Processed coral may be used in bone grafts

A group based at the University of Technology, Sydney has developed a unique method of processing coral, which may allow it to be used in orthopaedic implants.

Prof Besim Ben-Nissan, of the Department of Chemistry, Materials and Forensic Science, and an international team of collaborators have worked out a way to coat processed coral which dramatically increases its biomechanical strength.

"Bone graft products converted from coral can't be used for load bearing implants unless you use metal plates and pins to strengthen them," said Ben-Nissan. "But when coated with Sol Gel HA, we got a 120 per cent increase in mechanical strength."

Before using in bone implants, coral is converted to hydroxyapatite by hydrothermal treatment, then coated with the Sol Gel HA, he said. This covers up the nanopores responsible for the brittle nature of the material, while leaving larger pores open to allow tissue growth into the structure to anchor it.

The Sol Gel coating is based on a colloidal solution, and while not a new technology, coral-coating represents a new use for it, said Ben-Nissan.

Ben-Nissan said he hoped the group could collaborate to further develop the process with commercialisation in mind. "We would like to do animal studies in rats to see if it can be used under load bearing conditions," he explained.

So far, the strength of the material has only been tested under laboratory conditions. If pre-clinical studies are successful, Ben-Nissan, said he hoped that the material would be used in clinical trials.

According to Ben-Nissan, negotiations with an interested company are underway.