Organ banks for transplants may become a reality
A new scientific advance can boost the number of donated organs available for transplant, and reduce a critical shortage that leads to thousands of deaths each year. Deep freezing organs and tissue through cryopreservation has been possible since 1980s, but rewarming them without cooking or destroying the tissue has proven difficult. Most donated organs can only last about four hours on ice. Now, in a first, researchers at the University of Minnesota have discovered a way to thaw animal heart valves and blood vessels using a process called “nanowarming”, said the report in Science Translational Medicine.

The method works by dispersing silica-coated iron oxide nanoparticles throughout a cryoprotectant solution. “The iron oxide nanoparticles act as tiny heaters around the tissue when they are activated using non-invasive electromagnetic waves to rapidly and uniformly warm tissue at rates of 100 to 200 degrees celsius per minute, 10 to 100 times faster than previous methods,” said the researchers.Tests performed after re-warming showed the tissues were unharmed, unlike tissue re-warmed slowly over ice or via convection heating. The solution could also be easily rinsed off the tissue afterwards. “This is the first time that anyone has been able to scale up to a larger biological system and demonstrate successful, fast and uniform warming… of preserved tissue without damaging the tissue,” said study author John Bischof. “These results can have a societal benefit if we can someday bank organs for transplant.” The next step for researchers is to try the technique on rat and rabbit organs. The advance may also allow freezing an entire human and then thawing the body to bring the person back to life. “We are cautiously optimistic that we’re going to be able to get into a kidney or maybe a heart,” he said.

Nearly 76,000 people are waiting for an organ transplant in the US. Experts said about 60% of the hearts and lungs donated for transplantation each year must be discarded because they cannot be kept on ice for long. On average, 22 people die every day while waiting for an organ.