Packing injured bone with synthetic bone material can speed regeneration, allowing even severe injuries involving missing bone or multiple fractures to resolve. Here researchers report on improvements to this class of approach, coercing the behavior of natural processes of bone growth and resorption to be more amenable to the regeneration that is desired.
Researchers have developed a way of combining a bone substitute and drugs to regenerate bone and heal severe fractures in the thigh or shin bone. The study was conducted on rats, but the researchers think that the method in various combinations will soon be commonplace in clinical settings. "The drugs and materials we used in the study for the regeneration of bone are already approved. We simply packaged them in a new combination. Therefore, there are no real obstacles to already using the method in clinical studies for certain major bone defects that are difficult to resolve in patients."
Bones in the human body have a fantastic ability to repair injury, but some defects are so large or complicated that the healing process is delayed or absent. This may be due to the bone having been subjected to a major trauma in connection with a traffic accident for example, or a tumour or infection causing a major bone defect. These cases are currently treated through bone transplantation, usually with bone taken from the patient's own pelvis.
So far, the injectable cocktail successfully mixed by the researchers consists of three different components: an artificial ceramic material, a bioactive bone protein (recombinant BMP-2) and a drug, bisphosphonate, that combats bone resorption. "The bone protein we use has had negative effects in previous studies due to a secondary premature bone resorption, among other things. We have successfully mitigated this effect with the bisphosphonate and, by packaging the drug in a slowly resorbing bone substitute, we can control the speed of release. In the current study with the combination, we achieved a six-fold reduction in the amount of protein compared to previous efforts, while still inducing bone formation. The result was that even fractures with an extensive bone defect could heal without complications. We believe this finding will be of great clinical use in the future."