Colloidal Supramolecular Cross-Linkers: A Versatile Platform for Physical Condensation of Oligopeptide Segments into All-Underwater Adhesives

The development of robust strategies capable of producing oligopeptide-based underwater adhesives constitutes a pivotal advancement toward potential bioapplications yet remains exceedingly challenging. Herein, we report a viable approach for designing underwater adhesives through physical condensation of cationic oligopeptides mediated by colloidal supramolecular cross-linkers. The amphiphilic cholesteric acid derivatives (CADs) self-assembled into stable nanofibers adorned with highly concentrated carboxylate groups on their surface. These colloidal nanofibers functioned as multivalent cross-linkers, effectively binding cationic oligopeptides in water, generating underwater adhesives. Depending on the types of substrates, the underwater adhesion strength varied from 186.7 to 11.6 kPa. Furthermore, the shear strength showed >50% retention after 7 days of immersion in PBS solution. Crucially, the adhesion performance can be modulated by adjusting the hydrophobicity of the CADs or the peptide sequences. This study establishes a versatile design platform for peptidyl biomimetic adhesives while elucidating critical structure-function relationships for performance optimization.