Three-dimensional organization of fibroblasts and collagen fibrils in rat tail tendon

1984 ◽  
Vol 238 (2) ◽  
Author(s):  
ChristopherA. Squier ◽  
W.H. Bausch
Keyword(s):  
Three Dimensional ◽  
Collagen Fibrils ◽  
Tail Tendon ◽  
Rat Tail

scholarly journals A damage model for collagen fibres with an application to collagenous soft tissues

2020 ◽  
Vol 476 (2236) ◽  
pp. 20190821
Author(s):  
Gerhard A. Holzapfel ◽  
Ray W. Ogden
Keyword(s):  
Soft Tissues ◽  
Damage Model ◽  
Three Dimensional ◽  
Collagen Fibres ◽  
Physiological Loading ◽  
Cross Links ◽  
Complex Boundary ◽  
Tail Tendon ◽  
Similar Basis ◽  
Rat Tail

We propose a mechanical model to account for progressive damage in collagen fibres within fibrous soft tissues. The model has a similar basis to the pseudoelastic model that describes the Mullins effect in rubber but it also accounts for the effect of cross-links between collagen fibres. We show that the model is able to capture experimental data obtained from rat tail tendon fibres, and the combined effect of damage and collagen cross-links is illustrated for a simple shear test. The proposed three-dimensional framework allows a straightforward implementation in finite-element codes, which are needed to analyse more complex boundary-value problems for soft tissues under supra-physiological loading or tissues weakened by disease.

An Estimate of the Mean Length of Collagen Fibrils in Rat Tail-Tendon as a Function of age

1989 ◽  
Vol 19 (1) ◽  
pp. 51-62 ◽  
Author(s):  
Alan S. Craig ◽  
Mervyn J. Birtles ◽  
James F. Conway ◽  
David A.D. Parry
Keyword(s):  
Collagen Fibrils ◽  
The Mean ◽  
Tail Tendon ◽  
Rat Tail

Interstitial exclusion of macromolecules studied by graded centrifugation of rat tail tendon

1997 ◽  
Vol 273 (6) ◽  
pp. H2794-H2803 ◽  
Author(s):  
Knut Aukland ◽  
Helge Wiig ◽  
Olav Tenstad ◽  
Eugene M. Renkin
Keyword(s):  
Molecular Weight ◽  
Hyaluronic Acid ◽  
Colloid Osmotic Pressure ◽  
Collagen Fibrils ◽  
Free Fluid ◽  
Mechanical Compression ◽  
The Third ◽  
Tail Tendon ◽  
Molecular Sieving ◽  
Rat Tail

Mechanical compression of cartilage and tendon has been shown to expel fluid both from collagen fibrils and from the extrafibrillar space. As reported previously, albumin (Alb) concentration and colloid osmotic pressure in tendon fluid (TF) expelled by repeated centrifugations fell progressively at increasing centrifugation force (G = 600, 2,400, and 13,100), suggesting either molecular sieving in compressed tendon or mobilization of protein-free (excluded) fluid. The present experiments, including analysis of 51Cr-EDTA, aprotinin (Ap), Alb, immunoglobulin G (IgG), and hyaluronan (hyaluronic acid; HA) with molecular weight (MW) ranging from 341 to 5 × 106, strongly favored the exclusion hypothesis; the fraction of Alb, IgG, and HA-free fluid (excluded) was already 0.23–0.36 in the first centrifugate, increasing to 0.73–0.82 in the third. The corresponding numbers were, respectively, 0.11 and 0.43 for Ap (MW 6,500), and 0 and 0.08 for51Cr-EDTA. These data, combined with calculated exclusion by collagen fibrils, proteoglycans, and HA, indicated that the first centrifugate was mainly derived from the extrafibrillar space, with increasing addition of macromolecular free intrafibrillar fluid in the second and third centrifugates, with each space contributing about equally to the total centrifugate volume. The calculations also indicated that Alb-, IgG-, and Ap-free fluid was mobilized from extrafibrillar space by increasing overlap of excluded territories. An excess of HA in tendon compared with that estimated from centrifugate concentrations suggests a large bound or immobilized HA fraction.

Tendon and ligament from the horse: an ultrastructural study of collagen fibrils and elastic fibres as a function of age

1978 ◽  
Vol 203 (1152) ◽  
pp. 293-303 ◽  
Keyword(s):  
Flexor Tendon ◽  
Extensor Tendon ◽  
Collagen Fibrils ◽  
Collagen Content ◽  
Elastic Fibres ◽  
Suspensory Ligament ◽  
Tail Tendon ◽  
Fibril Diameter ◽  
Rat Tail ◽  
Diameter Distributions

A study has been made of the ultrastructural organization of the collagen fibrils and elastic fibres in tendons and ligaments from horses of ages ranging from 2 months premature to 19 years. Diameter distributions of the collagen fibrils in the common digital extensor tendon, the superficial flexor tendon and the suspensory ligament are unimodal in the foetal tissue and at birth, and at these stages of development the three collagenous tissues are virtually indistinguishable. However, at maturity, the ligament and flexor tendon have bimodal distributions similar to that found for rat-tail tendon. The fibril distribution for extensor tendon remains unimodal until the onset of maturity, beyond which the distribution becomes bimodal. Fibril diameter distributions for ligament, extensor and flexor tendon at old age are, as at birth, virtually identical. An estimate has been made of fibrillar collagen content in the three tissues as a function of age. As with rat-tail tendon, the collagen content increases steadily from birth to maturity, at which stage the content remains fairly constant though it does drop slowly with increasing age. The presence of well developed elastic tissue in foetal and immature tendon and ligament shows that the development of the elastic fibres does not parallel the development of the collagen fibrils. In diseased tissues from a 3 year suspensory ligament and an 8.5 year superficial flexor tendon only immature elastic fibres have been observed. Furthermore, since the collagen fibril diameter distributions in these specimens show a marked change from the norm, it would be expected that the mechanical properties of these tissues would be altered significantly.

scholarly journals The supramolecular structure of bone: X-ray scattering analysis and lateral structure modeling

2016 ◽  
Vol 72 (9) ◽  
pp. 986-996 ◽  
Author(s):  
Hong-Wen Zhou ◽  
Christian Burger ◽  
Hao Wang ◽  
Benjamin S. Hsiao ◽  
Benjamin Chu ◽  
...  
Keyword(s):  
Collagen Fibrils ◽  
Bone Collagen ◽  
X Ray ◽  
X Ray Scattering ◽  
Mineralized Tissues ◽  
Collagen Molecules ◽  
Tail Tendon ◽  
Lateral Structure ◽  
Rat Tail ◽  
Ray Scattering

The evolution of vertebrates required a key development in supramolecular evolution: internally mineralized collagen fibrils. In bone, collagen molecules and mineral crystals form a nanocomposite material comparable to cast iron in tensile strength, but several times lighter and more flexible. Current understanding of the internal nanoscale structure of collagen fibrils, derived from studies of rat tail tendon (RTT), does not explain how nucleation and growth of mineral crystals can occur inside a collagen fibril. Experimental obstacles encountered in studying bone have prevented a solution to this problem for several decades. This report presents a lateral packing model for collagen molecules in bone fibrils, based on the unprecedented observation of multiple resolved equatorial reflections for bone tissue using synchrotron small-angle X-ray scattering (SAXS; ∼1 nm resolution). The deduced structure for pre-mineralized bone fibrils includes features that are not present in RTT: spatially discrete microfibrils. The data are consistent with bone microfibrils similar to pentagonal Smith microfibrils, but are not consistent with the (nondiscrete) quasi-hexagonal microfibrils reported for RTT. These results indicate that collagen fibrils in bone and tendon differ in their internal structure in a manner that allows bone fibrils, but not tendon fibrils, to internally mineralize. In addition, the unique pattern of collagen cross-link types and quantities in mineralized tissues can be can be accounted for, in structural/functional terms, based on a discrete microfibril model.

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