A model of pulmonary mucus made from snail slime!

Biomedical research generally comes up against the difficulty of obtaining controlled samples that are representative, available and reproducible. This is particularly true in the case of mucus, a liquid secreted by a large number of living organisms with exceptional rheological properties, and which, depending on the mucus type, has specific physiological functions.

At the LRP, we are interested in the pulmonary mucus that covers the epithelium of the bronchial apparatus, in connection with respiratory pathologies (cystic fibrosis, chronic obstructive bronchitis, asthma, bronchiectasis, etc.). In order to have an experimental model that would enable us to develop measurement protocols and advanced characterisation of samples from human patients, we came up with the idea of using the mucins present in snail slime, which is cultivated and harvested on a large scale for cosmetics. These mucins have similarities to those making up human lung mucus, but are both too small in size and too low in concentration to give the solution rheological properties comparable to those of lung mucus. In this study, we used a cross-linking agent, which, when mixed with commercial snail slime in a precise concentration range, enables flow properties identical to those of human lung mucus to be obtained and adjusted, even on a microscopic scale.