A team of materials scientists, bioelectronics experts, and medical researchers have teamed up to produce the world’s first-known device that monitors transplanted organs for signs of impending rejection. Smaller and thinner than the average pinky fingernail, the tiny interface can communicate physiological fluctuations to a patient’s medical team. While researchers have only tested the device in rodents, they believe their technology could help save human lives.
The weeks immediately following an organ transplant are highly stressful ones. With up to a 40% chance of experiencing rejection, patients must undergo constant monitoring to ensure their immune systems won’t fight off the new organ. Though immunosuppressive medications reduce the odds of rejection, doctors still have to watch for warning signs from tremors, nausea, and extreme fatigue to internal inflammation and infection. The latter are often found via biopsy, but beyond being invasive and expensive, they can be dangerous for immunocompromised patients. For kidney transplants, in particular, urine tests can help reveal signs of rejection, but the changes these tests rely upon don't occur until rejection has already begun to take hold.
This new device could alleviate healthcare workloads while providing consistent, long-term rejection monitoring in a non-invasive way. As described in the journal Science, the device is just 0.3 centimeters wide, 0.7 centimeters long, and 220 microns thick, making it easy to implant within an organ waiting for transplant. Once inside the recipient’s body, the device collects data involving the organ’s temperature and thermal conductivity—two windows into the health of newly transplanted tissue. A small package containing a battery and wireless transmitter sits beside the organ, connected to the device by a short cord. This lets the device communicate data to the patient’s medical team in real time.
The team, which consisted of researchers from both Northwestern University and the University of Chicago, tested their device in rats that had undergone kidney transplants. They found that the interface revealed concerning temperature and conductivity changes three weeks earlier than conventional monitoring methods. Though the device has yet to be used with human physiology, the results of the rodent test are promising: The earlier warning signs are spotted, the earlier doctors can intervene.
"If rejection is detected early, physicians can deliver anti-rejection therapies to improve the patient’s health and prevent them from losing the donated organ,” said John Rogers, a Northwestern University bioelectronics researcher who led the device's development. “In worst-case scenarios, if the rejection is ignored, it could be life-threatening. The earlier you can catch rejection and engage therapies, the better. We developed this device with that in mind.”
