Schwab Luciana P, Xing Zhiqing, Hasty Karen A, Smith Richard A
Department of Orthopaedic Surgery, University of Tennessee-Campbell Clinic, Memphis, Tennessee 38163, USA.
J Biomed Mater Res B Appl Biomater. 2006 Oct;79(1):66-73. doi: 10.1002/jbm.b.30512.
It is still unknown if wear-debris particles themselves induce osteolysis or if they serve a functional role as receptors for ligands that incite an inflammatory response that ultimately leads to bone resorption. In this study, commercially pure titanium particles (cpTi) were subjected to a serial combination of different cleaning methods to remove Lipopolysaccharide (LPS) or were incubated in LPS solutions of known concentrations. Then, the response of the macrophage cell line IC-21 to the cleaned particles, LPS-bound Ti particles, and soluble LPS was examined. It was found that cleaned particles up to 1000 particles per cell did not stimulate macrophages to release Tumor necrosis factor-alpha (TNF-alpha) or Interleukin 6 (IL-6), but they significantly increased the release of Prostaglandin E(2) (PGE(2)) when the particle concentration was higher than 500 particles per cell. At one particle per cell, Ti particles bound with LPS stimulated the release of IL-6 and TNF-alpha by macrophages. The level of released cytokines was dependent on, and correlated with, the amount of LPS present on the particles. The macrophages were more sensitive to soluble LPS than to particle-bound LPS, and the simultaneous addition of cleaned Ti particles did not have additional effects on the effects of soluble LPS. This study shows evidence that, cpTi particles and LPS have distinct mechanisms of action on the IC-21 macrophages, but that both contribute to the development of an inflammatory response.
磨损碎屑颗粒本身是否会引发骨溶解，或者它们是否作为配体的受体发挥功能作用，从而引发最终导致骨吸收的炎症反应，目前仍不清楚。在本研究中，对商业纯钛颗粒（cpTi）进行了一系列不同清洗方法的组合，以去除脂多糖（LPS），或将其在已知浓度的LPS溶液中孵育。然后，检测巨噬细胞系IC-21对清洗后的颗粒、LPS结合的Ti颗粒和可溶性LPS的反应。结果发现，每细胞高达1000个颗粒的清洗后颗粒不会刺激巨噬细胞释放肿瘤坏死因子-α（TNF-α）或白细胞介素6（IL-6），但当颗粒浓度高于每细胞500个颗粒时，它们会显著增加前列腺素E（2）（PGE（2））的释放。在每细胞一个颗粒时，与LPS结合的Ti颗粒刺激巨噬细胞释放IL-6和TNF-α。释放的细胞因子水平取决于颗粒上存在的LPS量，并与之相关。巨噬细胞对可溶性LPS比颗粒结合的LPS更敏感，同时添加清洗后的Ti颗粒对可溶性LPS的作用没有额外影响。本研究表明，cpTi颗粒和LPS对IC-21巨噬细胞有不同的作用机制，但两者都有助于炎症反应的发展。
