Shear Alignment of Bola-Amphiphilic Arginine-Coated Peptide Nanotubes.
Hamley, Ian W
da Silva, Emerson Rodrigo
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Hamley, I. W., Burholt, S., Hutchinson, J., Castelletto, V., da Silva, E. R., Alves, W., Gutfreund, P., et al. (2017). Shear Alignment of Bola-Amphiphilic Arginine-Coated Peptide Nanotubes.. Biomacromolecules, 18 (1), 141-149. https://doi.org/10.1021/acs.biomac.6b01425
The bola-amphiphilic arginine-capped peptide RFL4RF self-assembles into nanotubes in aqueous solution. The nanostructure and rheology are probed by in situ simultaneous rheology/small-angle scattering experiments including rheo-SAXS, rheo-SANS, and rheo-GISANS (SAXS: small-angle X-ray scattering, SANS: small-angle neutron scattering, GISANS: grazing incidence small-angle neutron scattering). Nematic alignment of peptide nanotubes under shear is observed at sufficiently high shear rates under steady shear in either Couette or cone-and-plate geometry. The extent of alignment increases with shear rate. A shear plateau is observed in a flow curve measured in the Couette geometry, indicating the presence of shear banding above the shear rate at which significant orientation is observed (0.1-1 s-1). The orientation under shear is transient and is lost as soon as shear is stopped. GISANS shows that alignment at the surface of a cone-and-plate cell develops at sufficiently high shear rates, very similar to that observed in the bulk using the Couette geometry. A small isotope effect (comparing H2O/D2O solvents) is noted in the CD spectra indicating increased interpeptide hydrogen bonding in D2O, although this does not influence nanotube self-assembly. These results provide new insights into the controlled alignment of peptide nanotubes for future applications.
Arginine, Humans, Micelles, Nanotubes, Peptide, Polyethylene Glycols, Rheology, Scattering, Small Angle, Shear Strength, X-Ray Diffraction
External DOI: https://doi.org/10.1021/acs.biomac.6b01425
This record's URL: https://www.repository.cam.ac.uk/handle/1810/292913
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