Scientists Achieve Successful Transplant of Preserved Rat Kidney
In a groundbreaking new study, researchers at the University of Minnesota have successfully transplanted frozen rat kidneys after letting them thaw from an intense, 100-day freeze. This is extremely revolutionary for the medical field, as it could prove the life-saving feasibility of long-term, low-temperature organ preservation.
This discovery has the potential to save thousands of human lives. The study, published in Nature Communications, details the previous obstacles caused by the formation of ice crystals that kill living tissue when frozen and the irreparable damage that occurs from uneven thawing. Five transplants were successfully performed in rats, with the kidneys functioning within 30 days of being frozen.
“This is the first time anyone has published a robust protocol for long-term storage, rewarming and successful transplantation of a functional preserved organ in an animal,” says Dr. John Bischof, a mechanical engineering professor and director of the U of M Institute of Engineering in Medicine. This study has been in the works for over a decade, and effective cryopreservation has been a goal in many medical, biological and agricultural industries for quite some time. But when it comes to organ preservation, this could be huge.
About 20% of donor kidneys go to waste, as they don’t reach the recipients in time. Cryopreservation has been around for decades, but the biggest problem has been rewarming the organs without significant damage from ice or cell rupture.
The team has developed a specialized nano-warming process that warms organs quickly and evenly by using tiny particles called iron oxide nanoparticles. These nanoparticles are mixed in a special liquid that protects the organ while it is being warmed up. The liquid with the nanoparticles is pumped through the organ's blood vessels. Then, special waves are used to activate the nanoparticles, which in turn heat up the organ. This method allows the organ to be warmed up from the inside rather than just on the surface.
“Even if a fraction of [wasted donor organs] could be used, we could really start to chip away at the growing transplant waiting list,” says Dr. Erik Finger, the study’s co-senior author, transplant surgeon and professor of surgery at U of M Medical School. Freezing would allow more time to find the best match between donor organs and recipients and address any racial or geographic inequities in organ distribution.
All aspects of this approach can be scaled to larger organs, and researchers plan to look next at pig kidneys. Dr. Bischof says attempts at human transplants are years away, but the team is confident that it will be successful in the future.