G020015 Evaluation of tribological performance of regenerated cartilage using MPC (2-methacryloyloxyethyl phosphorylcholine) polymer grafted surface

It is important to examine the tribological maturation of regenerated cartilage for planning the after-treatment. In the past experiment, we reported that hydration-lubrication-like phenomenon of the cartilage can be measured by using the MPC (2-methacryloyloxyethyl phosphorylcholine) polymer grafted surface as a counter face of frictional test. This paper evaluates frictional properties and maturation of regenerated cartilage by using MPC-polymer grafted surface. The regenerated cartilage was prepared by seeding chondrocytes from 4 weeks old Japanese white rabbit onto fibroin scaffold. The friction test was carried out by reciprocating friction apparatus using saline solution as the lubricant with applied normal load of 300 N (about 0.15 MPa), and with the sliding velocity of 0.008 mm/s, 0.08 mm/s, 0.8 mm/s and 4 mm/s. The load was applied for 600 seconds before the sliding began. The result showed that friction coefficient of regenerated cartilage was significantly lower than that of the control specimen but higher than that of the normal cartilage at 7 days and 14 days culture. These results showed that chondrocytes regenerated lubricating function but it is not matured as normal cartilage in 14 days cultivation.