Self-assembled collagen-like peptide fibers as templates for metallic nanowires

Abstract

Inspired by nature's ability to fabricate supramolecular nanostructures from the bottom-up, materials scientist have become increasingly interested in the use of biomolecules like DNA, peptides, or proteins as templates for the creation of novel nanostructures and nanomaterials. Although the advantages of self-assembling biomolecular structures clearly lie in their chemical diversity, spatial control, and numerous geometric architectures, it is challenging to elaborate them into functional hybrid inorganic-bionanomaterials without rendering the biomolecular scaffold damaged or dysfunctional. In this study, attachment of gold nanoparticles to collagen-related self-assembling peptides at L-lysine residues incorportated within the peptides sequence and the N-terminus led to metal nanoparticle-decorated fibers. After electroless silver plating, these fibers were completely metalized, creating electrically conductive nanowires under mild conditions while leaving the peptide fiber core intact. This study demonstrates the bottom-up assembly of synthetic peptidic fibers under mild conditions and their potential as templates for other complex inorganic-organic hybrid nanostructures.

Peptide tessellation yields micrometre-scale collagen triple helices

“…Nanofibers enabled by symmetric design owe their extraordinary stability solely to the sticky-ended association of peptides, and yield extended human-scale triple-helices. Although the self-assembly “alphabet” available for CMP-based nanostructures is crude in comparison with DNA/RNA, the ease of their interfacing with both biology 9,38 and nanotechnology 16,39 encourage their development.…”

Collagen Structure and Stability

“…This π-stacking approach has been used to generate thrombogenic collagen-like fibrils for applications in biomedicine (134). In addition, attachment of gold nanoparticles to these fibrils and subsequent electroless silver plating yielded collagen-based nanowires that conduct electricity (135). …”

Rational design of fiber forming supramolecular structures

“…126 Similarly, at higher pH, in which N-termini were uncharged, the peptide gained about 2 C of stability in melting experiments. 127 Further work by Chan et al has demonstrated the dependence of triple-helix stability on the identity, position, and environment of charged residues. 128 They embedded a collagen G-Y-X triplet in a host Ac(GPO) 3 -GXY-(GPO) 4 -GG-NH 2 sequence and substituted the Xxx and Yyy positions with ionizable residues.…”

“…131 Gottlieb et al produced conductive synthetic nanowires tens of microns in length by conjugating the collagen mimetic sequence pentafluoro-F-(GPO) 4 -GPK-(GPO) 5 -F with gold nanoparticles. 127 In 2007 the Hartgerink group demonstrated the development of a group of electrostatically stabilized ABC collagen mimetic heterotrimers. 132 These heterotrimeric systems were unique allowing tailored substitution in one, two, or all three peptide chains.…”