Ceramic Bone Graft Material Stimulates Bone Regrowth

Scientists from the School of Engineering and Materials Science at Queen Mary, University of London and the University of Twente (Enschede, Netherlands) have developed a material for bone grafts that could one day replace natural bone implants, today's gold standard for bone-replacement applications. As reported in the Proceedings of the National Academy of Sciences, the researchers show how particles of a ceramic material called calcium phosphate, the primary component of bone ash, can stimulate promising bone regrowth by attracting stem cells and 'growth factors' to promote healing and the integration of the grafted tissue.

"The rate of bone repair we see with these materials rivals that of traditional grafts using a patient's own bone," explains Joost de Bruijn. "And what sets it apart from other synthetic graft substitutes is its ability to attract stem cells and the body's natural growth factors, which coincide to form new, strong, natural bone around an artificial graft."

Comparing natural bone grafts with ceramic particles featuring varied structural and chemical properties, the scientists found that microporous ceramic particles composed of calcium phosphate induced stem cells to develop into bone cells and stimulated bone growth in mice, dogs, and sheep. Bone injuries treated with the ceramic particles exhibited similar healing properties to implants constructed from the animals' own bone, the researchers say. The study also shows that the results achieved by using the ceramic material match those using a commercially available product containing artificial growth factors. That material, however, 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, microporosity, microstructure, and degradation influence the graft's performance. The study also suggests that biomaterial-based bone grafts can manipulate cell behavior to repair injuries.

For a sampling of articles on bone-replacement technologies, see "Rattan Graduates from the Living Room to the Bone-Replacement Lab," "Bone-Replacement Material Sets Hard upon Implantation," and "Scientists Create Bioglass Nanofibers for Bone Regeneration." Or visit www.qmed.com/mpmn for many other articles on bone implant strategies.