ABSTRACT
Pulmonary surfactant, or lung surfactant (LS), is a natural biomaterial that coats the internal surfaces of mammalian lungs and enables normal breathing. It is a complex mixture composed of about 90% lipids and about 10% surfactant proteins (SPs). Both fractions are critical for its physiological function, which is to decrease the work of breathing by regulating surface tension at the air-liquid interface of the alveoli (the network of air sacs that perform gas exchange within the lung) as a function of alveolar surface area (1, 2). A deficiency of functional LS in premature infants results in the development of neonatal respiratory distress syndrome (RDS) (3), a leading cause of infant mortality. Two-thirds of infants born preterm are affected by RDS, with 60% of the incidence in infants born before 28 weeks of gestation (4). Left untreated, an infant with RDS will die. This has led to the development of exogenous lung surfactant replacements that can, if delivered within minutes of birth, either prevent RDS or mitigate its effects.
