The Effects of Polyethylene(UHMWPE) Particles on MG63 Osteoblastlike Cells

Han, Chang Dong; Lee, Woo Suk

Abstract

We performed an in vitro study to determine the effects of ultra high molecular weight polyethylene (UHMWPE) particles on the cell proliferation, matrix synthesis(type I collagen mRNA), and cytokines production(interleukin-lbeta and prostaglandin E2) of MG63 osteoblastlike cells. UHMWPE wear particles were isolated from osteolysis tissue of 8 patients during revision hip arthroplasties. Sub-micron UHMWPE powders were also isolated from fabricated virgin UHMWPE powders. Group I (control culture) contained no UHMWPE particles. In group II andIII, the UHMWPE wear particles and the UHMWPE powders were added to cultures of MG63 osteoblastlike cells with the different concentration of 0.2mg/ml, 0.02mg/ml, 0.002mg/ml, and 0.0002mg/ml. The average diameter of the retrieved UHMWPE particles was 0.4micrometa(ranged, 0.1 to 1.4 micrometa), and that of the fabricated UHMWPE powders was 0.6micrometa(ranged, 0.1 to 2.3micrometa). In group II and III, the UHMWPE particles induced an increase in osteoblastlike cell growth(p<0.05) but they inhibited the expression of type I collagen mRNA in a dose dependent manner(p<0.05). MG63 osteoblastlike cells exhibited a dose-dependent release of interleukin-1beta(IL-1beta) and prostaglandin E2(PGE2) in response to the exposure to the UHMWPE particles(p<0.05). There were no differences in the cell proliferation, the expression of type I collagen mRNA, and the release of PGE2 between the UHMWPE wear particles and the UHMWPE powders groups(p>0.05). The release of IL-lbeta was higher in group II than in group III(p<0.05). These data support the hypothesis that direct suppression and cytokines release of MG63 osteoblastlike cells by UHMWPE particles may play a role in particle-mediated osteolysis.