Cell & Tissue Science

Vitrification

Although most living organisms are composed of enormous amounts of water, it's not inevitable that freezing these organisms ends up in ice-formation. Among amphibians and insects that may tolerate freezing, there's wide variation in the quantity of freezing they'll tolerate. Species of frogs will spend days or weeks "with as much as 65 percent of their total body water as ice". Some amphibians attain their protection due to the glycerol produced by their livers. Glycerol is "antifreeze", it reduces ice formation and lowers freezing point. The sugar glucose is also cryoprotectants. Arctic frogs have a special type of insulin that accelerates glucose release and absorption into cells as temperatures approach freezing point. Cryoprotectants can be used to make water harden like glass with no crystal formation this is a process known as Vitrification. Freezing damage to cells is due to the formation of ice-crystals. Entire organs could also be solidified and kept at temperatures as low as -140°c. Scientists are working on ways in which reduce the toxicity of the cryoprotectants used to make water vitrify to allow banking of organs for transplantation. We tend to are optimistic that the toxicity that also can occur with vitrification of human organs that are going to be reversible with future molecular repair technology.