Exploiting Redox-Complementary Peptide/Polyoxometalate Coacervates for Spontaneously Curing into Antimicrobial Adhesives

Abstract

Recently, there has been a wave of reports on the fabrication of peptide-based underwater adhesives with the aim of understanding the adhesion mechanism of marine sessile organisms or creating new biomaterials beyond nature. However, the poor shear adhesion performance of the current peptide adhesives has largely hindered their applications. Herein, we proposed to sequentially perform the interfacial adhesion and bulk cohesion of peptide-based underwater adhesives using two redox-complementary peptide/polyoxometalate (POM) coacervates. The oxidative coacervates were prepared by mixing oxidative H5PMo10V2O40 and cationic peptides in an aqueous solution. The reductive coacervates consisted of K5BW12O40 and cysteine-containing reductive peptides. Each of the individual coacervate has well-defined spreading capacity to achieve fast interfacial attachment and adhesion, but their cohesion is poor. However, after mixing the two redox-complementary coacervates at the target surface, effective adhesion and spontaneous curing were observed. We identified that the spontaneous curing resulted from the H5PMo10V2O40-regulated oxidization of cysteine-containing peptides. The formed intermolecular disulfide bonds improved the cross-linking density of the dual-peptide/POM coacervates, giving rise to the enhanced bulk cohesion and mechanical strength. More importantly, the resultant adhesives showcased excellent bioactivity to selectively suppress the growth of Gram-positive bacteria due to the presence of the polyoxometalates. This work raises further potential in the creation of biomimetic adhesives through the orchestrating of covalent and noncovalent interactions in a sequential fashion.

Hydrogen-Bonding Interaction-Driven Catechin Assembly into Solvent-Free Supramolecular Adhesive with Antidrying and Antifreezing Properties

“…Supramolecular adhesives are a type of viscous substance constructed by noncovalent interactions, which have attracted more and more attention from scientists to explore their multifunctional applications due to structural superiorities, such as in biomedical engineering, manufacturing industry fields, and daily life. − They can easily hold two separate tissues or substrates together by relying on their own viscosity and exhibit captivating physicochemical and mechanical properties relying on the dynamic and reversible nature of noncovalent interactions. − In the long-term development of supramolecular adhesives, considerable efforts are mainly concentrated on the construction and application of viscous supramolecular polymers or gels formed in solution. − However, it has been disclosed that the recyclability and stability of supramolecular materials prepared in solution are dramatically reduced during use because the solvent evaporates. The volatilization or removal of solvents from supramolecular materials will give rise to the eventual depolymerization and collapse of these materials, which further evidently impacts the adhesion and processability properties.…”

Exploring the Reactivity of Polyoxometalates toward Proteins: From Interactions to Mechanistic Insights

“…53,93−101 Therefore, the multiple emerging biological and medical applications of POMs incite studying the redox chemistry of POMs toward biomolecules. 4,16,102 POMs are powerful oxidation catalysts since they are composed of several early transition metal centers in their highest oxidation state. 103,104 Moreover, these metal centers can be reversibly reduced multiple times, allowing them to engage in many different types of redox reactions involving single or multielectron transfers.…”

Polyoxometalate–peptide hybrid materials: from structure–property relationships to applications

“…Li's group have thoroughly explored this approach and proposed several designs for preparing underwater adhesives. 36,38,39,76,77 The supramolecular polymerisation of the peptide produces coacervates, i.e. liquid-liquid droplets, that promote this adhesion phenomenon.…”

“…12). 76 An interesting avenue for these materials would be to couple the oxidation of the peptide with the redox properties of the own POM. In this way, heteropolyblues (reduced POMs) could be prepared.…”