The Micromechanical Environment of Intervertebral Disc Cells: Effect of Matrix Anisotropy and Cell Geometry Predicted by a Linear Model

2000 ◽  
Vol 122 (3) ◽  
pp. 245-251 ◽  
Author(s):  
Anthony E. Baer ◽  
Lori A. Setton
Keyword(s):  
Intervertebral Disc ◽  
Mechanical Loading ◽  
Cell Morphology ◽  
Transversely Isotropic ◽  
Tensile Loading ◽  
Cell Geometry ◽  
Mechanical Environment ◽  
The Matrix ◽  
Disc Cells

Cells of the intervertebral disc exhibit spatial variations in phenotype and morphology that may be related to differences in their local mechanical environments. In this study, the stresses, strains, and dilatations in and around cells of the intervertebral disc were studied with an analytical model of the cell as a mechanical inclusion embedded in a transversely isotropic matrix. In response to tensile loading of the matrix, the local mechanical environment of the cell differed among the anatomic regions of the disc and was strongly influenced by changes in both matrix anisotropy and parameters of cell geometry. The results of this study suggest that the local cellular mechanical environment may play a role in determining both cell morphology in situ and the inhomogeneous response to mechanical loading observed in cells of the disc. [S0148-0731(00)00603-8]

Effect of Limited Nutrition on In Situ Intervertebral Disc Cells Under Simulated-Physiological Loading

Spine ◽  
2009 ◽  
Vol 34 (12) ◽  
pp. 1264-1271 ◽  
Author(s):  
Svenja Jünger ◽  
Benjamin Gantenbein-Ritter ◽  
Patrick Lezuo ◽  
Mauro Alini ◽  
Stephen J. Ferguson ◽  
...  
Keyword(s):  
Intervertebral Disc ◽  
Physiological Loading ◽  
Disc Cells

Effects of Endplate and Mechanical Loading on Solute Transport in Intervertebral Disc

2008 ◽  
Author(s):  
Yongren Wu ◽  
John Glaser ◽  
Hai Yao
Keyword(s):  
Finite Element ◽  
Intervertebral Disc ◽  
Finite Element Model ◽  
Solute Transport ◽  
Mechanical Loading ◽  
Disc Degeneration ◽  
Element Model ◽  
Nutrient Supply ◽  
Cartilage Endplate ◽  
Disc Cells

The intervertebral disc (IVD) is the largest cartilaginous structure in human body that contributes to flexibility and load support in the spine. To accomplish these functions, the disc has a unique architecture consisting of a centrally-located nucleus pulposus (NP) surrounded superiorly and inferiorly by cartilage endplates (CEP) and peripherally by the annulus fibrosus (AF). Disc degeneration is strongly linked to low back pain. Poor nutrient supply has been suggested as a potential mechanism for disc degeneration. Previous theoretical studies have shown that the distributions of nutrients and metabolites (e.g., oxygen, glucose, and lactate) within the IVD depended on tissue diffusivities, nutrient supply, and cellular metabolic rates [1, 2]. Based on a multiphasic mechano-electrochemical finite element model of human IVD [3], our recent theoretical study suggested that the mechanical loading has little effect on small solute transport (e.g., glucose), but significantly affects large solute transport (e.g., growth factor). The objective of this study was to further develop the multiphasic finite element model of IVD by including the cartilage endplate and considering the nutrient consumption of disc cells. Using this model, the effects of endplate and mechanical loading on solute transport in IVD were examined.

In situ x-ray CT under tensile loading using synchrotron radiation

1995 ◽  
Vol 10 (2) ◽  
pp. 381-386 ◽  
Author(s):  
T. Hirano ◽  
K. Usami ◽  
Y. Tanaka ◽  
C. Masuda
Keyword(s):  
Synchrotron Radiation ◽  
Tensile Loading ◽  
Ct Images ◽  
Matrix Cracking ◽  
Alloy Matrix ◽  
X Ray ◽  
Sic Fibers ◽  
Matrix Cracks ◽  
The Matrix

Internal damage in metal matrix composite (MMC) under static tensile loading was observed by in situ x-ray computed tomography based on synchrotron radiation (SR-CT). A tensile testing sample stage was developed to investigate the fracture process during the tensile test. Aluminum alloy matrix composites reinforced by long or short SiC fibers were used. The projection images obtained under tensile loading showed good performance of the sample stage, and matrix deformation and breaks of the long SiC fibers could be observed. In the CT images taken at the maximum stress just before failure, debondings of the short SiC fibers to the matrix, many pullouts of the fibers, and matrix cracking could be clearly observed. The in situ SR-CT allowed the observation of generation and growth of such defects under different tensile stress levels. The results from the nondestructive observation revealed that the MMC was broken by propagation of the matrix cracks which might be caused by stress concentration at the ends of the short fibers. A three-dimensional CT image reconstructed from many CT images provided easy understanding of the fiber arrangement, crack shape, and form of the void caused by fiber pullout. In situ SR-CT is a useful method for understanding failure mechanisms in advanced materials.

scholarly journals Mechanical loading affects the energy metabolism of intervertebral disc cells

2011 ◽  
Vol 29 (11) ◽  
pp. 1634-1641 ◽  
Author(s):  
Hanan N. Fernando ◽  
Jessica Czamanski ◽  
Tai-Yi Yuan ◽  
Weiyong Gu ◽  
Abdi Salahadin ◽  
...  
Keyword(s):  
Energy Metabolism ◽  
Intervertebral Disc ◽  
Mechanical Loading ◽  
Disc Cells

scholarly journals ROS: Crucial Intermediators in the Pathogenesis of Intervertebral Disc Degeneration

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Chencheng Feng ◽  
Minghui Yang ◽  
Minghong Lan ◽  
Chang Liu ◽  
Yang Zhang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Intervertebral Disc ◽  
Ros Generation ◽  
Antioxidant Supplementation ◽  
The Matrix ◽  
Disc Cells ◽  
Matrix Metabolism ◽  
Ivd Degeneration

Excessive reactive oxygen species (ROS) generation in degenerative intervertebral disc (IVD) indicates the contribution of oxidative stress to IVD degeneration (IDD), giving a novel insight into the pathogenesis of IDD. ROS are crucial intermediators in the signaling network of disc cells. They regulate the matrix metabolism, proinflammatory phenotype, apoptosis, autophagy, and senescence of disc cells. Oxidative stress not only reinforces matrix degradation and inflammation, but also promotes the decrease in the number of viable and functional cells in the microenvironment of IVDs. Moreover, ROS modify matrix proteins in IVDs to cause oxidative damage of disc extracellular matrix, impairing the mechanical function of IVDs. Consequently, the progression of IDD is accelerated. Therefore, a therapeutic strategy targeting oxidative stress would provide a novel perspective for IDD treatment. Various antioxidants have been proposed as effective drugs for IDD treatment. Antioxidant supplementation suppresses ROS production in disc cells to promote the matrix synthesis of disc cells and to prevent disc cells from death and senescence in vitro. However, there is not enough in vivo evidence to support the efficiency of antioxidant supplementation to retard the process of IDD. Further investigations based on in vivo and clinical studies will be required to develop effective antioxidative therapies for IDD.

scholarly journals Aberrant spinal mechanical loading stress triggers intervertebral disc degeneration by inducing pyroptosis and nerve ingrowth

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fangda Fu ◽  
Ronghua Bao ◽  
Sai Yao ◽  
Chengcong Zhou ◽  
Huan Luo ◽  
...  
Keyword(s):  
Intervertebral Disc ◽  
Mechanical Loading ◽  
Disc Degeneration ◽  
Sensory Nerves ◽  
Pcr Analysis ◽  
Mechanical Instability ◽  
The Matrix ◽  
Matrix Metabolism ◽  
Safranin O ◽  
Ivd Degeneration

AbstractAberrant mechanical factor is one of the etiologies of the intervertebral disc (IVD) degeneration (IVDD). However, the exact molecular mechanism of spinal mechanical loading stress-induced IVDD has yet to be elucidated due to a lack of an ideal and stable IVDD animal model. The present study aimed to establish a stable IVDD mouse model and evaluated the effect of aberrant spinal mechanical loading on the pathogenesis of IVDD. Eight-week-old male mice were treated with lumbar spine instability (LSI) surgery to induce IVDD. The progression of IVDD was evaluated by μCT and Safranin O/Fast green staining analysis. The metabolism of extracellular matrix, ingrowth of sensory nerves, pyroptosis in IVDs tissues were determined by immunohistological or real-time PCR analysis. The apoptosis of IVD cells was tested by TUNEL assay. IVDD modeling was successfully produced by LSI surgery, with substantial reductions in IVD height, BS/TV, Tb.N. and lower IVD score. LSI administration led to the histologic change of disc degeneration, disruption of the matrix metabolism, promotion of apoptosis of IVD cells and invasion of sensory nerves into annulus fibrosus, as well as induction of pyroptosis. Moreover, LSI surgery activated Wnt signaling in IVD tissues. Mechanical instability caused by LSI surgery accelerates the disc matrix degradation, nerve invasion, pyroptosis, and eventually lead to IVDD, which provided an alternative mouse IVDD model.

DNA Demethylation Regulates Anabolic and Catabolic Gene Expression in Intervertebral Disc Cells

2014 ◽  
Vol 4 (1_suppl) ◽  
pp. s-0034-1376587-s-0034-1376587
Author(s):  
N. Chutkan ◽  
R. Sangani ◽  
H. Zhou ◽  
S. Fulzele
Keyword(s):  
Gene Expression ◽  
Intervertebral Disc ◽  
Dna Demethylation ◽  
Catabolic Gene ◽  
Disc Cells

{10-12} Twinning Mechanism During In Situ Micro-Tensile Loading of Pure Mg: Role of Basal Slip and Twin-Twin Boundary Interaction

2020 ◽  
Author(s):  
Nicolò Maria della Ventura ◽  
Szilvia Kalácska ◽  
Daniele Casari ◽  
Thomas Edward James Edwards ◽  
Johann Michler ◽  
...  
Keyword(s):  
Twin Boundary ◽  
Basal Slip ◽  
Tensile Loading ◽  
Boundary Interaction
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