Induced removal of dipalmitoyl phosphatidylcholine by the exclusion of fibrinogen from compressed monolayers at air/liquid interfaces.
The induced removal of dipalmitoyl phosphatidylcholine (DPPC) by the exclusion of fibrinogen from mixed DPPC/fibrinogen monolayers at compressed air/liquid interfaces was analyzed. The surface pressure-area hysteresis curves of the monolayers at interfaces were obtained by a Langmuir trough. The hysteresis curves of equilibrium fibrinogen adsorption layers suggest that fibrinogen desorption during the area compression stage became significant at a higher bulk concentration of 1000 ppm. For mixed monolayers of DPPC with fibrinogen, the fibrinogen molecules were expelled from the interface upon compression due to the presence of insoluble DPPC molecules. The squeeze-out of fibrinogen molecules evidently removed a significant number of DPPC molecules from the interface, with the extent depending on fibrinogen surface concentration. During the subsequent area expansion stage, fibrinogen molecules entered the interface and participated in the rise of surface pressure. The induced loss of free DPPC molecules at the interface by the expelled fibrinogen molecules during the area compression stage was then evaluated from the hysteresis curves.
Kuo
Rong-Rong
RR
Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan 70101, ROC.
Chang
Chien-Hsiang
CH
Yang
Yu-Min
YM
Maa
Jer-Ru
JR
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry; D000818:Animals; D002417:Cattle; D005340:Fibrinogen / Q000737:chemistry; D011312:Pressure
D015060:1,2-Dipalmitoylphosphatidylcholine; D005340:Fibrinogen