Mechanical Reinforcement of Polymeric Fibers through Peptide Nanotube Incorporation

Abstract

High aspect ratio nanotubular assemblies can be effective fillers in mechanically reinforced composite materials. However, most existing nanotubes used for structural purposes are limited in their range of mechanical, chemical, and biological properties. We demonstrate an alternative approach to mechanical reinforcement of polymeric systems by incorporating synthetic D,L-cyclic peptide nanotube bundles as a structural filler in electrospun poly D-, L-lactic acid fibers. The nanotube bundles self-assemble through dynamic hydrogen bonding from synthetic cyclic peptides to yield structures whose dimensions can be altered based on processing conditions, and can be up to hundreds of micrometers long and several hundred nanometers wide. With 8 wt % peptide loading, the composite fibers are >5-fold stiffer than fibers composed of the polymer alone, according to atomic force microscopy-based indentation experiments. This represents a new use for self-assembling cyclic peptides as a load-bearing component in biodegradable composite materials.

Structural, Nanomechanical, and Computational Characterization of d,l-Cyclic Peptide Assemblies

“…This particular DLCP has also been shown to increase the elastic modulus of polylactides when incorporated as the filler component of a composite fiber. 29 While previous attempts at molecular dynamics simulations have given clues regarding the elastic modulus of a DLCP assembly, 31 this study represents the first experimental characterization of the mechanical properties of DLCP fibers. assembling laterally.…”

Composites of hydrophilic polymers and organic nanocrystals enable enhanced robustness

“…Recently, aiming at cost‐efficient self‐assembled materials, several groups developed organic‐organic hybrids, where polymers embed self‐assembled organic nanostructures of different shapes and sizes, eg, nanoscale peptide‐based systems. Thus, Gazit et al used peptide nanofibers to act as nano‐fillers in epoxy polymers, resulting in enhanced mechanical properties of the hybrid, and Joshi et al employed peptide nanotubes to reinforce lactic acid fibers . Stupp et al developed composites based on interacting polysaccharide and self‐assembled peptide system, of interest for biomedical applications …”

“…Thus, Gazit et al used peptide nanofibers to act as nano-fillers in epoxy polymers, resulting in enhanced mechanical properties of the hybrid, 8 and Joshi et al employed peptide nanotubes to reinforce lactic acid fibers. 9 Stupp et al developed composites based on interacting polysaccharide and self-assembled peptide system, of interest for biomedical applications. 10 Facile solution-phase assembly of polymer/nanostructure hybrids requires soluble components whose structure can be tuned in order to create optimal hybrid morphologies.…”

The Physical Properties and Self‐Assembly Potential of the RFFFR Peptide

“…Fibers of peptides also demonstrate potential for electronic devices, because they allow for significant downscaling of the sizes of circuit components in comparison with what is possible with traditional inorganic semiconductor technology . Furthermore, self‐assembled peptide fibers might also be applicable in materials science, due to their unique (silk‐like) mechanical properties …”