Power Law Rheology of Folded Protein Hydrogels

Fuente: arXiv
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Main Authors: Aufderhorst-Roberts, Anders, Cussons, Sophie, Brockwell, David J., Dougan, Lorna
Format: Preprint
Published: 2022
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author Aufderhorst-Roberts, Anders
Cussons, Sophie
Brockwell, David J.
Dougan, Lorna
author_facet Aufderhorst-Roberts, Anders
Cussons, Sophie
Brockwell, David J.
Dougan, Lorna
contents Folded protein hydrogels are prime candidates as tuneable biomaterials but it is unclear to what extent their mechanical properties have mesoscopic, as opposed to molecular origins. To address this, we probe hydrogels of the muscle-derived protein $I27_5$, using a multimodal rheology approach. Across multiple protocols, the hydrogels consistently exhibit power-law viscoelasticity in the linear viscoelastic regime with an exponent $β= 0.03$, suggesting a dense fractal meso-structure, with predicted fractal dimension $d_f = 2.48$. In the nonlinear viscoelastic regime, the hydrogel undergoes stiffening and energy dissipation, indicating simultaneous alignment and unfolding of the folded proteins. Remarkably, this behaviour is highly reversible, as the value of $β$, $d_f$ and the viscoelastic moduli return to their equilibrium value, even after multiple cycles of deformation. This highlights a previously unrevealed diversity of viscoelastic properties that originate on the mesoscopic scale. These considerations are likely to be key to controlling the viscoelasticity of folded protein hydrogels.
format Preprint
id arxiv_https___arxiv_org_abs_2207_13348
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Power Law Rheology of Folded Protein Hydrogels
Aufderhorst-Roberts, Anders
Cussons, Sophie
Brockwell, David J.
Dougan, Lorna
Soft Condensed Matter
Folded protein hydrogels are prime candidates as tuneable biomaterials but it is unclear to what extent their mechanical properties have mesoscopic, as opposed to molecular origins. To address this, we probe hydrogels of the muscle-derived protein $I27_5$, using a multimodal rheology approach. Across multiple protocols, the hydrogels consistently exhibit power-law viscoelasticity in the linear viscoelastic regime with an exponent $β= 0.03$, suggesting a dense fractal meso-structure, with predicted fractal dimension $d_f = 2.48$. In the nonlinear viscoelastic regime, the hydrogel undergoes stiffening and energy dissipation, indicating simultaneous alignment and unfolding of the folded proteins. Remarkably, this behaviour is highly reversible, as the value of $β$, $d_f$ and the viscoelastic moduli return to their equilibrium value, even after multiple cycles of deformation. This highlights a previously unrevealed diversity of viscoelastic properties that originate on the mesoscopic scale. These considerations are likely to be key to controlling the viscoelasticity of folded protein hydrogels.
title Power Law Rheology of Folded Protein Hydrogels
topic Soft Condensed Matter
url https://arxiv.org/abs/2207.13348