ASSESSMENT OF THREE-DIMENSIONAL ARCHITECTURE OF COLLAGEN FIBERS IN THE SUPERFICIAL ZONE OF BOVINE ARTICULAR CARTILAGE

2004 ◽  
Vol 08 (04) ◽  
pp. 167-179 ◽  
Author(s):  
J. P. Wu ◽  
T. B. Kirk ◽  
M. H. Zheng
Keyword(s):  
Articular Cartilage ◽  
Laser Scanning ◽  
3D Visualization ◽  
Articular Surface ◽  
3D Structure ◽  
Collagen Matrix ◽  
Laser Scanning Confocal Microscopy ◽  
Collagen Fibres ◽  
Superficial Zone ◽  
Bovine Articular Cartilage

The aim of this study is to investigate the structure and the collagen matrix of the superficial zone of articular cartilage using a 3D imaging technique. The split line thought to represent the orientation of the collagen fibres in the superficial zone was found using Hultkrantz's method. A semitransparent membrane was physically peeled off from the most superficial surface of bovine articular cartilage. Using fibre optic laser scanning confocal microscopy, the collagen matrix in normal cartilage, the membrane and the cartilage with the membrane peeled off were studied. The superficial zone was found to contain a more sophisticated 3D collagenous matrix than previously reported. The collagen matrix in the membrane consists of interwoven long collagen bundles, and the collagen fibres immediately subjacent to it align spatially in a predominantly oblique direction to the articular surface. The split line does not represent the orientation of the collagen in the membrane. This study presents a 3D visualization technique for a minimal-invasive examination of the 3D architecture of the collagen fibres in the superficial zone of articular cartilage, and offers a new insight into the 3D structure of the collagen matrix in the superficial zone of native cartilage.

UTILIZATION OF TWO-DIMENSIONAL FAST FOURIER TRANSFORM AND POWER SPECTRAL ANALYSIS FOR ASSESSMENT OF EARLY DEGENERATION OF ARTICULAR CARTILAGE

2005 ◽  
Vol 09 (03) ◽  
pp. 119-131 ◽  
Author(s):  
J. P. Wu ◽  
T. B. Kirk ◽  
Z. Peng ◽  
K. Miller ◽  
M. H. Zheng
Keyword(s):  
Spectral Analysis ◽  
Articular Cartilage ◽  
Confocal Microscopy ◽  
Laser Scanning ◽  
Fourier Transforms ◽  
Power Spectral Analysis ◽  
Collagen Matrix ◽  
Collagen Fibres ◽  
Superficial Zone ◽  
Power Spectral

Degeneration of articular cartilage begins from deterioration of the collagen fibres in the superficial zone. Standard histology using 2D imaging technique is often used to determine the microstructure of collagen fibres and the physiological functions of articular cartilage. However, information of the 3D collageneous structure in the cartilage could be lost and misinterpreted in 2D observations. In contrast, confocal microscopy permits studying the 3D internal structure of bulk articular cartilage with minimal physical disturbing. Using fibre optic laser scanning confocal microscopy, a 3D histology has been previously developed to visualize the collagen matrix in the superficial zone by means of identifying the early arthritic changes in articular cartilage. In this study, we characterized the collagen orientation in the superficial zone of normal cartilage, the cartilage with surface disruption and fibrillated cartilage using Fast Fourier transforms and power spectral analysis techniques. Thus, we have established an objective method for assessing the early pathology changes in the articular cartilage.

QUANTITATIVE CHARACTERIZATION OF COLLAGEN ORIENTATION IN THE SUPERFICIAL ZONE FOR STUDYING EARLY DEGENERATIVE CHANGES IN ARTICULAR CARTILAGE

2006 ◽  
Vol 10 (01) ◽  
pp. 1-12 ◽  
Author(s):  
J. P. Wu ◽  
T. B. Kirk ◽  
Z. Peng ◽  
K. Miller ◽  
M. H. Zheng
Keyword(s):  
Articular Cartilage ◽  
Confocal Microscopy ◽  
Laser Scanning ◽  
Visual Inspection ◽  
Physiological State ◽  
Laser Scanning Confocal Microscopy ◽  
Physiological Status ◽  
Collagen Fibres ◽  
Superficial Zone ◽  
Osteoarthritic Cartilage

Collagen fibres in the superficial zone are critical to the durability and stability of articular cartilage. Early osteoarthritis is often characterized by lesions on the surface of articular cartilage as a result of deterioration or degeneration of the collagen meshwork in the superficial zone. Therefore, traditional histology employing visual inspection of the microstructure of collagen fibres is one of the methods frequently used to evaluate the physiological state of articular cartilage in the medical field. However, traditional histology is often limited to 2D observations. It requires physical sectioning and dehydration of articular cartilage for stereological study. In addition, visual inspection is subjective and time consuming. Confocal microscopy provides a way to study the three-dimensional collagen structure in bulk hydrated articular cartilage. Utilizing fibre optical laser scanning confocal microscopy, the aim of the present study was to apply the spectral moment as a method for quantitatively describing the orientation of the collagen fibres in the superficial zone in relation to the physiological status of the cartilage, such as distinguishing normal cartilage from the early osteoarthritic cartilage.

scholarly journals Localization of proteoglycan monomer and link protein in the matrix of bovine articular cartilage: An immunohistochemical study.

1980 ◽  
Vol 28 (7) ◽  
pp. 621-635 ◽  
Author(s):  
A R Poole ◽  
I Pidoux ◽  
A Reiner ◽  
L H Tang ◽  
H Choi ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Articular Surface ◽  
Guanidine Hydrochloride ◽  
Cartilage Matrix ◽  
Binding Studies ◽  
Superficial Zone ◽  
Surface Culture ◽  
Bovine Articular Cartilage ◽  
Link Protein ◽  
The Matrix

Using monospecific antisera and immunofluorescence microscopy, proteoglycan monomer (PG), and link proteins were demonstrated throughout the extracellular matrix of bovine articular cartilage. A narrow band of strong pericellular staining was usually observed for both molecules, indicating a pericellular concentration of proteoglycan monomer: this conclusion was supported by dye-binding studies. Whereas PG was evenly distributed throughout the remaining matrix, more link protein was detectable in interterritorial sites in middle and deep zones. Well-defined zones of weaker territorial staining for link protein stained strongest for chondroitin sulfate. Trypsin treatment of cartilage resulted in a loss of most of the PG staining, but some selective retention of link protein, particularly around chondrocytes in the superficial zone at and near the articular surface. This residual staining was largely removed if sections were fixed after chondroitinase treatment. After extraction of cartilage with 4M guanidine hydrochloride, only PG remained and this was concentrated in the superficial zone. These observations are shown to support the concept of aggregation of PG and link protein with hyaluronic acid (HA) in cartilage matrix, and the binding of PG and link protein to HA, which is attached to the chondrocyte surface. Culture of cartilage depleted of PG and link protein by trypsin demonstrated that individual chondrocytes can secrete both PG and link proteins and that the organization of cartilage matrix can be regenerated in part over a period of 4 days.

Depth Dependent Diffusivity Profile in Bovine Articular Cartilage: Comparing Transverse and Axial Diffusivities

2007 ◽  
Author(s):  
Onyi N. Irrechukwu ◽  
Marc E. Levenston
Keyword(s):  
Extracellular Matrix ◽  
Articular Cartilage ◽  
Articular Surface ◽  
Deep Zone ◽  
Superficial Zone ◽  
Transport Pathway ◽  
Bovine Articular Cartilage ◽  
Extracellular Matrix Components ◽  
Matrix Components ◽  
Oriented Parallel

As articular cartilage is avascular, diffusion at a tissue length scale is the primary mode of solute and nutrient transport to its cells. The major extracellular matrix components are water (70–80%), chondrocytes, collagen (10–20%) and proteoglycans (5–10%) bearing sulfated glycosaminoglycans (GAG) [1]. Electron microscopy studies have shown that articular cartilage can be regarded as having three separate structural zones — superficial, middle and deep. The proportions of the various matrix components vary from the surface to the deep zone in any given joint and the greatest variations in content occur in the GAG content [2]. In addition the collagen fiber alignment varies, with fibers oriented parallel to the articular surface in the superficial zone, randomly oriented in the middle zone and oriented perpendicular to the surface in the deep zone. To a large extent, it is the spatially inhomogeneous composition of articular cartilage and microstructural orientation of its extracellular matrix components that determines the tortuosity of the transport pathway [3]. We therefore hypothesized that the diffusivity profile of a solute through the cartilage depth is inversely related to the GAG content and that the ratio between the axial and lateral diffusivities within each cartilage zone is related to the degree of anisotropy within the zone.

A Fibril Reinforced Poroelastic Model of Articular Cartilage Including Depth Dependent Material Properties

1999 ◽  
Author(s):  
L. P. Li ◽  
M. D. Buschmann ◽  
A. Shirazi-Adl
Keyword(s):  
Articular Cartilage ◽  
Regional Differences ◽  
Articular Surface ◽  
Collagen Fibrils ◽  
Superficial Zone ◽  
Cartilage Surface ◽  
Poroelastic Model ◽  
Oriented Parallel ◽  
Strain Dependent ◽  
Very High

Abstract Articular cartilage is a highly nonhomogeneous, anisotropic and multiphase biomaterial consisting of mainly collagen fibrils, proteoglycans and water. Noncalcified cartilage is morphologically divided into three zones along the depth, i.e. superficial, transitional and radial zones. The thickness, density and alignment of collagen fibrils vary from the superficial zone, where fibrils are oriented parallel to the articular surface, to the radial zone where fibrils are perpendicular to the boundary between bone, and cartilage. The concentration of proteoglycans increases with the depth from the cartilage surface. These regional differences have significant implications to the mechanical function of joints, which is to be explored theoretically in the present work by considering inhomogeneity along the cartilage depth. A nonlinear fibril reinforced poroelastic model is employed as per Li et al. (1999) in which the collagen fibrils were modeled as a distinct constituent whose tensile stiffness was taken to be very high and be strain dependent but whose compressive stiffness was neglected.

scholarly journals Removal of the superficial zone of bovine articular cartilage does not increase its frictional coefficient

2004 ◽  
Vol 12 (12) ◽  
pp. 947-955 ◽  
Author(s):  
R. Krishnan ◽  
M. Caligaris ◽  
R.L. Mauck ◽  
C.T. Hung ◽  
K.D. Costa ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Frictional Coefficient ◽  
Superficial Zone ◽  
Bovine Articular Cartilage

scholarly journals Revealing the True Morphological Structure of Macroporous Soft Hydrogels for Tissue Engineering

2020 ◽  
Vol 10 (19) ◽  
pp. 6672
Author(s):  
Bohumila Podhorská ◽  
Miroslav Vetrík ◽  
Eva Chylíková-Krumbholcová ◽  
Lucie Kománková ◽  
Niloufar Rashedi Banafshehvaragh ◽  
...  
Keyword(s):  
Sodium Chloride ◽  
Pore Size ◽  
Laser Scanning ◽  
Morphological Changes ◽  
3D Structure ◽  
Morphological Structure ◽  
Laser Scanning Confocal Microscopy ◽  
Future Application ◽  
Sem Images ◽  
Hydrogel Scaffolds

(1) Background: Macroporous hydrogel scaffolds based on poly [N-(2-hydroxypropyl) methacrylamide] are one of the widely studied biocompatible materials for tissue reparation and regeneration. This study investigated the morphological changes during hydrogel characterization which can significantly influence their future application. (2) Methods: Three types of macroporous soft hydrogels differing in pore size were prepared. The macroporosity was achieved by the addition of sacrificial template particles of sodium chloride of various sizes (0–30, 30–50, and 50–90 µm) to the polymerizing mixture. The 3D structure of the hydrogels was then investigated by scanning electron microscopy (SEM) and laser scanning confocal microscopy (LSCM). The SEM was performed with specimens rapidly frozen to various temperatures, while non-frozen gels were visualized with LSCM. (3 and 4) Results and Conclusion: In comparison to LSCM, the SEM images revealed a significant alteration in the mean pore size and appearance of newly formed multiple connections between the pores, depending on the freezing conditions. Additionally, after freezing for SEM, the gel matrix between the pores and the fine pores collapsed. LSCM visualization aided the understanding of the dynamics of pore generation using sodium chloride, providing the direct observation of hydrogel scaffolds with the growing cells. Moreover, the reconstructed confocal z-stacks were a promising tool to quantify the swollen hydrogel volume reconstruction which is not possible with SEM.

scholarly journals Depth-varying Density and Organization of Chondrocytes in Immature and Mature Bovine Articular Cartilage Assessed by 3D Imaging and Analysis

2005 ◽  
Vol 53 (9) ◽  
pp. 1109-1119 ◽  
Author(s):  
Kyle D. Jadin ◽  
Benjamin L. Wong ◽  
Won C. Bae ◽  
Kelvin W. Li ◽  
Amanda K. Williamson ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
3D Imaging ◽  
Articular Surface ◽  
Three Dimensional ◽  
Neighboring Cell ◽  
3D Images ◽  
Bovine Articular Cartilage ◽  
Stages Of Growth ◽  
Cell Organization ◽  
Heterogeneous Tissue

Articular cartilage is a heterogeneous tissue, with cell density and organization varying with depth from the surface. The objectives of the present study were to establish a method for localizing individual cells in three-dimensional (3D) images of cartilage and quantifying depth-associated variation in cellularity and cell organization at different stages of growth. Accuracy of nucleus localization was high, with 99% sensitivity relative to manual localization. Cellularity (million cells per cm3) decreased from 290, 310, and 150 near the articular surface in fetal, calf, and adult samples, respectively, to 120, 110, and 50 at a depth of 1.0 mm. The distance/angle to the nearest neighboring cell was 7.9 μm/31°, 7.1 μm/31°, and 9.1 μm/31° for cells at the articular surface of fetal, calf, and adult samples, respectively, and increased/decreased to 11.6 μm/31°, 12.0 μm/30°, and 19.2 μm/25° at a depth of 0.7 mm. The methodologies described here may be useful for analyzing the 3D cellular organization of cartilage during growth, maturation, aging, degeneration, and regeneration.

Sign in / Sign up

Export Citation Format

Share Document