Researchers from Queen Mary, University of London and University of Twente have discovered that ceramic particles made of calcium phosphate act like signaling beacons to attract stem cells and growth factors to the site of an artificial bone graft. Calcium phosphate is the main ingredient of bone and it is hoped that it will be used as an alternative to autologous bone grafting.
The researchers tested natural bone grafts against ceramic particles with varied structural and chemical properties. They found that micro-porous ceramic particles composed of calcium phosphate, the primary component of bone ash, induced stem cells to develop into bone cells in the test tube and stimulated bone growth in live tissue in mice, dogs and sheep.
Bone injuries packed with the ceramic particles healed similarly to implants constructed from the animals’ own bone, reports Professor de Bruijn along with collaborators from the University of Twente, Netherlands, in the journal Proceedings of the National Academy of Sciences. The study also shows how it also matches a commercially available product that contains artificial growth factors and has the undesirable side-effect of causing bone fragments to form in nearby soft tissue, such as muscle.
Although the researchers have not yet identified the mechanism that drives bone growth in the synthetic implants, they note that variations in the ceramic material’s chemistry, micro-porosity, micro-structure, and degradation influence the graft’s performance.
The study suggests that biomaterials-based bone grafts can manipulate cell behaviour in order to repair injury, and one day may be used to repair bone injuries in humans.
Press release: Synthetic bone graft recruits stem cells for faster bone healing …
Abstract in PNAS: Osteoinductive ceramics as a synthetic alternative to autologous bone grafting