The potential role of human osteoblasts for periprosthetic osteolysis following exposure to wear particles

Abstract

Abstract. Aseptic loosening in total hip replacement is mainly caused by wear particles inducing inflammation and osteolysis. Wear can be a consequence of micromotions at the interface between implant and bone cement. Due to complex cellular interactions, different mediators (e.g. cytokines, proteinases) are released, which can promote osteolytic processes in the periprosthetic tissue followed by loosening of the implant. Furthermore, a reduced matrix synthesis and an induced apoptosis rate can be observed. The purpose of this study was to evaluate to what extent human primary osteoblasts exposed to wear particles are involved in the osteolysis. The viability, the secretion of collagen and collagenases and the variety of released cytokines after particle exposure was examined. Therefore, human osteoblasts were incubated with particles experimentally generated in the interface between hip stems with rough and smooth surface finishings as well as different material compositions (Ti-6Al-7Nb, Co-28Cr-6Mo and 316L) and bone cement mantle made of Palacos R containing zirconium oxide particles. Commercially pure titanium particles, titanium oxide, polymethylmethacrylate and particulate zirconium oxide were used as references. The results revealed distinct effects on the cytokine release of human osteoblasts towards particulate debris. Thereby, human osteoblasts released increased levels of interleukine (IL)-6 and IL-8 after treatment with metallic wear particles. The expression of VEGF was slightly induced by all particle entities at lower concentrations. Apoptotic rates were enhanced for osteoblasts exposed to all the tested particles. Furthermore, the de novo synthesis of type 1 collagen was reduced and the expression of the matrix metalloproteinase (MMP)-1 was considerably increased. However, wear particles of Co-28Cr-6Mo stems seemed to be more aggressive, whereas particles derived from stainless steel stems caused less adverse cellular reaction. Among the reference particles, which caused less altered reactions in the metabolism of osteoblasts in general, ZrO 2 can be assumed as the material with the smallest cell biological effects.

Macrophage responses to implants: prospects for personalized medicine

“…In inflammatory conditions, this balance is altered. In response to wear particle stimulation, osteoblast ability to secrete osteoid is impaired [41], and collagen I synthesis is decreased [46]. Additionally, wear particles induce production of IL-1, IL-6, IL-8, TNF-a, CCL2, and MMP1 in osteoblasts [41,46], in addition to osteoclastogenesis factors, RANKL and M-CSF [47].…”

Perfluorodecalin and bone regeneration

“…Perfluorodecalin and bone regeneration It should also be remembered that halogenated decalins such as PFD can be partially brominated, increasing their radiopacity even further with little change in toxicity and physical properties (Long et al, 1971;Long et al, 1975;Lowe, 1991;Mattrey et al, 1987;McFarland et al, 1985).…”

“…Since the pH of the cell culture media was maintained at neutrality throughout both experimental conditions, it is possible that differences in cohesion could have caused the significant differences in cell survival between the waterbased CPC and the PFD-based CPC. Indeed particle release from biomaterials has been found to have a negative effect on cellular survival in the surrounding tissues (Lochner et al, 2011). However, the effect of particle release from cements on cellular survival needs further investigation.…”

Peri-prosthetic tissue cells show osteogenic capacity to differentiate into the osteoblastic lineage

“…The few studies investigating their role in bone formation show that peri‐prosthetic tissue cells produce factors that suppress osteoblast function and induce production of inflammatory cytokines 12, 13. Moreover, wear particles and metal ions can directly affect osteoblasts by reducing type one collagen production14, 15 and decreasing alkaline phosphatase activity as well as calcium deposition 16. In addition, wear particles have been shown to decrease osteoblast proliferation,15, 17 change the phenotype of mature osteoblasts,18 and stimulate osteoblasts to secrete inflammatory cytokines 14, 15, 16, 19.…”

“…Moreover, wear particles and metal ions can directly affect osteoblasts by reducing type one collagen production14, 15 and decreasing alkaline phosphatase activity as well as calcium deposition 16. In addition, wear particles have been shown to decrease osteoblast proliferation,15, 17 change the phenotype of mature osteoblasts,18 and stimulate osteoblasts to secrete inflammatory cytokines 14, 15, 16, 19. Remarkably, one study revealed that cells from the peri‐prosthetic tissue produce several osteoblastic proteins themselves 20.…”