Shear-Induced Adhesion of Alternating Peptides Prepared by Ugi Four-Center Three-Component Reaction.

The development of new peptide-based glues has been strongly urged from the viewpoints of industrial applications and biomedical engineering. However, the large-scale synthesis of polypeptides with an ordered sequence is highly challenging, which strictly restricts materials resources for the research and development of polypeptides. In this work, the framework of adhesive alternating peptides has been designed to be glycine (Gly)-N-substituted valine (Val) as the dipeptide repeating sequence, considering the peptapeptide repeating sequence of viscoelastic natural elastin as a motif. The alternating peptides are prepared via three-component polymerization exploiting Ugi four-center three-component reaction as the elemental polymerization reaction. The adhesive strength (SAdh ) values of the polymers are evaluated by a shear adhesive test method using two glass plates. Alternating peptides with Gly-N-benzylated Val dipeptide repeating units exhibit the optimal adhesive properties such as much higher SAdh than that of conventional fibrin glue and a unique readhesion capability. It is indicated that the remarkably high SAdh would be attributed to the shear-induced structural change of single polymer chain, the slow relaxation of extended structure, and the weak interchain interactions. Due to the favorable adhesive properties of alternating peptides, these adhesives may be highly suitable for real-world applications.