Application of axisymmetric drop shape analysis and brewster angle microscopy for assessment of clinical samples from prematurely born infants with NRDS

Bangyozova, Maya; Jordanova, A.; Tsanova, Asya; Stoyanova, Vishnya; Tasheva‐Terzieva, Elena; Ivanova, Krasimira; Todorov, R.; Hristova, Emilia; Lalchev, Zdravko

doi:10.1016/j.colsurfa.2016.05.062

Cited by 3 publications

(5 citation statements)

References 34 publications

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“…Our results compared by ANOVA test showed no statistically significant difference ( p > 0.05) between γ eq values of GA samples from the three groups studied: mean γ eq varied from 36.5 ± 5.6 mN/m for NRDS group to 39.1 ± 7.0 mN/m for the CST group (Table 1, Figure 1). These findings confirmed our previous data that the equilibrium surface tension was not a reliable parameter for lung maturity assessment, since in vivo the mechanism of the alveolar function was not performed in static conditions [22].…”

Section: Resultssupporting

confidence: 91%

“…Babies with NRDS were diagnosed by the following criteria: gestational age of 29 ± 3; body weight of 1050 ± 226 g; SatO2 <90%; positive Silverman test; abnormal X-chest radiography; unstable biochemical parameters. For collection of GA gastric tube was used immediately after delivery as previously described [22]. For all experiments an informed consent was obtained from all parents for each sample collected.…”

Section: Methodsmentioning

confidence: 99%

“…By an intergrated camera series of pictures were taken. An equilibrium value of the surface tension, γ equilibrium (γ eq , mN/m) in static conditions, as well as maximal surface tension (γ max , mN/m) at 100% drop surface (corresponding to 30 mm 2 drop surface area) and minimal surface tension (γ min , mN/m) at 20% drop surface (corresponding to 5 mm 2 drop surface area) were measured after 10-fold volume compression and decompression of the GA drop as previously described [22].…”

Section: Methodsmentioning

confidence: 99%

“…Insoluble GA monolayers were formed in a Langmuir trough by spreading 5 μl of GA samples over the subphase of 0.15 M NaCl. After 10 min (for reaching an equilibrium surface tension, hence adsorption of surface active molecules) BAM images were recorded by using Accurion Nanofilm Ultrabam (Accurion GmbH, Goettingen, Germany) as previously described [22].…”

Section: Methodsmentioning

confidence: 99%

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Rapid biophysical analyses of gastric aspirates from risk newborns for lung maturity assessment after corticosteroid therapy

Tsanova

Jordanova

Stoyanova

et al. 2019

Heliyon

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BackgroundOne of the main causes for the higher mortality among risk newborn children (including preterm infants) is neonatal respiratory distress syndrome (NRDS), which develops as a result of primary deficiency or secondary inactivation of alveolar surfactant (AS). Therefore, fast and early diagnostics of risk newborns lung maturity is crucial for their prompt therapy.Materials and methodsGastric aspirates (GA) were collected from 77 infants divided into three groups: a control of 38 healthy full-term infants; 16 prematurely newborns with NRDS, and 23 prematurely born infants after in vitro fertilization and corticosteroid therapy (CST). Surface parameters: equilibrium (γeq), maximal (γmax) and minimal (γmin) surface tension, and the shape of hysteresis curves of GA monolayers were measured by axisymmetric drop shape analysis (ADSA) of a pending drop. In addition, the morphology of GA monolayers was studied by Brewster angle microscopy (BAM).ResultsOur results showed that only γmin values were reliable and were significantly lower in full-term infants, as compared to the risk neonates. The results obtained were proved by the shape of hysteresis curves of GA surface active films. BAM images of GA monolayers from NRDS group showed impaired surface morphology due to the surfactant insufficiency, as compared to the control group. Corticosteroid therapy improved both GA surface characteristics and monolayer morphology.ConclusionsGAs analyses by ADSA and BAM are fast and informative approaches for lung maturity assessment. In addition, the corticosteroid therapy applied improved all GAs surface parameters due to AS maturation.

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Section: Resultssupporting

confidence: 91%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Rapid biophysical analyses of gastric aspirates from risk newborns for lung maturity assessment after corticosteroid therapy

Tsanova

Jordanova

Stoyanova

et al. 2019

Heliyon

Self Cite

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show abstract

“…The method is combined with the constrained sessile drop (CSD) test (Saad et al, 2010(Saad et al, , 2012 and it is also used for the pendant drop (PD) test by circular approximation of the droplet profile (Saad et al, 2011). Recently, Bangyozova et al (2017) employ the Brewster angle microscopy (BAM) and ADSA technique for the assessment of healthy and diseased pulmonary surfactants. For thin films, alternative approaches like the pressure balance technique can be used to directly measure the surface forces in terms of the disjoining pressure (e.g.…”

Section: Experimental Methodsmentioning

confidence: 99%

A finite membrane element formulation for surfactants

Roohbakhshan

Sauer

2019

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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Surfactants play an important role in various physiological and biomechanical applications. An example is the respiratory system, where pulmonary surfactants facilitate the breathing and reduce the possibility of airway blocking by lowering the surface tension when the lung volume decreases during exhalation. This function is due to the dynamic surface tension of pulmonary surfactants, which depends on the concentration of surfactants spread on the liquid layer lining the interior surface of the airways and alveoli. Here, a finite membrane element formulation for liquids is introduced that allows for the dynamics of concentration-dependent surface tension, as is the particular case for pulmonary surfactants. A straightforward approach is suggested to model the contact line between liquid drops/menisci and planar solid substrates, which allows the presented framework to be easily used for drop shape analysis. It is further shown how line tension can be taken into account. Following an isogeometric approach, NURBSbased finite elements are used for the discretization of the membrane surface. The capabilities of the presented computational model is demonstrated by different numerical examples -such as the simulation of liquid films, constrained and unconstrained sessile drops, pendant drops and liquid bridges -and the results are compared with experimental data.

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