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Region specific response of intervertebral disc cells to complex dynamic loading: an organ culture study using a dynamic torsion-compression bioreactor.

Chan SC, Walser J, Käppeli P, Shamsollahi MJ, Ferguson SJ, Gantenbein-Ritter B - PLoS ONE (2013)

Bottom Line: Our results provided strong evidence that complex loading induced a stronger degree of disc degeneration compared to one degree of freedom loading.Cell apoptotic activity and glycosaminoglycan content were also quantified but there were no statistically significant differences found.Our results stress the importance of complex loading on the initiation and progression of disc degeneration.

View Article: PubMed Central - PubMed

Affiliation: Tissue and Organ Mechanobiology group, Institute for Surgical Technology & Biomechanics, University of Bern, Bern, Switzerland.

ABSTRACT
The spine is routinely subjected to repetitive complex loading consisting of axial compression, torsion, flexion and extension. Mechanical loading is one of the important causes of spinal diseases, including disc herniation and disc degeneration. It is known that static and dynamic compression can lead to progressive disc degeneration, but little is known about the mechanobiology of the disc subjected to combined dynamic compression and torsion. Therefore, the purpose of this study was to compare the mechanobiology of the intervertebral disc when subjected to combined dynamic compression and axial torsion or pure dynamic compression or axial torsion using organ culture. We applied four different loading modalities [1. control: no loading (NL), 2. cyclic compression (CC), 3. cyclic torsion (CT), and 4. combined cyclic compression and torsion (CCT)] on bovine caudal disc explants using our custom made dynamic loading bioreactor for disc organ culture. Loads were applied for 8 h/day and continued for 14 days, all at a physiological magnitude and frequency. Our results provided strong evidence that complex loading induced a stronger degree of disc degeneration compared to one degree of freedom loading. In the CCT group, less than 10% nucleus pulposus (NP) cells survived the 14 days of loading, while cell viabilities were maintained above 70% in the NP of all the other three groups and in the annulus fibrosus (AF) of all the groups. Gene expression analysis revealed a strong up-regulation in matrix genes and matrix remodeling genes in the AF of the CCT group. Cell apoptotic activity and glycosaminoglycan content were also quantified but there were no statistically significant differences found. Cell morphology in the NP of the CCT was changed, as shown by histological evaluation. Our results stress the importance of complex loading on the initiation and progression of disc degeneration.

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Percentage change in disc dimension relative to the starting of the experiment.There was a 10% increase in disc volume in the No loading (NL) group, but increase was minor in all the other 3 groups. CC: cyclic compression, CT: cyclic torsion, CCT: combined compression torsion. Plot of means ± SEM. N = 6.
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pone-0072489-g003: Percentage change in disc dimension relative to the starting of the experiment.There was a 10% increase in disc volume in the No loading (NL) group, but increase was minor in all the other 3 groups. CC: cyclic compression, CT: cyclic torsion, CCT: combined compression torsion. Plot of means ± SEM. N = 6.

Mentions: Discs used in this study had a mean dimension of 16.63±1.55 mm diameter and 9.58±1.22 mm height at day 0. By the end of the experiment, disc volume was increased by 10±5.76% for NL, but increase in disc volume were less than 2% in all the other groups with loading (Figure 3). There was a slight increase in mean disc height of around 3% in the NL and CT groups, while disc height was decreased by about 2% in the groups with cyclic compression (CC and CCT). There was a 2–3% increase in disc diameter for all groups except for CT, where rotation was applied with a 0.2 MPa static compression, in which disc diameter decreased by 0.5% (Figure 3).


Region specific response of intervertebral disc cells to complex dynamic loading: an organ culture study using a dynamic torsion-compression bioreactor.

Chan SC, Walser J, Käppeli P, Shamsollahi MJ, Ferguson SJ, Gantenbein-Ritter B - PLoS ONE (2013)

Percentage change in disc dimension relative to the starting of the experiment.There was a 10% increase in disc volume in the No loading (NL) group, but increase was minor in all the other 3 groups. CC: cyclic compression, CT: cyclic torsion, CCT: combined compression torsion. Plot of means ± SEM. N = 6.
© Copyright Policy
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3755972&req=5

pone-0072489-g003: Percentage change in disc dimension relative to the starting of the experiment.There was a 10% increase in disc volume in the No loading (NL) group, but increase was minor in all the other 3 groups. CC: cyclic compression, CT: cyclic torsion, CCT: combined compression torsion. Plot of means ± SEM. N = 6.
Mentions: Discs used in this study had a mean dimension of 16.63±1.55 mm diameter and 9.58±1.22 mm height at day 0. By the end of the experiment, disc volume was increased by 10±5.76% for NL, but increase in disc volume were less than 2% in all the other groups with loading (Figure 3). There was a slight increase in mean disc height of around 3% in the NL and CT groups, while disc height was decreased by about 2% in the groups with cyclic compression (CC and CCT). There was a 2–3% increase in disc diameter for all groups except for CT, where rotation was applied with a 0.2 MPa static compression, in which disc diameter decreased by 0.5% (Figure 3).

Bottom Line: Our results provided strong evidence that complex loading induced a stronger degree of disc degeneration compared to one degree of freedom loading.Cell apoptotic activity and glycosaminoglycan content were also quantified but there were no statistically significant differences found.Our results stress the importance of complex loading on the initiation and progression of disc degeneration.

View Article: PubMed Central - PubMed

Affiliation: Tissue and Organ Mechanobiology group, Institute for Surgical Technology & Biomechanics, University of Bern, Bern, Switzerland.

ABSTRACT
The spine is routinely subjected to repetitive complex loading consisting of axial compression, torsion, flexion and extension. Mechanical loading is one of the important causes of spinal diseases, including disc herniation and disc degeneration. It is known that static and dynamic compression can lead to progressive disc degeneration, but little is known about the mechanobiology of the disc subjected to combined dynamic compression and torsion. Therefore, the purpose of this study was to compare the mechanobiology of the intervertebral disc when subjected to combined dynamic compression and axial torsion or pure dynamic compression or axial torsion using organ culture. We applied four different loading modalities [1. control: no loading (NL), 2. cyclic compression (CC), 3. cyclic torsion (CT), and 4. combined cyclic compression and torsion (CCT)] on bovine caudal disc explants using our custom made dynamic loading bioreactor for disc organ culture. Loads were applied for 8 h/day and continued for 14 days, all at a physiological magnitude and frequency. Our results provided strong evidence that complex loading induced a stronger degree of disc degeneration compared to one degree of freedom loading. In the CCT group, less than 10% nucleus pulposus (NP) cells survived the 14 days of loading, while cell viabilities were maintained above 70% in the NP of all the other three groups and in the annulus fibrosus (AF) of all the groups. Gene expression analysis revealed a strong up-regulation in matrix genes and matrix remodeling genes in the AF of the CCT group. Cell apoptotic activity and glycosaminoglycan content were also quantified but there were no statistically significant differences found. Cell morphology in the NP of the CCT was changed, as shown by histological evaluation. Our results stress the importance of complex loading on the initiation and progression of disc degeneration.

Show MeSH
Related in: MedlinePlus