Cell washing and pre-formulation are critical, yet often under-analysed, steps in allogeneic therapy manufacturing. While seemingly straightforward, many current workflows still fall short, presenting unique process challenges that can compromise the final therapeutic product. These steps must be efficient, reproducible, gentle, and meet strict quality requirements for regulatory compliance.

Why Many Cell Washing Workflows Still Fall Short

The challenges in current cell washing and formulating processes often stem from several key areas:

• Incomplete removal of media components: Achieving high-efficiency buffer exchange is essential for product consistency and patient safety.
• Manual and open handling steps: Workflows that rely on open processes involving centrifuge tubes, biosafety cabinets, or manual buffer exchanges significantly increase the risk of contamination and introduce operator variability. Such methods are also notoriously difficult to scale or validate for GMP environments.
• Limited throughput and processing bottlenecks: Manual and single-sample workflows inherently slow down batch processing, increase the time required "in-suite," and create significant bottlenecks as production scales up to meet clinical and commercial demand. Efficient, automated systems are vital to maintain pace.

What High-Performing Wash and Pre-Formulation Systems Do Differently

To truly improve consistency, reduce risk, and preserve cell integrity, cell washing and pre-formulation systems must be purpose-built for therapeutic applications. They cannot merely be adapted from research tools or time-intensive filtration workflows. The following design elements are critical for achieving high-performance results at clinical and commercial scales:

• Low shear, high recovery: Minimising mechanical stress is paramount for preserving cell quality. Systems like the UniFuge® operate at moderate G-forces and controlled flow rates. These conditions are specifically designed to reduce shear and turbulence, helping to protect cell health throughout the entire washing operation. In UniFuge systems, typical outcomes include greater than 90% recovery and less than 5% viability loss, even with notoriously shear-sensitive cell types such as iPSCs, MSCs, NK cells, and CAR-T cells.
• Automated, high-efficiency buffer exchange: Manual buffer exchange introduces significant variation and inefficiency. Automated systems that incorporate buffer rinses and resuspension functions enable multiple exchanges within a single, closed cycle. This approach consistently achieves high contaminant removal without relying on excessive buffer volumes, improving both throughput and reproducibility. It also supports smoother tech transfer by standardising buffer exchange protocols across different scales and production sites. UniFuge systems routinely achieve buffer exchange efficiency above 90%, without the high volumes or manual steps often associated with less optimised methods.

How to Safely Introduce Cryoprotectants Without Compromising Viability or System Integrity

Cryopreservation workflows often involve the use of cryoprotectants, such as DMSO, which require careful handling. While DMSO is highly effective at preserving cells during freezing, it is cytotoxic and can degrade system components if not managed properly.

• Pre-formulation flexibility: In many workflows, pre-formulation buffers, such as cryopreservation media or excipients, are introduced after final washing and resuspension to achieve target cell concentration and streamline subsequent processing. Systems like the UniFuge support this by enabling direct buffer integration within the wash protocol, allowing teams to prepare concentrated cell suspensions ready for pre-formulation, vialing, bag fill, or storage. By integrating washing and final buffer exchange in a single, closed system, platforms like UniFuge significantly reduce the need for separate mixing vessels or additional transfer steps.

Four Signs Your Cell Washing and Pre-Formulation Workflow Needs Attention

The wash and pre-formulation phase is often under-analysed, but evaluating this step with clear performance and compliance goals can reveal significant opportunities to improve consistency, reduce risk, and streamline downstream operations.

Key questions to assess your current approach include:

1. Are you achieving sufficient wash efficiency without excessive buffer volume? Poor exchange efficiency can leave behind residual proteins or salts that impact cell health or downstream performance.
2. What is your current viable cell recovery during wash and pre-formulation? Even small losses can reduce the available therapeutic dose and lower overall process yield, impacting your bottom line.
3. Is your workflow automated and designed for reliable, GMP-scale manufacturing? Manual steps introduce variability and make it harder to ensure consistent, reproducible processing as batch volumes increase.
4. Are you achieving target cell concentrations during resuspension and using the right technology for your scale? Matching buffer volumes and processing capabilities to your batch size is critical, whether you're working with UF Micro, UF Mini, or UF Pilot modules.

Small changes in this step can have an outsized impact on your overall process efficiency and product quality. Starting with a clear understanding of where your current workflow may be underperforming is the first step toward optimisation.

Build Your Process on a Scalable Cell Washing and Pre-Formulation Platform – and Protect Your Product

Cell washing and pre-formulation profoundly shape the final quality and consistency of a cell therapy product, whether you're working with iPSCs, MSCs, NK cells, CAR-T cells, or other allogeneic immune cell types. Optimising this step means more than just protecting viability; it streamlines operations, reduces risk, and supports seamless integration with downstream processes, ultimately contributing to a more robust and compliant manufacturing pathway.

Learn how BPES can help you enhance your allogeneic therapy manufacturing. Explore Carr Biosystem's UniFuge range for purpose-built cell washing and pre-formulation solutions.