Kyomoto Masayuki, Moro Toru, Miyaji Fumiaki, Konno Tomohiro, Hashimoto Masami, Kawaguchi Hiroshi, Takatori Yoshio, Nakamura Kozo, Ishihara Kazuhiko
Research Division, Japan Medical Materials Corporation, Osaka, Japan.
J Biomed Mater Res B Appl Biomater. 2008 Feb;84(2):320-7. doi: 10.1002/jbm.b.30874.
We assumed that the extra energy supplied by gamma-ray irradiation produced cross-links in 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer grafted cross-linked polyethylene (CLPE-g-MPC) and investigated its effects on the tribological properties of CLPE-g-MPC. In this study, we found that the gamma-ray irradiation produced cross-links in three kinds of regions of CLPE-g-MPC: poly(MPC) layer, CLPE-MPC interface, and CLPE substrate. The dynamic coefficient of friction of CLPE-g-MPC slightly increased with increasing irradiation doses. After the simulator test, both the nonsterilized and gamma-ray sterilized CLPE-g-MPC cups exhibited lower wear than the untreated CLPE ones. In particular, the gamma-ray sterilized CLPE-g-MPC cups showed extremely low and stable wear. As for the nonsterilized CLPE-g-MPC cups, the weight change varied with each cup. When the CLPE surface is modified by poly(MPC) grafting, the MPC graft polymer leads to a significant reduction in the sliding friction between the surfaces that are grafted because water thin films formed can behave as extremely efficient lubricants. Such a cross-link of poly(MPC) slightly increases the friction of CLPE by gamma-ray irradiation but provides a stable wear resistant layer on the friction surface. The cross-links formed by gamma-ray irradiation would give further longevity to the CLPE-g-MPC cups.
我们假定伽马射线辐照提供的额外能量在2-甲基丙烯酰氧乙基磷酰胆碱（MPC）聚合物接枝交联聚乙烯（CLPE-g-MPC）中产生了交联，并研究了其对CLPE-g-MPC摩擦学性能的影响。在本研究中，我们发现伽马射线辐照在CLPE-g-MPC的三种区域产生了交联：聚（MPC）层、CLPE-MPC界面和CLPE基材。CLPE-g-MPC的动摩擦系数随辐照剂量的增加而略有增加。模拟器测试后，未灭菌和经伽马射线灭菌的CLPE-g-MPC杯的磨损均低于未处理的CLPE杯。特别是，经伽马射线灭菌的CLPE-g-MPC杯表现出极低且稳定的磨损。对于未灭菌的CLPE-g-MPC杯，每个杯子的重量变化各不相同。当CLPE表面通过聚（MPC）接枝进行改性时，MPC接枝聚合物会导致接枝表面之间的滑动摩擦显著降低，因为形成的水薄膜可作为极其有效的润滑剂。聚（MPC）的这种交联通过伽马射线辐照略微增加了CLPE的摩擦力，但在摩擦表面提供了一个稳定的耐磨层。伽马射线辐照形成 的交联将使CLPE-g-MPC杯具有更长的使用寿命。
