Gradual Cryopreservation Becoming a Possibility

A new study with water--still one of the least understood of all liquids in spite of a century of concentrated research--seems to back up the possibility that cells, tissues, and even the total human body could be cyropreserved without the formation of destructive ice crystals.

University of Helsinki (Finland) researcher Anatoli Bogdan, Ph.D., performed the study, which will be published in the July 6, 2006, issue of the Journal of Physical Chemistry B. Medically, cryopreservation involves preserving organs and tissues for transplantation or other uses. Only specific types of cells and tissues, including sperm and embryos, currently can be frozen and effectively rewarmed. A major obstacle hampering expanded use of cyropreservation is the formation of ice crystals, which damage cell structures. Cyropreservation may be most recognizable, however, as the controversial hypothesis that humans, suffering with incurable diseases, might be frozen and then revived years or decades later when cures are available.

Dr. Bogdan's studies involved a form of water called "glassy water,” or low-density amorphous (LDA) ice, which is generated by gradually supercooling diluted aqueous droplets. LDA melts into highly viscous water (HVW). Dr. Bogdan reported that HVW is not a new form of water, as some scientists believed.

"That HVW is not a new form of water [i.e., normal and glassy water are thermodynamically connected] may have some interesting practical implications in cryobiology, medicine, and cryonics,” Dr. Bogdan said. "It may seem fantastic, but the fact that in aqueous solution, [the] water component can be slowly supercooled to the glassy state and warmed back without the crystallization implies that, in principle, if the suitable cyroprotectant is created, cells in plants and living matter could withstand a large supercooling and survive.”

In present cyropreservation, the cells being preserved are often damaged due to freezing of water either on cooling or subsequent warming to room temperature. "Damage of the cells occurs due to the extra-cellular and intra-cellular ice formation, which leads to dehydration and separation into the ice and concentrated unfrozen solution. If we could, by slow cooling/warming, super cool, and then warm the cells without the crystallization of water then the cells would be undamaged,” stated Dr. Bogdan.



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