Ultrafine particle deposition in a realistic human airway at multiple inhalation scenarios
Ultrafine particle deposition in a realistic human airway at multiple inhalation scenarios
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多种吸入场景下真实人体气道中的超细颗粒沉积
DOI：
10.1002/cnm.3215
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发表时间：
2019-07-01
影响因子：
2.1
通讯作者：
Tu, Jiyuan
中科院分区：
文献类型：
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作者：
Dong, Jingliang;Shang, Yidan;Tu, Jiyuan
远端呼吸道局部沉积数据的缺乏是当前毒理学和药理学研究的一个重要挑战。为了弥补这一差距，本研究建立了一个从鼻腔和口腔开口延伸到远端支气管气道的具有不同路径长度的真实气道模型。采用数值模拟方法研究了1 ~ 100 nm的超细颗粒物（UFP）在大气中的输运和沉积特性，并考虑了不同吸入情景的影响。为了使层间颗粒沉积比较，调整后的参数，统一的沉积增强因子（UDEF），提出了量化的局部沉积浓度。结果表明，在所考虑的粒径范围的超细端附近，室颗粒沉积达到峰值，并随着粒径的增加而迅速下降。不同的吸入方式对肺结核患者的肺外沉积影响显著，而肺结核患者肺内的肺外沉积影响相对较小，对于大于10 nm的UFP，预测的肺外沉积效率在所有粒径范围内均处于最低水平，说明10 ~ 100 nm的UFP可以通过整个呼吸道模型并逃逸至肺泡区。此外，在大多数分叉顶点附近观察到高增强因子，并且在1 nm颗粒情况下观察到更均匀的UDEF分布。而对于100 nm的情况，沉积颗粒倾向于集中在少数“热点”（相对于周围表面的高沉积浓度区域），气管支气管气道中的UDEF更大。
The scarcity of regional deposition data in distal respiratory airways represents an important challenge for current toxicology and pharmacology research. To bridge this gap, a realistic airway model extending from nasal and oral openings to distal bronchial airways with varying pathway length was built in this study. Transport and deposition characteristics of naturally inhaled ultrafine particles (UFPs) ranging from 1 to 100 nm were numerically investigated, and effects of different inhalation scenarios were considered. To enable intercase particle deposition comparison, an adjusted parameter, unified deposition enhancement factor (UDEF), was proposed for quantifying the localised deposition concentration. Results show that compartment particle deposition peaked around the ultrafine end of the considered size range, and it dropped rapidly with the increase of particle size. Different inhalation modes caused notable deposition changes in the extrathoracic region, while its effects in the TB airway are much less. For UFPs larger than 10 nm, predicted deposition efficiencies in all compartments are all at lowest levels among considered particle size range, implying UFPs ranging from 10 to 100 nm can travel through the whole respiratory airway model and escape to the alveolar region. Furthermore, high enhancement factors were observed at the vicinity of most bifurcation apexes, and more even UDEF distribution was observed from 1‐nm particle cases. While for 100‐nm cases, the deposited particles tend to concentrate at few “hot spots” (areas of high deposition concentration in relation to surrounding surfaces) with greater UDEF in the tracheobronchial airway.