Breakthrough in supercooling pig kidneys marks step toward organ banks
A new study details how pig kidneys survived supercooling to −4 °C and were successfully reimplanted, offering a potential solution to the critical shortage of donor organs that typically survive only hours outside the body.
Scientists are making significant progress in preserving human organs outside the body to address donor shortages. A team led by Matthew Powell Palm successfully supercooled pig kidneys to −4 °C and reimplanted them, marking a landmark achievement without the use of cryoprotectants. Other developments include machine perfusion systems that maintain organs like livers, kidneys, and eyeballs for up to 24 hours, and a device nicknamed "Mother" that kept a human uterus alive for a day. While cryopreservation remains routine for cells and embryos, freezing whole organs remains difficult due to ice crystal damage.
The primary obstacle in organ transplantation is time. Donor organs typically survive only a few hours outside the body, even when kept on ice. This short window prevents doctors from running extensive tests, finding the best matches for recipients, or transporting organs over long distances. The medical community aims to establish "organ banks" capable of storing organs for days, weeks, or months, which would alleviate the current shortage and improve surgical outcomes.
In a study described as a landmark achievement, researchers at Texas A&M University supercooled pig kidneys to −4 °C and successfully reimplanted them. The kidneys performed better than those stored on traditional ice, and notably, the process did not require cryoprotectants. This approach avoids the formation of ice crystals, which typically cause severe damage to tissue and render organs unusable during freezing.
Other research teams are exploring different methods to extend organ viability. Machine perfusion systems, which pump nutrients into organs to mimic bodily functions, are now being adapted for a wider range of tissues. These systems have been used to maintain livers and kidneys for up to 24 hours, and recent protocols have successfully kept eyeballs alive, potentially paving the way for whole-eye transplants.
In Valencia, scientists developed a perfusion device nicknamed "Mother" that kept a human uterus alive for 24 hours. Meanwhile, cryopreservation remains a standard practice for cells and embryos, which are cooled to −196 °C and can be stored for decades. However, freezing whole organs remains elusive, and no human organs have yet been successfully cryopreserved and thawed for transplantation.
The field also intersects with cryonics, where bodies or brains are stored at ultra-low temperatures in hopes of future reanimation. For instance, gerontologist Stephen L. Coles had his brain cryopreserved at Alcor in Arizona after his death in 2014. While brain cells showed resilience upon rewarming, experts caution that this does not confirm viability or the potential for reanimation.
MIT Technology Review indicates further coverage on chemical cocktails for lower-temperature storage is forthcoming. As research accelerates, the goal remains to transform organ preservation from a race against time into a manageable logistical process, bringing the dream of widespread organ banks closer to reality.
