钛颗粒在刺激人单核／巨噬细胞引起人工关节松动中的作用

The effect of titanium particles on the aseptic loosening of artificial joints

目的分析不同直径、不同浓度的钛颗粒对人单核／巨噬细胞的作用。方法应用梯度离心法分离人单核／巨噬细胞，去除钛颗粒表面的内毒素，将直径（15．47±5．18）μm和（2．54±0．86）μm的钛颗粒，分别以颗粒体积（μm^3）：细胞数比为10：1及100：1的浓度刺激人单核／巨噬细胞。在钛颗粒刺激细胞24h后，运用ELISA检测培养上清液中的骨溶解介质白介素-1β（IL-1β）、白介素-6（IL-6）和细胞坏死因子-α（TNF-α）的浓度。结果钛颗粒刺激单核／巨噬细胞可分泌IL-6、TNF-α和IL-1β；颗粒体积：细胞数比为100：1时，平均直径2．54μm的钛颗粒刺激单核／巨噬细胞产生IL-6、TNF-α和IL-1β的作用均大于直径15.47μm的钛颗粒，差异有统计学意义（P〈0.05）。结论不含内毒素的钛颗粒本身具有刺激单核／巨噬细胞产生溶骨介质的作用；高浓度、直径小的钛颗粒可刺激人单核／巨噬细胞分泌更多的溶骨介质，具有较强的生物活性。

Objective To evaluate the responses of human monocyte/macrophages challenged with titanium particles of different sizes and concentrations, Methods Monocyte/macrophages were separated from the peripheral blood of 5 donors by density gradient centrifugation. Purity of particles （absence of endotoxin） was guaranteed by the isolation process, Commercially titanium particles [ sizes： （15.47 ± 5.18） μm and （2. 54±0. 86） μm] were co-cultured with human （98% pure） monocyte/macrophages. All particle fractions were evaluated at particle volume （μm^3） to cell number ratios of 10：1 and 100： 1, The production of proinflammatory cytokines IL-6, IL-1β, TNF-α was assessed by ELISA. Results The macrophages could be activated to secrete IL-6, IL-1β and TNF-α significantly by titanium particles. The cytokine levels （IL-6, IL-1β and TNF-α） on the small particles （mean size = 2.54 μm） were higher than on large particles （mean size = 15.47μm） when particle volume to cell number ratio was 100： 1. Conclusions The titanium particles （absence of endotoxin） can activate human monoeyte/maerophages to secrete osteolytie mediators. The size and concentration of titanium particles are critical factors in maerophage activation. The eytokine levels may increase under the effects of smaller size of titanium particles and higher particle volume to cell number ratio.