History Understanding structure-function relationships in the temporomandibular joint (TMJ) disc is

History 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. 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. Results 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 music group regions no modification in compressive properties was noticed pursuing GAG depletion though these areas showed the best compressive properties general. Conclusions Although GAGs aren’t the main extracellular matrix molecule from the TMJ disk they are in charge of a number of the viscoelastic compressive properties from the cells. Furthermore the mechanised part of sulfated GAGs in the disk varies regionally in the cells and GAG great quantity does not often correlate with higher compressive Kaempferol properties. Overall this research discovered that sulfated GAGs are essential to TMJ disk technicians in the intermediate area an important finding for establishing design characteristics for future tissue engineering efforts. test was used where necessary. Additionally treated and untreated samples within a single region of the disc were compared directly using a student’s t-test (Table 1 and Appendix Table 2 Treated and untreated hyaline cartilage samples were also compared with a student’s t-test. Since biochemical and biomechanical analysis was performed on the same samples pairwise Kaempferol correlations were run on these samples using JMP statistical software (SAS Cary NC). A significance level of α = 0.05 was used for all statistical analysis. Table 1 Biomechanical and biochemical properties of GAG depleted TMJ disc samples. Data is Rabbit Polyclonal to CLCNKA. presented as mean ± SD. Results Compressive Properties The Kelvin solid viscoelastic model was able to fit all stress-relaxation curves with a high degree of accuracy (R2 > 0.9 Experimental results are shown in Fig. 3 and the raw data can be found in Table 1. Regional variations in all compressive properties of the TMJ disc were consistent with prior reports using the same testing modality [14 15 25 Figure 3 Viscoelastic compressive properties of GAG depleted TMJ disc and hyaline cartilage samples. (A) GAG removal with C-ABC did not produce a significant difference in the instantaneous modulus of the TMJ disc. (B) C-ABC treatment also had no effect on the … Instantaneous Modulus While C-ABC treatment was able to deplete sulfated GAGs from the TMJ disc it had no effect on the instantaneous modulus of the tissue (Fig. 3A). Regionally the bands of the disc PB and AB were stiffer than the intermediate zone with moduli Kaempferol of 1 1.49 and 0.93 MPa respectfully (p<0.0001). Similar Kaempferol to the TMJ disc C-ABC treatment of hyaline cartilage also produced no statistically significant difference in instantaneous modulus although it did appear to trend lower with treatment (Fig. 3B). The instantaneous modulus of hyaline cartilage was at least twice that of all regions of the disc with a mean value of 4.31 MPa. Relaxation Modulus An overall comparison using a 2-way ANOVA showed no significant change in the relaxation modulus of the disc following C-ABC treatment (Fig. 3C). Regional variations were seen with PB possessing the highest relaxation modulus at 30.0 kPa (p<0.0001). Additional analysis of treated and untreated samples within a single region (t-test) indicated that GAG depletion did produce a statistically significant decrease in IZL (p<0.02 Desk 1). The entire decrease in rest modulus of IZL was ~12.5% from 24.1 to 21.1 kPa. As opposed to the disc C-ABC treatment of hyaline cartilage created a far more dramatic reduction in rest modulus (Fig. 3 Treatment led to a 50% drop in modulus from 591 to 295 kPa (p<0.0001). Overall the rest modulus from the TMJ disk was >10 moments significantly less than hyaline cartilage. Coefficient of Viscosity Set alongside the moduli C-ABC treatment produced more modification in the coefficient of viscosity considerably. A 2-method.