title: Numerical and experimental investigation of mucociliary clearance breakdown in cystic fibrosis.
abstract: The human tracheobronchial tree surface is covered with mucus. A healthy mucus is a heterogeneous material flowing toward the esophagus and a major defense actor against local pathogen proliferation and pollutant deposition. An alteration of mucus or its environment such as in cystic fibrosis dramatically impacts the mucociliary clearance. In the present study, we investigate the mechanical organization and the physics of such mucus in human lungs by means of a joint experimental and numerical work. In particular, we focus on the influence of the shear-thinning mucus mobilized by a ciliated epithelium for mucociliary clearance. The proposed robust numerical method is able to manage variations of more than 5 orders of magnitude in the shear rate and viscosity. It leads to a cartography that allows to discuss major issues on defective mucociliary clearance in cystic fibrosis. Furthermore, the computational rheological analysis based on measurements shows that cystic fibrosis shear-thinning mucus tends to aggregate in regions of lower clearance. Yet, a rarefaction of periciliary fluid has a greater impact than the mucus shear-thinning effects.
authors.affiliation: Université de Lyon, ENI Saint Etienne, LTDS, UMR CNRS 5513, 58 rue Jean Parot, 42023 Saint-Etienne Cedex 2, France.
authors.forename: Robin
authors.initials: R
authors.lastname: Chatelin
authors.affiliation: Institut de Mécanique des Fluides de Toulouse (IMFT) - Université de Toulouse, CNRS-INPT-UPS, Allée Camille Soula, Toulouse, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Anne-Archard
authors.affiliation: Service de pneumologie et allergologie, CHU de Toulouse, Hôpital Larrey, 24 chemin de Pouvourville, TSA 30030, F-31059 Toulouse Cedex 9, France.
authors.forename: Marlène
authors.initials: M
authors.lastname: Murris-Espin
authors.affiliation: CNRS, Lab. JL. Lions, UMR CNRS 7598, University P. & M. Curie, 75252 Paris, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Thiriet
authors.affiliation: University Pau & Pays Adour, LMAP, UMR CNRS 5142, IPRA, avenue de l׳Université, F-64013 Pau, France. Electronic address: philippe.poncet@univ-pau.fr.
authors.forename: Philippe
authors.initials: P
authors.lastname: Poncet
mesh_terms: D003550:Cystic Fibrosis / Q000503:physiopathology*; D006801:Humans; D008168:Lung / Q000503:physiopathology; D008954:Models, Biological; D009079:Mucociliary Clearance / Q000502:physiology*; D009093:Mucus / Q000502:physiology; D012212:Rheology; D014783:Viscosity
keywords: Computational biology; Cystic fibrosis; Generalized Stokes equations; Grid-particle methods; Modeling; Mucociliary clearance; Penalization; Rheology