Hebrew U scientists may have found key to preserve transplant cells and organs

“The ability to freeze organs and thaw them without damaging them would be revolutionary in terms of our chances to save lives,” expert says.

By JUDY SIEGEL-ITZKOVICH
Schneider courtesy photo of baby after transplant surgery. (photo credit: Courtesy)
Schneider courtesy photo of baby after transplant surgery.
(photo credit: Courtesy)
Hebrew University scientists believe that after decades of studies, they have made a breakthrough in preserving body organs and tissues for transplant. A heart or lung can be kept viable for transplantation for only six hours before deterioration begins, while a liver or pancreas would go to waste after 12 hours in storage and a kidney could be kept outside the body for less than 30 hours.
These time constraints pose a huge logistical challenge for the procedure of transplanting donated organs. Transplantation is most successful when carried out as quickly as possible after the donor surgery, and – given these time frames – many organs end up being wasted. One of the main problems preventing the storage of organs for more than a few hours is the growth of ice; when organs are frozen, expanding ice crystals damage the cells until they can’t be revived.
Therefore, once a heart, kidney, liver, lung or intestine is removed from a donor, it is kept cool but not frozen, reducing its lifespan to only a number of hours.
“The ability to freeze organs and thaw them without damaging them would be revolutionary in terms of our chances to save lives,” said Prof. Ido Braslavsky from HU’s Institute of Biochemistry, Food Science and Nutrition at the Robert H. Smith Faculty of Agriculture, Food and Envirionment.
Perfecting cryopreservation – the process of preserving cells, tissues and organs in sub-zero temperatures – would enable long-term banking of tissues and organs and efficient matching between donor and patient, eventually saving lives of millions of people around the world, he said. Together with his team that includes Dr. Maya Bar Dolev, Dr. Liat Bahari, Dr. Amir Bein, Dr. Ran Drori, Dr. Victor Yeshunsky and with Prof. Peter Davies from Queens University in Canada, he studies anti-freeze proteins that help organisms resist or withstand freezing both in sea and on land.
Ice-binding proteins, discovered some 50 years ago in Antarctic fish, are now known to exist in cold-resistant fish, plants, insects and microorganisms. They actively inhibit the formation and growth of crystalline ice, and their superiority over other anti-freeze substances is that they are needed in very low amounts to do it effectively.
“We investigate the interaction of ice-binding proteins with ice crystals. Since we are working at temperatures of sub-zero Celsius degrees and we need high accuracy of working temperature, we designed a specialized microscope with a stage cooler that allows a millidegree-level control of temperature and also freezing. Using fluorescent illumination, we can see where the proteins, which are tagged with fluorescent dyes, are located. With these devices, we can follow ice crystals as they grow and melt in the presence of ice-binding proteins," Braslavsky concluded.