AI-rewritten: This is a summary of an article from MIT Technology Review, rewritten by AI (Qwen, running locally) to make it easier to read. The facts come from the original article – read it for the full story.

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Scientists at the University of Minnesota have successfully rewarmed pig kidneys that were frozen to -150 °C for over a year, proving they can function again. The kidneys, which are similar in size to human ones, were cooled into a glass-like state using a process called vitrification. This method prevents ice crystals from forming by turning the tissue solid like glass. To achieve this, researchers infused the organs with iron oxide nanoparticles that release heat when activated by an electromagnetic field during rewarming.

Erik Finger, a transplant surgeon who co-led the work, noted that ten years ago he had low hopes such a procedure would succeed. The team flushed the kidneys of blood and loaded them with cryoprotectants and nanoparticles over two hours before cooling them rapidly. Once vitrified, the organs could be stored in freezers for extended periods without damage. After rewarming, the kidneys regained their color and began producing urine within minutes, indicating they were working.

While the results represent a milestone, the research has not yet been peer-reviewed and the team aims to replicate these findings with human organs. Experts like Peter Kilbride and Korkut Uygun called the achievement revolutionary for transplantation medicine. Currently, organ preservation limits transplant availability because organs must be transplanted within 24 to 36 hours. Long-term organ banking could allow doctors more time to match donors with recipients and potentially reduce the lifelong need for immune-suppressing drugs that carry side effects.