A new bone-healing material: a hyaluronic acid-like bacterial exopolysaccharide.

Critical size defect (CSD) technique was used to evaluate the bone regeneration capacity of a newly discovered hyaluronic acid-like exopolysaccharide synthesized by a bacteria originating from a deep sea hydrothermal vent. A 5 mm-diameter hole was made on each parietal bone of male rats. The right hole was filled with either a new bacterial exopolysaccharide referenced HE 800 or with collagen used as negative control, while the left hole remained free of any treatment. After 15 days, the holes and surrounding tissues were examined by direct examination, X-ray films, and histological staining. Using HE 800, bone healing was almost complete after only 15 days, with osteoblasts onto lying external bone surfaces and enhancing osteocyte inclusion. Neovascularization was also observed along with an organized trabecular bone. No abnormal bone growth or conjunctival abnormalities were noticed. At the end of the experiment, 95.9% (+/-6.2) bone healing (n = 20) was observed. Conversely, the collagen-treated animals did not demonstrate significant healing-17.8% (+/-18.1).