Pulmonary and airway phospholipid membranes (PS)

Pulmonary and airway phospholipid membranes, primarily known as pulmonary surfactant, are essential lipid-protein complexes that line the alveolar surface of the lungs (StatPearls, NBK532971). Their primary biological role is to reduce surface tension at the air-liquid interface, which prevents alveolar collapse (atelectasis) during expiration and minimizes the work required for lung expansion (NIH, PMC4445298). These membranes are composed of approximately 90% phospholipids, predominantly dipalmitoylphosphatidylcholine (DPPC), and 10% specialized surfactant proteins such as SP-A and SP-B (Wikipedia, Pulmonary Surfactant). In addition to mechanical functions, they contribute to the lung's innate immunity by trapping and neutralizing inhaled pathogens through opsonization (PubMed, 11588355). Clinically, these membranes are the primary target of surfactant replacement therapies, such as Poractant alfa and Beractant, which are standard of care for Neonatal Respiratory Distress Syndrome (NRDS) (PubChem, CID 11954222). Furthermore, the integrity of these phospholipid layers is critical for the effective absorption and distribution of inhaled pharmacological agents (Journal of Controlled Release, 2014).

Other names

Pulmonary surfactantLung surfactantAlveolar lining layerAirway surface liquid phospholipidsAlveolar phospholipid bilayer

Exogenous surfactant drugs spread rapidly as a phospholipid monolayer over the alveolar surface, reducing surface tension to prevent alveolar collapse and improving lung compliance (StatPearls, NBK532971).