Amino Acid-Induced Dynamic Networks of Interface-Enriched Adhesive Molecules for High-Strength, Recyclable, and Substrate-Adaptive Protein Adhesives.

Abstract

Protein-based bioadhesives are emerging as sustainable alternatives to traditional adhesives, with potential applications in biomedicine, tissue engineering, and electronics. However, challenges such as low adhesive strength, poor substrate and environmental adaptability, and limited recyclability persist. Unlike previous studies that focused on replicating key chemical units, interaction patterns, liquid-liquid phase separation (LLPS), and nano/microscale structures in natural adhesives, a novel strategy is proposed that partially disrupts the noncovalent interactions between polyphenols and proteins through amino acid modulation. This approach facilitates the migration and enrichment of polyphenol adhesive molecules at substrate interfaces along with amino acid, where they synergistically enhance substrate adaptability. The high cohesion and dynamic nature of the resulting network, driven by noncovalent interactions, ensures both high adhesive strength and full recyclability of polyphenol-protein adhesives (PPA). Importantly, this strategy expands the PPA toolbox, incorporating proteins (gelatin, collagen, silk, keratin) and polyphenols (tannic acid, proanthocyanidins, epigallocatechin gallate), broadening their applications in daily-use adhesives, industrial products, and cultural relic restoration across both dry and wet environments. This work enhances the understanding of balancing adhesion and cohesion, providing insights for the design of high-performance bioadhesives.