IInspired by the way cafes bake milk, as well as sticky candies and crunchy pop rock, the researchers designed three gas-trapping materials to deliver a low dose of carbon monoxide to the body for potential treatment of gastrointestinal disorders.
Carbon monoxide is fatal when inhaled at high concentrations, but the team’s results, published in Science Translational Medicine on Wednesday, show that the three systems – using foam, hydrogel and solid – can efficiently deliver carbon monoxide to mice. The foam method was found to reduce tissue injury and inflammation in mouse models of chemically induced colitis, radiation-induced proctitis, and liver damage due to acetaminophen overdose, and was also tested in pigs.
The foam gas trap, or GEM, is inspired by the breakwater siphons used at Starbucks, said James D. Byrne, the study’s first author and now an assistant professor of oncology and biomedical engineering at the University of Iowa Health Care. The researchers made their own breaking siphon and put it at a pressure of up to 200 psi, almost seven times the pressure of a car tire. They were able to trap carbon monoxide in small bubbles in the GEM foam.
Because the invention is simply a pressure system, it can be easily transported and used in different parts of the world, said Byrne, who worked on the research as a postdoctoral fellow at the Massachusetts Institute of Technology. The team also tested a carbon monoxide gel using what Byrne described as “ionic cross-linked sodium alginate in calcium chloride solution,” in other words, a sticky bear-type system.
“One of the key goals from the beginning was to really use low-cost starting reagents or ingredients, one for scalability and a product that is viable, not just efficient,” said Giovanni Traverso, an assistant professor in mechanical engineering. engineering at MIT and co-author.
Finally, the team went to YouTube to see how Pop Rocks are made, and applied the same strategy to make solid GEMs that would allow controlled release of carbon monoxide in the gut.
Although toxic at high levels, carbon monoxide is considered a potential therapeutic agent that can modulate inflammation, said Leo E. Otterbain, a professor of surgery at Beth Israel Deaconess Medical Center and the other co-author.
Inhaled carbon monoxide has been shown to help patients with respiratory distress and has been tested on patients with lung disease in ongoing clinical trials. “There are 30 walking people who have been treated with carbon monoxide during their kidney transplant,” he added.
Because rectally applied foam delivers carbon monoxide directly to the affected areas of the gastrointestinal tract, this reduces the amount of CO required. The team found that carbon monoxide can relieve bowel damage and inflammation of the colon. Then, as the blood from the intestines drained into the liver, they found that it could also deal with inflammation of the liver.
“Any therapeutic agent, including food or water, is toxic when taken at certain levels,” Traverso said. “It’s important to recognize that when delivered or administered properly, things can also benefit.”
Producing adequate amounts of foam for humans and ensuring that it meets the Food and Drug Administration’s safety standards will require more work, said Joseph Oniya, an assistant professor of gastroenterology at the University of Colorado School of Medicine who did not participate in the study. .
The researchers then plan to increase the pressure of the breaking siphon to trap and release more carbon monoxide with more smaller bubbles inside the foam. This would reduce the amount of material that needs to be delivered to patients.
“We give rectal formulations all the time and they are usually well tolerated by patients, but they do not necessarily want to stay in them indefinitely,” said Oniya, stressing the need for more tests to improve a longer-lasting and ideally formula once a day.
Researchers say the foam can be delivered rectally or orally. And GEM has applications far beyond the gut. Otterbein noted that the captured gases could be useful for the Ministry of Defense when, for example, it has to deliver long-distance oxygen cylinders to the front lines of conflict.
“I’m impressed with the innovative approach that combines traditional research with techniques that use gastronomy to come up with a viable product,” Onyiah said. “It’s out of the box.”