Supercooling prolongs the life of the donor liver
Researchers at the Massachusetts General Practice Clinic have developed a method of supercooling, which allows to increase the period of preservation of donor organs outside the body. Transferring the results obtained in experiments on rats into clinical practice will help partially solve the problem of acute shortage of donor organs.
Supercooled rat liver in a preservative solution in a machine perfusion system
The currently used combination of cooling and immersion in the composition, developed by scientists at the University of Wisconsin-Madison in 1983, allows you to save a donor liver for 24 hours. The approach developed by the authors can increase this period by three times.
At the first stage, rat livers were saturated with oxygen and nutrients by machine perfusion. At the same time, 3-O-methyl-D-glucose (3-OMG), a non–toxic glucose derivative that is not metabolized by hepatocytes, but accumulates in them, preventing damage to cellular organelles during cooling, was added to the perfusion solution. To protect the cell membranes, polyethylene glycol was also added to the composition, which reduces the freezing point of the solution.
After that, the organs were slowly cooled to a temperature of 21 degrees Fahrenheit (approximately -6 degrees Celsius). After 72 or 96 hours (3-4 days), the cooled organ was warmed up and again saturated with oxygen and nutrients using machine perfusion.
A pump system that provides liver perfusion before and after supercooling.
The blue color is due to the antifreeze that maintains the desired temperature of the system components.
All rats that had liver transplants preserved under supercooling conditions for 3 days survived for at least three months, which could not be achieved with any animal that underwent organ transplantation treated using traditional techniques. The survival rate of animals after liver transplantation, preserved in supercooling conditions for 4 days, was 58%.
After that, the authors alternately checked the criticality of each of the components of the developed approach. When polyethylene glycol or 3-OMG was removed from the perfusion composition, recipient rats died within a week after transplantation. And in case of exclusion of machine perfusion or supercooling – within an hour after transplantation.
The authors are very inspired by the results obtained, however, they note that before conducting clinical trials, their proposed approach should be thoroughly tested and improved.
Article by Tim A Berendsen et al. Supercooling enables long-term transplantation survival following 4 days of liver preservation published in the journal Nature Medicine.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on Medical Xpress materials:
Researchers extend liver preservation for transplantation.
02.07.2014