Biomimetic chitosan-graft-polypeptides for improved adhesion in tissue and metal

Inspired by the mussel foot protein and chitosan-based macromolecular adhesives, a series of chitosan-graft-polypeptides were synthesized by ring-opening polymerization of three N-carboxyanhydrides (NCAs) -3,4-di-hydroxyphenylalanine-N-carboxyanhydride (DOPA-NCA), cysteine-NCA (Cys-NCA) and arginine-NCA (Arg-NCA) - using partial-NH2-protected chitosan as an initiator. These copolymers demonstrated good biodegradability and low cytotoxicity. The results of lap-shear adhesion test showed that the maximum lap-shear adhesion strength on the porcine skin and aluminum sheet were 195.97 +/- 21.1 kPa and 3080 +/- 320 kPa, respectively, and the maximum tensile adhesion strength on bone was 642.70 +/- 61.1 kPa. The rat experiment in vivo showed that these copolymers exhibited good hemostatic performance and can promote the healing of skin wound and bone fracture. It is expected that thesecopolymeric adhesives will have broad applications in hemostasis and soft tissue adhesions.