Tardigrade proteins could help stabilize drugs without refrigeration, scientists say

Tardigrades — those darling, near-microscopic critters that are nearly indestructible — carry proteins that could keep critical drugs and medical treatments stable without refrigeration, scientists say.

In a study published Monday (March 20) in the journal Scientific Reports, scientists tested this idea with human blood clotting factor VIII, a protein used to treat an inherited bleeding disorder called hemophilia A. Due to a genetic mutation, people with this disorder don't make enough factor VIII and their blood can't clot properly. People with hemophilia A bleed spontaneously, and bleed excessively after injury or surgery. 

Treating hemophilia A usually involves injecting factor VIII into the body, to make up for the patient's deficiency. Many factor VIII products require refrigeration, and those that don't can typically be kept at room temperature for only a limited amount of time and within a narrow temperature range. 

Tardigrades, on the other hand, have a remarkable ability called anhydrobiosis, where they essentially dry themselves out and enter a state of suspended animation. In this state, the so-called water bears can withstand temperatures as low as minus 328 degrees Fahrenheit (minus 200 degrees Celsius) and as high as 300 F (148.9 C).

Related: Tardigrades survive being dried out thanks to proteins found in no other animals on Earth

The study authors wanted to see if the tardigrade's remarkable resilience could be carried over to medical treatments.

"Our work provides a proof of principle that we can stabilize Factor VIII, and likely many other pharmaceuticals, in a stable, dry state at room or even elevated temperatures using proteins from tardigrades," senior study author Thomas Boothby, an assistant professor of molecular biology at the University of Wyoming, said in a statement. "And, thus, provide critical live-saving medicine to everyone everywhere."

The team drew two substances from the tardigrade Hypsibius exemplaris: a sugar called trehalose and a protein called cytoplasmic abundant heat soluble (CAHS) D. Both substances help preserve the  tardigrades' bodies during anhydrobiosis so that they survive to be "rehydrated" later on.

The team tweaked both substances' biophysical properties to boost their ability to stabilize factor VIII. They then used the substances to store factor VIII without refrigeration and under unfavorable conditions, such as repeated dehydration and rehydration, extreme heat and long-term dry storage. Both compounds worked, but CAHS D worked better than trehalose, the team noted.

The authors think this approach could potentially be used for other medicines that currently require refrigeration. But we're still in the early days of this research.

"This will not only be beneficial for global health initiatives in remote or developing parts of the world, but also for fostering a safe and productive space economy which will be reliant on new technologies that break our dependance on the cold-chain for the storage of medicine, food, and other biomolecules," the authors wrote.