Scientists at MIT and Freie Universität Berlin have developed a new type of glue inspired by the natural world, combining the waterproof stickiness of mussel plaques with the germ-proof properties of mucus.
A Sticky Combination: New Glue Inspired by Mussels and Mucus
The natural world has long been a source of inspiration for engineers and scientists seeking to develop innovative materials and technologies. Recently, researchers from MIT and Freie Universität Berlin have made a breakthrough in the development of a new type of glue that combines the waterproof stickiness of mussel plaques with the germ-proof properties of mucus.
Mussel plaques, also known as mussel fouling, are a type of marine growth that can attach to surfaces in aquatic environments.
These plaques are formed by mussels, specifically species like Mytilus galloprovincialis and Mytilus edulis.
Mussels secrete a strong adhesive substance called byssal threads, which allows them to anchor themselves to surfaces.
This process can lead to the formation of large aggregations of mussels, causing damage to ships' hulls, water intake systems, and other infrastructure.
Mussels: Masters of Underwater Adhesion
Mussels are marine molluscs that cluster atop rocks and along the bottoms of ships, holding fast against the ocean’s waves thanks to a gluey plaque they secrete through their foot. These tenacious adhesive structures have prompted scientists in recent years to design similar bioinspired, waterproof adhesives.
Mussels are a type of saltwater clam that belong to the family Mytilidae.
There are over 100 species of mussels, with the most common being the edible mussel (Mytilus galloprovincialis).
These marine bivalves have been a staple in coastal cuisine for centuries, particularly in Europe and Asia.
Mussels are filter feeders, using their siphons to draw in water and extract plankton and algae for food.
They can grow up to 12 inches in length and live for several years.
A New Type of Glue
The MIT researchers combined sticky, mussel-inspired polymers with mucus-derived proteins, or mucins, to form a gel that strongly adheres to surfaces. The new mucus-derived glue prevented the buildup of bacteria while keeping its sticky hold, even on wet surfaces.
Applications and Future Directions
The team’s new glue-making approach could be adjusted to incorporate other natural materials, such as keratin, a fibrous substance found in feathers and hair. This could enable the development of sustainable packaging materials or multifunctional biomedical adhesives that prevent infections.
A Two-Part Epoxy
To test their idea, the researchers combined solutions of natural mucin proteins with synthetic mussel-inspired polymers and observed how the resulting mixture solidified and stuck to surfaces over time. ‘It’s like a two-part epoxy,’ said George Degen, a postdoc in MIT‘s Department of Mechanical Engineering. ‘You combine two liquids together, and chemistry starts to occur so that the liquid solidifies while the substance is simultaneously gluing itself to the surface.’
Controlling the Speed of Gelation
The team deposited a range of compositions between two surfaces and found that the resulting adhesive held the surfaces together with forces comparable to commercial medical adhesives used for bonding tissue. The researchers also tested the adhesive’s bacteria-blocking properties by depositing the gel onto glass surfaces and incubating them with bacteria overnight.
A Strong and Protective Alternative
The team says that with a bit of tuning, they can further improve the adhesive’s hold. Then, the material could be a strong and protective alternative to existing medical adhesives. ‘We are excited to have established a biomaterials design platform that gives us these desirable properties of gelation and adhesion,’ said Degen. ‘As a starting point, we’ve demonstrated some key biomedical applications. We’re now ready to expand into different synthetic and natural systems and target different applications.’
Medical adhesives are a crucial component in modern healthcare, used to bond medical devices and tissues together.
They come in various forms, including hydrocolloid dressings, acrylic adhesives, and cyanoacrylate-based products.
Medical adhesives are used for wound closure, securing catheters and drains, and attaching orthotics and prosthetics.
According to the FDA, medical adhesives must meet strict standards for biocompatibility and safety.
In 2020, the global medical adhesive market size was estimated at $8.3 billion, with a projected growth rate of 7.5% by 2025.
