The regional contribution of glycosaminoglycans to temporomandibular joint disc compressive properties

Vincent P. Willard, Kerem N. Kalpakci, Andrew J. Reimer, Kyriacos A. Athanasiou

Research output: Contribution to journalArticle

24 Citations (Scopus)

Abstract

Understanding structure-function relationships in the temporomandibular joint (TMJ) disc is a critical first step toward creating functional tissue replacements for the large population of patients suffering from TMJ disc disorders. While many of these relationships have been identified for the collagenous fraction of the disc, this same understanding is lacking for the next most abundant extracellular matrix component, sulfated glycosaminoglycans (GAGs). Though GAGs are known to play a major role in maintaining compressive integrity in GAG-rich tissues such as articular cartilage, their role in fibrocartilaginous tissues in which GAGs are much less abundant is not clearly defined. Therefore, this study investigates the contribution of GAGs to the regional viscoelastic compressive properties of the temporomandibular joint (TMJ) disc. Chondroitinase ABC (C-ABC) was used to deplete GAGs in five different disc regions, and the time course for >95% GAG removal was defined. The compressive properties of GAG depleted regional specimens were then compared to non-treated controls using an unconfined compression stress-relaxation test. Additionally, treated and non-treated specimens were assayed biochemically and histologically to confirm GAG removal. Compared to untreated controls, the only regions affected by GAG removal in terms of biomechanical properties were in the intermediate zone, the most GAG-rich portion of the disc. Without GAGs, all intermediate zone regions showed decreased tissue viscosity, and the intermediate zone lateral region also showed a 12.5% decrease in modulus of relaxation. However, in the anterior and posterior band regions, no change in compressive properties was observed following GAG depletion, though these regions showed the highest compressive properties overall. Although GAGs are not the major extracellular matrix molecule of the TMJ disc, they are responsible for some of the viscoelastic compressive properties of the tissue. Furthermore, the mechanical role of sulfated GAGs in the disc varies regionally in the tissue, and GAG abundance does not always correlate with higher compressive properties. Overall, this study found that sulfated GAGs are important to TMJ disc mechanics in the intermediate zone, an important finding for establishing design characteristics for future tissue engineering efforts.

Original languageEnglish (US)
Article number011011
JournalJournal of Biomechanical Engineering
Volume134
Issue number1
DOIs
StatePublished - 2012

Fingerprint

Temporomandibular Joint Disc
Glycosaminoglycans
A73025
Tissue
Temporomandibular Joint
Extracellular Matrix
Chondroitin ABC Lyase
Temporomandibular Joint Disorders
Population Dynamics
Articular Cartilage

Keywords

  • chondroitinase-abc
  • disc
  • glycosaminoglycans
  • stress relaxation
  • temporomandibular joint

ASJC Scopus subject areas

  • Biomedical Engineering
  • Physiology (medical)

Cite this

The regional contribution of glycosaminoglycans to temporomandibular joint disc compressive properties. / Willard, Vincent P.; Kalpakci, Kerem N.; Reimer, Andrew J.; Athanasiou, Kyriacos A.

In: Journal of Biomechanical Engineering, Vol. 134, No. 1, 011011, 2012.

Research output: Contribution to journalArticle

Willard, Vincent P. ; Kalpakci, Kerem N. ; Reimer, Andrew J. ; Athanasiou, Kyriacos A. / The regional contribution of glycosaminoglycans to temporomandibular joint disc compressive properties. In: Journal of Biomechanical Engineering. 2012 ; Vol. 134, No. 1.
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