Dilatational properties and morphology of surface films spread from clinically used lung surfactants

Ivanova, Tz.; Minkov, I.; Panaı̈otov, I.; Saulnier, Patrick; Proust, J. E.

doi:10.1007/s00396-004-1073-8

Cited by 20 publications

(14 citation statements)

References 20 publications

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“…The appearance of the plateau region in the 40-50 mN/m range is controversially discussed. Some authors pointed this plateau region as the film collapse [47,48]. However, other authors report a first plateau region within this pressure range and describe it as the transition of monolayer-to-multilayers [9,49].…”

Section: Comparison Of Compression Isothermsmentioning

confidence: 99%

Interplay of mycolic acids, antimycobacterial compounds and pulmonary surfactant membrane: A biophysical approach to disease

Pinheiro

Giner‐Casares

Lúcio

et al. 2013

Biochimica et Biophysica Acta (BBA) - Biomembranes

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This work focuses on the interaction of mycolic acids (MAs) and two antimycobacterial compounds (Rifabutin and N'-acetyl-Rifabutin) at the pulmonary membrane level to convey a biophysical perspective of their role in disease. For this purpose, accurate biophysical techniques (Langmuir isotherms, Brewster angle microscopy, and polarization-modulation infrared reflection spectroscopy) and lipid model systems were used to mimic biomembranes: MAs mimic bacterial lipids of the Mycobacterium tuberculosis (MTb) membrane, whereas Curosurf® was used as the human pulmonary surfactant (PS) membrane model. The results obtained show that high quantities of MAs are responsible for significant changes on PS biophysical properties. At the dynamic inspiratory surface tension, high amounts of MAs decrease the order of the lipid monolayer, which appears to be a concentration dependent effect. These results suggest that the amount of MAs might play a critical role in the initial access of the bacteria to their targets. Both molecules also interact with the PS monolayer at the dynamic inspiratory surface. However, in the presence of higher amounts of MAs, both compounds improve the phospholipid packing and, therefore, the order of the lipid surfactant monolayer. In summary, this work discloses the putative protective effects of antimycobacterial compounds against the MAs induced biophysical impairment of PS lipid monolayers. These protective effects are most of the times overlooked, but can constitute an additional therapeutic value in the treatment of pulmonary tuberculosis (Tb) and may provide significant insights for the design of new and more efficient anti-Tb drugs based on their behavior as membrane ordering agents.

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Section: Comparison Of Compression Isothermsmentioning

confidence: 99%

Interplay of mycolic acids, antimycobacterial compounds and pulmonary surfactant membrane: A biophysical approach to disease

Pinheiro

Giner‐Casares

Lúcio

et al. 2013

Biochimica et Biophysica Acta (BBA) - Biomembranes

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“…Some studies have analyzed to what extent clinical surfactants do capture this structural hallmark of native surfactant and how much the existence of membrane phase segregation could be also associated with proper functional properties [17][18][19]. In the same line, a recent study has compared in detail the structure of films formed by different clinical surfactants, as seen under atomic force microscopy (AFM) [20].…”

Section: Introductionmentioning

confidence: 99%

Interfacial behavior and structural properties of a clinical lung surfactant from porcine source

Blanco

Cruz

Ospina

et al. 2012

Biochimica et Biophysica Acta (BBA) - Biomembranes

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Surfacen® is a clinical surfactant preparation of porcine origin, partly depleted of cholesterol, which is widely used in Cuba to treat pre-term babies at risk or already suffering neonatal respiratory distress. In the present study we have characterized the interfacial behavior of Surfacen in several in vitro functional models, including spreading and compression-expansion cycling isotherms in surface balances and in a captive bubble surfactometer, in comparison with the functional properties of whole native surfactant purified from porcine lungs and its reconstituted organic extract, the material from which Surfacen is derived. Surfacen exhibited similar properties to native porcine surfactant or its organic extract to efficiently form stable surface active films at the air-liquid interface, able to consistently reach surface tensions below 5mN/m upon repetitive compression-expansion cycling. Surfacen films, however, showed a substantially larger and stable compression-driven segregation of condensed lipid phases than exhibited by films formed by native surfactant or its organic extract. In spite of structural differences observed at microscopic level, Surfacen membranes showed a similar thermotropic behavior to membranes from native surfactant or its organic extract, characterized by calorimetry or fluorescence spectroscopy of samples doped with the Laurdan probe. On the other hand, analysis by atomic force microscopy of films formed by Surfacen or by the organic extract of native porcine surfactant revealed a similar network of interconnected condensed nanostructures, suggesting that the organization of the films at the submicroscopic level is the essential feature to support the proper stability and mechanical properties permitting the interfacial surfactant films to facilitate the work of breathing.

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“…3,4 Moreover, some enzymatic processes occurring at the membrane level depend on the lipid/protein film surface packing and elasticity.…”

Section: Introductionmentioning

confidence: 99%

Adsorption kinetics and dilatational rheological studies for the soluble and anchored forms of alkaline phosphatase at the air/water interface

Caseli¹,

Masui²,

Furriel³

et al. 2005

J. Braz. Chem. Soc.

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Este trabalho apresenta aspectos de equilíbrio e dinâmicos da adsorção na interface ar/líquido de duas formas de fosfatase alcalina de placa óssea de ratos: DSAP, solubilizada com tensoativo não-iônico (C 12 E 9 ), contendo uma âncora de glicosilfosfatidilinositol (GPI), e PLSAP, com a porção hidrofóbica da âncora clivada por fosfolipase-C. A tensão superficial dinâmica, γ dyn , e o módulo de elasticidade superficial dilatacional, ε, foram determinados para soluções de PLSAP, DSAP e C 12 E 9 pelo método de oscilação harmônica e análise do formato da gota eixo-simétrica. Cinéticas de adsorção revelaram que DSAP adsorve trinta vezes mais rapidamente que PLSAP, apresentando um mínimo, e, para PLSAP, a tensão superficial cai continuamente. Para o sistema DSAP/C 12 E 9 , ε atinge um máximo na concentração crítica de agregação (CAC), mas para PLSAP, ε diminui continuamente com a concentração. Soluções de C 12 E 9 apresentam ε mais elevados, decrescentes com a concentração. Um modelo, baseado na influência da âncora GPI, é proposto para explicar os resultados obtidos.This work presents equilibrium and dynamic aspects for the adsorption at the air/liquid interface of two rat osseous plate alkaline phosphatase forms: DSAP, solubilized by a surfactant, C 12 E 9 , and containing a glycosylphosphatidylinositol (GPI) anchor; and PLSAP, resulting from phospholipase-C cleavage of the hydrophobic portion of the GPI anchor. Dynamic surface tension, γ dyn , and surface elasticity modulus, ε, were determined for PLSAP, DSAP and pure C 12 E 9 solutions using harmonic oscillation and axisymmetric drop shape analysis Adsorption kinetics studies revealed that DSAP adsorbs thirty times faster than PLSAP, presenting a minimum in the curve. For DSAP/ C 12 E 9 mixed system, ε increases with concentration and a maximum appears at the critical aggregation concentration (CAC). For PLSAP, a continuous decreasing with concentration for γ dyn and ε was observed. For pure C 12 E 9 solution , the elasticity modulus increases with concentration and ε values are higher when compared to the mixed system. A model based on the influence of the GPI anchor is proposed.Keywords: dynamic surface tension, adsorption kinetics, dilatational surface elasticity, alkaline phosphatase, axisymmetric drop shape analysis IntroductionSurface elasticity is associated with the ability of a system to establish a new surface tension value due to a timely area variation. Considering that it is a nonequilibrium phenomenon, changes in surface tension occur either as a consequence of a sudden compression/ expansion of the interface, or due to a local concentration variation. Since elasticity values are associated with diffusion processes, adsorption/desorption, as well as the rearrangement of molecules at the interface, they depend on the time scale (or frequency) in which the perturbation is applied. In addition, these processes are influenced by molecular weight, shape and molecular interactions of the species present at the interface.Surface elasticity is directly relate...

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Dilatational properties and morphology of surface films spread from clinically used lung surfactants

Cited by 20 publications

References 20 publications

Interplay of mycolic acids, antimycobacterial compounds and pulmonary surfactant membrane: A biophysical approach to disease

Interplay of mycolic acids, antimycobacterial compounds and pulmonary surfactant membrane: A biophysical approach to disease

Interfacial behavior and structural properties of a clinical lung surfactant from porcine source

Adsorption kinetics and dilatational rheological studies for the soluble and anchored forms of alkaline phosphatase at the air/water interface

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