Surface properties of sulfur- and ether-linked phosphonolipids with and without purified hydrophobic lung surfactant proteins.
ABSTRACT Two novel C16:0 sulfur-linked phosphonolipids (S-lipid and SO(2)-lipid) and two ether-linked phosphonolipids (C16:0 DEPN-8 and C16:1 UnDEPN-8) were studied for surface behavior alone and in mixtures with purified bovine lung surfactant proteins (SP)-B and/or SP-C. Synthetic C16:0 phosphonolipids all had improved adsorption and film respreading compared to dipalmitoyl phosphatidylcholine, and SO(2)-lipid and DEPN-8 reached maximum surface pressures of 72mN/m (minimum surface tensions of <1mN/m) in compressed films on the Wilhelmy balance (23 degrees C). Dispersions of DEPN-8 (0.5mg/ml) and SO(2)-lipid (2.5mg/ml) also reached minimum surface tensions of <1mN/m on a pulsating bubble surfactometer (37 degrees C, 20cycles/min, 50% area compression). Synthetic lung surfactants containing DEPN-8 or SO(2)-lipid+0.75% SP-B+0.75% SP-C had dynamic surface activity on the bubble equal to that of calf lung surfactant extract (CLSE). Surfactants containing DEPN-8 or SO(2)-lipid plus 1.5% SP-B also had very high surface activity, but less than when both apoproteins were present together. Adding 10wt.% of UnDEPN-8 to synthetic lung surfactants did not improve dynamic surface activity. Surfactants containing DEPN-8 or SO(2)-lipid plus 0.75% SP-B/0.75% SP-C were chemically and biophysically resistant to phospholipase A(2) (PLA(2)), while CLSE was severely inhibited by PLA(2). The high activity and inhibition resistance of synthetic surfactants containing DEPN-8 or SO(2)-lipid plus SP-B/SP-C are promising for future applications in treating surfactant dysfunction in inflammatory lung injury.
- 39th Annual Symposium on Frequency Control. 1985; 02/1985
- JAMA The Journal of the American Medical Association 09/2005; 294(8):898-9; author reply 899. DOI:10.1001/jama.294.8.898-b · 30.39 Impact Factor
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ABSTRACT: The respreading of a lung surfactant monolayer at the air-water interface is investigated with broad bandwidth sum frequency generation (BBSFG) spectroscopy. The lung surfactant mixture contains chain perdeuterated dipalmitoylphosphatidylcholine (DPPC-d62), palmitoyloleoylphosphatidylglycerol (POPG), palmitic acid (PA), and KL4 (a 21-residue polypeptide analogue to the surfactant protein SP-B). DPPC-d62 serves as a probe molecule for the spectroscopic investigation. The BBSFG spectra of DPPC-d62 in the lung surfactant mixture are obtained in the C-D stretching region in real-time during film compression and expansion in a Langmuir trough. The BBSFG intensity of the CD3 stretch peak from DPPC-d62 terminal methyl groups is used as a measure of the interfacial density of DPPC-d62 after careful consideration of orientation effects. For the first time, the interfacial loss of DPPC in a complex lung surfactant mixture is quantified. Spectroscopic results reveal that there is an 18% DPPC-d62 interfacial loss during film respreading. However, the surface pressure-area isotherm measurements demonstrate that there is a rather large trough area reduction (37%) during film expansion. The relatively small interfacial loss of DPPC-d62 and the rather large trough area reduction indicate that the respreading of DPPC and non-DPPC components in the lung surfactant is not uniform and a surface refinement process exists during film compression and expansion. This refinement process results in a DPPC-enriched monolayer with a significant depletion of non-DPPC components after film respreading. Implication for replacement surfactant design from this work is discussed.Langmuir 01/2007; 22(26):11267-74. DOI:10.1021/la061476k · 4.46 Impact Factor