Characterization of viscoelastic properties of normal and osteoarthritic chondrocytes in experimental rabbit model

The goal of this study was to characterize the changes of the viscoelastic properties of rabbit chondrocytes from normal and osteoarthritic cartilage. All samples were harvested from rabbit articular cartilage with the same age, sex, body weight, breed and osteoarthritic degree. Anterior cruciate ligament transection was utilized to induce rabbit osteoarthritic model. Micropipette aspiration technique coupled with a viscoelastic model was used to characterize viscoelastic properties of rabbit chondrocytes. The present results indicate that the viscoelastic behaviors of osteoarthritic chondrocytes have decreased during the progress of osteoarthritis and exhibited a significantly lower equilibrium modulus, instantaneous modulus and apparent viscosity (E( proportional, variant)=0.39+/-0.14 kPa, E(0)=0.68+/-0.27 kPa, mu=0.39+/-0.14 kPa.s, n=67) compared with normal chondrocytes (E( proportional, variant)=0.55+/-0.11 kPa, E(0)=0.98+/-0.14 kPa, mu=6.36+/-1.12 kPa.s, n=52) (p<0.0001). These findings may be relevant for chondrocyte-based cartilage tissue engineering.