In their study, the researchers, from the UK and China, harvested sea coral from South China and partially converted the calcium carbonate into CHA to form CHACC.
According to the paper, the CHACC composition, which contains 15 per cent of CHA in a thin layer around the calcium carbonate, has the strong, porous structure that has made CHA commercially successful, but contains significantly improved biodegrading properties to support natural bone healing.
In their study, the researchers constructed CHACC and tested its physical and chemical properties using a number of microscopic and spectroscopic techniques. The CHACC was then mixed with human mesenchymal stem cells and implanted subcutaneously in mice for 10 weeks. The results showed that new bone formation was visible on the surface of the CHACC.
In a preliminary clinical study, 16 patients (11 male and five female) with a range of four different bone defects were surgically implanted with CHACC. Results showed there was clinical bone healing four months after surgery and the majority of the implanted CHACC degraded after 18 to 24 months in each patient.
Bone remodelling can be a complex and slow process by which old bone is continuously replaced by new bone tissue. In the case of fracture healing, the complete remodelling phase can take between three and five years depending on the individual, so a synthetic bone graft must biodegrade within a time window that relates to the natural bone remodelling cycle.
The researchers acknowledge that there is some way to go until the material can match the benefits of an autograft and be used on the several million people worldwide who undergo bone grafting procedures each year.
"Although our study has provided promising results, the CHACC material does not contain a bone organic matrix, living cells and the ability to
|Contact: Michael Bishop|
Institute of Physics