Oyster Glue Could Inspire New Medical Adhesives

A team of researchers from Purdue University (West Lafayette, IN) has deciphered the chemical components of the adhesive produced by oysters. Their findings could aid scientists in creating wet-setting adhesives for a variety of products, including medical applications.

Jonathan Wilker, a Purdue professor of chemistry and materials engineering, led the team that analyzed the most common oyster in the United States, Crassostrea virginica, known as the common Eastern oyster. By comparing oyster shells with the material that connects the animals to each other, the researchers were able to determine its chemical composition. The results showed that the adhesive had almost five times the amount of protein and more water than what is found in the shell. The oyster adhesive, according to Wilker, is more of an inorganic cementlike substance than the organic gluelike material produced by other marine animals.

"The oyster cement appears to be harder than the substances mussels and barnacles use for sticking to rocks," he remarks. "The adhesives produced by mussels and barnacles are mostly made of proteins, but oyster adhesive is about 90% calcium carbonate, or chalk. On its own, chalk is not sticky. So the key to oyster adhesion may be a unique combination of this hard, inorganic component with the remaining 10%."

This 10% of oyster cement, however, does bear some similarity to mussel glue in its composition of proteins and the presence of iron. In earlier studies, Wilker found that iron plays a key role in the hardening, or curing, of mussel adhesive, and it may serve a similar purpose in oyster adhesive, he says.

Wilker's team will next investigate the interaction of the different components within oyster cement and use this information for developing new synthetic materials.

More information about the research into oyster adhesive can be found at the Purdue newsroom. For another take on scientists' quest to develop new medical device materials based on models in the natural world, see "Mimicking Mother Nature," published in the March 2010 issue of MPMN.