On the importance of lung fluid rheology for medical applications and toxicology
Abstract: Inhaled nanoparticles (< 100 nm) reaching the deep region of the lungs first interact with the pulmonary surfactant, a thin lipid film lining the alveolar epithelium [1,2]. To date, most biophysical studies have focused on the interfacial properties of the film, and comparatively less work has been done on bulk properties, including structure and rheology [3]. Here we investigate the structural and viscoelastic properties of the biomimetic lung surfactant Curosurf as such, and in the presence of engineered nanoparticles [4]. Curosurf is a medication that is provided to premature infants born before the 7th month of age and suffering from acute respiratory distress syndrome (ARDS). We first show that for medical applications, the rheology of pulmonary surfactant plays a crucial role [5], and that very little information is actually available on this subject. In particular, we explore the possibility of using biomimetic surfactants to treat adults also suffering from ARDS in relation to COVID-19. We then address the issue of surfactant rheology in the presence of model nanoparticles. In the cases of 40 nm-silica and alumina nanoparticles, we show that these interactions induce profound changes in the flow properties of the surfactant, including a transition to a soft-solid behavior [6]. In terms of toxicology, these results suggest that changes in structure and viscosity may interfere with the fluid reorganization and recirculation that occurs during respiration.
References
1 F. Mousseau, C. Puisney, S. Mornet, R. Le Borgne, A. Vacher, M. Airiau, A. Baeza-Squiban, J.-F. Berret, Nanoscale, 9 (2017) 14967-14978.
2 M. Radiom, M. Sarkis, O. Brookes, E.K. Oikonomou, A. Baeza-Squiban, J.F. Berret, Sci. Rep., 10 (2020).
3 J.-F. Berret, Nat. Commun., 7 (2016) 10134.
4 F. Mousseau, J.-F. Berret, Soft Matter, 14 (2018) 5764-5774.
5 L.-P.-A. Thai, F. Mousseau, E. Oikonomou, J.-F. Berret, Colloids Surf. B, 178 (2019) 337-345.
6 L.-P.-A. Thai, F. Mousseau, E. Oikonomou, M. Radiom, J.-F. Berret, ACS Nano, 14 (2020) 466-475.