Tendon glycosaminoglycan proteoglycan sidechains promote collagen fibril sliding—AFM observations at the nanoscale

2013 ◽  
Vol 46 (4) ◽  
pp. 813-818 ◽  
Author(s):  
S. Rigozzi ◽  
R. Müller ◽  
A. Stemmer ◽  
J.G. Snedeker
Keyword(s):  
Collagen Fibril

Ultrastructural analysis of collagen formation in the developing primate amnion

1990 ◽  
Vol 48 (3) ◽  
pp. 106-107
Author(s):  
Barry F. King ◽  
Grete N. Fry
Keyword(s):  
Golgi Apparatus ◽  
Collagen Fibril ◽  
Fibril Formation ◽  
Amniotic Cavity ◽  
Cytological Evidence ◽  
Mammalian Embryo ◽  
Intracellular Location ◽  
Collagen Formation ◽  
Amniotic Epithelium ◽  
Extraembryonic Mesoderm

The amnion surrounding the mammalian embryo consists of the amniotic epithelium facing the amniotic cavity, a layer of extraembryonic mesoderm bordering the exocoelom and an intervening layer of extracellular matrix (Fig. 1). During gestation the amnion expands remarkably to acommodate the rapidly growing embryo. In this study we have examined the process of collagen fibril formation in the developing amnion of the rhesus monkey between 20 and 60 days of gestation.Most cytological evidence of collagen fibril formation was observed in association with the extraembryonic mesodermal cells rather than the amniotic epithelium. The mesodermal cells h ad abundant cisternae of rough endoplasmic reticulum and a prominent Golgi apparatus. Elongated secretory vacuoles were associated with the Golgi apparatus and often contained parallel aggregates of fine filaments (Fig. 2). In some secretory vacuoles, periodic densities also were observed. Some striated collagen fibrils were observed in an apparent intracellular location in long, membrane-limited compartments (Fig. 3). Still other striated fibrils were observed in dense bodies, presumably lysosomes (Fig. 4).

scholarly journals Tyrosine-rich acidic matrix protein (TRAMP) accelerates collagen fibril formation in vitro.

1993 ◽  
Vol 268 (26) ◽  
pp. 19826-19832
Author(s):  
J.R. MacBeath ◽  
D.R. Shackleton ◽  
D.J. Hulmes
Keyword(s):  
Collagen Fibril ◽  
Matrix Protein ◽  
Fibril Formation

scholarly journals Pilot study on the effects of preservatives on corneal collagen parameters measured by small angle X-ray scattering analysis

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Susyn Joan Kelly ◽  
Lizette duPlessis ◽  
John Soley ◽  
Frazer Noble ◽  
Hannah Carolyn Wells ◽  
...  
Keyword(s):  
Small Angle ◽  
Collagen Fibril ◽  
Diameter Distribution ◽  
X Ray ◽  
X Ray Scattering ◽  
Saxs Analysis ◽  
Triton X ◽  
Fibril Diameter ◽  
Corneal Collagen ◽  
Ray Scattering

Abstract Objective Small angle X-ray scattering (SAXS) analysis is a sensitive way of determining the ultrastructure of collagen in tissues. Little is known about how parameters measured by SAXS are affected by preservatives commonly used to prevent autolysis. We determined the effects of formalin, glutaraldehyde, Triton X and saline on measurements of fibril diameter, fibril diameter distribution, and D-spacing of corneal collagen using SAXS analysis. Results Compared to sections of sheep and cats’ corneas stored frozen as controls, those preserved in 5% glutaraldehyde and 10% formalin had significantly larger mean collagen fibril diameters, increased fibril diameter distribution and decreased D-spacing. Sections of corneas preserved in Triton X had significantly increased collagen fibril diameters and decreased fibril diameter distribution. Those preserved in 0.9% saline had significantly increased mean collagen fibril diameters and decreased diameter distributions. Subjectively, the corneas preserved in 5% glutaraldehyde and 10% formalin maintained their transparency but those in Triton X and 0.9% saline became opaque. Subjective morphological assessment of transmission electron microscope images of corneas supported the SAXS data. Workers using SAXS analysis to characterize collagen should be alerted to changes that can be introduced by common preservatives in which their samples may have been stored.

scholarly journals Collagen fibril formation. Optimal in vitro conditions and preliminary kinetic results.

1978 ◽  
Vol 253 (18) ◽  
pp. 6578-6585 ◽  
Author(s):  
B.R. Williams ◽  
R.A. Gelman ◽  
D.C. Poppke ◽  
K.A. Piez
Keyword(s):  
Collagen Fibril ◽  
Fibril Formation

scholarly journals Percolation networks inside 3D model of the mineralized collagen fibril

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fabiano Bini ◽  
Andrada Pica ◽  
Andrea Marinozzi ◽  
Franco Marinozzi
Keyword(s):  
Collagen Fibril ◽  
Experimental Investigations ◽  
Volume Fractions ◽  
Human Bone Tissue ◽  
Width Direction ◽  
Lower Volume ◽  
Apatite Mineral ◽  
Critical Mineral ◽  
Mineralized Collagen Fibril ◽  
Mineralized Collagen

AbstractBone is a hierarchical biological material, characterized at the nanoscale by a recurring structure mainly composed of apatite mineral and collagen, i.e. the mineralized collagen fibril (MCF). Although the architecture of the MCF was extensively investigated by experimental and computational studies, it still represents a topic of debate. In this work, we developed a 3D continuum model of the mineral phase in the framework of percolation theory, that describes the transition from isolated to spanning cluster of connected platelets. Using Monte Carlo technique, we computed overall 120 × 106 iterations and investigated the formation of spanning networks of apatite minerals. We computed the percolation probability for different mineral volume fractions characteristic of human bone tissue. The findings highlight that the percolation threshold occurs at lower volume fractions for spanning clusters in the width direction with respect to the critical mineral volume fractions that characterize the percolation transition in the thickness and length directions. The formation of spanning clusters of minerals represents a condition of instability for the MCF, as it could be the onset of a high susceptibility to fracture. The 3D computational model developed in this study provides new, complementary insights to the experimental investigations concerning human MCF.

scholarly journals Collagen fibril formation during embryogenesis.

1983 ◽  
Vol 80 (11) ◽  
pp. 3354-3358 ◽  
Author(s):  
R. Fleischmajer ◽  
B. R. Olsen ◽  
R. Timpl ◽  
J. S. Perlish ◽  
O. Lovelace
Keyword(s):  
Collagen Fibril ◽  
Fibril Formation

Ageing Changes in the Tensile Properties of Tendons: Influence of Collagen Fibril Volume Fraction

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
K. L. Goh ◽  
D. F. Holmes ◽  
H.-Y. Lu ◽  
S. Richardson ◽  
K. E. Kadler ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Collagen Fibril ◽  
Volume Fraction ◽  
Area Fraction ◽  
Sectional Area ◽  
Cross Sectional ◽  
P Values ◽  
Age Related ◽  
Fibril Diameter ◽  
Age Related Changes

Connective tissues are biological composites comprising of collagen fibrils embedded in (and reinforcing) the hydrated proteoglycan-rich (PG) gel within the extracellular matrices (ECMs). Age-related changes to the mechanical properties of tissues are often associated with changes to the structure of the ECM, namely, fibril diameter. However, quantitative attempts to correlate fibril diameter to mechanical properties have yielded inconclusive evidence. Here, we described a novel approach that was based on the rule of mixtures for fiber composites to evaluate the dependence of age-related changes in tendon tensile strength (σ) and stiffness (E) on the collagen fibril cross-sectional area fraction (ρ), which is related to the fibril volume fraction. Tail tendons from C57BL6 mice from age groups 1.6–35.3months old were stretched to failure to determine σ and E. Parallel measurements of ρ as a function of age were made using transmission electron microscopy. Mathematical models (rule of mixtures) of fibrils reinforcing a PG gel in tendons were used to investigate the influence of ρ on ageing changes in σ and E. The magnitudes of σ, E, and ρ increased rapidly from 1.6monthsto4.0months (P-values <0.05) before reaching a constant (age independent) from 4.0monthsto29.0months (P-values >0.05); this trend continued for E and ρ (P-values >0.05) from 29.0monthsto35.3months, but not for σ, which decreased gradually (P-values <0.05). Linear regression analysis revealed that age-related changes in σ and E correlated positively to ρ (P-values <0.05). Collagen fibril cross-sectional area fraction ρ is a significant predictor of ageing changes in σ and E in the tail tendons of C57BL6 mice.

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