Exploring issues for a cartilage degradation model

Abstract

The primary goal of this work was to establish a model system wherein a controlled level of damage is induced to a sample of normal cartilage, such that damage and repair can be observed by the dGEMRIC method of MR imaging. Primarily this included the iterative design of a cartilage tissue holder and testing of its ability to approximate uniaxial diffusion, as well as observation of glycosaminoglycan degradation induced by ADAMTS using dGEMRIC and DMMB assays. The mean uniaxial degradation rate for 20nM ADAMTS was 0.17 mm/day ± 0.08 (1 [delta], n = 4). The shape of the diffusion front was mostly flat, with attributable factors such as vascular structures affecting the shape. These consistencies made ADAMTS an acceptable choice for a degradation agent in the model system. A final holder design was created that proved largely successful in limiting access of ADAMTS to a single surface, as demonstrated by the flat diffusion/degradation front. This led to a good approximation of uni-axial diffusion and fit well with simple mathematical models of diffusion and previously determined diffusivities of Gadolinium agents in cartilage. A model system using ADAMTS as a degradation agent and dGEMRIC methods of observation can now be implemented for exploration of cartilage's ability to repair itself.