Electrostatic field may regulate proliferation and immune responses of macrophages induced by polyethylene wear particles

Effects of electrostatic field on the macrophage responses induced by ultra-high molecular weight polyethylene (UHMWPE) wear particles have been investigated in this study. An inverted cell culture system was applied to study the interactions between UHMWPE wear particles and macrophage cells. The electrostatic field induced device (EFID) was installed on the cell culture system. The high voltage and low current stimulations generated from EFID were first applied to the UHMWPE particles/macrophage co-culture system. The proliferation and tumor necrosis factor-alpha, interleukin (IL)-6, and IL-1β cytokine expressions of J774A.1 macrophage cells were analyzed. The EFID applied voltage of 0.5 kV, 1.0 kV, 1.3 kV, and 1.6 kV were investigated. Our result indicated that the 0.5 kV and 1 kV voltages increased the proliferation of macrophage cells and activated the expression of related cytokines under the co-culture of UHMWPE wear particles. However, with the increasing applied voltage of 1.3 kV and 1.6 kV, the inhibition of the macrophage proliferation and expression of immunological cytokines were observed. There exists a critical applying EFID voltage to modulate the UHWMPE particle induced immune responses. The electrostatic field induced device presents a potential non-invasive therapy for particle induced bone resorption and osteolysis.