Layered mechanical and electrical properties of porcine articular cartilage

The complex structure and composition of articular cartilage make its performance show depth-dependent characteristics, but its related parameters are not complete at present. In this study, porcine articular cartilage was divided into three zones along the thickness direction, and the cartilage tissue in each zone was tested for electrical impedance, compression relaxation, and permeability to obtain their mechanical and electrical impedance parameters. The results showed that there were significant differences in mechanical and electrical properties of cartilage tissue in different zones in which resistivity, elastic modulus, relaxation time, and final relaxation rate increased gradually from superficial zone to deep zone along the direction of cartilage thickness while the permeability decreased gradually. Bioimpedance analysis can capture the phenomenon of very slight histological changes, which is expected to provide information for predicting cartilage degeneration, but the electrical impedance parameters of cartilage are still very lacking. These data are expected to provide reference for the treatment of clinical osteoarthritis and the research of cartilage repair materials.