New super-glue inspired by slug slime

Surgeons close internal incisions with stitches and staples but they, and their patients, would benefit from a glue that stays stuck even to wet tissue and organs. Researchers from McGill University in Montreal are making progress with a powerful new glue inspired by the the sticky slime secreted by scared slugs. Science News surveys the state-of-the-art in adhesives that take inspiration from marine worms, mussels, and geckos:

>Using the (slug-inspired) glue to plug a hole in the pig heart worked so well that the heart still held in liquid after being inflated and deflated tens of thousands of times. (McGill University's Jianyu) Li, who did the research while at Harvard University, and colleagues also tested the glue in live rats with liver lacerations. It stopped the rats’ bleeding, and the animals didn’t appear to suffer any bad reaction from the adhesive...

One layer of the material is a polymer, a type of material made from long molecules built from many repeated subunits, like a string of beads. Positively charged appendages dangling off the polymers are drawn to wet tissue surfaces by the same forces underlying static electricity. This first layer weaves into another layer, a water-based gel. The gel layer acts like a shock absorber in a car, Li says. It soaks up energy that might otherwise dislodge or snap the adhesive.

Despite being 90 percent water, the material is both sticky and tough, Li says. The fact that it’s mostly water makes it more likely to be nontoxic to humans.

"Animal goo inspires better glue" (Science News)