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Nanomedicine Against COVID-19
Published in Hanadi Talal Ahmedah, Muhammad Riaz, Sagheer Ahmed, Marius Alexandru Moga, The Covid-19 Pandemic, 2023
Saima Zulfiqar, Zunaira Naeem, Shahzad Sharif, Ayoub Rashid Ch., M. Zia-Ul-Haq, Marius Moga
Deposition of virus coated droplet nuclei on filter media depends on size larger size droplets will not go too deep, but smaller droplets will go in-depth to fibrous matrix. Facepiece masks use for filtration purposes, particle deposition can be changed through cyclical breathing process. Droplet nuclei have the ability to absorb moisture, so in humid air, they absorb water and swell, causing filter fibers to retain particles which results in their redistribution or breakdown.
Physiology of the Airways
Published in Anthony J. Hickey, Sandro R.P. da Rocha, Pharmaceutical Inhalation Aerosol Technology, 2019
Anthony J. Hickey, David C. Thompson
The nature of particle deposition forces and their relationship to aerodynamic particle size have been the subject of many studies and reports. A variety of models for aerosol deposition in the respiratory tract have been proposed. The most notable are those of Findeisen (1935), Landahl (1950a, 1950b), and Weibel (1963).
Mathematical modeling of inhaled therapeutic aerosol deposition in the respiratory tract
Published in Anthony J. Hickey, Heidi M. Mansour, Inhalation Aerosols, 2019
Jeffry Schroeter, Bahman Asgharian, Julia Kimbell
The main mechanisms by which particles deposit in the respiratory tract are inertial impaction, sedimentation, and diffusion, with interception if the particle is elongated or fiber-shaped (29). The degree to which each mechanism contributes to particle deposition depends on the geometry of the airway and the airflow passing through it, as well as the characteristics of the particles, including size and shape, density, chemical composition, surface structure, initial velocity, electrical charge, interactions with each other and the surrounding air, and the way they are generated and introduced to the respiratory tract. Sprayers, inhalers, and some nebulizers inject particles with nonzero, often substantial, initial velocities. Initial particle velocity can be zero, as in the cases of ambient air pollutants in still air, or assumed to be zero compared to inspiratory airflow rates in the case of many nebulized products. A recent review describes these factors and their effects on deposition in detail (29).
Bridging inhaled aerosol dosimetry to physiologically based pharmacokinetic modeling for toxicological assessment: nicotine delivery systems and beyond
Published in Critical Reviews in Toxicology, 2019
A. R. Kolli, A. K. Kuczaj, F. Martin, A. W. Hayes, M. C. Peitsch, J. Hoeng
The total deposited dose of an aerosol is dependent on both particulate (i.e. solid and/or liquid) and gaseous phases. Primary mechanisms of particle deposition include impaction, diffusion, interception, sedimentation, and electrostatic precipitation, as shown in Figure 3 (Hinds 2012; Nordlund and Kuczaj 2015). It must be noted that modulation of the physical aerosol characteristics mentioned earlier (particle size distribution) directly affects the magnitude and subsequently the physical location of the aerosol deposition governed by these mechanisms. The absorption of gases depends on several factors, such as solubility, diffusivity, surrounding temperature, humidity, and concentration (Nordlund and Kuczaj 2015). Combination of both phenomena (aerosol particles deposition and gas phase absorption) contributes to the overall substance-specific dosimetry quantification. These substances are then either further absorbed into the lung tissue structure or cleared by MCC.
Computational modeling of lung deposition of inhaled particles in chronic obstructive pulmonary disease (COPD) patients: identification of gaps in knowledge and data
Published in Critical Reviews in Toxicology, 2019
Koustav Ganguly, Ulrika Carlander, Estella DG Garessus, Markus Fridén, Ulf G Eriksson, Ulrika Tehler, Gunnar Johanson
A certain fraction of inhaled particles is deposited in the respiratory system following contact with the lining fluid of the airways (Edsbäcker et al. 2008). Particle deposition is influenced by several factors related to the particle properties as well as physiological and anatomical features of the subject inhaling those particles (Schulz 1998; Schulz and Muhle 2000). The main physical processes determining pulmonary particle deposition are (i) impaction, (ii) sedimentation and (iii) diffusion (Tena and Clarà 2012). The extent and pattern of particle deposition are driven by: (i) particle size, shape and density, (ii) physicochemical properties of the inhaled aerosol, (iii) airflow velocity, (iv) breathing patterns, (v) lung geometry (e.g. airway diameter and number of alveoli) and structure, (vi) anatomy of the nasal, oral and pharyngeal areas, and (vii) temperature and humidity (Tena and Clarà 2012; Jinxiang et al. 2014; Borghardt et al. 2015). COPD associated changes in the airway dimensions (bronchoconstriction and hyperinflation), lung structure (emphysema) (Wagner 2003), altered airflows and breathing patterns (Löring et al. 2009) and reduced lung elasticity (Wagner 2003) may affect particle deposition. Thus, modeling of a COPD lung warrants consideration of the associated structural, dimensional and functional changes.
Detailed deposition analysis of inertial and diffusive particles in a rat nasal passage
Published in Inhalation Toxicology, 2018
Jingliang Dong, Yidan Shang, Lin Tian, Kiao Inthavong, Jiyuan Tu
This article presents a comprehensive study of particle transport and deposition analysis for a wide size range (from 1 nm to 4 µm) including diffusive and inertial particles. Both overall and regional particle deposition results were analyzed in detail. The rat nasal vestibule showed high particle filtration for inertial particles (2 µm and above), and more than 70% of all inhaled inertial particles were trapped in this region. For diffusive nanoparticles, the vestibule filtration effect is reduced – only less than 60% of inhaled nanoparticles were trapped by the anterior nasal structures. Particles in the size range of 10 nm to 1.2 µm, pass through the vestibule region smoothly with low deposition loss (less than 10%), and the consequent overall particle deposition for the whole nasal passage was below 25%. The particle exposure in the olfactory region showed notable deposition for diffusive nanoparticles, which peaked at 9.4% for 5 nm particles. Although the olfactory deposition remaining at a low level, the ratio between the olfactory and the main nasal passage was 30–40% for 10–800 nm particles, which indicates a particle-size-independent distribution pattern in the main nasal passage.