Overcoming surfactant inhibition with polymers

Inhibition of the function of pulmonary surfactant in the alveolar space is an important element of the pathophysiology of many lung diseases, includi ng meconium aspiration syndrome, pneumonia and acute respiratory distress s yndrome. The known mechanisms by which surfactant dysfunction occurs are (a ) competitive inhibition of phospholipid entry into the surface monolayer ( e.g. by plasma proteins), and (b) infiltration and destabilization of the s urface film by extraneous lipids (e.g. meconium-derived free fatty acids). Recent data suggest that addition of non-ionic polymers such as dextran and polyethylene glycol to surfactant mixtures may significantly improve resis tance to inhibition. Polymers have been found to neutralize the effects of several different inhibitors, and can produce near-complete restoration of surfactant function. The anti-inhibitory properties of polymers, and their possible role as an adjunct to surfactant therapy, deserve further explorat ion.