Mending a broken bone may become a lot easier with a new bandage engineered by researchers at Duke University. The bandage can capture and retain a molecule that promotes healing at the site of the break.
In the study, the researchers suggest a novel method that could improve bone repair after damage, and can be incorporated into products such as implant coatings, bone grafts for critical defects or biodegradable bandages.
The healing molecule - adenosine
Adenosine, a biomolecule that is naturally found in the body, can play an important role in healing bone breaks the researchers found. "Adenosine is ubiquitous throughout the body in low levels and performs many important functions that have nothing to do with bone healing," said Shyni Varghese, lead author of the study.
While studying the effectiveness of popular biomaterials made of calcium phosphate in promoting bone repair and regeneration, they discovered that adenosine plays an important role in the stimulation of bone growth. Employing mice for the study, they found that when adenosine molecules are concentrated around the area of the break, blood floods to the area naturally. However, these localized levels of adenosine were metabolized by the body quickly.
This led the researchers to speculate if the availability of adenosine for longer duration could support the healing process. "To avoid unwanted side effects, we had to find a way to keep the adenosine localized to the damaged tissue and at appropriate levels," said Varghese.
The researchers designed a biomaterial bandage that contained boronate molecules that grab onto the adenosine and were directly applied to the damaged bone. Nevertheless, the bonds between the molecules are not permanent. This aids in the slow release of adenosine from the bandage only at the site of the break.
In the current study, they demonstrated that porous biomaterials incorporated with boronates were able to capture the localized increase of adenosine after an injury. Next, they applied bandages programmed to capture the host's own adenosine or bandages preloaded with adenosine to tibia fractures in mice.
After a week, the mice treated using the bandages showed better healing than those that were treated with bandages not primed for adenosine capture. After three weeks, the mice treated with either kind of adenosine containing bandages exhibited higher bone volume and better bone formation.
The researchers deliberated on the potential applications in human beings. While they work in mice, understanding the possible outcomes in human beings is the next step of their research. "The bandages could be engineered to capture and hold on to adenosine more efficiently. And of course we also have to find out whether these results hold in humans or could cause any side effects," said Varghese.