Researchers have successfully supercooled and preserved pig kidneys at −39 °F (25 °F) for several days before successful re-implantation. This milestone suggests a shift from relying on immediate donor availability to a future where organs can be stored, tested, and transported with much greater flexibility. (source)
The core problem is a race against time. Currently, most human organs can only survive for a few hours outside the body. This limitation creates a massive shortage, as doctors cannot easily store organs for later use. To fix this, scientists are exploring methods to keep organs "alive" without them deteriorating or forming destructive ice crystals.
Isochoric supercooling is the primary breakthrough here. Unlike standard freezing, which creates jagged ice crystals that shred cell membranes, isochoric supercooling keeps the organ's volume constant. By preventing the pressure changes that trigger ice formation, researchers can drop the temperature significantly. In a recent study, pig kidneys—which are similar in size to human ones—were maintained at −39 °F (25 °F) for multiple days. When rewarmed and transplanted, the animals survived for 30 days with stabilized kidney function.
Cryopreservation remains a separate, more extreme challenge. While we can routinely cryopreserve eggs and embryos at −385 °F in under 2 seconds, human organs are much larger and more complex. While some individuals, like gerontologist Stephen L. Coles, have had their brains cooled to −295 °F for future study, we cannot yet safely thaw and transplant complex organs from such extreme states.
Machine perfusion offers a different, but complementary, path. Instead of extreme cold, these devices mimic the human body by pumping nutrient-rich fluids through the organ. This technology is already standard for livers and kidneys, typically maintaining them for 24 hours. Scientists are now expanding this to other parts of the body, including:
- Uteruses, which were kept alive for a full day using a custom perfusion system.
- Eyeballs, which may soon be eligible for whole-eye transplants.
- Kidneys, which are being adapted for longer durations using hybrid cooling methods.
The goal is a functional organ bank.
