(322f) Confocal Microscopy and Lung Surfactant: Slicing Through the Interface

Lung surfactant is a mixture of lipids and proteins that lines the air-liquid interface of the alveolar walls and plays an integral role in normal respiration.  It modulates the otherwise high surface tension in the lungs to reduce the mechanical work of breathing and prevent alveolar collapse.  The disruption of this surface tension modulation is characteristic in both neonatal and acute respiratory distress syndromes, caused either by the deficiency and/or dysfunction of lung surfactant.  A better understanding of the adsorption, spreading, and other interfacial characteristics of lung surfactant allows for intelligent design of exogenous surfactant therapies for treating these diseases.

Here, we present a new methodology for visualizing interfacial phenomena in a Langmuir trough using confocal microscopy.  Confocal microscopy offers two distinct advantages over traditionally used widefield fluorescence microscopy: shallow depth of field and easy integration of multiple acquisition channels.  We have overcome many of the difficulties and optical aberrations present when imaging an air-liquid interface, therefore providing three dimensional, in situ, real time, and nondestructive visualization of multiple components of our lung surfactant system.  As a result, we have more thoroughly examined the mechanisms of lung surfactant dysfunction during acute respiratory distress syndrome, as well as ways to reverse it.  In general, our approach is easily adapted for visualizing the behavior of any number of surfactant systems at not only air-liquid interfaces, but other fluid-fluid interfaces as well.