Silk Mussel Glue
Silk mussel glue
Here we report a new biomaterial composed by silk fibroin, polydopamine and Fe3+ with tunable adhesive properties superior to any bioinspired adhesive and some commercial glues. This material exhibits astonishing adhesion even underwater, mimicrying natural mussel byssus. Moreover, it is a completely biodegradable and atoxic (potentially edible) material that only need water as a solvent to be activated. This new biomaterial was designed in order to create a long and stable polypeptidic backbone with silk fibroin, interacting through cross-link reactions and supramolecular interactions with polydopamine, a well-known polymer rich in catechols moieties able to bind iron and other metals. Furthermore, comparing our new glue to other synthetic or bioinspired ones, we use an extremely low quantity of material, from 4 to 100 times lower. Finally, synthetic procedure and curing conditions are the simplest ever reported: once the water soluble polymers are mixed together and spreaded on the surface, the simple addition of a solution of oxidant and/or Fe3+ on the other face of the material is enough to obtain adhesion. Simply varying the polymers and/or oxidant/iron ratios, we have created a totally water-based, biocompatible and non-toxic bioinspired adhesive with the highest underwater adhesive properties today known in literature.
US Provisional Patent Application 62/864,444 filed 6/20/2019