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Go to www.uspto.gov to access the full text of the patent (Sep.14) assigned to 21st Century Medicine Inc., Patent No. 5,952,168. The inventors listed are Brian G. Wowk, Michael G. Federowicz, Sandra R. Russell, and Steven B. Harris. It runs about 18 printed pages. Title is "Method for vitrification of biological materials using alkoxylated compounds."
Naturally, we at Cryonics Institute will investigate the procedures and substances mentioned.
There are many interesting features in the patent, not least the structure of claims. The claims start broadly, including any alkoxylated organic compound in a concentration sufficient to permit vitrification and cooling until vitrified; and the application of this to any organ, tissue, or animal. More specific claims relate to use of 2-methoxyethanol and 3-methoxy-1,2-propanediol.
The inventors acknowledge that glycol ethers have been used before to preserve embryos and cell suspensions, but believe they have priority in application to tissues, organs, and animals. Obviously, there are potentially interesting questions in patent law--both as to the relation between these inventors and prior users of glycol ethers, and between these inventors and later users of new variations and applications.
"Summary" of the invention mentions perfusing an inert fluid through the vascular system and controlling the temperature of the fluid; and a class of new glycol ether CPAs. Oddly enough, the Claims do not (to my legally untutored mind) appear to make any direct or specific reference to cooling methods, even though in the "Summary" that seems important.
"Glycol ethers" are understood to include compounds containing alkoxy--and particularly methoxy--functional groups. Included are alkoxylated alkanes and alkoxylated alcohols and polyols, with several sub-groups given.
For some organs, cooling and rewarming rates can exceed 100 degC per minute. [This seems to suggest possible use with other CPAs, such as amides.]
"Large animals can be perfused with high concentrations of glycol ethers near 0 C with rapid equilibration, no dehydration, no edema or other visible evidence of toxic effects. Histologic preservation is excellent at microscopic and ultrastructural levels." In other words, they claim an important advance in minimizing damage in cryopreservation. This is not recent news, but many of the details have previously been withheld pending patent protection.
References include Skrecky's proposal in Cryonet #5174, 1995; Cryonics: Reaching for Tomorrow (Wowk & Darwin, 1991; The Prospect of Immortality, Ettinger, 1964; and a Darwin/Hixon piece in Cryonics July 1984, as well as various patents and publications in recognized journals.
I have not found any patent entries under "ice blockers," although this patent says that suppression of ice formation is an important feature. I believe 21CM has a different class of substances it calls ice blockers, acting through a different mechanism.
The "Conclusion" mentions unprecedentedly high rates of cooling and rewarming,;and the advantages of the new CPAs, including penetration and low viscosity, rapid equilibration, ice inhibition, minimization of toxicity, and glass forming properties.
Congratulations to all the inventors involved. Lots of work ahead.
Robert Ettinger, Cryonics Institute, Immortalist Society
Link to the U.S. Patent Office web site item on this patent.