Experimental gel may aid bone defect healing

Bone defects in rat tibias injected with Oxiplex healed more extensively at seven and 14 days compared to rats left untreated.

A novel injectable gel developed for percutaneous drug delivery may help accelerate the healing of bone defects, preclinical studies suggest.

The gel — called Oxiplex (FzioMed Inc.) — is a synthetic, bioabsorbable gel made from polyethylene oxide, sodium carboxymethylcellulose and calcium chloride. The company formulated it for use in several surgical applications, including the prevention of postsurgical adhesions in spine, gynecologic and general surgeries.

However, new research involving rats found filling bone defects with the gel resulted in faster healing. Combining the gel with an experimental bone growth factor, called FZ231, further accelerated the healing process, according to a FzioMed press release.

The studies were led by Richard Berg, PhD, vice president of research and development at the company. He presented the results in a poster presentation at the 12th International Meeting on Advanced Spine Techniques (IMAST) held in Banff, Alberta.

In the first study, the researchers showed that Oxiplex could be used for delivering ampicillin without affecting the antibiotic's activity or diffusion.

In the second study, the researchers evaluated the gel's effect on the healing process using an experimental bone defect model. After creating 1.4 mm defects in the right tibias of rats using a dental drill, scientists then either filled the defect with Oxiplex gel, Oxiplex combined with FZ231, or left the defect untreated.

After seven days, control animals had healed 13% ± 5.4% of the defect and Oxiplex-treated animals had healed 27.9% ± 12.42%. At 14 days, control animals healed to 35.6% ± 7.1% and Oxiplex-treated animals healed to 67.9% ± 10.9%. However, at 29 days both control and Oxiplex-treated animals had healed to a similar extent, with about 97% of the defect filled, according to the study.

Rats injected with the Oxiplex gel containing the growth factors had more accelerated healing, the authors noted. At seven days, these rats had healed to 40.7% ± 11.8%, according to the study.

“These results demonstrated the potential for Oxiplex gel to serve as an injectable vehicle for the delivery of a bone growth factor,” the authors said.

Oxiplex/SP is currently approved in the European Union and certain countries outside the U.S. for reducing epidural postsurgical adhesions following discectomy, laminectomy and laminotomy procedures.

For more information:

Berg RA, Rodgers K, et. al. Oxiplex/SP gel spinal adhesion barrier as an injectable drug delivery system for a novel bone growth factor. Presented at the 12th International Meeting on Advanced Spine Techniques. July 7-9, 2005. Banff, Alberta.