Mussel-inspired catechol-conjugated chitosan: Preparation, characterization, and applications

Abstract

Tissue adhesive biomaterials are attractive sources of medical devices for the wound dressing, sur-gical tissue adhesives, wrinkle fillers and hemostasis in surgical procedures as well as local drug depots and tissue engineered scaffolds. However, it has been difficult to synthesize the tissue adhesive biomaterials to be attached robustly on target tissues mainly due to the presence of water in human body and large amount of water content of crosslinked hydrogels. In nature, the countless marine creatures such as mussels, sandcastle worms, and sea cucumbers have strong adhesiveness to various organic/inorganic materials. Especially, adhe-sion behavior of the marine mussels is one of the well-known studies that can be opportunity to develop the biocompatible, adhesive medical devices. Blue marine mussel (Mytilus edulis) secretes adhesive proteins, called Mytilus edulis foot protein (Mefp), which have an unusual amino acid, L-3,4-dihydroxy-L-phenylalanine (DOPA). The major driving forces of mussel adhesion are related to catechol (ortho-dihydroxyphenyl) groups of DOPA showing the superior adhesiveness to various materials including rocks, ships, Teflon (Polytetrafluoroethylene) and even biomacromolecules. Importantly, mussel adhesive proteins contain the positively charged residues (e.g., Lys, His) that show the lack of negatively charged residues. It is noted that amine groups are co-contributed with the catechol groups to mussel adhesion via covalent/non-covalent reactions such as Michael-type addition reactions, Schiff-base formations, and π-cation bonds. Thus, catechol and amine groups are significant elements to enhance the under-water adhesion. In other word, polymers with catecholamine moieties might be superior to the ones with just catechol-tethered polymers in adhesion and other biological effects. Inspired by mussel adhesion behaviors, we synthesized a multiple catechol groups-conjugated chi-tosan (CHI-C) to fabricate the biocompatible, adhesive medi...