactate monitoring 

• Scale-Up & Automation

We enable seamless scale-up from lab to production:

• DoE-based screening in small scale
• CFD-supported scale-up
• Stirred tank bioreactors (2 L scale demonstrated)
• Homogeneous shear improves cytotoxicity
• ATF perfusion with in-line lactate monitoring for automated and intensified production

→ Result: Automated NK cell production with real-time control 

Technologies & Infrastructure

• Bioreactor systems (Ambr250, 2 L STR)
• In-line sensors (pH, pO₂, spectroscopy)
• Flow cytometry & metabolite analytics
• Soft sensors & neural network models
• High-throughput screening platforms 

Collaboration

We collaborate with partners in academia and industry in the field of cell and gene therapy (CGT).

Our expertise includes:

• Process development & intensification
• Cytotoxicity and potency optimization
• Process analytics and modeling 

Scientific output

• von Werz V., Szarzynski A, Hadrbolec M., Mattert G., Zigon-Branc S, Kozma B., Dammermann W. and Spadiut O. “A novel cultivation strategy to recover NK cell cytotoxicity“ Front. Bioeng. Biotechnol.,2026, doi: 10.3389/fbioe.2026.1797129.
• von Werz V., van Heuvel Y., Hadrbolec M., Wagner M., Eibl P., Huber F., Meyer M., Bongratz P., Witz C. and Spadiut O. “Homogeneous shear distribution improves NK-92 cell cytotoxicity in a clinically relevant 2 L membrane-stirred bioreactor“ Front. Bioeng. Biotechnol., 2026, 4:18049452026. doi: 10.3389/fbioe.2026.1804945
• von Werz V., Hadrbolec M., Kozma B., Szarzynski A. and Spadiut O. ”Process for the production of natural killer cell formulations for cell therapy”; Patent No. A50177/2025 
• von Werz V., Hadrbolec M., Kozma B., Szarzynski A. and Spadiut O. ”Process for the production of natural killer cell formulations for cell therapy”; Patent No. PCT/EP2026/057586
• von Werz V., Birner-Grünberger R. and Spadiut O. ”TME-resistant NK cells”; Patent No. A50338/2025
• von Werz V., Szarzynski A, Zigon-Branc S, and Spadiut O. “Quality standards for NK cell immunotherapies“ Front. Bioeng. Biotechnol., 2025, 13:1716975. doi : 10.3389/fbioe.2025.1716975
• von Werz V., Szarzynski A, Mattert G., Zigon-Branc S, Dammermann W. and Spadiut O. “Cultivation strategy optimisation for NK-92 cell line expansion in static conditions“. BMC Biotechnol., 2026, 26:28. doi: 10.1186/s12896-026-01116-2.
• Szarzynski A., Spadiut O., Reisbeck M., Jobst G., Paterson R.L., Kamenskaya A., Gateau E., Lesch H.P., Henry L. and Kozma B. “CGT 4.0: a distant dream or inevitable future? Smart process automation is critical to make efficient scalability of CGT manufacturing a reality“ Front. Bioeng. Biotechnol., 2025, 13: 1563878. doi: 10.3389/fbioe.2025.1563878