Amyloid-inspired Peptide Self-assembly/Disassembly as Intervened by Gold Nanoparticles and Polydopamine Coating to Dictate Spatiotemporal Organization

Spatiotemporal control for supramolecular polymerization has rendered a paradigm shift towards designing complex multi-component supramolecular materials and derived nanocomposites. In this paper, we demonstrate self-assembly/disassembly of amyloid-inspired peptide nanostructures from Fmoc-VFFAKK, 1 using gold nanoparticles (AuNPs)/cysteine mediated coupled equilibrium. We report the use of AuNPs to disaggregate the beta-sheets of the peptide nanofibers 1(NF) and twisted bundles 1(TB) to furnish dormant metastable nanoparticles. Upon cysteine mediated sequestration of the AuNPs the peptide fibers are regenerated. Such self-assembly/disassembly of the fibers shows implication in tuning the mechanical strength of the resulting hydrogels. Further, a conformal coating of polydopamine (PDA) over the peptide fibers using the lysine amines furnishes rather robust fibers and orthogonally safeguard itself from AuNPs mediated disassembly of the fibers. Finally, such active coating with PDA having amine/quinone moieties allows selective attachment of AuNPs to furnish 1-D organization of AuNPs over the coated peptide fibers.

Automated summary

This study demonstrates the spatiotemporal control of self-assembly/disassembly of amyloid-inspired peptide nanostructures using gold nanoparticles and cysteine mediated coupled equilibrium. The results show that the self-assembly/disassembly of the fibers has implications in tuning the mechanical strength of the resulting hydrogels, and the conformal coating of polydopamine protects the fibers from disassembly. Furthermore, the active coating allows selective attachment of gold nanoparticles to achieve 1-D organization.