Boston Children’s Hospital researchers have developed a device that can detect real-time oxygen levels in mitochondria and predict the effect those levels will have on organs.
Their study dealt specifically with predicting heart failure, a common consequence of mitochondrial disease.
The team collaborated with Pendar Technologies on the device’s development. Their article in the journal Science Translational Medicine was titled “Responsive monitoring of mitochondrial redox states in heart muscle predicts impending cardiac arrest.”
“We wanted to create an organ-specific, continuous, reliable readout of how adequately mitochondria are being fed oxygen,” Dr. John Kheir of Boston Children’s Heart Center, co-senior author of the study, said in a news release. “This is the first demonstration of a device that can monitor mitochondria in living tissues to predict impending organ failure.”
Mitochondria are cell components that generate the energy necessary for cells to function properly. They use oxygen to convert nutrients to energy. When oxygen levels are too low, mitochondria cannot produce the energy that cells need. This means cells can no longer function properly, and the result can be tissue and organ damage.
The researchers developed a device to check whether enough oxygen is reaching mitochondria, and if mitochondria are working properly. They call it 3RMR.
When mitochondrial are working normally, energy will flow throughout the body. When low oxygen levels impair energy production, the energy stays in mitochondria rather than going elsewhere.
3RMR harnesses resonance Raman spectroscopy to detect energy changes.
When a laser shines light into tissue, the light is scattered in different patterns, depending on the amount of energy that has accumulated in mitochondria. Resonance Raman spectroscopy records the light patterns, providing a real-time view of how mitochondria are functioning.
“This system tells us how satisfied the mitochondria are with their oxygen supply,” Kheir said.
“Distinguishing mitochondrial signals from other biological signals with accuracy and speed was the most significant scientific advance here,” said Dr. Daryoosh Vakhshoori, CEO of Pendar and co-senior supervisor of the study.
The team tested the device in a rat model of mitochondrial disease that was affecting the heart. It recorded with almost perfect accuracy changes in heart-tissue oxygen levels that were predictive of reduced heart function and cardiac arrest. The device outperformed all other heart-function measurement techniques commonly used.
Researchers also tested the device during simulated congenital heart surgery in a pig with mitochondria-related cardiac problems. The experiment showed that the device can be used to monitor in real time whether heart muscle is healthy or not during an operation. This is something that is not possible with currently available techniques, the team said.
“With current technologies, we cannot predict when a patient’s heart will stop,” Kheir said. “Our likely first application of this device will be to monitor oxygen delivery during and after heart surgery.”
The team will continue developing the device so it has broader diagnostic use. Researchers will also seek U.S: Food and Drug Administration approval to market the device and to test it to monitor patients’ heart activity.