ABSTRACT
Mollusks such as the blue mussel (Mytilus edulis) secrete adhesive proteins that exhibit strong and reliable underwater adhesion. A key adhesive component in these adhesive proteins is an amino acid, 3,4-dihydroxyphenylalanine (DOPA), which is responsible for both interfacial binding and intermolecular cross-linking. DOPA is a unique and versatile adhesive moiety, capable of binding to both inorganic and organic surfaces through either strong reversible bonds or covalent attachment. This chapter reviews the chemistry of DOPA side chain and the use of DOPA and its derivatives (e.g., dopamine) as building blocks in developing mussel-inspired adhesives, coatings, and multifunctional polymeric anchors for various applications. 6.1 Introduction
Performance of most man-made adhesives is significantly compromised in the presence of moisture, which has traditionally
been treated as a surface contaminant that needs to be removed to prevent the formation of a weak boundary layer [1]. In many applications, and particularly those in the medical field, development of moisture-resistant adhesives is in high demand. Marine mussel, a bivalve mollusk, secretes protein-based adhesives to secure itself to wet surfaces in the turbulent intertidal zone [2]. 3,4-dihydroxyphenylalanine (DOPA, Fig. 6.1a), an amino acid posttranslationally modified from tyrosine, is found in large abundance in these adhesive proteins and is responsible for both curing of the adhesive and interfacial binding [3-5]. DOPA is a unique and versatile adhesive molecule, capable of binding to both inorganic and organic surfaces through either strong reversible bonds or covalent attachment [6,7].
