Phragmatopoma californica, a marine polychaete, builds protective mineral composite tubes with a secreted protein-based adhesive underwater. A biomimetic strategy to reverse engineer P. californica’s underwater adhesive through a high-level combination of biology, chemistry, and engineering is proposed. The goal is to develop an analog synthetic medical adhesive designed to bond bone-to-bone, bone-to metal implant, and bone-to-synthetic tissue scaffolding.

The first generation of synthetic bioadhesive was successfully synthesized with the key functionalities and at the densities of the natural adhesive proteins. Several features of the natural adhesive setting mechanism model have been demonstrated with the biomimetic synthetic copolymers including pH dependant complex coacervation and pH triggered DOPA-mediated oxidative crosslinking.

The shear modulus and strength at failure were measured with bovine cortical bone specimens wet bonded with the first generation biomimetic adhesive. The effects of Mg2+/Ca2+ on bond strength were investigated. The strength of the synthetic adhesive is about 1/3 the strength of superglue and natural P. californica adhesive both estimated to be 270-350 kPa.