Pam Harrison

TORONTO (Reuters Health) - French investigators have observed exceptional bone regeneration in a short period of time in animal models in which material produced by deep-sea bacteria was used to heal experimentally induced defects.

The findings were presented here during the 22nd annual meeting of the American Society of Bone and Mineral Research.

Dr. Philippe Zanchetta, a doctoral student from the Dental University in Brest, and colleagues evaluated the regenerative properties of an exopolysaccharide secreted by Vibrio diabolicus, which is found in deep-sea hydrothermal vents.

Holes 5 mm or 8 mm in diameter were drilled into parietal bones in 10 male rats and filled with the bacterial polysaccharide. Two other polysaccharides were tested in control animals. The rats were sacrificed between 15 and 28 days later.

On direct examination, x-ray, histologic staining and other measurements, the investigators observed complete bone healing in the holes treated with the bacterial polysaccharide in only 15 days. This healing was associated "with perfect collagen fiber orientation, osteoblasts lying on external bone surfaces and osteocytes," they report in a meeting abstract.

In contrast, either no or only modest bone healing was observed with the control polysaccharides, Dr. Zanchetta noted.

The investigators also tested the bacterial polysaccharide in culture, where they observed enhanced cell proliferation and mineralization within 5 days. No mineralizing medium was necessary to produce this effect, Dr. Zanchetta indicated. "And when we used the exopolysaccharide in human osteoblasts, we observed mineralization within 45 days." Cortical and trabecular structures were observed in human osteoblast cultures as well, he said.

The French team has patented the new material and is hoping to attract an industrial partner to pursue its use as a bone-healing compound. They expect that the new material could be injected into any fracture site or be used to facilitate dental implant osteointegration.

(From Reuters Heath)