Atomic-precision π-driven peptide hydrogel nanofibers with ordered water channels

Area of Science:

• Supramolecular chemistry
• Materials science
• Biomaterials

Background:

• Aromatic interactions drive supramolecular assembly, while peptides form soft materials via hydrogen bonding.
• Terminally capped peptides achieve strong aromatic stacking, but uncapped peptides rarely form highly ordered materials.
• Uncapped peptides typically organize water via polar end groups.

Purpose of the Study:

• To create supramolecular hydrogels with structural order by integrating a π-extended aromatic unit into a terminally uncapped peptide.
• To investigate the self-assembly behavior and material properties of pyrene-modified dipeptides.
• To bridge conjugated materials and biomolecular matter for novel functional soft materials.

Main Methods:

• Modification of a dipeptide with a pyrene unit.
• Hierarchical self-assembly studies.
• Cryo-electron microscopy (Cryo-EM) for high-resolution structural analysis.

Main Results:

• Successful creation of a new class of supramolecular hydrogels with structural order.
• Pyrene-modified dipeptide self-assembles into monodisperse helical nanofibers and self-healing hydrogels.
• Cryo-EM revealed nanofibers with tightly packed protofilaments, ordered water channels, and a unidirectional dipole.

Conclusions:

• Reinforced aromatic stacking, polar interactions, and water organization orchestrate emergent electrostatics and mechanical resilience.
• This approach enables the creation of functional soft materials by combining features of conjugated materials and biomolecular matter.
• The study demonstrates a novel strategy for designing ordered peptide-based supramolecular materials.