Researchers at the University of Utah have created a synthetic version of the superglue that sandcastle worms combine with sand and shell to build their sturdy tube-shaped homes, and believe that it may one day be used to repair shattered bones in knees, other joints and the face.
"You would glue some of the small pieces together," says Russell Stewart, associate professor of bioengineering, and senior author of the study to be published online within a week in the journal Macromolecular Biosciences.
"When you break the top of a bone in a joint, those fractures are difficult to repair because if they are not aligned precisely, you end up with arthritis and the joint won't work anyway. So it's very important to get those pieces aligned as well as possible," he adds.
He says that this glue may be tested on animals within a year or two, and on humans in five to 10 years.
Stewart has made it clear that the synthetic sandcastle worm glue will not be suitable for repairing large fractures such as major leg and arm bones, for which rods, pins and screws are used.
He, however, envisions that it may be used for gluing together small bone fragments in fractured knees, wrists, elbows, ankles, other joints, and the face and skull.
"If a doctor rebuilds a joint with pins and screws, generally weight is kept off that joint until it's healed. So our goal isn't to rebuild a weight-bearing joint with glue. It is to hold the pieces together in proper alignment until they heal. ... We see gluing the small fragments back into the joint," Stewart says.
In their study report, the researchers wrote: "It is especially difficult to maintain alignment of small bone fragments by drilling them with screws and wires. An adjunctive adhesive could reduce the number or volume of metal fixators while helping maintain accurate alignment of small bone fragments to improve clinical outcomes."
Bioengineer Patrick Tresco, associate dean for research at the University of Utah's College of Engineering, says: "Most current adhesives do not work when surfaces are wet so they are no good for holding together bone, which is wet and bloody. There is nothing like it (the synthetic worm glue) on the market today."
The researchers also say that the synthetic glue can deliver pain killers, growth factors, antibiotics, anti-inflammatory medicines or even stem cells to sites where bone fragments are glued, "simultaneously fixing the bone and delivering potent drugs or even genes to the spots where they are needed."
According to them, it may also be used to firmly attach "tissue scaffolds" where pieces of bone are cut out due to cancer, in order to encourage regrowth of the missing bone.
Stewart hopes to make better versions that have more bonding power, are biocompatible in the human body and biodegradable.
"Ultimately, we intend to make it so it is replaced by natural bone over time. We don't want to have the glue permanently in the fracture." Stewart says some synthetic superglues or "instant glues" are used instead of sutures for superficial skin wounds. But because of toxicity or toxic byproducts, "they are not suitable for deep tissue use," including bone repair, he says.