Effects of Vitamin E-Stabilized Ultra High Molecular Weight Polyethylene on Oxidative Stress Response and Osteoimmunological Response in Human Osteoblast

Abstract

High Crosslink process was introduced in the development of joint prosthetic devices, in order to decrease the wear rate of ultrahigh molecular weight polyethylene (UHMWPE), but it also triggers the formation of free radicals and oxidative stress, which affects the physiological bone remodeling, leading to osteolysis. Vitamin E stabilization of UHMWPE was proposed to provide oxidation resistance without affecting mechanical properties and fatigue strength. The aim of this study is to evaluate the antioxidant effect of vitamin E added to UHMWPE on oxidative stress induced osteolysis, focusing in particular on the oxidative stress response in correlation with the production of osteoimmunological markers, Sclerostin and DKK-1, and the RANKL/OPG ratio compared to conventional UHMWPE wear debris. Human osteoblastic cell line SaOS2 were incubated for 96 h with wear particles derived from crosslinked and not crosslinked Vitamin E-stabilized, UHMWPE without Vitamin E, and growth medium as control. Cellular response to oxidative stress, compared to not treat cells, was evaluated in terms of proteins O-GlcNAcylation, cellular levels of OGA, and OGT proteins by immunoblotting. O-GlcNAcylation and its positive regulator OGT levels are increased in the presence of Vitamin E blended UHMWPE, in particular with not crosslinked Vit E stabilized UHMWPE. Conversely, the negative regulator OGA increased in the presence of UHMWPE not blended with Vitamin E. Vitamin E-stabilized UHMWPE induced a decrease of RANKL/OPG ratio compared to UHMWPE without Vitamin E, and the same effect was observed for Sclerostin, while DKK-1 was not significantly affected. In conclusion, Vitamin E stabilization of UHMWPE increased osteoblast response to oxidative stress, inducing a cellular mechanism aimed at cell survival. Vitamin E antioxidant effect influences the secretion of osteoimmunological factors, shifting the bone turnover balance toward bone protection stimuli. This suggests that Vitamin E-Stabilization of UHMWPE could contribute to reduction of oxidation-induced osteolysis and the consequent loosening of the prosthetic devices, therefore improving the longevity of total joint replacements.

Myxofibrosarcoma Mimicking Inflammatory Lesion of Temporomandibular Joint—Case Presentation

“…Even though UHMW-PE presents lots of advantages its imperfection remains significant-it is not visible on an X-ray examination [13]. Implants made of UHMW-PE are being modified-to decrease its wear rate and the formation of free radicals that lead to oxidative stress, vitamin E is added [15]. Vitamin E is described as an antioxidant in a human's body, reacting with free radicals in cell membrane and protecting from the degradation processes (due to oxidation) and polyunsaturated fatty acids [16].…”

Interaction between and impact of IL‐6 genotype and alpha‐tocopherol levels on periodontal condition in aging individuals

“…Patients with periodontal disease have been found to show an increased concentration of oxidation damage markers 27 . In addition, it has been reported that oxidative stress can be reduced through the use of antioxidants, including α‐tocopherol, an important lipid‐phase, free‐radical, chain‐breaking antioxidant in the body, 28 this could help explain the association between serum antioxidants (eg, vitamin E) and periodontal condition 20,29,30 . Previous studies have reported a negative association between serum and plasma levels of ascorbic acid and α‐tocopherol as an oxidative stress marker 31,32 .…”

O-GlcNAcylation: roles and potential therapeutic target for bone pathophysiology

“…Massaccesi’s group reported that Vitamin E significantly increased levels of OGT, improving the ability of osteoblasts to respond to oxidative stress and ultimately reducing osteolysis caused by oxidation (Fig. 5 ) [ 115 ]. This study provides new insights into preventing osteolysis and improving the longevity of total joint replacements.…”