Tissue Preservation and Biobanking

Vitrification

Although most living organisms are composed of large amounts of water, it is not inevitable that freezing these organisms results in ice-formation. Among amphibians and insects that can tolerate freezing, there is wide variation in the amount of freezing they can tolerate. Species of frogs can spend days or weeks "with as much as 65 percent of their total body water as ice". Some amphibians achieve their protection due to the glycerol manufactured by their livers. Glycerol is "antifreeze", it reduces ice formation and lowers freezing point. Glycerol (glycerin), like ethylene glycol (automobile anti-freeze) is cryoprotectants. The sugar glucose is also cryoprotectants — and arctic frogs have a special form of insulin that accelerates glucose release and absorption into cells as temperatures approach freezing. Cryoprotectants can make water harden like glass — with no crystal formation — a process called Vitrification. Freezing-damage to cells is due to the formation of ice-crystals. Entire organs can be solidified and stored at temperatures as low as -140° C. Scientists are working on ways to reduce the toxicity of the cryoprotectants used to make water vitrify to allow banking of organs for transplantation. At Alcor, we are optimistic that the toxicity that still does occur with vitrification of human organs will be reversible with future molecular repair technology.