Properties of mixed monolayers of DPPC and viscoelasticity-giving substances

Static surface pressures and dynamic surface pressures for the mixed monolayers consisting of dipalmitoylphosphatidylcholine (DPPC), cholesterol linoleate (Cho-Linoleate), stearyl alcohol (StOH) and oleic acid (Ole-Ac) on the buffer were measured by using a modified Wilhelmy balance to obtain the surface rheological data such as surface elasticity, surface viscosity, and hysteresis loops of dynamic surface tension. These surface rheorogical data for the mixed monolayers with the molar ratios of DPPC:Cho-Linoleate:StOH:Ole-Ac = 11:1:7:1 showed similar to those obtained for a lung surfactant, TA, developed by Fujiwara et al. (T. Fujiwara et al., Elsevier Science, Amsterdam, 1984, pp. 479) which is known to be effective on the treatment of respiratory distress syndrome (RDS). (C) 2000 Elsevier Science B.V. All rights reserved.