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Fracture Mechanics of Collagen Fibrils: Influence of Natural Cross-Links

Svensson, Rene B.; Mulder, Hindrik LU ; Kovanen, Vuokko and Magnusson, S. Peter (2013) In Biophysical Journal 104(11). p.2476-2484
Abstract
Tendons are important load-bearing structures, which are frequently injured in both sports and work. Type I collagen fibrils are the primary components of tendons and carry most of the mechanical loads experienced by the tissue, however, knowledge of how load is transmitted between and within fibrils is limited. The presence of covalent enzymatic cross-links between collagen molecules is an important factor that has been shown to influence mechanical behavior of the tendons. To improve our understanding of how molecular bonds translate into tendon mechanics, we used an atomic force microscopy technique to measure the mechanical behavior of individual collagen fibrils loaded to failure. Fibrils from human patellar tendons, rat-tail tendons... (More)
Tendons are important load-bearing structures, which are frequently injured in both sports and work. Type I collagen fibrils are the primary components of tendons and carry most of the mechanical loads experienced by the tissue, however, knowledge of how load is transmitted between and within fibrils is limited. The presence of covalent enzymatic cross-links between collagen molecules is an important factor that has been shown to influence mechanical behavior of the tendons. To improve our understanding of how molecular bonds translate into tendon mechanics, we used an atomic force microscopy technique to measure the mechanical behavior of individual collagen fibrils loaded to failure. Fibrils from human patellar tendons, rat-tail tendons (RTTs), NaBH4 reduced RTTs, and tail tendons of Zucker diabetic fat rats were tested. We found a characteristic three-phase stress-strain behavior in the human collagen fibrils. There was an initial rise in modulus followed by a plateau with reduced modulus, which was finally followed by an even greater increase in stress and modulus before failure. The RTTs also displayed the initial increase and plateau phase, but the third region was virtually absent and the plateau continued until failure. The importance of cross-link lability was investigated by NaBH4 reduction of the rat-tail fibrils, which did not alter their behavior. These findings shed light on the function of cross-links at the fibril level, but further studies will be required to establish the underlying mechanisms. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Biophysical Journal
volume
104
issue
11
pages
2476 - 2484
publisher
Cell Press
external identifiers
  • wos:000320423700022
  • scopus:84878893133
ISSN
1542-0086
DOI
10.1016/j.bpj.2013.04.033
language
English
LU publication?
yes
id
f4186e9e-a730-4c77-9b50-4e0d435d588e (old id 3979810)
date added to LUP
2013-09-04 11:51:19
date last changed
2019-09-17 01:30:23
@article{f4186e9e-a730-4c77-9b50-4e0d435d588e,
  abstract     = {Tendons are important load-bearing structures, which are frequently injured in both sports and work. Type I collagen fibrils are the primary components of tendons and carry most of the mechanical loads experienced by the tissue, however, knowledge of how load is transmitted between and within fibrils is limited. The presence of covalent enzymatic cross-links between collagen molecules is an important factor that has been shown to influence mechanical behavior of the tendons. To improve our understanding of how molecular bonds translate into tendon mechanics, we used an atomic force microscopy technique to measure the mechanical behavior of individual collagen fibrils loaded to failure. Fibrils from human patellar tendons, rat-tail tendons (RTTs), NaBH4 reduced RTTs, and tail tendons of Zucker diabetic fat rats were tested. We found a characteristic three-phase stress-strain behavior in the human collagen fibrils. There was an initial rise in modulus followed by a plateau with reduced modulus, which was finally followed by an even greater increase in stress and modulus before failure. The RTTs also displayed the initial increase and plateau phase, but the third region was virtually absent and the plateau continued until failure. The importance of cross-link lability was investigated by NaBH4 reduction of the rat-tail fibrils, which did not alter their behavior. These findings shed light on the function of cross-links at the fibril level, but further studies will be required to establish the underlying mechanisms.},
  author       = {Svensson, Rene B. and Mulder, Hindrik and Kovanen, Vuokko and Magnusson, S. Peter},
  issn         = {1542-0086},
  language     = {eng},
  number       = {11},
  pages        = {2476--2484},
  publisher    = {Cell Press},
  series       = {Biophysical Journal},
  title        = {Fracture Mechanics of Collagen Fibrils: Influence of Natural Cross-Links},
  url          = {http://dx.doi.org/10.1016/j.bpj.2013.04.033},
  volume       = {104},
  year         = {2013},
}