Composition and transport properties of human ankle and knee cartilage

Abstract

ABSTRACT:The incidence of osteoarthritis is significantly higher in the knee as compared to the ankle, suggesting that differences in the properties of cartilage from these joints may contribute to the development of osteoarthritis. As an avascular tissue, articular cartilage depends primarily upon diffusion for molecular transport. The goal of this study was to determine if differences in the structure and composition between ankle and knee cartilage were also reflected as differences in solute transport properties. The diffusion coefficient and partition coefficient of a 70-kDa dextran molecule were measured in human ankle and knee articular cartilage using fluorescence recovery after photobleaching (FRAP) and were compared to the proteoglycan, collagen, water, and DNA contents within each zone. The mean partition coefficient was significantly lower in the ankle compared to the knee (0.010 AE 0.002 vs. 0.022 AE 0.003, p < 0.01), but no differences in the diffusion coefficients were observed (34.6 AE 0.9 mm 2 s À1 vs. 35.4 AE 2.4 mm 2 s À1 , p ¼ 0.70). Ankle cartilage exhibited higher proteoglycan content as well as a trend toward lower water content, suggesting that ankle cartilage has a smaller effective pore size than knee cartilage. These findings suggest that differences in the composition of ankle and knee cartilage contribute to a difference in the partition coefficient. The results of this study provide further support for the hypothesis that the transport properties of cartilage may play a role in the differences in the incidence of osteoarthritis in these joints by altering the effective concentration of growth factors and cytokines to which chondrocytes are exposed. ß

Comparison study of intraarticular and intravenous gadolinium-enhanced magnetic resonance imaging of cartilage in a canine model

“…BASHIR et al reported that the intravenous administration of gadolinium compounds allowed the contrast agents to diffuse into patellar cartilage from both the articular surface and the subchondral bone (20). However, articular cartilage depends primarily upon diffusion for molecular transport (47), and articular cartilage on the femoral condyle is thinner than patellar cartilage (20,48). Thus, recent reports have shown that the direct administration of Gd-DTPA 22 has potential advantages for the MR imaging of cartilage (26,27,49).…”

Nutrient Channels Aid the Growth of Articular Surface-Sized Engineered Cartilage Constructs

“…9B, D) are robust, but remain below native values (G*: 5-10 MPa at 0.01 Hz, collagen: 10-15%/ww); they are on par with engineered cartilage from previous studies. [52][53][54][55][56][57][58][59][60] On average by day 56, large constructs had reached sizes of Ø52 · 4.3 mm, weighed 8.1 g, had E Y of 450 kPa, and had 8.1%/ww GAG and 2.6%/ww collagen. The most robust Ø40 mm construct was cast with P0 cells and reached E Y = 623 kPa, 8.9%/ww GAG, and 3.5%/ww collagen.…”

Changes in pore morphology and fluid transport in compressed articular cartilage and the implications for joint lubrication

“…For uncompressed cartilage tissue, we measure an average parallel diffusion coefficient, D k, within the middle zone of 3.8 mm 2 sec À1 . In a similar FRAP experiment, Fetter et al [31] reported a D k for the middle zone of 34 mm 2 sec À1 , which is 10 times higher. Earlier, Leddy and Guilak [27] measured an average perpendicular diffusion coefficient, D t , in the middle zone of around 55 mm 2 sec À1 .…”

“…Our experiments were performed on 30 mm thick microtomed sections taken from the cartilage middle zone. Fetter et al [31] studied full-thickness explants, and Leddy and Guilak [27] studied perpendicular diffusion in 2 mm thick sections. In all three experiments, the analysis of the fluorescence recovery assumes that diffusion occurs only in two-dimensions, i.e., parallel to the focal plane, ignoring any contribution to D k , from diffusion perpendicular to this plane (from D t ).…”