Polypeptide Nanoribbon Hydrogels Assembled through Multiple Supramolecular Interactions

We investigated the formation of nanoribbon hydrogels in a mixed system of zinc ions, bis(ligand)s, and triblock peptide copolymers. Using a combination of experimental techniques: dynamic light scattering, cryo-transmission electron microscopy, small-angle X-ray scattering and circular dichroism, we arrived tit a model for the formation of nanoribbon hydrogels in which well-defined nanoribbons tire formed out of multiple supramolecular interactions: (1) metal coordination that yields supramolecular polyelectrolytes; (2) electrostatic complexation between the supramolecular polyelectrolytes and the oppositely charged blocks of the peptide copolymers (3) hydrogen bond and (4) hydrophobic interactions that support the secondary and ternary Structure of the ribbons (5) van der Waals interactions that enable bundling of the ribbons.