Adhesive, self-healing and antibacterial properties of Cu-coordinated soft gel based on histamine-conjugated polyaspartamide

Metal-ligand coordination bonding is a non-covalent interaction that has been extensively studied as an effective way to improve the mechanical properties of hydrogels or to generate novel supramolecular self-healing gels. In this study, biodegradable polyaspartamide derivatives conjugated with histamine were synthesized and used to prepare the metal-coordinated supramolecular gel with several different metal-ions such as Cu(II), Ni(II), and Zn(II) in an aqueous solution. The resulting gels showed high adhesive properties on glass and plastics substrates, and the adhesive strength could be modulated by using different metal-ion species as well as the concentration and medium pH. In particular, the Cu(II)-coordinated gel exhibited a reversible self-healing behavior and good antibacterial activity. These wholly bio-based supramolecular polymer gels have potential for various biomedical applications with their multifunctional properties comprising adhesive, self-healing and antimicrobial properties in wet gel state.