Future Applications of Freeze-Tolerant Mechanisms

The mechanisms employed by insects during freezing may improve the cryopreservation of cells and tissues frequently used in organ transplantation and assisted reproductive techniques. Cryopreservation refers to the process in which cells or whole tissues are preserved by cooling to sub-zero temperatures, usually at the boiling point of liquid nitrogen, -196˚C. This halts all biological activity, including the activity that would lead to cell death. Theoretically these cells can be cryopreserved indefinitely. Still the process of cryopreservation is harmful; damage to cryopreserved tissues and cells often occurs when they approach low temperatures or warm to room temperature. Freezable tissues include semen, stem cells, umbilical cord blood, eggs, embryos, and ovarian tissues (Wikipedia). Clearly cryopreservation methods are important in improving reproductive techniques. Unfortunately there are still many challenges associated with cryopreservation.

There have been numerous studies on the natural cold-tolerance of insects that have improved our knowledge of cryobiology. Researchers have determined that cryoprotectants may be injected to induce ice formation using ice nucleating agents, but this does not mean that these cells or tissues will be cold-tolerant (Ramlov, 2000). The structures of many ice nucleating agents have been established but this has not yet been applied to biotechnology and cryobiology. The use of anti-freeze proteins is also an attractive solution because of its ability to control ice formation and prevent damaging re-crystallization (Fuller, 2004).

Photo of cryopreservation techniques using liquid nitrogen.