Fish Antifreeze

The oceans near the poles are cold—really cold. Because of the salt content, water temperatures can remain below freezing for most or all of the year. And that can be bad for life. Ice crystals can develop in the blood and other fluids, destroying cells. Yet many species of fish thrive in these frigid environments. In part, that’s because they produce proteins that work like antifreeze.

Inspired by those fish, researchers have developed a synthetic version of the proteins. The “mimics,” as they’re called, could prevent medications that have to be kept cold from freezing. They also could be used to prevent the formation of ice crystals in many other products.

Earlier studies nailed down the details of the fish proteins. Whenever a crystal begins to form, the proteins wrap it up. They change the structure of the crystal, keep it from getting any bigger, and lower the freezing temperature. That combo prevents the cold from damaging cells.

Researchers isolated the key features of the proteins, then found a way to replicate them in the lab. They tested their brew in living cells. It protected the cells from freezing, and it wasn’t toxic. It also wasn’t a problem for the bacteria in the human digestive system.

The researchers say their antifreeze can be manufactured easily and inexpensively. So it could make it easier to store and ship some medications, and extend the shelf-life of ice cream and other frozen foods—a gift from some cold, cold fish.