Matthew Powell Palm supercools pig kidneys for 72 hours, reversing organ storage limits

In organ donation, time is not a scheduling problem. It is a biology problem. Once a kidney is removed, it starts to deteriorate, and surgeons typically have only hours to get it into a recipient. In most cases, kidneys are kept on ice at around 4 °C (39 °F), which limits storage to roughly 24 hours. Matthew Powell Palm at Texas A&M University and his colleagues are now challenging that ceiling. In new pig research, they used a device to cool kidneys to -4 °C (25 °F) without forming ice, and the organs still recovered after being stored for days.

The headline number is 72 hours. Kidneys supercooled for 72 hours were transplanted back into the original donor pigs, and the organs recovered and appeared to be working normally within about 10 days. Powell Palm also reports that kidneys stored for 48 and 72 hours performed similarly, and even a 72-hour kidney “recovers once it is transplanted back into a pig.” Once the 24-hour supercooled kidneys were transplanted, they “immediately began producing urine,” a key indicator of kidney function. For context, that recovery timing is the real operational pain point with longer preservation. Heidi Yeh, a transplant surgeon at Mass General Brigham for Children who also researches organ preservation technologies, says kidneys stored for 48 hours in other studies often take a week or two before they start working again.

So what exactly is Powell Palm’s approach? The device is essentially a hermetically sealed chamber with a transparent lid. At its base, it monitors the organ’s temperature and checks for ice formation. The kidneys are submerged in a solution that is already commonly used to preserve transplant organs, and the team aims to keep the temperature a little below 0 °C without freezing. The thermodynamics idea is straightforward: cooling slows metabolism, and keeping constant pressure helps prevent ice from forming, avoiding the damage that ice crystals can cause. Just as important for clinical translation, the researchers say the process does not require cryoprotective chemicals, which in earlier routes have been a sticking point because of potential side effects and the need for approval before use in human transplants.

The experimental design is built like a systems test, not a curiosity experiment. Powell Palm and colleagues removed single kidneys from pigs, flushed them with the same commonly used preservation solution to remove blood, and then compared storage conditions. Some kidneys were kept on ice for either two hours or 24 hours, mimicking standard conditions used in human transplantation. Others were placed into the supercooling device for 24, 48, or 72 hours. Each stored kidney was then transplanted back into the original donor pig by removing the pig’s other kidney and reimplanting only the stored one, isolating the effect of the storage method. After transplantation, the team tracked kidney function markers and also measured longer-term growth and health. Over a 30-day period, the pigs grew by around 30 percent, and the kidneys grew with them, almost doubling in size to compensate for both the pigs’ growth and the lack of a second kidney. The team monitored one pig for 200 days, and Powell Palm says the kidney still looked healthy at the end.

Executives should care because this is not just “cooler science.” It is a logistics lever for an industry that bleeds time. In the US, there are more than 104,000 people waiting for a kidney transplant, and it’s estimated that 17 people die every day while waiting. Myer says that’s partly due to a lack of donated kidneys, but also because many available kidneys never make it to recipients. In some years, around one in three donated kidneys ends up discarded, often because it becomes too degraded by the time it reaches a recipient. The conventional ice-based window is one of the obvious failure points. Myer of LifeGift, an organ procurement organization based in Texas and not involved in the research, argues that scientists and clinicians need more time for evaluation, matching, and transport. “Today,” he says, kidneys can be stored on ice for around 24 hours, and devices that mimic body conditions also target up to around 24 hours. That may be too short to find a suitable recipient and physically move the organ.

This is why Powell Palm frames extra hours as a potential “change everything” moment. Myer says the assumed limit for kidney transplantation is 18 to 24 hours, and if the window could extend to 72 hours, it would open new possibilities like international donations and cheaper transport options. There are also second-order incentives for boards and operators at tissue banks and procurement orgs: longer preservation windows can reduce discard rates by making it more likely that an organ stays within usable quality thresholds when a match is found.

Regulators and clinical development plans now enter the picture. Because Powell Palm’s method doesn’t require cryoprotective chemicals, the team hopes for an accelerated approval from the US Food and Drug Administration to test the device in human transplantations. That hope is not a guarantee, but it signals a potential path where the hard part is not only biology, but paperwork. The group presented findings at the American Transplant Congress in Boston last month, and Powell Palm says they may even push beyond 72 hours. Preliminary studies suggest organs stored for up to 120 hours appeared healthy, although those organs have not yet been transplanted. On the operational side, Powell Palm says the device is simple and compact, and that it has been used to transport supercooled kidneys across the US in the back of a Kia Sorento. It has not been tested for air travel yet, but Powell Palm views the stability as a high bar because the system is designed to maintain conditions and monitor ice formation.

Finally, there is an early-company signal that matters for investors and operators: Powell Palm and colleague Sebastian Giwa plan to launch a company dedicated to developing the technology, along with other protocols that “stop biological time,” in the coming months. If this moves from pigs to humans, the payoff is bigger than a better cooler. It is a chance to stretch the donation pipeline, reduce wasted organs, and give transplant teams more real-world slack. In a system where time kills eligibility, “days instead of hours” is not incremental. It is competitive advantage for every stakeholder that touches matching, logistics, and outcomes.