Prevention of bacterial adhesion and biofilm formation on a vitamin E-blended, cross-linked polyethylene surface with a poly(2-methacryloyloxyethyl phosphorylcholine) layer

摘要

In the construction of artificial hip joint replacements, the surface and substrate of a cross-linked polyethylene (CLPE) liner are designed to achieve high wear resistance and prevent infection by bacteria. In this study, we fabricated a highly hydrophilic and antibiofouling poly(2-methacryloyloxyethyl phosphorylcholine [MPC]) (PMPC)-graft layer on the vitamin E-blended CLPE (HD-CLPE(VE)) surface. The 100-nm-thick, smooth, and electrically neutral PMPC layer was successfully fabricated on the HD-CLPE(VE) surface using photoinduced graft polymerization. The PMPC-grafted HD-CLPE(VE) was found to prevent bacterial adherence and biofilm formation on the surface because of the formation of a highly hydrophilic polyzwitterionic layer on the surface of HD-CLPE(VE), which can serve as an extremely efficient antibiofouling layer. The number of bacterial adhered on the PMPC-grafted HD-CLPE(VE) surface was reduced by 100-fold or more by PMPC grafting, regardless of the biofilm-production characteristics of the strains. In contrast, vitamin E blending did not affect bacterial adhesion. Moreover, the number of planktonic bacteria did not differ significantly, regardless of PMPC grafting and vitamin E blending. In conclusion, the PMPC-grafted HD-CLPE(VE) provided bacteriostatic effects associated with smooth, highly hydrophilic surfaces with a neutral electrostatic charge owing to the zwitterionic structure of the MPC unit. Thus, this modification may prove useful for the production of artificial hip joint replacement materials.