Multi-cycling of exogenous pulmonary surfactant reveals inhalant gas and loading history dependency

Abstract

All mammalian lungs inflate and deflate cyclically while holding a gas and consist of hollow cavities (alveoli), at the end of airway trees, which are internally lined with a liquid known as pulmonary surfactant (PS). The main function of PS is to reduce the surface tension at a liquid-gas interface. Proper function of PS is critical for healthy breathing, and surfactant dysfunction is associated with several pulmonary pathologies. Different parameters cause the PS dysfunction, one of which is increased levels of oxygen, which are administered for patients suffering from acute or chronic pulmonary pathologies and/or trauma. This increase can lead to oxygen toxicity, which can affect the cells that form the alveoli as well as the PS. There are ways to improve the function of a lung by making changes to the PS, such as using exogenous PS for NRDS (Neonatal Respiratory Distress System) patients or taking a deep breath to increase the secretion of PS. In this study we utilized a Langmuir-Wilhelmy balance (LWB) to perform systematic experiments, with controlled environmental conditions, on exogenous PS (Infasurf