Ion Valency as a Molecular Switch for Salt-Resistant Underwater Adhesion

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Supramolecular Chemistry

Background:

• Underwater adhesion is difficult due to hydration layers and ionic interference.
• Peptide-based adhesives often struggle in saline conditions, limiting their applications.

Purpose of the Study:

• To investigate how ion valency affects underwater adhesion in peptide systems.
• To elucidate the molecular mechanisms behind ion-mediated adhesion enhancement.
• To guide the design of responsive bio-inspired materials for saline environments.

Main Methods:

• Utilized adhesive peptide systems with π-π and cation-π interactions.
• Investigated the effects of monovalent (K+) and multivalent (Mg2+, Y3+) ions.
• Employed molecular dynamics simulations, quantum mechanical analyses, and NMR spectroscopy.
• Developed a thermodynamic model to analyze binding dynamics.

Main Results:

• Monovalent ions weakened peptide interactions and adhesion.
• Multivalent ions, especially Y3+, formed stable π-cation-π networks, significantly boosting adhesion.
• Y3+ demonstrated exceptional bridging capabilities, enhancing stress dissipation.
• NMR confirmed cation-dependent interactions with peptide residues (Phe, Lys).

Conclusions:

• Ion valency is critical for modulating underwater adhesion in peptide systems.
• Multivalent ions, particularly Y3+, offer a promising strategy for achieving robust underwater adhesion.
• This research provides molecular insights for developing ionically responsive biomaterials for marine and biomedical applications.