Pulsed gradient stimulated echo (PGStE) NMR shows spatial dependence of fluid diffusion in human stage IV osteoarthritic cartilage
- Mailhiot, Sarah E. [ Montana State University: Mechanical & Industrial Engineering ]
- Codd, Sarah L. [ Montana State University: Mechanical & Industrial Engineering ]
- Brown, Jennifer R. [ Montana State University: Chemical & Biological Engineering ]
- Seymour, Joseph D. [ Montana State University: Chemical & Biological Engineering ]
- June, Ronald K. [ Montana State University: Mechanical & Industrial Engineering ]
PURPOSE Human osteoarthritic (OA) articular cartilage was investigated with spatially resolved pulsed gradient stimulated echo (PGStE) NMR using strong gradients. In this study, the diffusivity of fluid and biopolymer was characterized as a function of depth within human OA cartilage cores. METHODS One dimensional (1D) spatially resolved diffusion profiles were measured for human OA cartilage using a standard pulsed gradient stimulated echo (PGStE) sequence with the addition of a read imaging gradient. Low gradient values (0.05 to 1.5 Tm-1 ) were used to measure fluid motion and high gradients (2.50 to 17.81 Tm-1 ) enabled analysis of biopolymer motion. Structural damage to cartilage was simulated using either salt or collagenase. RESULTS These data demonstrate that fluid diffusion is sensitive to salt treatment and collagenase digestion, while biopolymer diffusion is sensitive only to collagenase digestion. Biopolymer and fluid diffusion are donor specific for human OA cartilage samples. CONCLUSION These data support that fluid diffusion is sensitive to the structure of cartilage while biopolymer diffusion is sensitive to the molecular weight of the biopolymers. The results show that diffusion of fluid and biopolymers in articular cartilage are sensitive to OA and provide complimentary information.