Bone that grows in lab may cut need for bone grafts

PUBLISHED : Monday, 12 June, 2006, 12:00am
UPDATED : Monday, 12 June, 2006, 12:00am

University of Hong Kong dental professors have found a way to produce bone in a laboratory that they believe could revolutionise treatment for a wide range of ailments.

The Prince Philip Dental Hospital team mixed a commercial bone graft material with a synthetic human growth factor they developed, eliminating the need for a bone graft.

The research was detailed in the International Journal of Surgery and was awarded first runner-up of the journal's Harold Ellis Prize in Surgery.

They tested the mixture on New Zealand White rabbits. It created 100 per cent more bone after 60 days when compared with using the commercial substance alone.

The team plans to start clinical trials but needs $2 million to start the testing.

If the compound works, it could benefit 'endless number of patients', said Bakr Rabie, professor of orthodontics.

'The range goes from something not as life-threatening as gum disease to tumour resection and having lost bones [as in osteoporosis],' he said.

Doctors now harvest bone from the hip or ribs to graft onto the site where the bone was lost.

But taking bone from patients can lead to pain and complications from having two surgical sites.

'The advantage of what we did was we tried to eliminate the need to take bone from the patient,' Professor Rabie said.

As well as a patient's own bone, doctors also use bone from cadavers. But using such bones risks transmitting diseases, such as Creutzfeldt-Jakob disease, the human equivalent of mad cow disease.

Research has also shown that when grafting a patient's own bone, the patient loses 65 per cent of the graft in the first two years.

'That is why we thought of enhancing that bone by enriching it with a growth factor that resists bone resorption and adds more bone to it,' Professor Rabie said.

The material, called vascular endothelial growth factor, is produced naturally in the body and stimulates new blood vessel formation, which is important in bone healing.

The team made a synthetic version of the growth factor, then combined it with a commercially available bone graft material.

'Now you have both of them working in a very powerful manner that can enhance the bone-forming ability,' he said.

Apart from growth factors, the team has been investigating 10 Chinese herbs and some natural plants for their possible bone-formation ability.

Assistant professor Ricky Wong Wing-kit said one of them was naringin, the substance that gives grapefruits their bitter taste.

Following successful laboratory experiments, 23 patients with gum disease are undergoing a clinical trial using naringin extracts.