Assessment of respiratory tract deposition of nanoparticles is a key link to understanding their health impacts. An instrument was developed to measure respiratory tract deposition of nanoparticles in a single breath. Monodisperse nanoparticles are generated, inhaled and sampled from a determined volumetric lung depth after a controlled residence time in the lung. The instrument was characterized for sensitivity to inter-subject variability, particle size (22, 50, 75 and 100 nm) and breath-holding time (3–20 s) in a group of seven healthy subjects. The measured particle recovery had an inter-subject variability 26–50 times larger than the measurement uncertainty and the results for various particle sizes and breath-holding times were in accordance with the theory for Brownian diffusion and values calculated from the Multiple-Path Particle Dosimetry model. The recovery was found to be determined by residence time and particle size, while respiratory flow-rate had minor importance in the studied range 1–10 L/s. The instrument will be used to investigate deposition of nanoparticles in patients with respiratory disease. The fast and precise measurement allows for both diagnostic applications, where the disease may be identified based on particle recovery, and for studies with controlled delivery of aerosol-based nanomedicine to specific regions of the lungs.
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机译：评估纳米颗粒在呼吸道中的沉积是了解其对健康的影响的关键环节。开发了一种用于测量单次呼吸中纳米颗粒在呼吸道中沉积的仪器。在肺中控制停留时间后，从确定的肺体积容积中生成，吸入和采样单分散纳米颗粒。该仪器的特点是对七名健康受试者的一组受试者之间的变异性，粒径（22、50、75和100µnm）和屏气时间（3–20µs）敏感。所测得的粒子回收率具有比测定不确定度大26-50倍的对象间变异性，并且各种粒度和屏气时间的结果均符合布朗扩散理论和根据多径粒子剂量法计算得出的值模型。发现恢复时间取决于停留时间和粒径，而呼吸流速在研究范围1–10 L / s中次要重要性。该仪器将用于研究呼吸系统疾病患者的纳米颗粒沉积。快速而精确的测量既可用于诊断应用，也可根据颗粒回收率确定疾病，也可用于将基于气溶胶的纳米药物控制递送至肺部特定区域的研究。
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