Shellfish-Inspired Sticky Glue to Repair Ships
Inspired by sticky proteins naturally secreted by shellfish, MIT engineers have created stronger waterproof glue that could be used to repair ships and even help heal wounds and surgical incisions, according to a new study.
Researchers at the Massachusetts Institute of Technology (MIT) engineered bacteria to produce a hybrid material that incorporates naturally sticky mussel proteins as well as a bacterial protein found in biofilms - slimy layers formed by bacteria growing on a surface.
When combined, these proteins form even stronger underwater adhesives than those secreted by mussels.
"The ultimate goal for us is to set up a platform where we can start building materials that combine multiple different functional domains together and to see if that gives us better materials performance," Timothy Lu, an associate professor of biological engineering and electrical engineering and computer science, said in a statement.
Shellfish like muscles and barnacles secrete what are known as muscle foot proteins, which allow them to cling to any surface, even underwater. This is the reason why boaters must keep diligent about cleaning the hulls of their boats, otherwise they will find them teeming with sticky shellfish.
"A lot of underwater organisms need to be able to stick to things, so they make all sorts of different types of adhesives that you might be able to borrow from," explained Lu, the paper's senior author.
The MIT team wanted to engineer bacteria to produce two different foot proteins - mussel foot protein 3 or mussel foot protein 5 - combined with bacterial proteins called curli fibers - fibrous proteins that can clump together and assemble themselves into much larger and more complex meshes.
After purifying these proteins from the bacteria and letting them incubate to form dense, fibrous meshes, the resulting material had a regular yet flexible structure that binds strongly to both dry and wet surfaces.
"The result is a powerful wet adhesive with independently functioning adsorptive and cohesive moieties," said Herbert Waite, a professor of chemistry and biochemistry at the University of California at Santa Barbara, who was not involved in the study.
The new adhesives are the strongest biologically inspired, protein-based underwater adhesives reported to date.
The research was published in the journal Nature Nanotechnology.