Researchers have developed a synthetic version of an antifreeze protein found in the blood of polar fish, creating a new tool to prevent the formation of damaging ice crystals in frozen foods and life-saving medicines. The innovation from a team at the University of Utah provides a non-toxic and scalable alternative to naturally occurring proteins, which are difficult and costly to extract for commercial use.
This new polypeptide mimics the ice-inhibiting properties of the natural proteins that allow certain fish to survive in sub-zero waters. By simplifying the protein’s structure to its essential components, the engineers created a version that can be manufactured affordably through chemistry, without requiring any fish or biological cells. The synthetic protein has already been shown to protect the texture of ice cream and preserve the stability of a sensitive anti-cancer drug at extreme temperatures, signaling broad potential applications in the food industry and pharmaceutical cold-chain logistics.
Inspired by Nature’s Antifreeze
For decades, scientists have been interested in the natural antifreeze proteins found in organisms that thrive in freezing environments, including certain fish, insects, and plants. These proteins work by binding to the surface of small ice crystals, preventing them from growing into larger, jagged structures that can damage cells and ruin the texture of food. This microscopic damage is responsible for freezer burn in consumer products and can destroy the delicate molecular structure of biological medicines like enzymes and antibodies, which must be stored and transported at low temperatures.
While effective, harvesting these proteins directly from animals like the Antarctic toothfish is not commercially viable. Previous attempts to harness their properties have been limited by the high cost and complexity of extraction. Conventional chemical antifreezes, such as ethylene glycol used in vehicles, are toxic and cannot be used in products intended for human consumption. This created a long-standing challenge for industries reliant on cold storage, prompting the search for a safe, effective, and economical alternative.
Designing a Simplified Synthetic Protein
The breakthrough came from a team in the John and Marcia Price College of Engineering at the University of Utah, led by Associate Professor Jessica Kramer and graduate student Thomas McPartlon. Their research, published in the journal Advanced Materials, focused on identifying the most critical structural features of the natural proteins required for antifreeze activity. By isolating these key components, they designed a simplified, stripped-down polypeptide that retained the same ice-blocking function.
“Ultimately, we simplified the structure to only the parts we thought were required for antifreeze activity, which makes production less complicated and expensive,” Kramer said. The researchers were able to synthesize these mimics using chemistry alone, a process that is significantly more scalable and cost-effective than biological extraction. “Despite those changes, this study showed that our mimics bind to the surface of ice crystals and inhibit crystal growth, just like natural antifreeze proteins,” she added. McPartlon noted the key advantage of their method: “we make these mimics entirely using chemistry—no fish or cells required.”
Protecting Food and Pharmaceuticals
Successful Real-World Tests
To validate their synthetic protein, the researchers applied it to several real-world test cases. In one experiment, they added the polypeptide to ice cream, which was then chilled to minus 4 degrees Fahrenheit. The additive successfully prevented the formation of large ice crystals, preserving the smooth texture of the product. This application could extend the shelf life of frozen foods and reduce quality degradation from freezer burn.
In another critical test, the team used the protein to protect Trastuzumab, an anti-cancer drug that is sensitive to freezing and thawing. The synthetic antifreeze preserved the drug’s stability even at cryogenic temperatures as low as minus 323 degrees Fahrenheit. This demonstrates the potential for the technology to revolutionize the cold chain for biologic drugs, ensuring they remain effective from production to patient delivery.
Safety and Digestibility
A crucial hurdle for any new food or drug additive is safety. The University of Utah team conducted tests showing their synthetic protein is non-toxic to human cells. Furthermore, they confirmed that the polypeptides are digestible by common human gut enzymes, a critical step for their approval in consumable products. The material is produced using what the study authors described as “ultracheap materials in a relatively expedient and green manner,” making it an attractive option for widespread use.
Future Commercial and Industrial Impact
The successful development of this potent and economical antifreeze polypeptide opens the door to numerous applications. Beyond preserving food and drugs, the technology could be used in agriculture, specialty coatings, and other biomedical fields where preventing ice damage is critical. The researchers are now in the process of patenting their creation and are working to commercialize the technology through a startup company named Lontra Bio LLC.
By providing a scalable and affordable solution, this synthetic protein could address long-standing challenges in cryopreservation. It promises to improve the quality of frozen foods for consumers and enhance the stability and reliability of life-saving medicines that depend on a fragile cold chain. The ability to manufacture the protein entirely through chemical synthesis marks a significant advance, moving a concept inspired by polar fish from a scientific curiosity to a viable industrial and medical tool.
