Matthew Harrington wears a blue collared shirt and stands outside in front of a brick wall.
Matthew Harrington studies how organisms produce complex materials and how these processes could be applied to create novel materials for human use.
Laura Harrington

Intertidal mussels live life on the edge, subjected to the constant crashing of waves threatening to rip them off their precarious perches. To stay secure on the rocky shore, mussels manufacture dozens of protein-based fibers called byssal threads, which attach to the substrate via tiny discs known as byssal plaques.

This system may appear simple at first, but for McGill University biochemist Matthew Harrington, there’s more to the mussel than meets the eye. “The more you look into it, the more details you discover,” he said. “Every time I think I’m done studying this, there’s a new detail that just draws me in. It’s incredibly complex.”

While humans struggle to make effective underwater glues, mussels produce super strong, waterproof bioadhesives that cure while immersed in seawater. The strength of the adhesive, and of the byssus itself, relies in part on 3,4-dihydroxyphenylalanine (DOPA), which Harrington called “a very weird amino acid.”

DOPA forms coordination bonds with certain metal ions, like iron and vanadium.1 This type of bond is strong, but it re-forms easily when broken, creating a material that is self-healing at the molecular level.

     A blue cuboid reconstruction of mussel tissue with round plaque vesicles shown in green.
A three-dimensional reconstruction of a focused ion beam scanning electron microscopy dataset depicts adhesive secretory vesicles (green), which are an important component of the underwater glue.
Tobias Priemel

The mussel’s manufacturing process is surprisingly sophisticated. “These things are like little polymer fabrication factories,” said Harrington. His team showed that the mussel secretes DOPA-containing plaque proteins and metal storage particles containing iron or vanadium ions into microchannels in the mussel foot.2 Then cilia mix the proteins and ions together within the low-pH environment of the microchannel. As the mixture is secreted, the seawater environment triggers bonding between the DOPA and the metal ions, turning the glue from a liquid to a solid.

Harrington currently explores how these mussel materials could inspire new forms of biomedical adhesives, self-healing polymers, and pH-responsive scaffolds for tissue engineering.3

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  1. Harrington MJ, et al. Science. 2010;328(5975):216-220.
  2. Priemel T, et al. Science. 2021;374(6564):206-211.
  3. Rammal M, et al. ACS Appl Mater Interfaces. 2023;15(24):29004-29011.