Slug-inspired bio-glue binds like cartilage

(Credit: Wyss Institute at Harvard University)

The research was carried out by members of Harvard’s Wyss Institute for Biologically Inspired Engineering and John A Paulson School of Engineering and Applied Sciences (SEAS). Seeking to improve on current medical adhesives, the team was inspired by the slug, which secretes a special mucus when threatened that helps it stay fixed to its surface.

Previous studies had shown the mucus was formed of a tough matrix interspersed with positively charged proteins. This inspired the Harvard team to create a double-layered hydrogel, consisting of an alginate-polyacrylamide matrix. The matrix then supports an adhesive layer that has positively charged polymers protruding from its surface.

These polymers form a triple bond with biological surfaces: via electrostatic attraction, covalent bonds and physical penetration. According to the team, the hydrogel’s strength and flexibility come from a combination of the polymers and the supporting matrix.