Peptidomimetic Wet-Adhesive PEGtides with Synergistic andMultimodal Hydrogen Bonding

The remarkable underwater adhesion of mussel footproteinshaslongbeenaninspirationinthedesignofpeptidomimetic materials. Although the synergistic wet adhesionof catechol and lysine has been recently highlighted, the criticalrole of the polymeric backbone has remained largely underex-plored. Here, we present a peptidomimetic approach usingpoly(ethylene glycol) (PEG) as a platform to evaluate thesynergistic compositional relation between the key amino acidresidues (i.e., DOPA and lysine), as well as the role of the polyetherbackbone in interfacial adhesive interactions. A series of PEG-basedpeptides (PEGtides) were synthesized using functional epoxidemonomers corresponding to catechol and lysineviaanionic ring-opening polymerization. Using a surface force apparatus, highly synergistic surface interactions among these PEGtides with respectto the relative compositional ratio were revealed. Furthermore, the critical role of the catechol-amine synergy and diverse hydrogenbonding within the PEGtides in the superior adhesive interactions was verified by molecular dynamics simulations. Our study shedslight on the design of peptidomimetic polymers with reduced complexity within the framework of a polyether backbone.