In a proof-of-principle study with mice, the bandage helped to accelerate callus formation and vascularisation to achieve better bone repair by three weeks.
The research points toward a general method for improving bone repair after damage that could be applied to medical products such as biodegradable bandages, implant coatings or bone grafts for critical defects. The results appear in the journal Advanced Materials.
While studying how popular biomaterials made of calcium phosphate promote bone repair and regeneration, researchers 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 metabolised and don’t last long.
Adenosine is ubiquitous throughout the body in low levels and performs many important functions that have nothing to do with bone healing. To avoid unwanted side effects researchers had to
find a way to keep the adenosine localised to the damaged tissue and at appropriate levels.
The solution was to let the body dictate the levels of adenosine while helping the biochemical stick around the injury a little bit longer. Researchers designed a biomaterial bandage applied directly to the broken bone that 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, it was first demonstrated that porous biomaterials incorporated with boronates were capable of capturing the local surge of adenosine following an injury. Researchers then applied bandages primed to capture the host’s own adenosine or bandages preloaded with adenosine to tibia fractures in mice.
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.