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Nanoscale characterization of collagen structural responses to in situ loading in rat Achilles tendons

Silva Barreto, Isabella LU orcid ; Pierantoni, Maria LU orcid ; Hammerman, Malin LU ; Törnquist, Elin LU ; Le Cann, Sophie LU ; Diaz, Ana ; Engqvist, Jonas LU ; Liebi, Marianne ; Eliasson, Pernilla and Isaksson, Hanna LU orcid (2023) In Matrix Biology 115. p.32-47
Abstract

The specific viscoelastic mechanical properties of Achilles tendons are highly dependent on the structural characteristics of collagen at and between all hierarchical levels. Research has been conducted on the deformation mechanisms of positional tendons and single fibrils, but knowledge about the coupling between the whole tendon and nanoscale deformation mechanisms of more commonly injured energy-storing tendons, such as Achilles tendons, remains sparse. By exploiting the highly periodic arrangement of tendons at the nanoscale, in situ loading of rat Achilles tendons during small-angle X-ray scattering acquisition was used to investigate the collagen structural response during load to rupture, cyclic loading and stress relaxation. The... (More)

The specific viscoelastic mechanical properties of Achilles tendons are highly dependent on the structural characteristics of collagen at and between all hierarchical levels. Research has been conducted on the deformation mechanisms of positional tendons and single fibrils, but knowledge about the coupling between the whole tendon and nanoscale deformation mechanisms of more commonly injured energy-storing tendons, such as Achilles tendons, remains sparse. By exploiting the highly periodic arrangement of tendons at the nanoscale, in situ loading of rat Achilles tendons during small-angle X-ray scattering acquisition was used to investigate the collagen structural response during load to rupture, cyclic loading and stress relaxation. The fibril strain was substantially lower than the applied tissue strain. The fibrils strained linearly in the elastic region of the tissue, but also exhibited viscoelastic properties, such as an increased stretchability and recovery during cyclic loading and fibril strain relaxation during tissue stress relaxation. We demonstrate that the changes in the width of the collagen reflections could be attributed to strain heterogeneity and not changes in size of the coherently diffracting domains. Fibril strain heterogeneity increased with applied loads and after the toe region, fibrils also became increasingly disordered. Additionally, a thorough evaluation of radiation damage was performed. In conclusion, this study clearly displays the simultaneous structural response and adaption of the collagen fibrils to the applied tissue loads and provide novel information about the transition of loads between length scales in the Achilles tendon.

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Please use this url to cite or link to this publication:
author
; ; ; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Achilles tendon, Collagen structure, In situ loading, Nanomechanics, Small-angle X-ray scattering
in
Matrix Biology
volume
115
pages
16 pages
publisher
Elsevier
external identifiers
  • pmid:36435426
  • scopus:85143304562
ISSN
0945-053X
DOI
10.1016/j.matbio.2022.11.006
project
PhD project: Multi-modal characterization of musculoskeletal tissues
language
English
LU publication?
yes
id
a4b07671-97de-49b0-9183-48c289f7758b
date added to LUP
2023-02-07 15:29:19
date last changed
2024-07-26 04:14:41
@article{a4b07671-97de-49b0-9183-48c289f7758b,
  abstract     = {{<p>The specific viscoelastic mechanical properties of Achilles tendons are highly dependent on the structural characteristics of collagen at and between all hierarchical levels. Research has been conducted on the deformation mechanisms of positional tendons and single fibrils, but knowledge about the coupling between the whole tendon and nanoscale deformation mechanisms of more commonly injured energy-storing tendons, such as Achilles tendons, remains sparse. By exploiting the highly periodic arrangement of tendons at the nanoscale, in situ loading of rat Achilles tendons during small-angle X-ray scattering acquisition was used to investigate the collagen structural response during load to rupture, cyclic loading and stress relaxation. The fibril strain was substantially lower than the applied tissue strain. The fibrils strained linearly in the elastic region of the tissue, but also exhibited viscoelastic properties, such as an increased stretchability and recovery during cyclic loading and fibril strain relaxation during tissue stress relaxation. We demonstrate that the changes in the width of the collagen reflections could be attributed to strain heterogeneity and not changes in size of the coherently diffracting domains. Fibril strain heterogeneity increased with applied loads and after the toe region, fibrils also became increasingly disordered. Additionally, a thorough evaluation of radiation damage was performed. In conclusion, this study clearly displays the simultaneous structural response and adaption of the collagen fibrils to the applied tissue loads and provide novel information about the transition of loads between length scales in the Achilles tendon.</p>}},
  author       = {{Silva Barreto, Isabella and Pierantoni, Maria and Hammerman, Malin and Törnquist, Elin and Le Cann, Sophie and Diaz, Ana and Engqvist, Jonas and Liebi, Marianne and Eliasson, Pernilla and Isaksson, Hanna}},
  issn         = {{0945-053X}},
  keywords     = {{Achilles tendon; Collagen structure; In situ loading; Nanomechanics; Small-angle X-ray scattering}},
  language     = {{eng}},
  pages        = {{32--47}},
  publisher    = {{Elsevier}},
  series       = {{Matrix Biology}},
  title        = {{Nanoscale characterization of collagen structural responses to in situ loading in rat Achilles tendons}},
  url          = {{https://lup.lub.lu.se/search/files/167262056/SilvaBarreto_MatrixBiology_accepted.pdf}},
  doi          = {{10.1016/j.matbio.2022.11.006}},
  volume       = {{115}},
  year         = {{2023}},
}