Molecular surface chemistry in marine bioadhesion

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Marine Biology

Background:

• Marine biofouling, caused by organisms like mussels, algae, and barnacles, relies on effective bioadhesives for settlement and survival.
• Larval and adult stages of marine organisms exhibit distinct adhesive compositions and strategies.
• Limited understanding of the chemical composition and binding mechanisms of marine bioadhesives.

Purpose of the Study:

• To review the in situ molecular physicochemical characterization of bioadhesives from key marine foulers.
• To elucidate the adhesion strategies employed by mussels, algae, and barnacles.
• To provide insights for developing novel antifouling solutions and wet-adhesion materials.

Main Methods:

• Focus on in situ molecular physicochemical characterization of bioadhesives.
• Analysis of adhesive secretions from mussels, algae, and barnacles.
• Survey of recurrent functional groups (catechol, carboxylate, monoester-sulphate, -phosphate).
• Description of binding modes to wet mineral/metal oxide surfaces.
• Ranking of functionalities based on adsorption constants and competitive adsorption.
• Application of Hard and Soft Acids and Bases principle, Hofmeister effects, and entropic considerations.

Main Results:

• Identified recurrent functional groups in marine bioadhesives: catechol, carboxylate, monoester-sulphate, and -phosphate.
• Described binding modes of these functionalities to wet oxide surfaces.
• Ranked adhesive functionalities based on their binding affinity to hydrophilic surfaces.
• Provided explanations for bioadhesive binding to hydrous metal oxide surfaces.

Conclusions:

• Understanding marine bioadhesives' molecular mechanisms is crucial for antifouling innovation.
• Insights gained can lead to the synthesis of robust, water-resistant adhesive materials.
• Knowledge of functional group binding informs the design of next-generation antifouling coatings and adhesives.