Limits...
Bovine explant model of degeneration of the intervertebral disc.

Roberts S, Menage J, Sivan S, Urban JP - BMC Musculoskelet Disord (2008)

Bottom Line: Bovine explant model systems have many advantages but it is not possible to inject any significant volume into an intact disc.The integrity of the surrounding tissue was mostly in tact with cells in the outer annulus appearing viable.Biochemical analysis demonstrated greatly reduced glycosaminoglycan content in these compared to untreated discs.

View Article: PubMed Central - HTML - PubMed

Affiliation: Centre for Spinal Studies, Robert Jones and Agnes Hunt Orthopaedic Hospital, Oswestry, Shropshire SY10 7AG, UK. sally.roberts@rjah.nhs.uk

ABSTRACT

Background: Many new treatments for degeneration of the intervertebral disc are being developed which can be delivered through a needle. These require testing in model systems before being used in human patients. Unfortunately, because of differences in anatomy, there are no ideal animal models of disc degeneration. Bovine explant model systems have many advantages but it is not possible to inject any significant volume into an intact disc. Therefore we have attempted to mimic disc degeneration in an explant bovine model via enzymatic digestion.

Methods: Bovine coccygeal discs were incubated with different concentrations of the proteolytic enzymes, trypsin and papain, and maintained in culture for up to 3 weeks. A radio-opaque solution was injected to visualise cavities generated. Degenerative features were monitored histologically and biochemically (water and glycosaminoglycan content, via dimethylmethylene blue).

Results and conclusion: The central region of both papain and trypsin treated discs was macro- and microscopically fragmented, with severe loss of metachromasia. The integrity of the surrounding tissue was mostly in tact with cells in the outer annulus appearing viable. Biochemical analysis demonstrated greatly reduced glycosaminoglycan content in these compared to untreated discs. We have shown that bovine coccygeal discs, treated with proteolytic enzymes can provide a useful in vitro model system for developing and testing potential new treatments of disc degeneration, such as injectable implants or biological therapies.

Show MeSH

Related in: MedlinePlus

Radiographic images of motion segments injected with radio-opaque medium 72 hours after incubation with 1, 5 or 10 mg/ml trypsin.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2266744&req=5

Figure 2: Radiographic images of motion segments injected with radio-opaque medium 72 hours after incubation with 1, 5 or 10 mg/ml trypsin.

Mentions: Macroscopic changes to the structure of the enzyme treated discs were visible by the naked eye on dissection of the motion segments (Figure 1). The integrity of the control discs appeared intact at all time points; in contrast, all enzyme treated discs had cavities in the centre. This alteration was restricted to the nucleus pulposus for trypsin treated discs at all time points and at weeks 1 and 2 for papain-treated. At 3 weeks after papain injection, however, the disruption extended into the annulus for all samples so treated. Radiograph imaging of motion segments injected with radio-opaque dye demonstrate that the amount which could be injected into the centre of the disc increased with the amount of enzyme used (Figure 2), occupying approximately 10–25% of the disc volume after a week.


Bovine explant model of degeneration of the intervertebral disc.

Roberts S, Menage J, Sivan S, Urban JP - BMC Musculoskelet Disord (2008)

Radiographic images of motion segments injected with radio-opaque medium 72 hours after incubation with 1, 5 or 10 mg/ml trypsin.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2266744&req=5

Figure 2: Radiographic images of motion segments injected with radio-opaque medium 72 hours after incubation with 1, 5 or 10 mg/ml trypsin.
Mentions: Macroscopic changes to the structure of the enzyme treated discs were visible by the naked eye on dissection of the motion segments (Figure 1). The integrity of the control discs appeared intact at all time points; in contrast, all enzyme treated discs had cavities in the centre. This alteration was restricted to the nucleus pulposus for trypsin treated discs at all time points and at weeks 1 and 2 for papain-treated. At 3 weeks after papain injection, however, the disruption extended into the annulus for all samples so treated. Radiograph imaging of motion segments injected with radio-opaque dye demonstrate that the amount which could be injected into the centre of the disc increased with the amount of enzyme used (Figure 2), occupying approximately 10–25% of the disc volume after a week.

Bottom Line: Bovine explant model systems have many advantages but it is not possible to inject any significant volume into an intact disc.The integrity of the surrounding tissue was mostly in tact with cells in the outer annulus appearing viable.Biochemical analysis demonstrated greatly reduced glycosaminoglycan content in these compared to untreated discs.

View Article: PubMed Central - HTML - PubMed

Affiliation: Centre for Spinal Studies, Robert Jones and Agnes Hunt Orthopaedic Hospital, Oswestry, Shropshire SY10 7AG, UK. sally.roberts@rjah.nhs.uk

ABSTRACT

Background: Many new treatments for degeneration of the intervertebral disc are being developed which can be delivered through a needle. These require testing in model systems before being used in human patients. Unfortunately, because of differences in anatomy, there are no ideal animal models of disc degeneration. Bovine explant model systems have many advantages but it is not possible to inject any significant volume into an intact disc. Therefore we have attempted to mimic disc degeneration in an explant bovine model via enzymatic digestion.

Methods: Bovine coccygeal discs were incubated with different concentrations of the proteolytic enzymes, trypsin and papain, and maintained in culture for up to 3 weeks. A radio-opaque solution was injected to visualise cavities generated. Degenerative features were monitored histologically and biochemically (water and glycosaminoglycan content, via dimethylmethylene blue).

Results and conclusion: The central region of both papain and trypsin treated discs was macro- and microscopically fragmented, with severe loss of metachromasia. The integrity of the surrounding tissue was mostly in tact with cells in the outer annulus appearing viable. Biochemical analysis demonstrated greatly reduced glycosaminoglycan content in these compared to untreated discs. We have shown that bovine coccygeal discs, treated with proteolytic enzymes can provide a useful in vitro model system for developing and testing potential new treatments of disc degeneration, such as injectable implants or biological therapies.

Show MeSH
Related in: MedlinePlus