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Bone Bandage Soaks Up Pro-healing Biochemical
Researchers at Duke University have engineered a bandage that captures and holds a pro-healing molecule at the site of a bone break to enhance the natural healing process.
In earlier research, Shyni Varghese, professor of biomedical engineering, mechanical engineering and materials science, and orthopedics at Duke, and her laboratory team discovered that the biomolecule adenosine plays a particularly large role in spurring bone growth. After further study, they found that the body naturally floods the area around a new bone injury with the pro-healing adenosine molecules, but those locally high levels are quickly metabolized and don't last long. Varghese wondered if maintaining those high levels for longer would help the healing process.
But there was a catch.
"Adenosine is ubiquitous throughout the body in low levels and performs many important functions that have nothing to do with bone healing," Varghese said. "To avoid unwanted side effects, we had to find a way to keep the adenosine localized to the damaged tissue and at appropriate levels."
Varghese's solution was to let the body dictate the levels of adenosine while helping the biochemical stick around the injury a little bit longer. She and Yuze Zeng, a graduate student in Varghese's laboratory, designed a biomaterial bandage applied directly to the broken bone. The bandage contains boronate molecules that grab onto the adenosine. However, the bonds between the molecules do not last forever, which allows a slow release of adenosine from the bandage without accumulating elsewhere in the body.
In the current study, the researchers first demonstrated that porous biomaterials incorporated with boronates were capable of capturing the local surge of adenosine following an injury. The researchers then applied bandages primed to capture the host's own adenosine or bandages preloaded with adenosine to tibia fractures in mice.
After more than a week, the mice treated with both types of bandages were healing faster than those with unprimed bandages. After three weeks, while all mice in the study showed healing, those treated with either kind of adenosine-laced bandage showed better bone formation, higher bone volume and better vascularization.
The results showed that not only do the adenosine-trapping bandages promote healing, they work whether they're trapping native adenosine or are artificially loaded with it, which has important implications in treating bone fractures associated with aging and osteoporosis.
Source: Science Daily News, December 13, 2019