Wild mussels inspire superstrong glue for fetal surgery

The biggest risk involved in performing surgery on a fetus is that the protective amniotic sac must be broken, and repairing it is no easy task. It’s so fragile that surgeons struggle to sew it shut, and because it’s wet, surgical glue can’t easily take hold to repair the sac. But surgery on a fetus can correct birth defects, most notably spina bifida, which causes the developing brain and spinal cord to fail to form properly.

So researchers at the University of California at Berkeley are turning to wild mussels for inspiration. Mussels latch onto slippery rocks with ease, thanks to a chemical called dihydroxyphenylalanine, or DOPA. The sticky substance can be created in the lab, but resulting hydrogels can be toxic to fetuses. So the Cal Berkeley team developed an alternative: A biocompatible liquid polymer that can be applied with a syringe.

The team then tested their creation on a model of an amniotic sac made of separate pieces of wet membranes that surround a cow’s heart. After an hour, the pieces were stuck together, according to a release. The researchers presented their findings at the 254th National Meeting & Exposition of the American Chemical Society (ACS).

The search for suture alternatives has inspired a number of new technologies. In June, for example, California-based ZipLine Medical collected $12 million in a Series E financing to develop a flexible device that closes skin wounds and prevents them from opening when patients move. Earlier this year, a Stanford University team showed that when they injected mice with the protein HGFA, it sped up the body’s natural process of repairing wounds.

But repairing the amniotic sac is a unique challenge.

"If it tears completely, premature labor is likely," said Diederik Balkenende, Ph.D., a postdoctoral researcher at Berkeley who participated in the mussel-glue research. "Because these operations are often done in the second trimester well before the fetus is fully developed, early delivery increases the risk of fetal morbidity. An adhesive that can prevent the amniotic sac from tearing could help the fetus remain in the womb longer, which would potentially lead to a healthier future for the baby."

The research team is now investigating the idea of injecting their liquid polymer prior to fetal surgery as a way of preventing the hole in the amniotic sac from rupturing. They are also perfecting the glue and planning animal trials to validate the approach.