Mussels attach themselves tenaciously to rocks and other substrates to survive the pummeling of harsh ocean waves. The secret to their powerful bond is a type of natural glue. Made of multiple proteins, this “glue” coats the mussel’s foot and sticks it to surfaces.
Engineers have sought to understand this “glue” better and create their own version of the substance. Now, researchers at Northwestern University think they’ve cracked the code of the mussel glue.
According to the researchers, in an attempt to mimic the mussel’s glue, they somehow improved upon it. The new substance, which is made of protein-like polymers, could be useful for medicine.
“The polymer could be used as an adhesive in a biomedical context, which means now you could stick it to a specific tissue in the body,” said Northwestern’s Nathan Gianneschi. “And keep other molecules nearby in one place, which would be useful in wound healing or repair.”
In the natural mussel glue, there are chains of amino acids that give the substance the properties of being stretchy, sticky and strong. This is very hard for researchers to replicate. Study first author Or Berger found a way to mimic these same properties in the lab, placing the amino acid building blocks into a synthetic polymer.
“Proteins arrange amino acids as chains, but instead we took them and arranged them in parallel, on a dense synthetic polymer backbone,” said Gianneschi. “This was the same thing we have begun to do for controlling specific biological interactions, so the same platform technology we will use for future therapeutics has really become potentially interesting in materials science.”
After creating their version of mussel glue, the scientists tested the substance alongside the native glue. They put both substances on glass plates and then watched to see which would adhere more cells to the plate. It turned out that their synthetic glue held more cells than the native mussel glue.
“We actually didn’t mean to improve on the mussel’s properties,” said Berger. “We only meant to mimic it, but when we went and tested it in several different assays, we actually got better properties than the native material in these settings.”
The scientists already have other ideas of nature-based synthetic materials, such as those inspired by substances found in insect legs and wings.
The study is published in the Journal of American Chemistry Society.