Worm glue could mend fractures

By Lana Groves, Asst. News Editor

The simple glue that holds a sandcastle worm’s home together is also strong enough to hold bones together and repair fractures.

By observing the ability of a sandcastle worm to secrete glue, U researcher Russell Stewart has re-created the chemical quality of the glue to design a type that could mend fractures without needing screws to hold small bones together.

“This glue is chemically very much different than the common superglue,” Stewart said. “I’m not aware of any other adhesives used for repairing bone fractures in a clinic.”

The glue the worm makes from a major organ in the thorax can’t be used in a human because the body’s immune system would reject it.

Researchers have been studying marine bioadhesives for years, and researchers in the early 1900s observed the sandcastle worm’s self-made glue to see if it could be used for medical purposes.

Stewart said it’s only now with advanced analyzing instruments that he and members of his laboratory have been able to copy the glue and make sure it isn’t toxic for humans.

Within the next year, Stewart said his group will begin animal tests on rats to see how the glue performs and whether any part of it is toxic.

“We have to make sure there’s not a strong reaction by a living organism to the material,” he said. “We expect it’s going to have low toxicity and be bio-capable.”

Hui Shao, a doctoral biomedical engineering student, said they have tested the glue on cow bones bought from a grocery store, but they still need to find a way to make the glue dissolve in the body over time.

“We don’t want the glue to stay in the body for a long time,” she said.

Yet even with that, Stewart said the glue will probably only work on small fractures, such as broken fingers, that require screws to stay in place with a cast. Broken leg or arm bones will still need a cast to hold together.

This is partly because the glue is not as strong as the average superglue. Stewart said the sandcastle worm glue is 37 percent as strong as superglue, but the body is less likely to reject it.

The glue also brings another healing solution to the table, researchers say.

Besides holding small bones in place, because of the glue’s water-soluble quality, it has the potential to contain medicines for better healing.

“It can simultaneously fix the fracture and deliver a medicine that could help fix the fracture,” Stewart said.

For now, researchers are continuing tests on cow bones and hope to move on to clinical trials in the next four years.

The study will be published next week in the journal Macromolecular Bioscience. Stewart will attend the Adhesion Society Annual Meeting in February in Georgia to discuss the bioadhesive and other possible bioadhesives created in nature.

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University of Utah

U bioengineer Russell Stewart looks over a chunk taken from a sandcastle worm colony. Stewart has developed a synthetic version of the glue that the worms use to make the sand castle that has the possibility of being used to glue together small pieces of bones.