Deposition of inhaled aerosols: a biological-fluid mechanical analysis of the deposition of particles in a respiratory model to assess the propagation of inhaled agents and the efficiency and toxicity of active substances in human airways using allicin as reference substance

• Applicants: Dr. Martin Gruhlke; Dr.-Ing. Michael Klaas
• Subject Area: Fluid Mechanics ; Plant Physiology
• Term: from 2021 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 468940454

• Final Report Year: 2024

Final Report Abstract

The measurement of aerosol deposition inside the human respiratory tract still is a challenge in biological fluid dynamics. To better understand the influence of the flow field on the particle deposition behaviour, combined velocity and aerosol deposition measurements at two Reynolds numbers of Re = 400 and Re = 1180 were presented. A unique approach of analysing the flow field and the particle deposition in a physiologically correct model of the human respiratory tract from the nasal/oral cavities up to the 6th bronchi generation is presented. The investigations comprise two geometrically identical models of the human airway system, one for the analysis of the particle deposition in the human airways and one for the investigation of the velocity field, to determine the relationship between aerosol deposition and flow structures. While the aerosol deposition of synthetic allicin is measured with a surface-coated biological model (BIO model) using a colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, the flow field is determined based on high speed particle-image velocimetry (HS-PIV) in a fully refractive-index matched model (PIV-model). In addition, initial approaches to further improve the airway model with dye-free reporter and detection systems at pathogen and cell level are presented. The study investigates the influence of the volume flux on the deposition behaviour and the flow field. The results of the presented study show a very good agreement to numerical data from. Although the inhibition of bacterial growth is different for the two volume fluxes, similar flow structures were observed for both Reynolds numbers at steady inspiration.

Publications

• Allicin, the Odor of Freshly Crushed Garlic: A Review of Recent Progress in Understanding Allicin’s Effects on Cells. Molecules, 26(6), 1505.
  Borlinghaus, Jan; Foerster, (née Reiter) Jana; Kappler, Ulrike; Antelmann, Haike; Noll, Ulrike; Gruhlke, Martin & Slusarenko, Alan
  
• Allicin as a Volatile or Nebulisable Antimycotic for the Treatment of Pulmonary Mycoses: In Vitro Studies Using a Lung Flow Test Rig. International Journal of Molecular Sciences, 23(12), 6607.
  Schier, Christina; Foerster, (née Reiter) Jana; Heupel, Monika; Dörner, Philipp; Klaas, Michael; Schröder, Wolfgang; Rink, Lothar; Slusarenko, Alan J. & Gruhlke, Martin C. H.
  
• Seeing the smell of garlic: Detection of gas phase volatiles from crushed garlic (Allium sativum), onion (Allium cepa), ramsons (Allium ursinum) and human garlic breath using SESI-Orbitrap MS. Food Chemistry, 397, 133804.
  Mengers, Hendrik G.; Schier, Christina; Zimmermann, Martin; C., H. Gruhlke Martin; Block, Eric; Blank, Lars M. & Slusarenko, Alan J.
  
• Combined Velocity and Aerosol Deposition Measurements in the Respiratory Tract using HS-PIV and MTT Assay. 15th International Symposium on Particle Image Velocimetry – ISPIV 2023 June 19–21, 2023, San Diego, California, USA
  Johanning-Meiners, B. H., Schier, C., Meyer, T., Dörner, T., Gruhlke, M. C. H., Rink, L., Schröder, W. & Klaas, M.