Sandcastle Worms Help Create New Bone Adhesive

The sandcastle worm got its name from its ability to synthesize a glue in order to build a protective home out of sand grains and shell fragments found on the seafloor. The strength of the adhesive is impressive, and researchers at the University of Utah have managed to replicate it synthetically hoping to create a material that may help repair bones without the use screws, pins, and other woodworking tools that Zimmer and DePuy are famous for.

Russell Stewart’s challenge was to devise a water-based adhesive that remained insoluble in wet environments and was able to bond to wet objects. The team also concentrated on key details of the natural adhesive solidification process — a poorly timed hardening of the glue would make it useless, Stewart said. They learned the natural glue sets in response to changes in pH, a mechanism that was copied into the synthetic glue.
The new glue, says Stewart, a bioengineer at the University of Utah in Salt Lake City, has passed toxicity studies in cell culture. It is at least as strong as Super Glue and is twice as strong as the natural adhesive it mimics, he notes.
"We recognized that the mechanism used by the sandcastle worm is really a perfect vehicle for producing an underwater adhesive," Stewart said. "This glue, just like the worm’s glue, is a fluid material that, although it doesn’t mix with water, is water soluble."
Stewart has begun pilot studies focused on delivering bioactive molecules in the adhesive that could allow it to fix bone fragments and deliver medicines to the fracture site, such as antibiotics, pain relievers or compounds that might accelerate healing.