Nanoparticle Mass Transfer From Lung Airways to Systemic Regions—Part I: Whole-Lung Aerosol Dynamics

This is a two-part paper describing inhaled nanoparticle (NP) transport and deposition in a model of a human respiratory tract (Part I) as well as NP-mass transfer across barriers into systemic regions (Part II). Specifically, combining high-resolution computer simulation results of inhaled NP deposition in the human airways (Part I) with a multicompartmental model for NP-mass transfer (Part II) allows for the prediction of temporal NP accumulation in the blood and lymphatic systems as well as in organs. An understanding of nanoparticle transport and deposition in human respiratory airways is of great importance, as exposure to nanomaterial has been found to cause serious lung diseases, while the use of nanodrugs may have superior therapeutic effects. In Part I, the fluid-particle dynamics of a dilute NP suspension was simulated for the entire respiratory tract, assuming steady inhalation and planar airways. Thus, a realistic airway configuration was considered from nose/mouth to generation 3, and then an idealized triple-bifurcation unit was repeated in series and parallel to cover the remaining generations. Using the current model, the deposition of NPs in distinct regions of the lung, namely extrathoracic, bronchial, bronchiolar, and alveolar, was calculated. The region-specific NP-deposition results for the human lung model were used in Part II to determine the multicompartmental model parameters from experimental retention and clearance data in human lungs. The quantitative, experimentally validated results are useful in diverse fields, such as toxicology for exposure-risk analysis of ubiquitous nanomaterial as well as in pharmacology for nanodrug development and targeting.

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Nanoparticle Mass Transfer From Lung Airways to Systemic Regions—Part II: Multi-Compartmental Modeling

Journal of Biomechanical Engineering ◽

10.1115/1.4025333 ◽

2013 ◽

Vol 135 (12) ◽

Cited By ~ 13

Author(s):

Arun V. Kolanjiyil ◽

Clement Kleinstreuer

Keyword(s):

Mass Transfer ◽

Model Parameters ◽

Computationally Efficient ◽

Nanoparticle Deposition ◽

Aerosol Dynamics ◽

Multicompartmental Model ◽

Quantitative Results ◽

Species Extrapolation ◽

Critical Insight ◽

Lung Airways

This is the second article of a two-part paper, combining high-resolution computer simulation results of inhaled nanoparticle deposition in a human airway model (Kolanjiyil and Kleinstreuer, 2013, “Nanoparticle Mass Transfer From Lung Airways to Systemic Regions—Part I: Whole-Lung Aerosol Dynamics,” ASME J. Biomech. Eng., 135(12), p. 121003) with a new multicompartmental model for insoluble nanoparticle barrier mass transfer into systemic regions. Specifically, it allows for the prediction of temporal nanoparticle accumulation in the blood and lymphatic systems and in organs. The multicompartmental model parameters were determined from experimental retention and clearance data in rat lungs and then the validated model was applied to humans based on pharmacokinetic cross-species extrapolation. This hybrid simulator is a computationally efficient tool to predict the nanoparticle kinetics in the human body. The study provides critical insight into nanomaterial deposition and distribution from the lungs to systemic regions. The quantitative results are useful in diverse fields such as toxicology for exposure-risk analysis of ubiquitous nanomaterial and pharmacology for nanodrug development and targeting.

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A theory of aerosol deposition in the human respiratory tract

Journal of Applied Physiology ◽

10.1152/jappl.1975.38.1.77 ◽

1975 ◽

Vol 38 (1) ◽

pp. 77-85 ◽

Cited By ~ 116

Author(s):

D. B. Taulbee ◽

C. P. Yu

Keyword(s):

Particle Size ◽

Respiratory Tract ◽

Particle Deposition ◽

Particle Concentration ◽

Diffusion Mechanism ◽

Aerosol Deposition ◽

Lung Model ◽

Brownian Diffusion ◽

Human Respiratory Tract ◽

Apparent Diffusion

The deposition of inhaled aerosol particles in the human respiratory tract is due to the mechanisms of inertia impaction, Brownian diffusion, and gravitational settling. A theory is developed to predict the particle deposition and its distribution in human respiratory tract for any breathing condition. A convection-diffusion equation for the particle concentration with a loss term is used to describe the transport and deposition of particles. In this equation, an apparent diffusion coefficient due to the velocity dispersion in the lung is present and found to be the dominant diffusion mechanism for the cases considered here. Expressions for deposition by various mechanisms are also derived. The governing equation is solved numerically with Weibel's lung model A. The particle concentration at the mouth is calculated during washin and washout and compared favorably with experimental recordings for 0.5-mum diameter di(2-ethylhexyl) sebacate particles. The total deposition in the lung for particle size ranging from 0.05 to 5 mum is also computed for a 500-cm-3 tidal volume and 15 breaths/min. The results in general agree with recent measurements of Heyder et al. However, a particle size of minimum deposition is found to exist theoretically near 0.3 mum.

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Guide for the Practical Application of the ICRP Human Respiratory Tract Model

Annals of the ICRP ◽

10.1016/s0146-6453(03)00011-3 ◽

2002 ◽

Vol 32 (1-2) ◽

pp. 13-14 ◽

Cited By ~ 17

Author(s):

J. Valentin

Keyword(s):

Respiratory Tract ◽

Reference Values ◽

Model Parameters ◽

Specific Information ◽

Guidance Document ◽

Human Respiratory Tract ◽

Additional Information ◽

Dose Coefficients ◽

Bioassay Data ◽

Parameter Values

The ICRP Publication 66 Human Respiratory Tract Model for Radiological Protection (HRTM) has been applied to calculate dose coefficients (doses per unit intake) and bioassay functions in ICRP Publications 68, 71, 72 and 78. For these purposes, ICRP assigned numerical values to a range of model parameters, such as the size of the inhaled particles and the breathing rate of the subjects. These are known as ‘default’ or ‘reference’ values, and were chosen to be typical, representative values. In any particular situation the actual values of many parameters can be considerably different from the reference values. Usually, doses from intakes of radionuclides are low compared with the relevant limit or constraint, and the resulting difference is unimportant. There are, however, circumstances where more reliable assessments of intake and dose are desirable. This Guidance Document therefore gives advice on applying specific information within the framework of the HRTM for assessing occupational and environmental exposures and for interpreting bioassay data. Chapters on each aspect of the model (morphometry, physiology, deposition, clearance, gases and vapours, dosimetry) provide: A summary of how the HRTM treats that topic; Information on the reference values of relevant parameters; Guidance on choosing between default values; Information on how doses and bioassay quantities (lung retention, urine, and faecal excretion) vary with the values of selected parameters, giving guidance on the importance of obtaining specific information; Simple examples of the use of specific information relating to the topic. Annexes give additional information for those directly involved in applying the HRTM to specific situations, including guidance on obtaining parameter values. A brief overview is given of the deposition, characterisation, and sampling of aerosols, with references to further information, as there are relevant text books already available. Issues specific to radioactive aerosols, such as low particle number concentrations for high specific activity materials are, however, addressed. Guidance on obtaining information about absorption of inhaled radionuclides into blood is given in greater detail, because this is a topic on which ICRP has traditionally given guidance, and because a compilation of such information is not readily available elsewhere. Several detailed examples are also provided. One involves assessment of an individual's intake and committed dose from comprehensive bioassay monitoring data. The others deal with the derivation of HRTM absorption parameter values from experimental data, and their application, with additional information on e.g. size distribution, to calculate dose coefficients and interpret bioassay data.

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The degree of inhomogeneity of the absorbed cell nucleus doses in the bronchial region of the human respiratory tract

Radiation and Environmental Biophysics ◽

10.1007/s00411-019-00814-0 ◽

2019 ◽

Vol 59 (1) ◽

pp. 173-183 ◽

Cited By ~ 3

Author(s):

Péter Füri ◽

Árpád Farkas ◽

Balázs G. Madas ◽

Werner Hofmann ◽

Renate Winkler-Heil ◽

...

Keyword(s):

Respiratory Tract ◽

Lung Model ◽

Radiological Protection ◽

Radon Progeny ◽

Cell Nuclei ◽

Human Respiratory Tract ◽

Radiation Burden ◽

Precise Calculation ◽

Absorbed Doses ◽

Regional Lung

Abstract Inhalation of short-lived radon progeny is an important cause of lung cancer. To characterize the absorbed doses in the bronchial region of the airways due to inhaled radon progeny, mostly regional lung deposition models, like the Human Respiratory Tract Model (HRTM) of the International Commission on Radiological Protection, are used. However, in this model the site specificity of radiation burden in the airways due to deposition and fast airway clearance of radon progeny is not described. Therefore, in the present study, the Radact version of the stochastic lung model was used to quantify the cellular radiation dose distribution at airway generation level and to simulate the kinetics of the deposited radon progeny resulting from the moving mucus layer. All simulations were performed assuming an isotope ratio typical for an average dwelling, and breathing mode characteristic of a healthy adult sitting man. The study demonstrates that the cell nuclei receiving high doses are non-uniformly distributed within the bronchial airway generations. The results revealed that the maximum of the radiation burden is at the first few bronchial airway generations of the respiratory tract, where most of the lung carcinomas of former uranium miners were found. Based on the results of the present simulations, it can be stated that regional lung models may not be fully adequate to describe the radiation burden due to radon progeny. A more realistic and precise calculation of the absorbed doses from the decay of radon progeny to the lung requires deposition and clearance to be simulated by realistic models of airway generations.

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Evaluation of the Deposition of Nanoparticles on the Human Respiratory Tract from the Burning of Diesel/ Biodiesel/ Additive

JOURNAL OF BIOENGINEERING AND TECHNOLOGY APPLIED TO HEALTH ◽

10.34178/jbth.v4i1.147 ◽

2021 ◽

Vol 4 (1) ◽

pp. 2-8

Author(s):

Clara Rodrigues Pereira ◽

Pedro Bancillon Ventin Muniz ◽

Katheelin Rios Santa Rosa ◽

Lílian Lefol Nani Guarieiro ◽

Ednildo Andrade Torres

Keyword(s):

Binary Mixture ◽

Respiratory Tract ◽

Human Health ◽

Ternary Mixture ◽

Lung Model ◽

Pollutant Emissions ◽

Human Respiratory Tract ◽

Accumulation Mode ◽

The Impact

This study aimed to evaluate the deposition in the respiratory tract of nanoparticles (11.5nm to 365.2nm) from the burning of diesel, biodiesel, and additives. The studied fuels were pure diesel (D), a binary mixture of pure diesel with 11% biodiesel (B11), and a ternary mixture of pure diesel, with 11% biodiesel and with the biocatalyst Xmile (B11X). The impact of nanoparticles on health was assessed using the MPPD lung model. From the tests, the burning of the studied fuels showed a concentration of some particles in the accumulation mode (50nm to 120 nm). When comparing fuels, it was clear that B11 emits more particles and has a greater deposition capacity in the lung. B11X is efficient in reducing pollutant emissions as well as impacting human health.

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A model for deposition of stable and unstable aerosols in the human respiratory tract

AIHAJ ◽

10.1080/15298667991430703 ◽

1979 ◽

Vol 40 (12) ◽

pp. 1055-1066 ◽

Cited By ~ 7

Author(s):

E. AUSTIN ◽

J. BROCK ◽

E. WISSLER

Keyword(s):

Respiratory Tract ◽

Human Respiratory Tract

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Numerical assessment of natural respiration and particles deposition in the computed tomography scan airway with a glomus tumour

Proceedings of the Institution of Mechanical Engineers Part E Journal of Process Mechanical Engineering ◽

10.1177/09544089211024063 ◽

2021 ◽

pp. 095440892110240

Author(s):

Digamber Singh

Keyword(s):

Computed Tomography ◽

Respiratory Tract ◽

Particle Deposition ◽

Flow Characteristics ◽

Glomus Tumour ◽

Computed Tomography Scan ◽

Human Respiratory Tract ◽

Airflow Pattern ◽

Human Airways ◽

Tomography Scan

The human respiratory tract has a complex airflow pattern. If any obstruction is present in the airways, it will change the airflow pattern and deposit particles inside the airways. This is the concern of breath quality (inspired air), and it is decreasing due to the unplanned production of material goods. This is a primary cause of respiratory illness (asthma, cancer, etc.). Therefore, it is important to identify the flow characteristics in the human airways and airways with a glomus tumour with particle deposition. A numerical diagnosis is presented with an asymmetric unsteady-state light breathing condition (10 l/min). An in vitro human respiratory tract model has been reconstructed using computed tomography scan techniques and an artificial glomus tumour developed 2 cm above a carina on the posterior wall of the trachea. The transient flow characteristics are numerically simulated with a realizable (low Reynolds number) k–ɛ turbulence model. The flow disturbance is captured around the tumour, which influenced the upstream and downstream of the flow. The flow velocity pattern, wall shear stress and probable area of inflammation (hotspot) due to suspended particle deposition are determined, which may assist doctors more effectively in aerosol therapy and prosthetics of human airways illness.

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