Due to the exponential increase in the development and utilization of rare earth oxide nanoparticles (REO NPs) in various fields, the possibility of exposure in humans by inhalation has increased. However, there are little information about hazards of REO NPs and its mechanisms of toxicity. In this study, we evaluated the acute pulmonary inflammation using 10 REO NPs (Dy₂O₃, Er₂O₃, Eu₂O₃, Gd₂O₃ La₂O₃, Nd₂O₃, Pr₆O₁₁, Sm₂O₃, Tb₄O₇, and Y₂O₃) and four well-known toxic particles (CuO, NiO, ZnO, and DQ12). Minimum three doses per NP were instilled into the lungs of female Wistar rats at surface area dose metric and lung inflammation was evaluated at 24 h post-instillation by bronchoalveolar lavage fluid (BALF) analysis and histopathological observation. All types of REO NPs showed common pathological changes including mild to moderate infiltration of neutrophils and activated macrophages in the alveoli, peribronchial, and perivascular region. The inflammogenic potential evaluated by the number of granulocytes divided by the treated surface area dose showed all types of REO NPs has much higher inflammogenic potential than DQ12, ZnO, and NiO NPs. The correlation plot between the number of granulocytes and the potential for reactive oxygen species (ROS) generation showed a good correlation with exception of Pr₆O₁₁. The higher inflammogenic potential of REO NPs than that of well-known highly toxic particles imply that REO NPs need special attention for inhalation exposure and more studies are needed. In addition, the potential of ROS generation is one of the key factors producing lung inflammation by REO NPs.

中文翻译：

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稀土氧化物纳米颗粒的高发炎潜力：新的危险实体

由于在各个领域中稀土氧化物纳米颗粒（REO NPs）的开发和利用呈指数增长，因此通过吸入暴露在人体中的可能性增加了。但是，关于REO NPs的危害及其毒性机理的信息很少。在这项研究中，我们使用10种REO NPs（Dy ₂ O ₃，Er ₂ O ₃，Eu ₂ O ₃，Gd ₂ O ₃ La ₂ O ₃，Nd ₂ O ₃，Pr ₆ O ₁₁，Sm ₂ O ₃，总重₄ O ₇和Y ₂ O ₃）和四个众所周知的有毒颗粒（CuO，NiO，ZnO和DQ12）。每只NP至少以三剂剂量以表面积剂量滴入雌性Wistar大鼠的肺中，并在滴注后24 h通过支气管肺泡灌洗液（BALF）分析和组织病理学观察评估肺部炎症。所有类型的REO NPs均显示出常见的病理变化，包括在肺泡，支气管周围和血管周围区域中性粒细胞的轻度至中度浸润和活化的巨噬细胞。用粒细胞数除以处理的表面积剂量评估的发炎潜力表明，所有类型的REO NPs的发炎潜力均比DQ12，ZnO和NiO NPs高得多。₆ O ₁₁。REO NPs比已知的剧毒颗粒具有更高的发炎潜力，这意味着REO NPs需要特别注意吸入暴露，需要进行更多的研究。此外，ROS产生的潜力是REO NPs引起肺部炎症的关键因素之一。