NEW YORK (Reuters Health) – A microfluidic device delivered oxygen to blood intravenously, in real time, in experiments in human donor blood and in rats, cvs omeprazole 42 researchers say.
“This work is a… proof of concept that a microfluidic device can be used to create gas bubbles for intravenous (IV) gas delivery on demand,” Dr. John Kheir of Boston Children’s Hospital told Reuters Health by email.
However, he added, “Scale up, and the control and reliability of the devices are all major challenges” to bringing the device to the clinic.”
“COVID-19 and many other forms of critical illness can damage the lungs and compromise systemic oxygen delivery. Cells that are very active cannot tolerate deficiencies in energy production that result from oxygen deprivation. Hypoxemia that lasts even a few minutes can turn a healthy person into a neurologically devastated patient for life, and when refractory it is often lethal,” Dr. Kheir and colleagues write in Proceedings of the National Academy of Sciences.
Severe hypoxia refractory to standard care, they add, “requires skilled caregivers and use of specialized equipment (e.g., extracorporeal membrane oxygenation).”
The team’s microfluidic device could potentially support patients by delivering oxygen gas directly into the bloodstream on demand, using a process called sequential shear-induced bubble breakup.
By infusing oxygen gas into a liquid solution and passing the solution through a series of increasingly narrow nozzles to form micron-sized and nanometer-sized bubbles of oxygen via velocity-induced shear, the team is able to create oxygen bubbles that are smaller than a single red blood cell.
The bubbles are coated with a lipid membrane similar to other cell membranes, which prevents them from merging with other bubbles to create larger ones; provides a path for oxygen to diffuse out and into the blood; and minimizes the likelihood of material-related toxicities.
The device also allows the user to control the dosage of oxygen delivered.
Experiments on donor human blood showed that IV oxygenation could raise blood oxygen saturation from 15% to more than 95% within seconds to minutes, and experiments on rats showed oxygen levels rising by around 20%-50% above baseline levels after intravenous oxygenation.
Dr. Kheir added, “We are primarily focusing on ways to administer oxygen to the bloodstream through a syringe at this time. This work – generating oxygen on demand – has many scale up and other issues that will need to be navigated prior to clinical use.”
Dr. Thomas Kilkenny, Associate Director of Pulmonary Critical Care at Staten Island University Hospital and Associate Professor at the Zucker School Medicine at Hofstra Northwell in New York commented on the study by email.
“The technique of encapsulating usable oxygen into microscopic lipid O2 microparticle ‘packets’ that can then be infused into a patient is a unique method” to increase oxygen delivery to failing organs, he said.
“The technique is still at the bench research level and much further testing needs to be accomplished in animals and then in humans,” he said. “Many other items need to be worked on, such as safety in humans, dosing, storage and, ultimately, delivery of the treatment at the bedside.”
“This type of treatment is years from the patient’s bedside,” he said. “However, if all works out as planned it would revolutionize the care of critically ill patients. The ability to provide increased oxygen delivery to a patient’s organs through an artificial and apparently endless means would be a game-changer in the intensive care unit.”
SOURCE: https://bit.ly/3jc3RJn Proceedings of the National Academy of Sciences, online March 21, 2022.
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