Engineers have found a way to rapidly prepare frozen red blood cells for transfusion, which could make cryogenic transport even better.

It is already possible to cryopreserve human red blood cells in the presence of 40 percent glycerol, but is rarely done because of the time-consuming process to thaw and remove the glycerol from the blood. This can take an hour or more and makes it logistically difficult to use frozen blood.

But initial experiments and computer modelling of a proposed new process suggest that this hour-long process can be reduced to as little as three minutes, using a membrane-based, microfluidic device.

This could make it far more feasible to use frozen blood in emergency or time-constrained medical situations.

The findings are reported in the journal Biomicrofluidics.

“Only a small fraction of our blood supply is now frozen, because it’s often impractical to wait so long when a transfusion is needed immediately,” said Adam Higgins, an expert in medical bioprocessing and associate professor in the Oregon State University School of Chemical, Biological and Environmental Engineering.

“Because of that, our entire system depends on constantly balancing the use and supply of blood products that can only last six weeks or less with refrigeration,” he said.

“This is difficult, and can lead to loss of outdated blood, periodic shortages, and other inefficiencies that could be solved with the use of frozen blood.”

To thaw the frozen blood, extremely tiny microchannel plates and membranes could be used to precisely control removal of glycerol from blood at a time scale of seconds.

This would allow much more rapid thawing of frozen blood, which isn’t possible using the centrifugal cell washers - the only other way to remove glycerol from the blood.

The new approach should work, OSU experts say.

“Our results pave the way for development of a clinical device for ultra-rapid glycerol extraction, which would greatly improve the logistics of blood banking,” the researchers wrote in their report.

The study continues, with researchers hoping to create working prototypes of the needed technology for further development and testing of the concept.