The physics and physiology of lung surfactants

Zasadzinski, Joseph A.; Ding, Junqi; Warriner, Heidi E.; Bringezu, Frank; Waring, Alan J.

doi:10.1016/s1359-0294(01)00124-8

Cited by 172 publications

(165 citation statements)

References 40 publications

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“…All these observations are in accordance with the literature. 1,3,5 As an additional test a single lipid was placed at an air-water interface in a curled conformation. It was found that the lipid uncurled within 120 ps and remained uncurled during the subsequent 7.9 ns of simulation.…”

Section: Fluorescence Microscopymentioning

confidence: 99%

“…4 Lung surfactant modulates the surface tension of the lung, stabilizing alveoli against collapse during expiration and minimizing the work required to expand the alveoli again during inhalation. 5 The major component ͑Ͼ90%͒ of lung surfactant is phospholipid. The predominant species is DPPC ͑dipalmitoylphosphatidylcholine͒ which ranges from 40% to 80% by weight in natural surfactant.…”

Section: Introductionmentioning

confidence: 99%

“…1 The lipid chains tilt such that the projected area of the hydrocarbon chains in the plane parallel to the water surface matches that of the headgroups. 5 Upon decompression (AϾ0.47 nm 2 ) the C phase coexists 7 with a gel-like 8 liquid condensed ͑LC͒ phase 7 in which lipid chains have gauche defects 3 but are still aligned. 1 Between 0.50 and 0.80 nm 2 /molecule the LC phase coexists with a more disora͒ Author to whom correspondence should be addressed.…”

Section: Introductionmentioning

confidence: 99%

“…6 Between 1.0 and 4.0 nm 2 /molecule, a region in which the lateral pressure is effectively zero, 9 the LE phase is believed to coexist with a gas ͑G͒ phase 3,9 in which the lipid tails have substantial contact with the water surface, but little with each other. 5 Fluorescence microscopy has revealed that in the liquid ͑L͒-gas coexistence region of DPPC monolayers at small gas phase fractions the gas phase is present as holes ͓two-dimensional ͑2D͒ gas bubbles 10 ͔ in an interconnected liquid phase 9 such that the monolayer forms a two-dimensional foam. 11 However, due to the limited spatial resolution of fluorescence microscopy images 9 the precise onset of the L-G coexistence region cannot be determined directly using fluorescence microscopy.…”

Section: Introductionmentioning

confidence: 99%

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Simulation studies of pore and domain formation in a phospholipid monolayer

Knecht

Müller

Bonn

et al. 2004

The Journal of Chemical Physics

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Simulation studies of pore and domain formation in a phospholipid monolayer.Knecht, V.; Müller, M.; Bonn, M.; Marrink, S.J.; Mark, A.E. General rightsIt is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use, unless the work is under an open content license (like Creative Commons). Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Despite extensive study the phase behavior of phospholipid monolayers at an air-water interface is still not fully understood. In particular recent vibrational sum-frequency generation ͑VSFG͒ spectra of DPPC monolayers as a function of area density show a sharp transition in the order of the lipid chains at 1.10 nm 2 /molecule. This is in a region where the lateral pressure as a function of area is effectively constant. We have investigated the nature of this transition by studying the phase behavior of DPPC monolayers as a function of area density using molecular-dynamics simulations. The changes in order within the monolayer as a function of area density correlate well with the experimental signal. At 0.58 nm 2 /molecule we observe the onset of lateral separation of highly ordered and disordered lipids, indicating the coexistence of a gel-like liquid condensed and a fluidlike liquid expanded phase. At 0.97 nm 2 /molecule the monolayer ruptures, marking the onset of the liquid-gas ͑G͒ coexistence region. This is much earlier than suggested by fluorescence microscopy results and implies that at the point of rupture, the initial pores have an equilibrium size smaller than ϳ500 nm in diameter. The rupture of the monolayer leads to a sharp increase in the overall lipid order that explains the sharp transition observed in the VSFG measurements. VSFG measurements thus may represent a sensitive means to determine the onset of the liquid-gas ͑G͒ coexistence region for such systems.

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Section: Fluorescence Microscopymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Simulation studies of pore and domain formation in a phospholipid monolayer

Knecht

Müller

Bonn

et al. 2004

The Journal of Chemical Physics

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show abstract

“…The alveoli are covered with a thin film of lung surfactant that reduces the surface tension in the lung, which results in decreased work of breathing thus to confirm uniform lung inflation (Zasadzinski et al, 2001) Since Surfactant replacement therapy has been introduced in 1980s, it has proven its effect in premature infants with surfactant deficiency (Mazela et al, 2006). Several Randomized control trials (RCT) has proven the effectiveness of Surfactant replacement therapy in lung diseases such as Meconium aspiration syndrome (MAS) neonatal pneumonia, Acute respiratory distress syndrome (ARDS) and Acute lung injury (ALI) (Robertson and Halliday, 1998).…”

Section: Introductionmentioning

confidence: 99%