Can Blood Cells Be Frozen Without Toxic Chemicals? One cell biologist thinks so

Cell biologist Chris Pridgeon set out to challenge how we preserve one of the most vital substances in medicine: blood. Although his collaboration with the Finnish Red Cross Blood Service didn’t unfold as planned, the research is far from wasted.

Cell biologist Chris Pridgeon had heard a disturbing claim—that in some emergency situations, frozen blood from rare donors might be used before a toxic chemical added for preservation, DMSO, can be removed.

“I’m not entirely sure if the story was true — it does sound a bit cowboy,” he says now.

But the issue is real. To store blood cells for extended periods, especially for crisis or war zones, they need to be frozen. The problem? Water inside cells expands as it freezes, rupturing the cell membranes. A cryoprotectant like DMSO prevents that by acting as antifreeze. Unfortunately, it’s also toxic—comparable to alcohol in its harmfulness.

What’s more, deep-freezing blood requires ultra-low temperatures—minus 80 degrees Celsius or even liquid nitrogen—making it inaccessible for many parts of the world.

“There just aren’t that many –80 degree freezers in Central Africa or other poorer regions of the world,” Pridgeon notes.

Rethinking Preservation

That challenge sparked an idea: What if blood cells could be frozen without toxic additives or extreme cold?

Pridgeon’s research advisor, Marjo Yliperttula from the University of Helsinki, happened to know people both from the Finnish Red Cross Blood Service and a Finnish company called 2COOL.

The company 2COOL, based in Jämsä, was the only one in Europe with a magnetic freezer suitable for research purposes. This type of freezer had already been used for freezing delicate foods like berries and mushrooms—so why not blood cells as well? The 2COOL freezer promised to reduce ice expansion which, combined with researchers’ own innovations, had the potential to replace conventional cryoprotectants. In time, this may allow freeze drying of blood which could be stored at room temperature.

Pridgeon was excited about the opportunity to do research and promote academic innovation in a practical environment, like a company. Through Finland’s PoDoCo (Post Docs in Companies) program, which supports collaboration between researchers and businesses, he began working with 2COOL and the Finnish Red Cross Blood Service.

For six months, Pridgeon commuted to the small-town warehouse to run his experiments—until the research hit a roadblock.

A Promising Project Paused

PoDoCo, or Post Docs in Companies, brings together PhD graduates and businesses. A PoDoCo project lasts 1–2 years and is divided into two parts of 6–12 months each. The first phase is foundation-funded research, followed by an equally long applied phase funded by the company.

However, continuing the work after the foundation-funded phase is not guaranteed—both the researcher and the company can decide to end the collaboration. The hope, of course, is that it will continue.

In Pridgeon’s case, negotiations between the university and 2COOL over intellectual property rights slowed progress. Eventually, the Blood Service withdrew from the project.

In a letter to Pridgeon, they emphasized that the decision had nothing to do with the quality of his work, but the organization had simply shifted its focus. Finnish Red Cross Blood Service is engaged in a broader initiative focused on the development of blood products and blood cells. However, for now, the collaborative development work related to deep freezing has not been continued.

Product development manager Saara Laitinen says the challenge wasn’t the science—it was the system. “The implementation would have required changes not only in how the products are prepared, but also on the receiving end,” she says.

Even so, she supports further research. “This is absolutely a development worth pursuing.”

Laitinen adds that continuing the project independently is also possible. The Blood Service’s sample services assist researchers by providing surplus blood components for research, product development, or laboratory use.

Looking Ahead to Freeze-Drying

Although that collaboration ended, Pridgeon hasn’t given up. Currently, he is working on a different project, but also continues his freezing research in the background.

“We have a working protocol for freezing cells at a lower temperatures and without DMSO, but no blood to test it with. Even if we can do most of our research on cancer cells, I hope we can get back to blood cells soon.”

He’s also exploring the potential of freeze-drying—a method that could preserve blood cells in a stable form without freezing at all. During a conference trip in the United States, he heard that this technique is already being tested there.

Pridgeon is confident that the research already done has great value, as it forms a foundation not only for deep-freezing but also for exploring freeze-drying.

“If we could freeze-dry a blood cell and keep it alive, I think it would be more valuable than people realize. There are everyday benefits like easier transportation and energy savings—but it’s also a biologically fascinating problem. And I have a feeling it’s very solvable.”

By Sandra Järvenpää
Photos by Miikka Pirinen

Jenny and Antti Wihuri Foundation participates in the Post Docs in Companies (PoDoCo) program, which aims to promote PhD employment in companies and support the long-term renewal of Finnish business and industry.