Pigs' Kidneys Preserved For Days at Sub-Zero Temperatures

Researchers have successfully preserved pig kidneys for several days at temperatures as low as -4°C (25°F), marking a significant advancement in the quest for long-term organ storage. These supercooled kidneys were later successfully reimplanted into pigs, demonstrating their viability. This breakthrough addresses the critical shortage of donor organs, which is largely due to their limited survival time outside the body, typically only a few hours even when kept on ice.

The ability to preserve organs for extended periods would revolutionize transplantation by allowing for thorough testing, optimal recipient matching, and more flexible transportation logistics. A major hurdle in organ preservation has been the damaging effect of ice crystal formation when organs are frozen. Ice crystals cause cellular damage that renders organs unusable for transplantation.

While cryopreservation, a process of rapid extreme cooling that vitrifies cells into a glass-like state, is routine for gametes and embryos, it has not yet been achieved for whole human organs. This technique involves cooling to -196°C in under two seconds, allowing for storage for decades. Despite the challenges, many researchers continue to explore methods for organ preservation, including efforts to cryopreserve entire human bodies and brains with the hope of future reanimation.

One notable case involved the cryopreservation of gerontologist Stephen L. Coles's brain. Following his death in 2014, his brain was perfused with cryoprotective agents, removed, and cooled to -146°C at the Alcor cryonics facility in Arizona. This ongoing research highlights the diverse approaches and persistent efforts within the scientific community to overcome the biological limitations of organ viability.