Super-Cooling Helps Preserve Liver for Three Days: Study

New super-cooling technique helps preserve organs for longer durations, finds a study.

Researchers from the Harvard Medical School discovered a method that involves storing the organs at low temperatures without freezing. It also involves adding nutrient solutions and oxygen to blood vessels.

A test was carried on rats' liver and found the organs remained viable for three days compared to less than 24 hours using conventional procedures. If the method is proven effective in storing human organs it can help facilitate organ donation.

Cells in organs gradually start dying when removed from the body, but storing them in cool temperatures or 21 degrees Fahrenheit without freezing helps slow down the rate at which the cells are metabolized.  Moreover, different types of cells and tissues of the organs differ in their reaction to cold. To overcome this drawback, the scientists supplied necessary nutrients and oxygen for the survival of the rat livers followed by super-cooling and addition of non-toxic glucose solutions. The compound 3-OMG or 3-O-methyl-D-glucose prevented cell death by shielding it from extreme cold. In the final step, they administered another solution of PEG-35KD or Polyethylene glycol, an anti-freeze component that works by reducing the freezing point of glucose solution.

Four days after the organ storage, the livers were transplanted to rats and it was observed these animals had a survival rate of 58 percent. In addition, the study found the rats died within a week if they received the liver stored in the absence of 3-OMG and PEG-35KD solutions. In rats that received liver that was not super-cooled, deaths occurred within sixty minutes after transplantation.

"It is exciting to see such an achievement in small animals, by recombining and optimizing existing technology. The main point here is that using all of these approaches at once was what led to success. Halfway measures did not do. Such a tour de force reflects this team's very deep understanding of the complex processes at work here, and how they relate simultaneously to each other," said Rosemarie Hunziker, Ph.D., program director of Tissue Engineering and Regenerative Medicine at the National Institute of Biomedical Imaging and Bioengineering in a news release.

The authors believe the technique must be further tested before confirming its safety for human organs.

The new method will go a long way in overcoming the chronic shortage of organs for transplantation.

"The longer we are able to store donated organs, the better the chance the patient will find the best match possible, with both doctors and patients fully prepared for surgery. This is a critically important step in advancing the practice of organ storage for transplantation," added Hunziker.

The research was funded by the National Institutes of Health's National Institute of Biomedical Imaging and Bioengineering (NIBIB) and the National Institute of Diabetes and Digestive and Kidney Disease (NIDDK).More information is available online in the journal Nature Medicine.