Humidified and Heated Cascade Impactor for Aerosol Sizing

Majoral, Caroline; Coates, Allan L.; Pape, Alain Le; Vecellio, Laurent

doi:10.3389/fbioe.2020.589782

Cited by 6 publications

(4 citation statements)

References 39 publications

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“…However, aerosols with large numbers of droplets per unit volume, which is the case of this study, can actually self-humidify the surrounding air and therefore stop the size changes (Majoral et al, 2020). This phenomenon occurs when the number of droplets is high, i.e.…”

Section: A C C E P T E D Mmentioning

confidence: 86%

Inter-laboratory Comparison between Particle and Bacterial Filtration Efficiencies of Medical Face Masks in the COVID-19 Context

Fouqueau

Pourchez

Leclerc

et al. 2023

Aerosol Air Qual. Res.

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Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) transmission lead to the recommendation of mask wearing during the pandemic COVID -19. Bacterial filtration efficiency (BFE) measurements are used to measure the efficiency of medical face masks in preventing the spread of bioaerosols. Even though these measurements are simple, BFE testing still raise several scientific questions. This paper presents an inter-laboratory comparison between Bacterial Filtration Efficiency (BFE) and Particle Filtration Efficiency (PFE), in order to better understand and establish an overview of both ways for testing surgical masks.Filtration efficiency of six commercial surgical masks have been measured using such experimental methods, i.e. the BFE and the PFE using 3 µm particles initially developed for community face covering testing. The fractional filtration efficiencies have been measured and compared in order to explain the differences.Recommendations for improving associated EN14683:2019+AC standard are also proposed according to the results.

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Section: A C C E P T E D Mmentioning

confidence: 86%

Inter-laboratory Comparison between Particle and Bacterial Filtration Efficiencies of Medical Face Masks in the COVID-19 Context

Fouqueau

Pourchez

Leclerc

et al. 2023

Aerosol Air Qual. Res.

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“…Conditions at 37 °C/100% may modify the aerodynamic parameters of the phage aerosol and, thus, droplet size and phage concentration within the droplets due to evaporation or condensation (hygroscopic growth). In comparison with ambient conditions (22 °C/40%), liquid aerosols are mainly affected by evaporation (from nebulizers and metered-dose inhalers) while solid aerosols from dry powder inhalers by growth hygroscopy [ 47 ]. Condensation is limited for liquid aerosols thanks to a high concentration of droplets per unit volume, thus keeping a high level of self-humidity in the cloud [ 47 ].…”

Section: Discussionmentioning

confidence: 99%

“…In comparison with ambient conditions (22 °C/40%), liquid aerosols are mainly affected by evaporation (from nebulizers and metered-dose inhalers) while solid aerosols from dry powder inhalers by growth hygroscopy [ 47 ]. Condensation is limited for liquid aerosols thanks to a high concentration of droplets per unit volume, thus keeping a high level of self-humidity in the cloud [ 47 ]. Particle size distribution (PSD) of the phage aerosol generated by the nebulizer predicts phage droplet deposition pattern in the respiratory tract and was measured according to the European Pharmacopoeia method ( Figure 3 and Supplementary Data S2 ) [ 48 ].…”

Section: Discussionmentioning

confidence: 99%

Administration of Bacteriophages via Nebulization during Mechanical Ventilation: In Vitro Study and Lung Deposition in Macaques

Guellec

Pardessus

Bodier-Montagutelli

et al. 2023

Viruses

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Bacteriophages have been identified as a potential treatment option to treat lung infection in the context of antibiotic resistance. We performed a preclinical study to predict the efficacy of delivery of bacteriophages against Pseudomonas aeruginosa (PA) when administered via nebulization during mechanical ventilation (MV). We selected a mix of four anti-PA phages containing two Podoviridae and two Myoviridae, with a coverage of 87.8% (36/41) on an international PA reference panel. When administered via nebulization, a loss of 0.30–0.65 log of infective phage titers was measured. No difference between jet, ultrasonic and mesh nebulizers was observed in terms of loss of phage viability, but a higher output was measured with the mesh nebulizer. Interestingly, Myoviridae are significantly more sensitive to nebulization than Podoviridae since their long tail is much more prone to damage. Phage nebulization has been measured as compatible with humidified ventilation. Based on in vitro measurement, the lung deposition prediction of viable phage particles ranges from 6% to 26% of the phages loaded in the nebulizer. Further, 8% to 15% of lung deposition was measured by scintigraphy in three macaques. A phage dose of 1 × 109 PFU/mL nebulized by the mesh nebulizer during MV predicts an efficient dose in the lung against PA, comparable with the dose chosen to define the susceptibility of the strain.

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“…Williams and Suman [ 32 ] also described that the lack of mucosal surface and ciliary clearance constitutes a limitation for nasal anatomical models. The moisture content and temperature in the airways could also modify the particle size, affecting the deposition along the airways [ 33 ]. However, despite a similar lack of mucus, moisture, and body temperature (37 °C) in the airways model, a human 3D cast model was shown to provide results comparable to those obtained with in vivo human CT scans [ 10 ].…”

Section: Discussionmentioning

confidence: 99%

Comparison of Aerosol Deposition Between a Cynomolgus Macaque and a 3D Printed Cast Model of the Animal

et al. 2023

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Purpose Preclinical aerosol studies using animals are essential for evaluating toxic or therapeutic effects on human respiratory tract. Macaques are relevant animal models for respiratory studies, but they are sensitive, expensive and difficult-to-access. Methods In the context of preliminary studies before animal experiments, we set up an alternative in vitro anatomical model of macaque airways to reduce, refine and replace (3Rs) the animals. We printed an in vitro anatomical cast until the third bronchial division from X-ray computed tomography data of a healthy cynomolgus macaque. This in vitro model was then connected to a respiratory pump to mimic macaque’s breathing. We assessed the relevance of this in vitro model, by comparing aerosol deposition patterns obtained with the anatomical model and in three macaques using planar gamma camera imaging. DTPA- 99m Technetium aerosols were produced using three jet nebulizers, generating three different particle sizes: 13.1, 3.2 and 0.93 µm in terms of the mass median aerodynamic diameter (MMAD). Results The data showed no statistical differences between the animal and anatomical in vitro models in terms of total aerosol deposited in the airways. However, the distribution of the deposition in the airways showed a higher deposited fraction in the upper respiratory tract in the animals than the in vitro model for all particle sizes . Conclusions The anatomical printed model appears to be a relevant in vitro tool to predict total aerosol deposition in macaque airways.

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Humidified and Heated Cascade Impactor for Aerosol Sizing

Cited by 6 publications

References 39 publications

Inter-laboratory Comparison between Particle and Bacterial Filtration Efficiencies of Medical Face Masks in the COVID-19 Context

Inter-laboratory Comparison between Particle and Bacterial Filtration Efficiencies of Medical Face Masks in the COVID-19 Context

Administration of Bacteriophages via Nebulization during Mechanical Ventilation: In Vitro Study and Lung Deposition in Macaques

Comparison of Aerosol Deposition Between a Cynomolgus Macaque and a 3D Printed Cast Model of the Animal

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