Toxicokinetics of nanomaterials, including studies on the absorption, distribution, metabolism, and elimination of nanomaterials, are essential in assessing their potential health effects. The fate of nanomaterials after inhalation exposure to multiple nanomaterials is not clearly understood. Male Sprague–Dawley rats were exposed to similar sizes of silver nanoparticles (AgNPs, 10.86 nm) and gold nanoparticles (AuNPs, 10.82 nm) for 28 days (6-h/day, 5-days/week for four weeks) either with separate NP inhalation exposures or with combined co-exposure in a nose-only inhalation system. Mass concentrations sampled from the breathing zone were AuNP 19.34 ± 2.55 μg/m3 and AgNP 17.38 ± 1.88 μg/m3 for separate exposure and AuNP 8.20 μg/m3 and AgNP 8.99 μg/m3 for co-exposure. Lung retention and clearance were previously determined on day 1 (6-h) of exposure (E-1) and on post-exposure days 1, 7, and 28 (PEO-1, PEO-7, and PEO-28, respectively). In addition, the fate of nanoparticles, including translocation and elimination from the lung to the major organs, were determined during the post-exposure observation period. AuNP was translocated to the extrapulmonary organs, including the liver, kidney, spleen, testis, epididymis, olfactory bulb, hilar and brachial lymph nodes, and brain after subacute inhalation and showed biopersistence regardless of AuNP single exposure or AuNP + AgNP co-exposure, showing similar elimination half-time. In contrast, Ag was translocated to the tissues and rapidly eliminated from the tissues regardless of AuNP co-exposure. Ag was continually accumulated in the olfactory bulb and brain and persistent until PEO-28. Our co-exposure study of AuNP and AgNP indicated that soluble AgNP and insoluble AuNP translocated differently, showing soluble AgNP could be dissolved into Ag ion to translocate to the extrapulmonary organs and rapidly removed from most organs except the brain and olfactory bulb. Insoluble AuNPs were continually translocated to the extrapulmonary organs, and they were not eliminated rapidly.

中文翻译：

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亚急性共同吸入相同大小的金和银纳米粒子的生物动力学

纳米材料的毒代动力学，包括对纳米材料的吸收、分布、代谢和消除的研究，对于评估其潜在的健康影响至关重要。吸入暴露于多种纳米材料后纳米材料的命运尚不清楚。雄性 Sprague-Dawley 大鼠暴露于相似大小的银纳米粒子（AgNPs，10.86 nm）和金纳米粒子（AuNPs，10.82 nm）28 天（6 小时/天，5 天/周，持续 4 周），或者单独NP 吸入暴露或在仅鼻子吸入系统中联合暴露。从呼吸区采样的质量浓度分别为 AuNP 19.34 ± 2.55 μg/m3 和 AgNP 17.38 ± 1.88 μg/m3 以及共同暴露的 AuNP 8.20 μg/m3 和 AgNP 8.99 μg/m3。先前在暴露 (E-1) 的第 1 天 (6 小时) 和暴露后第 1、7 和 28 天 (分别为 PEO-1、PEO-7 和 PEO-28) 确定了肺保留和清除率. 此外，纳米粒子的命运，包括从肺部到主要器官的易位和消除，是在暴露后观察期间确定的。在亚急性吸入后，AuNP 被转移到肺外器官，包括肝脏、肾脏、脾脏、睾丸、附睾、嗅球、肺门和臂淋巴结以及大脑，并且无论 AuNP 单次暴露或 AuNP + AgNP 共同暴露，都显示出生物持久性，显示相似的半场淘汰赛。相反，无论 AuNP 共暴露如何，Ag 都会转移到组织并迅速从组织中消除。Ag 不断积累在嗅球和大脑中，并持续到 PEO-28。我们对 AuNP 和 AgNP 的共暴露研究表明，可溶性 AgNP 和不溶性 AuNP 的转运方式不同，表明可溶性 AgNP 可以溶解成 Ag 离子转运到肺外器官，并迅速从大脑和嗅球以外的大多数器官中移除。不溶性 AuNPs 不断转移到肺外器官，并且不会迅速消除。