Vitamin E-stabilized UHMWPE: Biological response on human osteoblasts to wear debris

UHMWPE doped with vitamin E was introduced to provide oxidation resistance upon sterilization, without affecting UHMWPE's mechanical properties. Particle-induced macrophage activation leads to periprosthetic bone resorption, requiring total joint replacements. During osteolysis, osteoblasts produce osteoimmunological factors such as RANKL and OPG, and the inhibitors of the Wnt pathway DKK-1 and Sclerostin. This study investigated in vitro how vitamin E-blended-UHMWPE wear debris might affect osteoblast-mediated osteolysis and the production of RANKL, OPG, Sclerostin and DKK-1, compared to conventional UHMWPE wear debris. Human osteoblastic SaOS2 cells were incubated with wear particles from Vitamin E doped and conventional UHMWPE and the gene expression and protein production of IL-6, RANKL, OPG, DKK-1, and Sclerostin was evaluated, RANKL, a bone erosion marker, was reduced, while OPG, a bone protective marker, were increased by the vitamin E-blended UHMWPE compared to conventional UHMWPE. Vitamin E doped UHMWPE reduced Sclerostin level, and partially affected DKK-1 production, thereby protecting against bone erosion. In conclusion, Vitamin E-blended UHMWPE induced an osteoimmunological response in bone cells that had positive effects on the osteolysis induced by wear debris, reducing aseptic loosening of the implants. In conclusion, this is the first study showing that Vitamin E-blended UHMWPE induced an osteoimmunological response in bone cells that positively affect the osteolysis induced by wear debris, thereby reducing the aseptic loosening of the implants.