Biological films and Respiratory Dysfunction – BioFiReaDy

The BioFiReaDy project aims at investigating mechanical dysfunction and airway clearance efficiency (or lack thereof) of the respiratory system, by a quantitative analysis of mucus motion. A large part of the project is dedicated to healthy configuration, cystic fibrosis (mucoviscidosis) and epithelium dysfunction consequent to consumption of cilia inhibiting drugs (eg nicotine) or recurrent virus and/or bacteria attack. Nevertheless, a large class of diseases is concerned by alteration of mucus mobility, as shown on figure 1.2 of scientific document. Mucus is a visco-elastic fluid secreted by the respiratory epithelium (see figure 1.1 of the proposal) that protects tracheo-bronchial tree mucosa from dehydration and traps inhaled particles (allergens, carcinogens, dust, micro-organisms, and inflammatory debris) that come into contact with it. Ciliary motions that are associated with mucus propulsion in the human respiratory tract cleans airways, as it flows from either the tracheo-bronchial tree or upper airways toward the pharynx, where it is swallowed (or expectorated). Strong mucus mobility is necessary to provide satisfying airway clearance and healthy behaviour of respiratory system. Otherwise either proliferation of pathogen agents is observed in stagnant mucus, either lack of mucoïd film let pathogens slip through pulmonary membrane. Its motion can be altered by its rheometry, thickness, geometry, epithelium vibration features (cilia motion) or respiration cycle alterations. The material used for this project is mainly computer biological flow simulation, followed by clinical validation. The mucus layer itself is in the micrometre scale, while the cilia of epithelium cells is close to nanometre, and air circulation and pulmonary tree goes from millimetre to centimetre. The project will also focus on the efficient coupling of these different scales. This project is hold by Toulouse Institute of Mathematics, and involves people from CHU Toulouse-Larrey, Lab. Jean Kuntzmann (Grenoble), Lab. Jacques-Louis Lions (University of Paris VI, and INRIA Team REO), and School of Natural Science, University of California Merced (USA).