In the world of marine marvels, mussels are unrivaled champions of underwater adhesion. These resilient molluscs anchor themselves to rocks and ship hulls, standing firm against relentless ocean waves. Their secret weapon?
A sticky plaque secreted from their foot that adheres with a tenacious grip. Inspired by this natural marvel, scientists have endeavored to create similarly durable, bioinspired waterproof adhesives.
Now, MIT and Freie Universität Berlin engineers have developed a groundbreaking new glue. This innovative adhesive combines the waterproof stickiness of mussel plaques with the germ-resistant properties of mucus, another natural wonder.
Aside from skin, our bodies are sheathed in a protective mucus layer. The engineers have ingeniously combined the adhesive power of mussel-inspired polymers with mucus-derived proteins, known as mucins, to craft a gel that adheres firmly to surfaces.
This mucus-derived glue prevents bacterial buildup while maintaining its sticky strength, even on wet surfaces. The team imagines a future where this optimized glue could be applied as a liquid, either through injection or spray, and then solidify into a sticky gel. It could be used to coat medical implants, helping to prevent infections and bacterial buildup.
How does mucus evolve?
Additionally, the engineers’ glue-making method could be modified to include other natural materials like keratin, a fibrous substance found in feathers and hair that has similar chemical properties to mucus.
“The applications of our materials design approach will depend on the specific precursor materials,” explains George Degen, a postdoctoral researcher in MIT’s Department of Mechanical Engineering. “Mucus-derived or mucus-inspired materials might serve as multifunctional biomedical adhesives that prevent infections. Alternatively, keratin-based materials could pave the way for sustainable packaging solutions.”
“Mussels can rapidly deposit materials that adhere to wet surfaces in seconds to minutes,” Degen explains. “These natural materials outperform existing commercial adhesives, particularly in sticking to wet and underwater surfaces—a longstanding technical challenge.”
Mussels secrete a protein-rich fluid to anchor themselves to rocks or ship hulls. This secretion forms chemical bonds or crosslinks, that act as connection points between proteins. These bonds enable the substance to solidify into a gel, allowing it to stick to wet surfaces.
Interestingly, mucin has similar crosslinking features. Upon joining MIT, Degen collaborated with McKinley, a professor of mechanical engineering with expertise in materials science and fluid flow, and Katharina Ribbeck, a biological engineering professor known for her mucus research. Together, they aimed to develop a crosslinking glue that combined the adhesive qualities of mussel plaques with the bacteria-blocking properties of mucus.
MIT researchers collaborated with Haag and his colleagues in Berlin, who are experts in synthesizing bioinspired materials. Haag and Ribbeck are part of a collaborative research group dedicated to developing dynamic hydrogels for biointerfaces. Haag’s team has successfully created mussel-like adhesives and mucus-inspired liquids by producing microscopic, fiber-like polymers that mimic the structure of natural mucin proteins.
In their latest work, the researchers focused on a key chemical feature in mussel adhesives: a bond between two chemical groups known as “catechols” and “thiols.” In the natural glue of mussels or plaque, these groups form catechol–thiol crosslinks, enhancing the cohesive strength of the plaque. Catechols also improve mussel adhesion by binding to surfaces like rocks and ship hulls.
Interestingly, thiol groups are also abundant in mucin proteins. Degen wondered if mussel-inspired polymers could bond with mucin thiols, enabling the mucins to transform from a liquid into a sticky gel quickly.
To test this idea, Degen combined solutions of natural mucin proteins with synthetic mussel-inspired polymers and observed how the resulting mixture solidified and adhered to surfaces over time.
“It’s like a two-part epoxy. You mix two liquids, and the chemistry kicks in, causing the liquid to solidify while simultaneously adhering to the surface,” Degen explains.
“By adjusting the amount of crosslinking, we can control the speed at which the liquids gel and adhere,” Haag adds. “We can achieve this on wet surfaces, at room temperature, and under mild conditions. This is unique.”
The team deposited various compositions between two surfaces and found that the resulting adhesive held the surfaces together with forces comparable to those of commercial medical adhesives used for bonding tissue. The researchers also tested the adhesive’s bacteria-blocking properties by applying the gel to glass surfaces and incubating them with bacteria overnight.
https://news.mit.edu/2025/engineers-turn-bodys-goo-into-new-glue-0217“We observed that bare glass surfaces without our coating developed a thick biofilm of bacteria, whereas surfaces coated with our gel largely prevented biofilm formation,” Degen notes.
The team believes that with some fine-tuning, they can further enhance the adhesive’s hold, making it a strong and protective alternative to existing medical adhesives.
“We are thrilled to have established a biomaterials design platform that provides desirable properties of gelation and adhesion. As a starting point, we’ve demonstrated key biomedical applications,” Degen says. “We are now ready to expand into different synthetic and natural systems and target various applications.”
Journal Reference:
- Corey Stevens, Gerardo Cárcamo-Oyarce, Jake Song, Katharina Ribbeck, and Gareth McKinley, Raju Bej, Peng Tang, and Rainer Haag of Freie Universität Berlin. Mussel-inspired crosslinking mechanisms enhance gelation and adhesion of multifunctional mucin-derived hydrogels.
Source: Tech Explorist
