For most of us, the greatest benefit marine mussels can provide is their usefulness in a dish combined with white wine, garlic, and butter sauce. Other than their culinary utility, mussels are mainly just a nuisance for the sailors whose boats they colonize.
But a recent review published in the journal Matter details how the same adhesive properties that allow mussels to aggressively attach themselves to boats also have widespread engineering applications.
Scientists from China and the United States combined in this research on the use of an amino acid group called dihydroxyphenylalanine (DOPA) in various industries. DOPA is part of the surprisingly strong byssus threads mussels use to attach themselves to rocks and ships.
Researchers around the world have found that DOPA can adhere to many types of solid substrates through molecular interactions. Previous research suggesting that dopamine, a molecule with similar structure to DOPA, can form a universal coating on a range of substrates resulted in the boom of mussel-inspired chemistry in material surface engineering and environmental science.
“Mussels are broadly regarded as a nuisance in marine industries because they will colonize submerged surfaces,” says Hao-Cheng Yang a researcher at the School of Chemical Engineering and Technology at Sun Yat-sen University in China. “But from another point of view, the robust attachment of mussels on substrates under water has inspired a biomimetic strategy to realize strong adhesion between materials in water.”
Already getting ahead of mussel technology, a group of researchers in China have developed a universal red blood cell, which can be transfused into individuals of every blood type. This is done by using mussel-inspired coatings to shield the cell from detection by the body’s immune system, thereby preventing the cell from being destroyed.
Another research project has developed superior materials for separating oil and water, which may one day help reduce environmental damage to marine environments after oil spills. Additionally, mussel-inspired tech has been used in water purification, creating materials for removing heavy metals, organic pollutants, and pathogens from wastewater – as DOPA easily binds to these contaminants.
While all of these advancements are exciting, there is still a lot to learn about these mussel-inspired chemicals.
“Despite simplicity and effectiveness, there are still some inherent limitations,” explains Yang. “Alkaline conditions are usually needed to realize the polymerization of dopamine, so it cannot be applied to materials that are unstable under alkaline conditions. Moreover, the deposition of [polydopamine] is a time-consuming process – it takes tens of hours to form a uniform coating on most material surfaces.”
Moving forward, researchers are hoping to overcome these challenges by finding low-cost, stable, and safe substitutes to polydopamine.
Image Credit: Shutterstock/Nigel Wallace