Sample records for human surfactant protein-asp-a

  1. Micelles of pulmonary surfactant in human amniotic fluid at term


    Nishijima, Koji; SHUKUNAMI, Ken-ichi; Tsukahara, Hirokazu; ORISAKA, Makoto; Miura, Junichiro; KOTSUJI, Fumikazu


    Studies using in vitro analysis have shown that the interaction between pulmonary surfactant and vemix caseosa could explain the appearance of amniotic fluid turbidity. That phenomenon is interpreted based on the "roll-up" hypothesis. We tested the roll-up hypothesis by examining the presence of micelles of pulmonary surfactant in human amniotic fluid at term. Amniotic fluid samples were collected from each of six healthy pregnant women at term and at 16 wk of gestation. These samples were st...

  2. Surfactant enhanced disinfection of the human norovirus surrogate, tulane virus with organic acids and surfactant (United States)

    Human infection with foodborne viruses can occur following consumption of contaminated food, person-to-person body contact, or release of aerosols. Combinatorial treatments of surfactants and organic acids may have synergistic or additive mechanisms to inactivate foodborne viruses and prevent outbr...

  3. Micelles of pulmonary surfactant in human amniotic fluid at term. (United States)

    Nishijima, Koji; Shukunami, Ken-Ichi; Tsukahara, Hirokazu; Orisaka, Makoto; Miura, Jun'Ichiro; Kotsuji, Fumikazu


    Studies using in vitro analysis have shown that the interaction between pulmonary surfactant and vernix caseosa could explain the appearance of amniotic fluid turbidity. That phenomenon is interpreted based on the "roll-up" hypothesis. We tested the roll-up hypothesis by examining the presence of micelles of pulmonary surfactant in human amniotic fluid at term. Amniotic fluid samples were collected from each of six healthy pregnant women at term and at 16 wk of gestation. These samples were stained negatively and analyzed using an electron microscope. Ultrastructures present in amniotic fluid were compared with the structure of micelles derived from suspended surfactant TA isolated from bovine lung. Surfactant TA formed spheroidal and rod-shaped micelles 10-70 nm in diameter above the critical micelle concentration. Identical micelle particles were described in human amniotic fluid at term. In addition, surfactant protein B was identified in the micelle fraction of amniotic fluid. However, no micelles were found in human amniotic fluid taken at 16 wk of gestation. Our results support the view that pulmonary surfactant could induce the detachment of vernix caseosa and increase the turbidity of the amniotic fluid.

  4. Structural characterisation of human proteinosis surfactant protein A

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    Leth-Larsen, Rikke; Holmskov, U; Højrup, P


    Human surfactant protein-A (SP-A) has been purified from a proteinosis patient and characterised by a combination of automated Edman degradation and mass spectrometry. The complete protein sequence was characterised. The major part of SP-A was shown to consist of SP-A2 gene product, and only...... a small amount of SP-A1 gene product was shown to be present. A cysteine extension to the N-terminal was indicated by sequence data, but was not definitely proven. All proline residues in the Y position of Gly-X-Y in the collagen-like region were at least partially modified to hydroxy...... domain were identified to be in the 1-4, 2-3 pattern common for collectins. Interchain disulfide bridges were discovered between two Cys-48 residues and cysteine residues in the N-terminal region. However, the exact disulfide bridge connections within the bouquet-like ultrastructure could...

  5. Surfactant-enhanced disinfection of the human norovirus surrogate, Tulane virus, with organic acids and surfactant (United States)

    Combination treatments of surfactants and phenolic or short-chained organic acids (SCOA) may act synergistically or additively as sanitizers to inactive foodborne viruses and prevent outbreaks. The purpose of this study was to investigate the effect of gallic acid (GA), tannic acid (TA), p-coumaric ...

  6. Surfactant-induced dermatitis: comparison of corneosurfametry with predictive testing on human and reconstructed skin. (United States)

    Piérard, G E; Goffin, V; Hermanns-Lê, T; Arrese, J E; Piérard-Franchimont, C


    Surfactants elicit alterations in the stratum corneum. Predictive tests that avoid animal experimentation are needed. This study compares three methods of rating and predicting shampoo-induced irritation. Corneosurfametry entails collection of stratum corneum followed by brief contact with diluted surfactants and measurement of variations in staining of samples. Corneosurfametry appears to correlate well with in vivo testing in volunteers with sensitive skin. However, corneosurfametry presents less interindividual variability than in vivo testing and allows better discrimination among mild products. Morphologic information about surfactant-induced loosening of corneocytes may be increased by testing surfactants on human skin equivalent. Results are similar to those provided by specimens used for corneosurfametry. The corneosurfametric prediction of surfactant irritancy correlates with in vivo testing and with in vitro evaluation on human skin equivalent.

  7. Interaction of biocompatible natural rosin-based surfactants with human serum albumin: A biophysical study

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    Ishtikhar, Mohd [Protein Biophysics Laboratory, Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002 (India); Ali, Mohd Sajid [Surfactant Research Chair, Department of Chemistry, King Saud University, P.O. Box-2455, Riyadh 11451 (Saudi Arabia); Atta, Ayman M. [Surfactant Research Chair, Department of Chemistry, King Saud University, P.O. Box-2455, Riyadh 11451 (Saudi Arabia); Petroleum Application department, Egyptian Petroleum Research Institute, Ahmad Elzomor St., Nasr city, Cairo-11727 (Egypt); Al-Lohedan, H.A. [Surfactant Research Chair, Department of Chemistry, King Saud University, P.O. Box-2455, Riyadh 11451 (Saudi Arabia); Nigam, Lokesh; Subbarao, Naidu [Centre for Computational Biology and Bioinformatics, School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi 110067 (India); Hasan Khan, Rizwan, E-mail: [Protein Biophysics Laboratory, Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002 (India)


    Biophysical insight into interaction of biocompatible rosin-based surfactants with human serum albumin (HSA) was studied at physiological conditions using various spectroscopic, calorimetric and molecular docking approaches. The binding constant (K{sub b}), enthalpy (ΔH{sup 0}), entropy (ΔS{sup 0}) and Gibbs free energy change (ΔG{sup 0}) were calculated by spectroscopic and calorimetric method. We have also calculated the probability of energy transfer by FRET analysis. The circular dichroism study showed that the cationic surfactant QRMAE significantly altered the secondary structure of HSA as compared to the nonionic rosin surfactants. The thermodynamic study was performed by ITC to determine binding constant as well as change in enthalpy of HSA in presence of rosin surfactants. It clearly showed that hydrogen binding and hydrophobic interaction play an important role in the binding of HSA to rosin surfactants. We have also performed molecular docking studies to locate the binding site on HSA and to visualize the mode of interaction. The present study provides a significant insight into HSA–rosin surfactants interaction, which also improves our understanding of the possible effect of rosin surfactants on human health. - Highlights: • RMPEG 750 has the highest Kb, Kq and Ksv value as compared to other rosin surfactants. • The probability of energy transfer from HSA to rosin surfactants was maximum in the case of RMPEG 750. • Cationic surfactant QRMAE significantly altered the secondary structure of the HSA as compared to other rosin surfactants. • Molecular docking and ITC experiment studies, to locate the binding site on HSA and to investigate the mode of interaction.

  8. Surfactant maturation is not delayed in human fetuses with diaphragmatic hernia.

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    Olivier Boucherat


    Full Text Available BACKGROUND: Pulmonary hypoplasia and persistent pulmonary hypertension account for significant mortality and morbidity in neonates with congenital diaphragmatic hernia (CDH. Global lung immaturity and studies in animal models suggest the presence of surfactant deficiency that may further complicate the pathophysiology of CDH. However, data about surfactant status in human fetuses with CDH at birth are contradictory. The lack of a chronological study of surfactant content in late pregnancy has been a significant limitation. The appropriateness of administering surfactant supplements to neonates with CDH is therefore a debated question. METHODS AND FINDINGS: We investigated surfactant content in human fetuses with CDH compared to age-matched fetuses with nonpulmonary diseases used as controls. Concentrations of disaturated phosphatidylcholine and surfactant proteins were found to be similar at a given stage of pregnancy, with both components showing a similar pattern of increase with progressing pregnancy in fetuses with CDH and in control fetuses. Thyroid transcription factor 1, a critical regulator of surfactant protein transcription, similarly displayed no difference in abundance. Finally, we examined the expression of three glucocorticoid-regulated diffusible mediators involved in lung epithelial maturation, namely: keratinocyte growth factor (KGF, leptin, and neuregulin 1 beta 1 (NRG1-beta1. KGF expression decreased slightly with time in control fetuses, but remained unchanged in fetuses with CDH. Leptin and NRG1-beta1 similarly increased in late pregnancy in control and CDH lungs. These maturation factors were also determined in the sheep fetus with surgical diaphragmatic hernia, in which surfactant deficiency has been reported previously. In contrast to the findings in humans, surgical diaphragmatic hernia in the sheep fetus was associated with decreased KGF and neuregulin expression. Fetoscopic endoluminal tracheal occlusion performed in

  9. Human Pulmonary Surfactant Protein SP-A1 Provides Maximal Efficiency of Lung Interfacial Films. (United States)

    Lopez-Rodriguez, Elena; Pascual, Alicia; Arroyo, Raquel; Floros, Joanna; Perez-Gil, Jesus


    Pulmonary surfactant is a lipoprotein complex that reduces surface tension to prevent alveolar collapse and contributes to the protection of the respiratory surface from the entry of pathogens. Surfactant protein A (SP-A) is a hydrophilic glycoprotein of the collectin family, and its main function is related to host defense. However, previous studies have shown that SP-A also aids in the formation and biophysical properties of pulmonary surfactant films at the air-water interface. Humans, unlike rodents, have two genes, SFTPA1 and SFTPA2. The encoded proteins, SP-A1 and SP-A2, differ quantitatively or qualitatively in function. It has been shown that both gene products are necessary for tubular myelin formation, an extracellular structural form of lung surfactant. The goal of this study was to investigate potential differences in the biophysical properties of surfactants containing human SP-A1, SP-A2, or both. For this purpose, we have studied for the first time, to our knowledge, the biophysical properties of pulmonary surfactant from individual humanized transgenic mice expressing human SP-A1, SP-A2, or both SP-A1 and SP-A2, in the captive bubble surfactometer. We observed that pulmonary surfactant containing SP-A1 reaches lower surface tension after postexpansion interfacial adsorption than surfactants containing no SP-A or only SP-A2. Under interfacial compression-expansion cycling conditions, surfactant films containing SP-A1 also performed better, particularly with respect to the reorganization of the films that takes place during compression. On the other hand, addition of recombinant SP-A1 to a surfactant preparation reconstituted from the hydrophobic fraction of a porcine surfactant made it more resistant to inhibition by serum than the addition of equivalent amounts of SP-A2. We conclude that the presence of SP-A1 allows pulmonary surfactant to adopt a particularly favorable structure with optimal biophysical properties. Copyright © 2016 Biophysical

  10. Cumulative effect of surfactants on cutaneous horny layers: adsorption onto human keratin layers in vivo. (United States)

    Imokawa, G; Mishima, Y


    An attempt has been made to determine the adsorption ability of surfactants by the human horny layers in vivo. For this purpose, a technique utilizing an acidic dye such as indigo carmine was applicable and convenient. Our in vivo study estimating adsorbing residual amounts of surfactants has revealed that there is a positive correlation between adsorbing and roughening effects. It is suggested that the pathogenesis of hand roughness is primarily related to the cumulative injury of the stratum corenum by adsorbing residual surfactant molecules.

  11. Pulmonary surfactant mitigates silver nanoparticle toxicity in human alveolar type-I-like epithelial cells. (United States)

    Sweeney, Sinbad; Leo, Bey Fen; Chen, Shu; Abraham-Thomas, Nisha; Thorley, Andrew J; Gow, Andrew; Schwander, Stephan; Zhang, Junfeng Jim; Shaffer, Milo S P; Chung, Kian Fan; Ryan, Mary P; Porter, Alexandra E; Tetley, Teresa D


    Accompanying increased commercial applications and production of silver nanomaterials is an increased probability of human exposure, with inhalation a key route. Nanomaterials that deposit in the pulmonary alveolar region following inhalation will interact firstly with pulmonary surfactant before they interact with the alveolar epithelium. It is therefore critical to understand the effects of human pulmonary surfactant when evaluating the inhalation toxicity of silver nanoparticles. In this study, we evaluated the toxicity of AgNPs on human alveolar type-I-like epithelial (TT1) cells in the absence and presence of Curosurf(®) (a natural pulmonary surfactant substitute), hypothesising that the pulmonary surfactant would act to modify toxicity. We demonstrated that 20nm citrate-capped AgNPs induce toxicity in human alveolar type I-like epithelial cells and, in agreement with our hypothesis, that pulmonary surfactant acts to mitigate this toxicity, possibly through reducing AgNP dissolution into cytotoxic Ag(+) ions. For example, IL-6 and IL-8 release by TT1 cells significantly increased 10.7- and 35-fold, respectively (Pion release and lysosomal disruption, but not with increased reactive oxygen species generation. This study provides a critical understanding of the toxicity of AgNPs in target human alveolar type-I-like epithelial cells and the role of pulmonary surfactant in mitigating this toxicity. The observations reported have important implications for the manufacture and application of AgNPs, in particular for applications involving use of aerosolised AgNPs. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Pulmonary haptoglobin (pHp) is part of the surfactant system in the human lung. (United States)

    Abdullah, Mahdi; Goldmann, Torsten


    Since the existence of pHp was demonstrated, it has been shown that this molecule and its receptor CD163 are regulated by different stimuli. Furthermore, a comparably fast secretion of pHp was described as well as the immuno-stimulatory effects. The intention of this study was to elucidate the role of pHp in the human lungs further. Here we show, by means of confocal microscopy and immune-electron-microscopy, a clear co-localization of pHp with surfactant protein-B in lamellar bodies of alveolar epithelial cells type II. These results are underlined by immunohistochemical stainings in differently fixed human lung tissues, which show pHp in vesicular and released form. The images of the released form resemble the intended position of surfactant in the human alveolus. pHp is secreted by Alveolar epithelial cells type II as previously shown. Moreover, pHp is co-localized with Surfactant protein-B. We conclude that the presented data shows that pHp is a native part of the surfactant system in the human lung.

  13. In Vitro Cytotoxicity and Phototoxicity Assessment of Acylglutamate Surfactants Using a Human Keratinocyte Cell Line

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    Abhay Kyadarkunte


    Full Text Available In the current study, human keratinocyte cell line was used as in vitro cell culture model to elucidate the effects of the fatty acid chain length of acylglutamate (amino acid-based surfactant namely, sodium cocoyl glutamate, sodium lauroyl glutamate, and sodium myristoyl glutamate on their cytotoxicity and the ultraviolet B induced phototoxicity. The endpoint used to assess toxicity was a tetrazolium-based assay whereas, the phototoxic potential of acylglutamate surfactants was predicted using two models namely, the Photo-Irritation Factor and Mean Photo Effect. The results of this study showed that the fatty acid chain length of acylglutamate greatly influences toxic effects on human keratinocyte cells. In addition, all the acylglutamate surfactants tested on human keratinocyte cells demonstrated significantly less cytotoxicity (when irradiated and non-irradiated with ultraviolet B light; p < 0.05 and no phototoxic potential was observed in any of the acylglutamate surfactants, when compared with the positive control chlorpromazine. In conclusion, the in vitro studies confirm the suitability of sodium lauroyl glutamate destined for the synthesis and stabilization of lipid nanoparticles.

  14. Disaturated-phosphatidylcholine and surfactant protein-B turnover in human acute lung injury and in control patients. (United States)

    Simonato, Manuela; Baritussio, Aldo; Ori, Carlo; Vedovelli, Luca; Rossi, Sandra; Dalla Massara, Lorenza; Rizzi, Sabina; Carnielli, Virgilio P; Cogo, Paola E


    Patients with adult respiratory distress syndrome (ARDS) and acute lung injury (ALI) have low concentrations of disaturated-phosphatidylcholine and surfactant protein-B in bronchoalveolar lavage fluid. No information is available on their turnover. To analyze disaturated-phosphatidylcholine and surfactant protein-B turnover in patients with ARDS/ALI and in human adults with normal lungs (controls). 2H2O as precursor of disaturated-phosphatidylcholine-palmitate and 113C-Leucine as precursor of surfactant protein-B were administered intravenously to 12 patients with ARDS/ALI and to 8 controls. Disaturated-phosphatidylcholine and surfactant protein-B were isolated from serial tracheal aspirates, and their fractional synthetic rate was derived from the 2H and 13C enrichment curves, obtained by gas chromatography mass spectrometry. Disaturated-phosphatidylcholine, surfactant protein-B, and protein concentrations in tracheal aspirates were also measured. 1) Surfactant protein-B turned over at faster rate than disaturated-phosphatidylcholine both in ARDS/ALI patients and in controls. 2) In patients with ARDS/ALI the fractional synthesis rate of disaturated-phosphatidylcholine was 3.1 times higher than in controls (p phosphatidylcholine and surfactant protein-B in tracheal aspirates were markedly and significantly reduced (17% and 40% of the control values respectively). 1) Disaturated-phosphatidylcholine and surfactant protein-B have a different turnover both in healthy and diseased lungs. 2) In ARDS/ALI the synthesis of these two surfactant components may be differently regulated.

  15. Effects of the human pulmonary surfactant protein-C (SP-C), SP-CL16(6-28) on surface activities of surfactants with various phospholipids. (United States)

    Otsubo, Eiji; Takei, Tsunetomo


    We previously reported that a human analogue of pulmonary surfactant protein-C (SP-C), SP-CL16(6-28), with 23 residues was the most active analogue in a reconstituted lipid mixture and had the shortest chain among the poly-leucine-analogues examined. There has been little research on the chemical components of synthetic lung surfactants (SLSs). In the present study, we attempted to compare SLS with various phospholipids in surface activity. That is, SP-CL16(6-28) plus various phosphatidylglycerols (PG) were tested for surface activity in a Langmuir-Wilhelmy surface balance (WSB) apparatus and pulsating bubble surfactmeter (PBS). Further, SLSs were examined for biological properties using an animal model of surfactant deficiency, infant respiratory distress syndrome (IRDS), in vivo. Palmitoyl-oleoyl-phosphatidylglycerol (POPG)-SLS exhibited minimum and maximum surface tensions of 1.7 mN/m and 28.6 mN/m in WSB and 8.5 mN/m and 36.2 mN/m in PBS, respectively. Moreover, in the IRDS model, POPG-SLS remarkably improved the lung volume (LV) of a premature lagomorph fetus at LV30 cmH2O and LV5 cmH2O. That is, a significant improvement equal to the LV of a full-term fetus was observed. The level of LV exhibited respiratory improvement equivalent to surfactant-TA. SLS seemed comparable in surface activity with Surfacten (Surfactant-TA), a modified surfactant preparation which has been used for the treatment of RDS.

  16. Disaturated-phosphatidylcholine and Surfactant protein-B turnover in human acute lung injury and in control patients

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    Rizzi Sabina


    Full Text Available Abstract Background Patients with Adult Respiratory Distress Syndrome (ARDS and Acute Lung Injury (ALI have low concentrations of disaturated-phosphatidylcholine and surfactant protein-B in bronchoalveolar lavage fluid. No information is available on their turnover. Objectives To analyze disaturated-phosphatidylcholine and surfactant protein-B turnover in patients with ARDS/ALI and in human adults with normal lungs (controls. Methods 2H2O as precursor of disaturated-phosphatidylcholine-palmitate and 113C-Leucine as precursor of surfactant protein-B were administered intravenously to 12 patients with ARDS/ALI and to 8 controls. Disaturated-phosphatidylcholine and surfactant protein-B were isolated from serial tracheal aspirates, and their fractional synthetic rate was derived from the 2H and 13C enrichment curves, obtained by gas chromatography mass spectrometry. Disaturated-phosphatidylcholine, surfactant protein-B, and protein concentrations in tracheal aspirates were also measured. Results 1 Surfactant protein-B turned over at faster rate than disaturated-phosphatidylcholine both in ARDS/ALI patients and in controls. 2 In patients with ARDS/ALI the fractional synthesis rate of disaturated-phosphatidylcholine was 3.1 times higher than in controls (p Conclusions 1 Disaturated-phosphatidylcholine and surfactant protein-B have a different turnover both in healthy and diseased lungs. 2 In ARDS/ALI the synthesis of these two surfactant components may be differently regulated.

  17. Surfactants enhance the tight-junction permeability of food allergens in human intestinal epithelial Caco-2 cells. (United States)

    Mine, Yoshinori; Zhang, Jie Wie


    Food additives are responsible for certain allergic types of symptoms. Here Caco-2 cell monolayers were used as a model of the intestinal epithelium for the study of the effect of a food grade surfactant. We determined whether or not the presence of a surfactant enhances the transportation of food allergens across human intestinal epithelial Caco-2 cells. This study investigated sucrose monoester fatty acids, which are a food grade surfactant. As an in vitro model of human epithelial cells, Caco-2 cells were grown in monolayers and exposed to different doses of the surfactant in conjunction with ovomucoid, a major egg white allergen. The integrity of the monolayer was assessed by measuring transepithelial electrical resistance (TEER). The permeability of tight junctions and transport of the antigen were studied. TEER correlated with the permeability of tight junctions. TEER significantly decreased upon exposure to a surfactant, indicating an increase in ovomucoid permeability without degradation. The surfactant induced shortening in microvilli, actin disbandment and structural separation of tight junctions. The results indicate that food grade surfactants can increase the paracellular uptake of food allergens. Copyright 2003 S. Karger AG, Basel

  18. Stabilization of human papillomavirus virus-like particles by non-ionic surfactants. (United States)

    Shi, Li; Sanyal, Gautam; Ni, Alex; Luo, Zheng; Doshna, Sarah; Wang, Bei; Graham, Tammy L; Wang, Ning; Volkin, David B


    Human papillomavirus (HPV) virus-like-particles (VLPs) produced by recombinant expression systems are promising vaccine candidates for prevention of cervical cancers as well as genital warts. At high protein concentrations, HPV VLPs, comprised of the viral capsid protein L1 and expressed and purified from yeast, are protected against detectable aggregation during preparation and storage by high concentrations of NaCl. At low protein concentrations, however, high salt concentration alone does not fully protect HPV VLPs from aggregation. Moreover, the analytical analysis of HPV VLPs proved to be a challenge due to surface adsorption of HPV VLPs to storage containers and cuvettes. The introduction of non-ionic surfactants into HPV VLP aqueous solutions provides significantly enhanced stabilization of HPV VLPs against aggregation upon exposure to low salt and protein concentration, as well as protection against surface adsorption and aggregation due to heat stress and physical agitation. The mechanism of non-ionic surfactant stabilization of HPV VLPs was extensively studied using polysorbate 80 (PS80) as a representative non-ionic surfactant. The results suggest that PS80 stabilizes HPV VLPs mainly by competing with the VLPs for various container surfaces and air/water interfaces. No appreciable binding of PS80 to intact HPV VLPs was observed although PS80 does bind to the denatured HPV L1 protein. Even in the presence of stabilizing level of PS80, however, an ionic strength dependence of HPV VLP stabilization against aggregation is observed indicating optimization of both salt and non-ionic surfactant levels is required for effective stabilization of HPV VLPs in solution. (c) 2005 Wiley-Liss, Inc.

  19. Innate Defense against Influenza A Virus: Activity of Human Neutrophil Defensins and Interactions of Defensins with Surfactant Protein D

    DEFF Research Database (Denmark)

    Hartshorn, Kevan L.; White, Mitchell R.; Tecle, Tesfaldet


    Surfactant protein D (SP-D) plays important roles in innate host defense against influenza A virus (IAV) infection, in part by modifying interactions with neutrophils. Human neutrophil defensins (HNPs) inhibit infectivity of enveloped viruses, including IAV. Our goal in this study...

  20. A human surfactant peptide-elastase inhibitor construct as a treatment for emphysema. (United States)

    Guarnieri, Frank; Spencer, Jean L; Lucey, Edgar C; Nugent, Matthew A; Stone, Phillip J


    Two million Americans suffer from pulmonary emphysema, costing $2.5 billion/year and contributing to 100,000 deaths/year. Emphysema is thought to result from an imbalance between elastase and endogenous inhibitors of elastase, leading to tissue destruction and a loss of alveoli. Decades of research have still not resulted in an effective treatment other than stopping cigarette smoking, a highly addictive behavior. On the basis of our previous work, we hypothesize that small molecule inhibitors of human neutrophil elastase are ineffective because of rapid clearance from the lungs. To develop a long-acting elastase inhibitor with a lung pharmacodynamic profile that has minimal immunogenicity, we covalently linked an elastase inhibitor, similar to a trifluoro inhibitor that was used in clinical trials, to a 25-amino-acid fragment of human surfactant peptide B. We used this construct to prevent human neutrophil elastase-induced emphysema in a rodent model. The elastase inhibitor alone, although in a 70-fold molar excess to elastase in a mixture with target organ with a synthetic small molecule inhibitor is a unique way of endowing an active compound with the pharmacodynamic profile needed to create in vivo efficacy.

  1. Cis-acting sequences from a human surfactant protein gene confer pulmonary-specific gene expression in transgenic mice

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    Korfhagen, T.R.; Glasser, S.W.; Wert, S.E.; Bruno, M.D.; Daugherty, C.C.; McNeish, J.D.; Stock, J.L.; Potter, S.S.; Whitsett, J.A. (Cincinnati College of Medicine, OH (USA))


    Pulmonary surfactant is produced in late gestation by developing type II epithelial cells lining the alveolar epithelium of the lung. Lack of surfactant at birth is associated with respiratory distress syndrome in premature infants. Surfactant protein C (SP-C) is a highly hydrophobic peptide isolated from pulmonary tissue that enhances the biophysical activity of surfactant phospholipids. Like surfactant phospholipid, SP-C is produced by epithelial cells in the distal respiratory epithelium, and its expression increases during the latter part of gestation. A chimeric gene containing 3.6 kilobases of the promoter and 5{prime}-flanking sequences of the human SP-C gene was used to express diphtheria toxin A. The SP-C-diphtheria toxin A fusion gene was injected into fertilized mouse eggs to produce transgenic mice. Affected mice developed respiratory failure in the immediate postnatal period. Morphologic analysis of lungs from affected pups showed variable but severe cellular injury confined to pulmonary tissues. Ultrastructural changes consistent with cell death and injury were prominent in the distal respiratory epithelium. Proximal components of the tracheobronchial tree were not severely affected. Transgenic animals were of normal size at birth, and structural abnormalities were not detected in nonpulmonary tissues. Lung-specific diphtheria toxin A expression controlled by the human SP-C gene injured type II epithelial cells and caused extensive necrosis of the distal respiratory epithelium. The absence of type I epithelial cells in the most severely affected transgenic animals supports the concept that developing type II cells serve as precursors to type I epithelial cells.

  2. In vivo evaluation of the inhibitory capacity of human plasma on exogenous surfactant function

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    B.F. Lachmann (Burkhard); E.P. Eijking (Eric); K.L. So; D.A.M.P.J. Gommers (Diederik)


    textabstractObjective: The adult respiratory distress syndrome (ARDS) and neonatal respiratory distress syndrome (RDS) are characterized by high permeability pulmonary edema which contains plasma-derived proteins inhibiting pulmonary surfactant function. Currently, discussion continues as to what

  3. Treatment of surfactant-damaged skin in humans with creams of different pH values. (United States)

    Buraczewska, Izabela; Lodén, Marie


    Skin surface has an acidic pH, whereas the body's internal environment maintains a near-neutral pH. The physiological role of the 'acidic mantle' and the function of the pH gradient throughout the stratum corneum remain unexplained. The pH gradient has been suggested to activate enzymes responsible for the maintenance of the skin barrier function and to facilitate the desquamation process in the stratum corneum. The aim of the study was to investigate the influence of pH of a moisturizing cream on barrier recovery in surfactant-damaged human skin. Volunteers had their skin damaged with sodium lauryl sulphate and treated those areas with the cream, adjusted to either pH 4.0 or 7.5. The study did not prove the superiority of a cream of pH 4.0 to a cream of pH 7.5 regarding promotion of skin barrier recovery, since no significant differences (p > 0.05) were found in transepidermal water loss, blood flow and skin capacitance between the treated areas. 2005 S. Karger AG, Basel.

  4. Surfactant-Enhanced Organic Acid Inactivation of Tulane Virus, a Human Norovirus Surrogate. (United States)

    Lacombe, Alison; Niemira, Brendan A; Gurtler, Joshua B; Kingsley, David H; Li, Xinhui; Chen, Haiqiang


    Combination treatments of surfactants and phenolic or short-chain organic acids (SCOA) may act synergistically or additively as sanitizers to inactive foodborne viruses and prevent outbreaks. The purpose of this study was to investigate the effect of gallic acid (GA), tannic acid, p-coumaric acid, lactic acid (LA), or acetic acid (AA), in combination with sodium dodecyl sulfate (SDS), against Tulane virus (TV), a surrogate for human norovirus. An aqueous stock solution of phenolic acids or SCOA with or without SDS was prepared and diluted in a twofold dilution series to 2× the desired concentration with cell growth media (M119 plus 10% fetal bovine serum). The solution was inoculated with an equal proportion of 6 log PFU/mL TV with a treatment time of 5 min. The survival of TV was quantified using a plaque assay with LLC-MK2 cells. The minimum virucidal concentration was 0.5:0.7% (v/v) for LA-SDS at pH 3.5 (4.5-PFU/mL reduction) and 0.5:0.7% (v/v) AA-SDS at pH 4.0 (2.6-log PFU/mL reduction). GA and SDS demonstrated a minimum virucidal concentration of 12.5 mM GA-SDS at pH 7.0 (0.2:0.3% GA-SDS) with an 0.8-log PFU/mL reduction and 50 mM GA-SDS (0.8:1.4% GA-SDS at pH 7.0) increased log reduction to 1.6 log PFU/mL. The combination treatments of AA or LA with SDS at pH 7.0 did not produce significant log reduction, nor did individual treatments of tannic acid, GA, p-coumaric acid, AA, LA, or SDS. This study demonstrates that a surfactant, such as SDS, aids in the phenolic acid and SCOA toxicities against viruses. However, inactivation of TV by combination treatments is contingent upon the pH of the sanitizing solution being lower than the pKa value of the organic acid being used. This information can be used to develop sanitizing washes to disinfect food contact surfaces, thereby aiding in the prevention of foodborne outbreaks.

  5. Comparative surfactant reactivity of canine and human stratum corneum: a plea for the use of the corneosurfametry bioassay. (United States)

    Goffin, V; Fontaine, J; Piérard, G E


    Comparative dermatology has paid little attention to the physiopathology of the stratum corneum. In this study, we investigated the responses of human and canine horny layers to marketed animal wash products by using the corneosurfametry bioassay. Previous work has shown that, with increasing surfactant aggressiveness to the stratum corneum, the colorimetric index of mildness (CIM) decreases, while both the corneosurfametry index (CSMI) and the overall difference in corneosurfametry (ODC) increase. In the present study, stratum corneum reactivity to wash products and inter-individual variability were significantly higher in humans than in dogs. For the three corneosurfametry variables, linear correlations were found between data gathered in the two panel groups. In conclusion, this pilot study suggests that mean stratum corneum reactivity to surfactants is stronger in humans than in dogs. Inter-individual variation, indicative of sensitive skin, also appears to be broader in humans. As a consequence, data gathered from dogs by using the corneosurfametry bioassay cannot be extrapolated to humans. Such variation between species could be important in the assessment of product safety and in supporting claims for mildness. 1999 FRAME.

  6. Surface free energy of the human skin and its critical surface tension of wetting in the skin/surfactant aqueous solution/air system. (United States)

    Krawczyk, J


    The purpose of these studies was to determine the surface free energy of the human skin and its critical surface tension of wetting in the skin--surfactant aqueous solution--air system in relation to different types of surfactants. The surface free energy of the skin and its components was calculated using the equilibrium advancing contact angle values of water, formamide, and diiodomethane on the forearm skin surface. Next, taking into account the measured values of the contact angle of aqueous solutions of SDDS, CTAB, TX-100 and TX-114 on the skin surface and data of their surface tension, the critical surface tension of the skin wetting was determined. We can classify the skin surface as low-energetic one. The critical surface tension of the skin wetting depends on the type of surfactant. It is possible to determine the critical surface tension of the human skin wetting on the basis of the values of the contact angle of aqueous solutions of surfactants and their surface tension. In this respect, nonionic surfactants seem to be the most appropriate. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Switchable Surfactants

    National Research Council Canada - National Science Library

    Yingxin Liu; Philip G. Jessop; Michael Cunningham; Charles A. Eckert; Charles L. Liotta


    .... We report that long-chain alkyl amidine compounds can be reversibly transformed into charged surfactants by exposure to an atmosphere of carbon dioxide, thereby stabilizing water/alkane emulsions...

  8. Surfactant protein D binds to human immunodeficiency virus (HIV) envelope protein gp120 and inhibits HIV replication

    DEFF Research Database (Denmark)

    Meschi, Joseph; Crouch, Erika C; Skolnik, Paul


    The envelope protein (gp120) of human immunodeficiency virus (HIV) contains highly conserved mannosylated oligosaccharides. These glycoconjugates contribute to resistance to antibody neutralization, and binding to cell surface lectins on macrophages and dendritic cells. Mannose-binding lectin (MBL......) binds to gp120 and plays a role in defence against the virus. In this study it is demonstrated that surfactant protein D (SP-D) binds to gp120 and inhibits HIV infectivity at significantly lower concentrations than MBL. The binding of SP-D was mediated by its calcium-dependent carbohydrate...... defence against HIV. A chimeric protein containing the N-terminal and collagen domains of SP-D linked to the neck and carbohydrate-recognition domains of MBL (called SP-D/MBL(neck+CRD)) had greater ability to bind to gp120 and inhibit virus replication than either SP-D or MBL. The enhanced binding of SP...

  9. Specific cleavage of the lung surfactant protein A by human cathepsin S may impair its antibacterial properties. (United States)

    Lecaille, Fabien; Naudin, Clément; Sage, Juliette; Joulin-Giet, Alix; Courty, Agnès; Andrault, Pierre-Marie; Veldhuizen, Ruud A W; Possmayer, Fred; Lalmanach, Gilles


    Human cysteine cathepsins (Cats) are implicated in lung injuries and tissue remodeling and have recently emerged as important players in pulmonary inflammations. The proteolytic activities of Cat B, L, K, S and H are dramatically increased in the sputum of patients with cystic fibrosis (CF), suggesting a possible involvement in the CF pathophysiology. We found that pulmonary surfactant protein A (SP-A) that participates to innate host defense is extensively degraded in CF expectorations. Breakdown of SP-A was markedly decreased in CF sputum by E-64 and Mu-Leu-Hph-VSPh, a Cat S inhibitor. Cat S cleaved efficiently and specifically SP-A within critical residues of the solvent-exposed loop of its carbohydrate recognition (C-type lectin) domain that allows binding to pathogens. Cat S decreased aggregation properties of SP-A (self-aggregation, aggregation of phospholipid vesicles and rough LPS). Moreover cleavage of SP-A by Cat S reduced binding to yeast mannan and impaired agglutination of Escherichia coli and Pseudomonas aeruginosa, a foremost detrimental pathogen colonizing the lungs of CF patients. Besides human neutrophil serine proteases and bacterial proteases, we propose that Cat S may participate in the pathophysiology of CF by weakening the antibacterial activity of SP-A. More broadly, present results provide further indication that Cat S, along with Cats B and L, could display immuno-modulatory functions by inactivating key proteins involved in the innate immunity defense. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Contributions of Phenylalanine 335 to Ligand Recognition by Human Surfactant Protein D: Ring Interactions with SP-D Ligands

    Energy Technology Data Exchange (ETDEWEB)

    Crouch,E.; McDonald, B.; Smith, K.; Cararella, T.; Seaton, B.; Head, J.


    Surfactant Protein D (SP-D) is an innate immune effector that contributes to antimicrobial host defense and immune regulation. Interactions of SP-D with microorganisms and organic antigens involve binding of glycoconjugates to the C-type lectin carbohydrate recognition domain (CRD). A trimeric fusion protein encoding the human neck+CRD (hNCRD) bound to the aromatic glycoside, p-nitrophenyl-alpha-D-maltoside, with nearly a log-fold higher affinity than maltose, the prototypical competitor. Maltotriose, which has the same linkage pattern as the maltoside, bound with intermediate affinity. Site-directed substitution of leucine for phenylalanine 335 (Phe335) decreased affinities for the maltoside and maltotriose without significantly altering the affinity for maltose or glucose, and substitution of tyrosine or tryptophan for leucine restored preferential binding to maltotriose and the maltoside. A mutant with alanine at this position failed to bind to mannan or maltose-substituted solid supports. Crystallographic analysis of the hNCRD complexed with maltotriose or p-nitrophenyl-maltoside showed stacking of the terminal glucose or nitrophenyl ring with the aromatic ring of Phe335. Our studies indicate that Phe335, which is evolutionarily conserved in all known SP-Ds, plays important - if not critical roles - in SP-D function.

  11. Cholesterol-mediated surfactant dysfunction is mitigated by surfactant protein A. (United States)

    Hiansen, Joshua Qua; Keating, Eleonora; Aspros, Alex; Yao, Li-Juan; Bosma, Karen J; Yamashita, Cory M; Lewis, James F; Veldhuizen, Ruud A W


    The ability of pulmonary surfactant to reduce surface tension at the alveolar surface is impaired in various lung diseases. Recent animal studies indicate that elevated levels of cholesterol within surfactant may contribute to its inhibition. It was hypothesized that elevated cholesterol levels within surfactant inhibit human surfactant biophysical function and that these effects can be reversed by surfactant protein A (SP-A). The initial experiment examined the function of surfactant from mechanically ventilated trauma patients in the presence and absence of a cholesterol sequestering agent, methyl-β-cyclodextrin. The results demonstrated improved surface activity when cholesterol was sequestered in vitro using a captive bubble surfactometer (CBS). These results were explored further by reconstitution of surfactant with various concentrations of cholesterol with and without SP-A, and testing of the functionality of these samples in vitro with the CBS and in vivo using surfactant depleted rats. Overall, the results consistently demonstrated that surfactant function was inhibited by levels of cholesterol of 10% (w/w phospholipid) but this inhibition was mitigated by the presence of SP-A. It is concluded that cholesterol-induced surfactant inhibition can actively contribute to physiological impairment of the lungs in mechanically ventilated patients and that SP-A levels may be important to maintain surfactant function in the presence of high cholesterol within surfactant. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Production and characterisation of recombinant forms of human pulmonary surfactant protein C (SP-C)

    DEFF Research Database (Denmark)

    Lukovic, Dunja; Plasencia, Inés; Taberner, Francisco J


    -C-derived peptides or recombinant humanized SP-C for inclusion in new preparations for therapeutic use. We describe herein the recombinant production in bacterial cultures of SP-C variants containing phenylalanines instead of the palmitoylated cysteines of the native protein, as fusions to the hydrophilic nuclease...... A (SN) from Staphylococcus aureus. The resulting chimerae were partially purified by affinity chromatography and subsequently subjected to protease digestion. The SP-C forms were recovered from the digestion mixtures by organic extraction and further purified by size exclusion chromatography. The two...

  13. [Exogenous surfactant therapy: new synthetic surfactants]. (United States)

    Lacaze-Masmonteil, Th


    There are numerous pulmonary conditions in which qualitative or quantitative anomalies of the surfactant system have been demonstrated. In premature newborns with immature lungs, a functional deficit in surfactant is the main physiopathologic mechanism of the neonatal respiratory distress syndrome (RDS). Since the landmark pilot study of Fujiwara, published more than 20 years ago, the efficacy of exogenous surfactant for the treatment of neonatal RDS has been established by numerous controlled studies and meta-analyses. Enlightened by a growing insight into both the structure and function of the different surfactant components, a new generation of synthetic surfactants has been developed. Various complementary approaches have confirmed the fundamental role of the two hydrophobic proteins, SP-B and SP-C, in the surfactant system, thus opening the way to the design of analogues, either by chemical synthesis or expression in a prokaryotic system. An example of these peptide-containing synthetic surfactant preparations, lucinactant (Surfaxin), has been recently tested in comparison to a synthetic surfactant that does not contain protein as well as to animal derived surfactant preparations. Major clinical outcomes between lucinactant and animal-derived surfactant preparations were fund similar in two randomized controlled trials, opening the way to a new generation of synthetic surfactants in the near future.

  14. Interindividual variability in the expression of surfactant protein A and B in the human lung during development

    Directory of Open Access Journals (Sweden)

    F. Cau


    Full Text Available The surfactant complex, thanks to its multiple actions including decrease of surface- tension and antimicrobial activity, plays a fundamental role in newborn survival, lowering the risk of respiratory distress syndrome. The aim of this work was to determine if the synthesis of two surfactant proteins (SP, SPA and pro-SPB, shows some inter-individual variability during lung development in the intrauterine life. Immunoreactivity for SPA and pro-SPB was investigated in the lungs of  40 subjects, including 15 fetuses, ranging from 14 to 22 weeks of gestation, and 25 neonates, from 24 to 41 weeks. Lung samples were formalin fixed, paraffin-embedded and routinely processed. SPA and pro-SPB were detected utilizing commercial antibodies.  A semi-quantitative grading system (1 to 4 was applied, based on the number of reactive cells and the intensity of immunostaining. Surfactant protein immunostaining was found in  three compartments: bronchi, bronchioles and alveoli, starting from 14 weeks of gestation in the bronchial epithelium and from the 21st week in the alveolar spaces. Differences were found regarding SPA and pro-SPB expression in the vast majority of subjects: in some lungs, SPA was more expressed whereas in others pro-SPB showed an higher degree of immunoreactivity. The expression of both surfactant proteins was not strictly correlated with gestational age. Whereas the highest levels of reactivity were detected in at term neonates, on the other hand one case with grade 3 was detected at 22 weeks and one negative case for both proteins was observed at 31 weeks. Our data clearly show a marked inter-individual variability regarding the production of SPA and pro-SPB and suggest the existence of other epigenetic factors, acting during gestation, that might influence surfactant production and, consequently, the survival potential of  neonates at birth. 

  15. Thermally cleavable surfactants (United States)

    McElhanon, James R.; Simmons, Blake A.; Zifer, Thomas; Jamison, Gregory M.; Loy, Douglas A.; Rahimian, Kamyar; Long, Timothy M.; Wheeler, David R.; Staiger, Chad L.


    Two new surfactant molecules are reported which contain thermally labile Diels-Alder adducts connecting the polar and non-polar sections of each molecule. The two surfactants possess identical non-polar dodecyl tail segments but exhibit different polar headgroups. The surfactants become soluble in water when anionic salts are formed through the deprotonation of the surfactant headgroups by the addition of potassium hydroxide. When either surfactant is exposed to temperature above about C., the retro Diels-Alder reaction occurs, yielding hydrophilic and hydrophobic fragments and the aqueous solutions of the surfactants subsequently exhibit loss of all surface-active behavior.

  16. The future of exogenous surfactant therapy. (United States)

    Willson, Douglas F; Notter, Robert H


    Since the identification of surfactant deficiency as the putative cause of the infant respiratory distress syndrome (RDS) by Avery and Mead in 1959, our understanding of the role of pulmonary surfactant in respiratory physiology and the pathophysiology of acute lung injury (ALI) has advanced substantially. Surfactant replacement has become routine for the prevention and treatment of infant RDS and other causes of neonatal lung injury. The role of surfactant in lung injury beyond the neonatal period, however, has proven more complex. Relative surfactant deficiency, dysfunction, and inhibition all contribute to the disturbed physiology seen in ALI and acute respiratory distress syndrome (ARDS). Consequently, exogenous surfactant, while a plausible therapy, has proven to be less effective in ALI/ARDS than in RDS, where simple deficiency is causative. This failure may relate to a number of factors, among them inadequacy of pharmaceutical surfactants, insufficient dosing or drug delivery, poor drug distribution, or simply an inability of the drug to substantially impact the underlying pathophysiology of ALI/ARDS. Both animal and human studies suggest that direct types of ALI (eg, aspiration, pneumonia) may be more responsive to surfactant therapy than indirect lung injury (eg, sepsis, pancreatitis). Animal studies are needed, however, to further clarify aspects of drug composition, timing, delivery, and dosing before additional human trials are pursued, as the results of human trials to date have been inconsistent and largely disappointing. Further study and perhaps the development of more robust pharmaceutical surfactants offer promise that exogenous surfactant will find a place in our armamentarium of treatment of ALI/ARDS in the future. 2011 Daedalus Enterprises

  17. Separation of total lipids on human lipoproteins using surfactant-coated multiwalled carbon nanotubes as pseudostationary phase in capillary electrophoresis. (United States)

    Su, Mei-Yu; Chen, Yen-Yi; Yang, Jian-Ying; Lin, You-Sian; Lin, Yang-Wei; Liu, Mine-Yine


    Surfactant-coated multiwalled carbon nanotubes (MWNTs) were used as pseudostationary phase (PSP) in CE to investigate the total lipids of high-density lipoproteins and low-density lipoproteins. To optimize the CE conditions, several experimental factors including carbon nanotube concentration, bile salt concentration, sodium phosphate (PB) concentration, organic modifier concentration and buffer pH value have been examined. In addition, the CE capillary temperature and applied voltage have also been examined. The optimal separation buffer selected was a mixture of 3.2 mg/L MWNT, 50 mM bile salt, 10 mM PB, 20% 1-propanol, pH 9.5. The optimal capillary temperature and applied voltage selected were 50°C and 20 kV, respectively. Phosphatidyl choline (PC) has been used as a model analyte and investigated by the optimal CE method. The linear range for PC was 0.1-3 mg/mL with a correlation coefficient of 0.9934, and the concentration LOD was 0.055 mg/mL. The optimal CE method has been used to characterize the total lipids of high-density lipoprotein and low-density lipoprotein. At absorbance 200 nm, one major peak and two or three minor peaks showed for the total lipids of lipoproteins within 13 minutes. Resolutions of the total lipids were enhanced using surfactant-coated MWNTs as PSPs in the CE separation buffer. However, resolutions of the total lipids were not enhanced using surfactant-coated single-walled carbon nanotubes as PSPs in the CE separation buffer. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Experimental Study on How Human Lung Surfactant Protein SP-B1-25 is Oxidized by Ozone in the Presence of Fe(II) and Ascorbic Acid (United States)

    Colussi, A. J.; Enami, S.; Hoffmann, M. R.


    We will report the results of experiments on the chemical fate of the human lung surfactant protein SP-B1-25 upon exposure to gaseous ozone in realistic aqueous media simulating the conditions prevalent in epithelial lining fluids in polluted ambient air. Our experiments consist of exposing aqueous microjets containing SP-B1-25, the natural antioxidant ascorbic acid, and the Fe2+ carried by most atmospheric fine particulates, under mild acidic conditions, such as those created by the innate lung host defense response. Reactants and the products of such interactions are detected via online electrospray ionization mass spectrometry. We will show that ascorbic acid largely inhibits the ozonation of SP-B1-25 in the absence of Fe2+, leading to the formation of an ascorbic acid ozonide (Enami et al., PNAS 2008). In the presence of Fe2+, however, the ozonide decomposes into reactive intermediates that result in the partial oxidation of SP-B1-25, presumable affecting its function as surfactant. We infer that these experimental results establish a plausible causal link for the observed synergic adverse health effects of ambient ozone and fine particulates

  19. Surfactant in airway disease. (United States)

    Enhorning, Goran


    Beta(2)-adrenergic agonists cause a release of pulmonary surfactant into lung airways. The surfactant phospholipids maintain the patency of the conducting airways, but this function is inhibited by plasma proteins entering an inflamed airway. The physical behavior of the surfactant can be studied with a pulsating bubble surfactometer and a capillary surfactometer. Calf lung surfactant extract was found to be inhibited by plasma proteins and by a lowering of temperature. Severe breathing difficulties and malfunctioning surfactant developed in BALB/c mice inhaling ozone or infected with respiratory syncytial virus, mainly as a result of proteins invading the airways. Patients with asthma were challenged with allergens in an area of one lung. BAL fluid (BALF) from such an area contained a surfactant that functioned poorly (ie, an inability to maintain airway openness) compared with BALF from the other lung or from the lungs of healthy volunteers. When proteins in the BALF were removed, surfactant performance clearly improved. Eosinophils, so prominent in asthmatic patients, synthesize the enzyme lysophospholipase, which, together with the enzyme phospholipase A(2), catalyzes the hydrolysis of the main component of the surfactant, phosphatidylcholine. Such hydrolysis incapacitates the ability of the surfactant to maintain airway patency. The treatment of asthma with beta(2)-adrenergic agonists and steroids will have a valuable effect on the surfactant system. It will cause a release of fresh surfactant into terminal airways. Surfactant can also be nebulized and inhaled, which has been shown to be an effective treatment.

  20. The effect of interleukin-13 (IL-13 and interferon-γ (IFN-γ on expression of surfactant proteins in adult human alveolar type II cells in vitro

    Directory of Open Access Journals (Sweden)

    Mason Robert J


    Full Text Available Abstract Background Surfactant proteins are produced predominantly by alveolar type II (ATII cells, and the expression of these proteins can be altered by cytokines and growth factors. Th1/Th2 cytokine imbalance is suggested to be important in the pathogenesis of several adult lung diseases. Recently, we developed a culture system for maintaining differentiated adult human ATII cells. Therefore, we sought to determine the effects of IL-13 and IFN-γ on the expression of surfactant proteins in adult human ATII cells in vitro. Additional studies were done with rat ATII cells. Methods Adult human ATII cells were isolated from deidentified organ donors whose lungs were not suitable for transplantation and donated for medical research. The cells were cultured on a mixture of Matrigel and rat-tail collagen for 8 d with differentiation factors and human recombinant IL-13 or IFN-γ. Results IL-13 reduced the mRNA and protein levels of surfactant protein (SP-C, whereas IFN-γ increased the mRNA level of SP-C and proSP-C protein but not mature SP-C. Neither cytokine changed the mRNA level of SP-B but IFN-γ slightly decreased mature SP-B. IFN-γ reduced the level of the active form of cathepsin H. IL-13 also reduced the mRNA and protein levels of SP-D, whereas IFN-γ increased both mRNA and protein levels of SP-D. IL-13 did not alter SP-A, but IFN-γ slightly increased the mRNA levels of SP-A. Conclusions We demonstrated that IL-13 and IFN-γ altered the expression of surfactant proteins in human adult ATII cells in vitro. IL-13 decreased SP-C and SP-D in human ATII cells, whereas IFN-γ had the opposite effect. The protein levels of mature SP-B were decreased by IFN-γ treatment, likely due to the reduction in active form cathpesin H. Similarly, the active form of cathepsin H was relatively insufficient to fully process proSP-C as IFN-γ increased the mRNA levels for SP-C and proSP-C protein, but there was no increase in mature SP-C. These observations

  1. Dimeric Surfactants: Promising Ingredients of Cosmetics and Toiletries

    Directory of Open Access Journals (Sweden)

    Naveen Kumar


    Full Text Available Surfactants are an essential ingredient for cosmetic, toiletries and personal care products for enhancing their performance. Dimeric surfactants demonstrate superiority compared to conventional surfactants in all areas of application. Dimeric surfactants are extremely promising for utilization in various cosmetic formulations viz. shampoo, lotions, creams, conditioners etc. These surfactants possess extremely unique surface properties viz. lower surface tension, unique micellization, low critical micelle concentration (CMC and antimicrobial activity, higher solubilization etc. Dimerics enhance the performances of cosmetics in an extraordinary manner and provide eco-friendly preparations for human epidermis.

  2. Physicochemical characteristics of PFC surfactants for dry decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Won Jin; Lee, Chi Woo [Korea University, Seoul (Korea)


    Even the trace amount of the used nuclear fuels of high radioactivity are hazardous to the earth and humans. Perfluorocarbons and perfluorocarbon surfactants are emerging to be efficient chemicals in the dry decontamination process of the used fuels of high radioactivity. The theme was undertaken to increase the knowledge on perfluorocarbon surfactants to develop the perfluorocarbon system in the dry decontamination process in Korea. Several cationic and anionic pfc surfactants were synthesized. Effects of pfc surfactants on electrochemical etching of silicon were investigated to form porous silicons. Forces were measured between silicon surfaces and AFM tip in the absence and presence of pfc surfactants. 7 refs., 10 figs. (Author)

  3. Identification of CD245 as myosin 18A, a receptor for surfactant A: A novel pathway for activating human NK lymphocytes. (United States)

    De Masson, A; Giustiniani, J; Marie-Cardine, A; Bouaziz, J D; Dulphy, N; Gossot, D; Validire, P; Tazi, A; Garbar, C; Bagot, M; Merrouche, Y; Bensussan, A


    CD245 is a human surface antigen expressed on peripheral blood lymphocytes, initially delineated by two monoclonal antibodies DY12 and DY35. Until now, CD245 molecular and functional characteristics remained largely unknown. We combined immunological and proteomic approaches and identified CD245 as the unconventional myosin 18A, a highly conserved motor enzyme reported as a receptor for the surfactant protein A (SP-A), that plays a critical role in cytoskeleton organization and Golgi budding. We report that the recruitment of CD245 strongly enhanced NK cell cytotoxicity. Further, we show that the enhancement of the NK lymphocytes killing ability toward CD137-ligand expressing target cells could result from the induction of CD137 expression following CD245 engagement. The SP-A receptor could therefore represent a novel and promising target in cancer immunotherapy.

  4. Human salivary agglutinin binds to lung surfactant protein-D and is identical with scavenger receptor protein gp-340

    DEFF Research Database (Denmark)

    Ligtenberg, T J; Bikker, F J; Groenink, J


    by quadrupole time-of-flight (Q-TOF) tandem MS. The sequence showed 100% identity with part of the scavenger receptor cysteine-rich ('SRCR') domain found in gp-340/DMBT1 (deleted in malignant brain tumours-1). The mass spectrum revealed 11 peaks with an identical mass as a computer-simulated trypsin digest....../PAGE and the amino acid composition of agglutinin, was found to be nearly identical with that of gp-340. It was shown by Western blotting that monoclonal antibodies against gp-340 reacted with salivary agglutinin, and monoclonals against agglutinin reacted with gp-340. It was demonstrated that gp-340 and agglutinin...... bound in a similar way to Streptococcus mutans and surfactant protein-D. Histochemically, the distribution of gp-340 in the submandibular salivary glands was identical with the agglutinin distribution, as shown in a previous paper [Takano, Bogert, Malamud, Lally and Hand (1991) Anat. Rec. 230, 307...

  5. Human surfactant protein A2 gene mutations impair dimmer/trimer assembly leading to deficiency in protein sialylation and secretion.

    Directory of Open Access Journals (Sweden)

    Yi Song

    Full Text Available Surfactant protein A2 (SP-A2 plays an essential role in surfactant metabolism and lung host defense. SP-A2 mutations in the carbohydrate recognition domain have been related to familial pulmonary fibrosis and can lead to a recombinant protein secretion deficiency in vitro. In this study, we explored the molecular mechanism of protein secretion deficiency and the subsequent biological effects in CHO-K1 cells expressing both wild-type and several different mutant forms of SP-A2. We demonstrate that the SP-A2 G231V and F198S mutants impair the formation of dimmer/trimer SP-A2 which contributes to the protein secretion defect. A deficiency in sialylation, but not N-linked glycosylation, is critical to the observed dimmer/trimer impairment-induced secretion defect. Furthermore, both mutant forms accumulate in the ER and form NP-40-insoluble aggregates. In addition, the soluble mutant SP-A2 could be partially degraded through the proteasome pathway but not the lysosome or autophagy pathway. Intriguingly, 4-phenylbutyrate acid (4-PBA, a chemical chaperone, alleviates aggregate formation and partially rescued the protein secretion of SP-A2 mutants. In conclusion, SP-A2 G231V and F198S mutants impair the dimmer/trimer assembly, which contributes to the protein sialylation and secretion deficiency. The intracellular protein mutants could be partially degraded through the proteasome pathway and also formed aggregates. The treatment of the cells with 4-PBA resulted in reduced aggregation and rescued the secretion of mutant SP-A2.

  6. Pulmonary surfactant therapy.


    Poulain, F R; Clements, J. A.


    Surfactant replacement therapy is now an integral part of the care of neonates since several clinical trials of natural surfactant extracts and synthetic preparations have shown efficacy in the treatment of infants with hyaline membrane disease. In these studies, early treatment with exogenous surfactant substantially reduced mortality and the incidence of air leak, although it did not appear to reduce the incidence of other complications, in particular bronchopulmonary dysplasia. Early repor...

  7. Surfactants in tribology

    CERN Document Server

    Biresaw, Girma


    Surface science and tribology play very critical roles in many industries. Manufacture and use of almost all consumer and industrial products rely on the application of advanced surface and tribological knowledge. The fourth in a series, Surfactants in Tribology, Volume 4 provides an update on research and development activities connecting surfactants and tribological phenomena. Written by renowned subject matter experts, the book demonstrates how improved design of surfactants can be harnessed to control tribological phenomena. Profusely illustrated and copiously referenced, the chapters also

  8. Surfactant-anti-surfactant immune complexes in infants with respiratory distress syndrome.


    Strayer, D. S.; Merritt, T A; Lwebuga-Mukasa, J.; Hallman, M


    The authors sought to determine whether treatment of respiratory distress syndrome (RDS) with human surfactant resulted in the formation of detectable circulating immune complexes. Preterm infants with severe RDS were divided into two groups: one group received human surfactant by intratracheal instillation and the other group did not. Both groups received ventilatory management involving intermittent mandatory ventilation. Plasma samples were drawn from these babies prior to treatment and at...

  9. Towards unravelling surfactant transport (United States)

    Sellier, Mathieu; Panda, Satyananda


    Surfactant transport arises in many natural or industrial settings. Examples include lipid tear layers in the eye, pulmonary surfactant replacement therapy, or industrial coating flows. Flows driven by the surface tension gradient which arises as a consequence of surfactant concentration inhomogeneity, also known as Marangoni-driven flows, have attracted the attention of fluid dynamists for several decades and has led to the development of sophisticated models and the undeniable advancement of the understanding of such flows. Yet, experimental confirmation of these models has been hampered by the difficulty in reliably and accurately measuring the surfactant concentration and its temporal evolution. In this contribution, we propose a methodology which may help shed some light on surfactant transport at the surface of thin liquid films. The surface stress induced by surfactant concentration induces a flow at the free surface which is visible and measurable. In the context of thin film flows for which the lubrication approximation hold, we demonstrate how the knowledge of this free surface flow field provides sufficient information to reconstruct the surfactant tension field. From the surface tension and an assumed equation of state, the local surfactant concentration can also be calculated and other transport parameters such as the surfactant surface diffusivity indirectly inferred. In this contribution, the proposed methodology is tested with synthetic data generated by the forward solution of the governing partial differential equations in order to illustrate the feasibility of the algorithm and highlight numerical challenges.

  10. Mechanisms to explain surfactant responses. (United States)

    Jobe, Alan H


    Surfactant is now standard of care for infants with respiratory distress syndrome. Surfactant treatments are effective because of complex metabolic interactions between surfactant and the preterm lung. The large treatment dose functions as substrate; it is taken up by the preterm lung and is reprocessed and secreted with improved function. The components of the treatment surfactant remain in the preterm lung for days. If lung injury is avoided, then surfactant inhibition is minimized. Prenatal corticosteroids complement surfactant to further enhance lung function. The magic of surfactant therapy results from the multiple interactions between surfactant and the preterm lung. Copyright (c) 2006 S. Karger AG, Basel.

  11. Dynamic covalent surfactants

    NARCIS (Netherlands)

    Minkenberg, C.B.


    In this thesis the development of surfactant aggregates with fast exchange dynamics between the aggregated and non-aggregated state is described. Dynamic surfactant exchange plays an important role in natural systems, for instance in cell signaling, cell division, and uptake and release of cargo.

  12. Human decidua-derived mesenchymal stem cells differentiate into functional alveolar type II-like cells that synthesize and secrete pulmonary surfactant complexes.

    Directory of Open Access Journals (Sweden)

    Alejandro Cerrada

    Full Text Available Lung alveolar type II (ATII cells are specialized in the synthesis and secretion of pulmonary surfactant, a lipid-protein complex that reduces surface tension to minimize the work of breathing. Surfactant synthesis, assembly and secretion are closely regulated and its impairment is associated with severe respiratory disorders. At present, well-established ATII cell culture models are not available. In this work, Decidua-derived Mesenchymal Stem Cells (DMSCs have been differentiated into Alveolar Type II- Like Cells (ATII-LCs, which display membranous cytoplasmic organelles resembling lamellar bodies, the organelles involved in surfactant storage and secretion by native ATII cells, and accumulate disaturated phospholipid species, a surfactant hallmark. Expression of characteristic ATII cells markers was demonstrated in ATII-LCs at gene and protein level. Mimicking the response of ATII cells to secretagogues, ATII-LCs were able to exocytose lipid-rich assemblies, which displayed highly surface active capabilities, including faster interfacial adsorption kinetics than standard native surfactant, even in the presence of inhibitory agents. ATII-LCs could constitute a highly useful ex vivo model for the study of surfactant biogenesis and the mechanisms involved in protein processing and lipid trafficking, as well as the packing and storage of surfactant complexes.

  13. Pulmonary surfactant and lung transplantation

    NARCIS (Netherlands)

    Erasmus, Michiel Elardus


    Pulmonary surfactant lowers the surface tension at the air-water interface inside the alveolus. This is achieved by adsorption of surfactant phospholipids at the air-water interface, a process controlled by surfactant-associated proteins, such as SP-A. In this way, surfactant prevents collapse of

  14. Metathesis depolymerizable surfactants (United States)

    Jamison, Gregory M.; Wheeler, David R.; Loy, Douglas A.; Simmons, Blake A.; Long, Timothy M.; McElhanon, James R.; Rahimian, Kamyar; Staiger, Chad L.


    A class of surfactant molecules whose structure includes regularly spaced unsaturation in the tail group and thus, can be readily decomposed by ring-closing metathesis, and particularly by the action of a transition metal catalyst, to form small molecule products. These small molecules are designed to have increased volatility and/or enhanced solubility as compared to the original surfactant molecule and are thus easily removed by solvent extraction or vacuum extraction at low temperature. By producing easily removable decomposition products, the surfactant molecules become particularly desirable as template structures for preparing meso- and microstructural materials with tailored properties.

  15. Phosphine oxide surfactants revisited. (United States)

    Stubenrauch, Cosima; Preisig, Natalie; Laughlin, Robert G


    This review summarizes everything we currently know about the nonionic surfactants alkyl dimethyl (C(n)DMPO) and alkyl diethyl (C(n)DEPO) phosphine oxide (PO surfactants). The review starts with the synthesis and the general properties (Section 2) of these compounds and continues with their interfacial properties (Section 3) such as surface tension, surface rheology, interfacial tension and adsorption at solid surfaces. We discuss studies on thin liquid films and foams stabilized by PO surfactants (Section 4) as well as studies on their self-assembly into lyotropic liquid crystals and microemulsions, respectively (Section 5). We aim at encouraging colleagues from both academia and industry to take on board PO surfactants whenever possible and feasible because of their broad variety of excellent properties. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Surfactants have multi-fold effects on skin barrier function. (United States)

    Lemery, Emmanuelle; Briançon, Stéphanie; Chevalier, Yves; Oddos, Thierry; Gohier, Annie; Boyron, Olivier; Bolzinger, Marie-Alexandrine


    The stratum corneum (SC) is responsible for the barrier properties of the skin and the role of intercorneocyte skin lipids, particularly their structural organization, in controlling SC permeability is acknowledged. Upon contacting the skin, surfactants interact with the SC components leading to barrier damage. To improve knowledge of the effect of several classes of surfactant on skin barrier function at three different levels. The influence of treatments of human skin explants with six non-ionic and four ionic surfactant solutions on the physicochemical properties of skin was investigated. Skin surface wettability and polarity were assessed through contact angle measurements. Infrared spectroscopy allowed monitoring the SC lipid organization. The lipid extraction potency of surfactants was evaluated thanks to HPLC-ELSD assays. One anionic and one cationic surfactant increased the skin polarity by removing the sebaceous and epidermal lipids and by disturbing the organization of the lipid matrix. Another cationic surfactant displayed a detergency effect without disturbing the skin barrier. Several non-ionic surfactants disturbed the lipid matrix organization and modified the skin wettability without any extraction of the skin lipids. Finally two non-ionic surfactants did not show any effect on the investigated parameters or on the skin barrier. The polarity, the organization of the lipid matrix and the lipid composition of the skin allowed describing finely how surfactants can interact with the skin and disturb the skin barrier function.

  17. Human surfactant protein D alters oxidative stress and HMGA1 expression to induce p53 apoptotic pathway in eosinophil leukemic cell line.

    Directory of Open Access Journals (Sweden)

    Lakshna Mahajan

    Full Text Available Surfactant protein D (SP-D, an innate immune molecule, has an indispensable role in host defense and regulation of inflammation. Immune related functions regulated by SP-D include agglutination of pathogens, phagocytosis, oxidative burst, antigen presentation, T lymphocyte proliferation, cytokine secretion, induction of apoptosis and clearance of apoptotic cells. The present study unravels a novel ability of SP-D to reduce the viability of leukemic cells (eosinophilic leukemic cell line, AML14.3D10; acute myeloid leukemia cell line, THP-1; acute lymphoid leukemia cell lines, Jurkat, Raji; and human breast epithelial cell line, MCF-7, and explains the underlying mechanisms. SP-D and a recombinant fragment of human SP-D (rhSP-D induced G2/M phase cell cycle arrest, and dose and time-dependent apoptosis in the AML14.3D10 eosinophilic leukemia cell line. Levels of various apoptotic markers viz. activated p53, cleaved caspase-9 and PARP, along with G2/M checkpoints (p21 and Tyr15 phosphorylation of cdc2 showed significant increase in these cells. We further attempted to elucidate the underlying mechanisms of rhSP-D induced apoptosis using proteomic analysis. This approach identified large scale molecular changes initiated by SP-D in a human cell for the first time. Among others, the proteomics analysis highlighted a decreased expression of survival related proteins such as HMGA1, overexpression of proteins to protect the cells from oxidative burst, while a drastic decrease in mitochondrial antioxidant defense system. rhSP-D mediated enhanced oxidative burst in AML14.3D10 cells was confirmed, while antioxidant, N-acetyl-L-cysteine, abrogated the rhSP-D induced apoptosis. The rhSP-D mediated reduced viability was specific to the cancer cell lines and viability of human PBMCs from healthy controls was not affected. The study suggests involvement of SP-D in host's immunosurveillance and therapeutic potential of rhSP-D in the eosinophilic leukemia and

  18. Recognition of Mannosylated Ligands and Influenza A Virus by Human Surfactant Protein D: Contributions of an Extended Site and Residue 343

    Energy Technology Data Exchange (ETDEWEB)

    Crouch, E.; Hartshorn, K; Horlacher, T; McDonald, B; Smith, K; Cafarella, T; Seaton, B; Seeberger, P; Head, J


    Surfactant protein D (SP-D) plays important roles in antiviral host defense. Although SP-D shows a preference for glucose/maltose, the protein also recognizes d-mannose and a variety of mannose-rich microbial ligands. This latter preference prompted an examination of the mechanisms of mannose recognition, particularly as they relate to high-mannose viral glycans. Trimeric neck plus carbohydrate recognition domains from human SP-D (hNCRD) preferred ?1-2-linked dimannose (DM) over the branched trimannose (TM) core, ?1-3 or ?1-6 DM, or d-mannose. Previous studies have shown residues flanking the carbohydrate binding site can fine-tune ligand recognition. A mutant with valine at 343 (R343V) showed enhanced binding to mannan relative to wild type and R343A. No alteration in affinity was observed for d-mannose or for ?1-3- or ?1-6-linked DM; however, substantially increased affinity was observed for ?1-2 DM. Both proteins showed efficient recognition of linear and branched subdomains of high-mannose glycans on carbohydrate microarrays, and R343V showed increased binding to a subset of the oligosaccharides. Crystallographic analysis of an R343V complex with 1,2-DM showed a novel mode of binding. The disaccharide is bound to calcium by the reducing sugar ring, and a stabilizing H-bond is formed between the 2-OH of the nonreducing sugar ring and Arg349. Although hNCRDs show negligible binding to influenza A virus (IAV), R343V showed markedly enhanced viral neutralizing activity. Hydrophobic substitutions for Arg343 selectively blocked binding of a monoclonal antibody (Hyb 246-05) that inhibits IAV binding activity. Our findings demonstrate an extended ligand binding site for mannosylated ligands and the significant contribution of the 343 side chain to specific recognition of multivalent microbial ligands, including high-mannose viral glycans.

  19. Allelic mRNA expression imbalance in C-type lectins reveals a frequent regulatory SNP in the human surfactant protein A (SP-A) gene. (United States)

    Azad, A K; Curtis, A; Papp, A; Webb, A; Knoell, D; Sadee, W; Schlesinger, L S


    Genetic variation in C-type lectins influences infectious disease susceptibility but remains poorly understood. We used allelic mRNA expression imbalance (AEI) technology for surfactant protein (SP)-A1, SP-A2, SP-D, dendritic cell-specific ICAM-3-grabbing non-integrin (DC-SIGN), macrophage mannose receptor (MRC1) and Dectin-1, expressed in human macrophages and/or lung tissues. Frequent AEI, an indicator of regulatory polymorphisms, was observed in SP-A2, SP-D and DC-SIGN. AEI was measured for SP-A2 in 38 lung tissues using four marker single-nucleotide polymorphisms (SNPs) and was confirmed by next-generation sequencing of one lung RNA sample. Genomic DNA at the SP-A2 DNA locus was sequenced by Ion Torrent technology in 16 samples. Correlation analysis of genotypes with AEI identified a haplotype block, and, specifically, the intronic SNP rs1650232 (30% minor allele frequency); the only variant consistently associated with an approximately twofold change in mRNA allelic expression. Previously shown to alter a NAGNAG splice acceptor site with likely effects on SP-A2 expression, rs1650232 generates an alternative splice variant with three additional bases at the start of exon 3. Validated as a regulatory variant, rs1650232 is in partial linkage disequilibrium with known SP-A2 marker SNPs previously associated with risk for respiratory diseases including tuberculosis. Applying functional DNA variants in clinical association studies, rather than marker SNPs, will advance our understanding of genetic susceptibility to infectious diseases.

  20. Natural surfactants used in cosmetics: glycolipids. (United States)

    Lourith, N; Kanlayavattanakul, M


    Cosmetic surfactant performs detergency, wetting, emulsifying, solubilizing, dispersing and foaming effects. Adverse reactions of chemical synthesis surfactant have an effect on environment and humans, particularly severe in long term. Biodegradability, low toxicity and ecological acceptability which are the benefits of naturally derived surfactant that promises cosmetic safety are, therefore, highly on demand. Biosurfactant producible from microorganisms exhibiting potential surface properties suitable for cosmetic applications especially incorporate with their biological activities. Sophorolipids, rhamnolipids and mannosylerythritol lipids are the most widely used glycolipids biosurfactant in cosmetics. Literatures and patents relevant to these three glycolipids reviewed were emphasizing on the cosmetic applications including personal care products presenting the cosmetic efficiency, efficacy and economy benefits of glycolipids biosurfactant.

  1. Are additive effects of dietary surfactants on intestinal tight junction integrity an overlooked human health risk? - A mixture study on Caco-2 monolayers. (United States)

    Glynn, Anders; Igra, Annachiara Malin; Sand, Salomon; Ilbäck, Nils Gunnar; Hellenäs, Karl Erik; Rosén, Johan; Aspenström-Fagerlund, Bitte


    Surfactants may cause dysfunction of intestinal tight junctions (TJs), which is a common feature of intestinal autoimmune diseases. Effects of dietary surfactants on TJ integrity, measured as trans-epithelial resistance (TEER), were studied in Caco-2 cell monolayers. Cytotoxicity was assessed as apical LDH leakage. Monolayers were apically exposed for 60 min to the dietary surfactants solanine and chaconine (SC, potato glycoalkaloids, 0-0.25 mM), perfluorooctane sulfonic acid (PFOS, industrial contaminant, 0-0.8 mM), and sucrose monolaurate (SML, food emulsifier E 473, 0-2.0 mM) separately and as a mixture. Dose-response modelling of TEER EC50 showed that SC were 2.7- and 12-fold more potent than PFOS and SML, respectively. The mixture was composed of 1 molar unit SC, 2.7 units PFOS and 12 units SML ("SC TEER equivalent" proportions 1:1:1). Mixture exposure (0-0.05 mM SC equivalents) dose-response modelling suggested additive action on TJ integrity. Increasing SC and SML concentrations caused increased LDH leakage, but PFOS decreased LDH leakage at intermediate exposure concentrations. In the mixture PFOS appeared to protect from extensive SC- and SML-induced LDH leakage. Complex mixtures of surfactants in food may act additively on intestinal TJ integrity, which should be considered in risk assessment of emulsifier authorisation for use in food production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Gemini (dimeric) Surfactants

    Indian Academy of Sciences (India)

    carboxylate, sulphonate), or nonionic (polyether, sugar). (iv) gemini surfactants. Symmetrical and nonsymmetrical GS are known (see[2]), that is, these mayor may not have two identical polar groups and two identical chains. (v) GS with three or more polar groups or chains are also known. Some representative examples [2] ...

  3. Gemini (dimeric) Surfactants

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 3. Gemini (dimeric) Surfactants - The Two-Faced Molecules. B S Sekhon. General Article Volume 9 Issue 3 March 2004 pp 42-49. Fulltext. Click here to view fulltext PDF. Permanent link: ...

  4. Diseases of Pulmonary Surfactant Homeostasis (United States)

    Whitsett, Jeffrey A.; Wert, Susan E.; Weaver, Timothy E.


    Advances in physiology and biochemistry have provided fundamental insights into the role of pulmonary surfactant in the pathogenesis and treatment of preterm infants with respiratory distress syndrome. Identification of the surfactant proteins, lipid transporters, and transcriptional networks regulating their expression has provided the tools and insights needed to discern the molecular and cellular processes regulating the production and function of pulmonary surfactant prior to and after birth. Mutations in genes regulating surfactant homeostasis have been associated with severe lung disease in neonates and older infants. Biophysical and transgenic mouse models have provided insight into the mechanisms underlying surfactant protein and alveolar homeostasis. These studies have provided the framework for understanding the structure and function of pulmonary surfactant, which has informed understanding of the pathogenesis of diverse pulmonary disorders previously considered idiopathic. This review considers the pulmonary surfactant system and the genetic causes of acute and chronic lung disease caused by disruption of alveolar homeostasis. PMID:25621661

  5. Mixed surfactant systems for enhanced oil recovery

    Energy Technology Data Exchange (ETDEWEB)

    Llave, F.M.; Gall, B.L.; Noll, L.A.


    The results of an evaluation of mixed surfactant systems for enhanced oil recovery are described. Several surfactant combinations have been studied. These include alkyl aryl sulfonates as primary surfactants and carboxymethylated ethoxylated (CME) surfactants and ethoxylated sulfonates (ES) as secondary surfactants. The ethoxylated surfactants increase the salinity tolerance of the primary surfactants and, in theory, allow tailoring of the surfactant system to match selected reservoir conditions. The experiments conducted included interfacial tension (IFT) measurements, phase behavior measurements, adsorption and/or chromatographic separation of mixed surfactant systems, measurements of solution properties such as the critical micelle concentration (CMC) of surfactant mixtures, and crude oil displacement experiments. The effects of temperature, surfactant concentration, salinity, presence of divalent ions, hydrocarbon type, and component proportions in the mixed surfactant combinations, and injection strategies on the performance potential of the targeted surfactant/hydrocarbon systems were studied. 40 refs., 37 figs., 8 tabs.


    Directory of Open Access Journals (Sweden)

    Pirog T. Р.


    Full Text Available The review is devoted to surface-active glycolipids. The general characteristics, the physiological role of the rhamnolipids, trehalose lipids, sophorolipids, mannosylerythritol lipids and their traditional producers — the representatives of the genera Pseudozyma, Pseudomonas, Rhodococcus and Candida are given. The detailed analysis of the chemical structure, the stages of the biosynthesis and the regulation of some low molecular glycolipids are done. The own experimental data concerning the synthesis intensification, the physiological role and the practical use of Rhodococcus erythropolis IMV Ac-5017, Acinetobacter calcoaceticus IMV B-7241 and Nocardia vaccinii IMV B-7405 surfactants, which are a complex of the glyco-, phospho-, amino- and neutral lipids (glycolipids of all strains are presented by trehalose mycolates are summarized. It was found that R. erythropolis IMV Ac-5017, A. calcoaceticus IMV B-7241 and N. vaccinii IMV B-7405 surfactants have protective, antimicrobial and antiadhesive properties. It was shown that R. erythropolis IMV Ac-5017, A. calcoaceticus IMV B-7241 and N. vaccinii IMV B-7405 surfactants preparation of cultural liquid intensified the degradation of oil in water due to the activation of the natural petroleum-oxidizing microflora.


    Directory of Open Access Journals (Sweden)

    T. P. Pirog


    Full Text Available The classification and the chemical structure of the lipopeptides and their producers (bacteria of the genera Bacillus and Pseudomonas are given. The role of the lipopeptides in cells motility, biofilm formation, metal binding and xenobiotics degradation and their action on the cells of pro- and eukaryotes is summarized. The stages of the nonribosomal lipopeptides synthesis and the role of two-component (GacA/GacS, ComA/ComP and the quorum system regulation of this process are shown. The potential of lactic acid bacteria and marine microorganisms as alternative surfactants producers (glycolipids, lipopeptides, phospholipids and fatty acids, glycolipopeptides are discussed. Their productivity and advantages over traditional producers are given as well. The properties of surfactants synthesized by lactic acid bacteria (the reduction of the surface tension, the critical micelle concentration, the stability in a wide range of pH, the temperature, the biological activity are summarized. Surfactants of nonpathogenic probiotic bacteria could be used as effective antimicrobial agents and antiadhesive and marine producers which able to synthesize unique metabolites that are not produced by other microorganisms.

  8. Nintedanib modulates surfactant protein-D expression in A549 human lung epithelial cells via the c-Jun N-terminal kinase-activator protein-1 pathway. (United States)

    Kamio, Koichiro; Usuki, Jiro; Azuma, Arata; Matsuda, Kuniko; Ishii, Takeo; Inomata, Minoru; Hayashi, Hiroki; Kokuho, Nariaki; Fujita, Kazue; Saito, Yoshinobu; Miya, Toshimichi; Gemma, Akihiko


    Idiopathic pulmonary fibrosis (IPF) is a progressive disease with a high mortality rate. Signalling pathways activated by several tyrosine kinase receptors are known to be involved in lung fibrosis, and this knowledge has led to the development of the triple tyrosine kinase inhibitor nintedanib, an inhibitor of vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR), and fibroblast growth factor receptor (FGFR), for the treatment of IPF. Pulmonary surfactant protein D (SP-D), an important biomarker of IPF, reportedly attenuates bleomycin-induced pulmonary fibrosis in mice. In this study, we investigated whether nintedanib modulates SP-D expression in human lung epithelial (A549) cells using quantitative real-time reverse transcriptase polymerase chain reaction and western blotting. To investigate the mechanisms underlying the effects of nintedanib, we evaluated the phosphorylation of c-Jun N-terminal kinase (JNK) and its downstream target c-Jun. The effect of the JNK inhibitor SP600125 on c-Jun phosphorylation was also tested. Activation of activator protein-1 (AP-1) was examined using an enzyme-linked immunosorbent assay-based test, and cell proliferation assays were performed to estimate the effect of nintedanib on cell proliferation. Furthermore, we treated mice with nintedanib to examine its in vivo effect on SP-D levels in lungs. These experiments showed that nintedanib up-regulated SP-D messenger RNA expression in a dose-dependent manner at concentrations up to 5 μM, with significant SP-D induction observed at concentrations of 3 μM and 5 μM, in comparison with that observed in vehicle controls. Nintedanib stimulated a rapid increase in phosphorylated JNK in A549 cells within 30 min of treatment and stimulated c-Jun phosphorylation, which was inhibited by the JNK inhibitor SP600125. Additionally, nintedanib was found to activate AP-1. A549 cell proliferation was not affected by nintedanib at any of the tested

  9. Surfactants at the Design Limit. (United States)

    Czajka, Adam; Hazell, Gavin; Eastoe, Julian


    This article analyzes how the individual structural elements of surfactant molecules affect surface properties, in particular, the point of reference defined by the limiting surface tension at the aqueous cmc, γcmc. Particular emphasis is given to how the chemical nature and structure of the hydrophobic tails influence γcmc. By comparing the three different classes of surfactants, fluorocarbon, silicone, and hydrocarbon, a generalized surface packing index is introduced which is independent of the chemical nature of the surfactants. This parameter ϕcmc represents the volume fraction of surfactant chain fragments in a surface film at the aqueous cmc. It is shown that ϕcmc is a useful index for understanding the limiting surface tension of surfactants and can be useful for designing new superefficient surfactants.

  10. Endogenous surfactant metabolism in critically ill infants measured with stable isotope labeled fatty acids

    NARCIS (Netherlands)

    Cogo, PE; Carnielli, VP; Bunt, JEH; Badon, T; Giordano, G; Zacchello, F; Sauer, PJJ; Zimmermann, LJI

    Little is known about endogenous surfactant metabolism in infants, because radioactive isotopes used for this purpose in animals cannot be used in humans. We developed a novel and safe method to measure the endogenous surfactant kinetics in vivo in humans by using stable isotope labeled fatty acids.


    Surfactants used to enhance remediation of soils by soil washing are often lost in the process. Neither the amount nor the cause of this loss is known. It is assumed that clays present in the soil are responsible for the loss of the surfactant. In this papere, adsorption prope...

  12. Novel Approaches to Surfactant Administration


    Gupta, Samir; Donn, Steven M.


    Surfactant replacement therapy has been the mainstay of treatment for preterm infants with respiratory distress syndrome for more than twenty years. For the most part, surfactant is administered intratracheally, followed by mechanical ventilation. In recent years, the growing interest in noninvasive ventilation has led to novel approaches of administration. This paper will review these techniques and the associated clinical evidence.

  13. Immunomodulatory properties of surfactant preparations. (United States)

    Bersani, Iliana; Kunzmann, Steffen; Speer, Christian P


    Surfactant replacement significantly decreased acute pulmonary morbidity and mortality among preterm neonates with respiratory distress syndrome. Besides improving lung function and oxygenation, surfactant is also a key modulator of pulmonary innate and acquired immunity regulating lung inflammatory processes. In this review, we describe the immunomodulatory features of surfactant preparations. Various surfactant preparations decrease the proinflammatory cytokine and chemokine release, the oxidative burst activity, and the nitric oxide production in lung inflammatory cells such as alveolar neutrophils, monocytes and macrophages; they also affect lymphocyte proliferative response and immunoglobulin production, as well as natural killer and lymphokine-activated killer cell activity. In addition, surfactant preparations are involved in airway remodeling, as they decrease lung fibroblast proliferation capacity and the release of mediators involved in remodeling. Moreover, they increase cell transepithelial resistance and VEGF synthesis in lung epithelial cells. A number of different signaling pathways and molecules are involved in these processes. Because the inhibition of local immune response may decrease lung injury, surfactant therapeutic efficacy may be related not only to its biophysical characteristics but, at least in part, to its anti-inflammatory features and its effects on remodeling processes. However, further studies are required to identify which surfactant preparation ensures the highest anti-inflammatory activity, thereby potentially decreasing the inflammatory process underlying respiratory distress syndrome. In perspective, detailed characterization of these anti-inflammatory effects could help to improve the next generation of surfactant preparations.

  14. Surfactant protein D of the innate immune defence is inversely associated with human obesity and SP-D deficiency infers increased body weight in mice

    DEFF Research Database (Denmark)

    Sorensen, G.L.; Hjelmborg, J.V.B.; Leth-Larsen, R.


    of the present study was to describe the association between serum SP-D and weight, waist circumference or BMI, and furthermore to observe body weight development in SP-D-deficient (Spd-/-) mice. As a part of the Danish population-based twin study (GEMINAKAR) on the metabolic syndrome, we analysed 1476 Danish...... twins for serum SP-D and investigated associations with weight, waist circumference and BMI by multiple regression analysis. Serum SP-D was significantly and inversely associated with weight (P = 0.001) and waist circumference in men (P ...Surfactant protein D (SP-D) is a key regulator of pathogen-induced inflammation. SP-D is further involved in lipid homeostasis in mouse lung and circulation and recent data have demonstrated that the body mass index (BMI; in kg/m(2)) is influenced by genes in common with SP-D. The objective...

  15. Innovation in surfactant therapy II: surfactant administration by aerosolization. (United States)

    Pillow, J Jane; Minocchieri, S


    Instilled bolus surfactant is the only approved surfactant treatment for neonatal respiratory distress syndrome. However, recent trends towards increased utilization of noninvasive respiratory support for preterm infants with surfactant deficiency have created a demand for a similarly noninvasive means of administering exogenous surfactant. Past approaches to surfactant nebulization met with varying success due to inefficient aerosol devices resulting in low intrapulmonary delivery doses of surfactant with variable clinical effectiveness. The recent development of vibrating membrane nebulizers, coupled with appropriate positioning of the interface device, indicates that efficient delivery of aerosolized surfactant is now a realistic goal in infants. Evidence of clinical effect despite low total administered dose in pilot studies, together with suggestions of enhanced homogeneity of pulmonary distribution indicate that this therapy may be applied in a cost-effective manner, with minimal patient handling and disruption. These studies need to be subjected to appropriately designed randomized controlled trials. Further work is also required to determine the optimum delivery route (mask, intranasal prong, nasopharyngeal or laryngeal), dosing amount and redosing interval. Copyright © 2012 S. Karger AG, Basel.

  16. Pulmonary surfactant function is abolished by an elevated proportion of cholesterol. (United States)

    Gunasekara, Lasantha; Schürch, Samuel; Schoel, W Michael; Nag, Kaushik; Leonenko, Zoya; Haufs, Michael; Amrein, Matthias


    A molecular film of pulmonary surfactant strongly reduces the surface tension of the lung epithelium-air interface. Human pulmonary surfactant contains 5-10% cholesterol by mass, among other lipids and surfactant specific proteins. An elevated proportion of cholesterol is found in surfactant, recovered from acutely injured lungs (ALI). The functional role of cholesterol in pulmonary surfactant has remained controversial. Cholesterol is excluded from most pulmonary surfactant replacement formulations, used clinically to treat conditions of surfactant deficiency. This is because cholesterol has been shown in vitro to impair the surface activity of surfactant even at a physiological level. In the current study, the functional role of cholesterol has been re-evaluated using an improved method of evaluating surface activity in vitro, the captive bubble surfactometer (CBS). Cholesterol was added to one of the clinically used therapeutic surfactants, BLES, a bovine lipid extract surfactant, and the surface activity evaluated, including the adsorption rate of the substance to the air-water interface, its ability to produce a surface tension close to zero and the area compression needed to obtain that low surface tension. No differences in the surface activity were found for BLES samples containing either none, 5 or 10% cholesterol by mass with respect to the minimal surface tension. Our findings therefore suggest that the earlier-described deleterious effects of physiological amounts of cholesterol are related to the experimental methodology. However, at 20%, cholesterol effectively abolished surfactant function and a surface tension below 15 mN/m was not obtained. Inhibition of surface activity by cholesterol may therefore partially or fully explain the impaired lung function in the case of ALI. We discuss a molecular mechanism that could explain why cholesterol does not prevent low surface tension of surfactant films at physiological levels but abolishes surfactant


    Directory of Open Access Journals (Sweden)

    T. P. Pirog


    Full Text Available It was shown literature and own experimental data concerning the use of microbial surface active glycolipids (rhamno-, sophoro- and trehalose lipids and lipopeptides for water and soil purification from oil and other hydrocarbons, removing toxic heavy metals (Cu2+, Cd2+, Ni2+, Pb2+, degradation of complex pollution (oil and other hydrocarbons with heavy metals, and the role of microbial surfactants in phytoremediation processes. The factors that limit the use of microbial surfactants in environmental technologies are discussed. Thus, at certain concentrations biosurfactant can exhibit antimicrobial properties and inhibit microorganisms destructing xenobiotics. Microbial biodegradability of surfactants may also reduce the effectiveness of bioremediation. Development of effective technologies using microbial surfactants should include the following steps: monitoring of contaminated sites to determine the nature of pollution and analysis of the autochthonous microbiota; determining the mode of surfactant introduction (exogenous addition of stimulation of surfactant synthesis by autochthonous microbiota; establishing an optimal concentration of surfactant to prevent exhibition of antimicrobial properties and rapid biodegradation; research both in laboratory and field conditions.

  18. Measurement of cytotoxicity and irritancy potential of sugar-based surfactants on skin-related 3D models. (United States)

    Lu, Biao; Miao, Yong; Vigneron, Pascale; Chagnault, Vincent; Grand, Eric; Wadouachi, Anne; Postel, Denis; Pezron, Isabelle; Egles, Christophe; Vayssade, Muriel


    Sugar-based surfactants present surface-active properties and relatively low cytotoxicity. They are often considered as safe alternatives to currently used surfactants in cosmetic industries. In this study, four sugar-based surfactants, each with an eight carbon alkyl chain bound to a glucose or a maltose headgroup through an amide linkage, were synthesized and compared to two standard surfactants. The cytotoxic and irritant effects of surfactants were evaluated using two biologically relevant models: 3D dermal model (mouse fibroblasts embedded in collagen gel) and reconstituted human epidermis (RHE, multi-layered human keratinocytes). Results show that three synthesized surfactants possess lower cytotoxicity compared to standard surfactants as demonstrated in the 3D dermal model. Moreover, the IC50s of surfactants against the 3D dermal model are higher than IC50s obtained with the 2D dermal model (monolayer mouse fibroblasts). Both synthesized and standard surfactants show no irritant effects after 48h of topical application on RHE. Throughout the study, we demonstrate the difficulty to link the physico-chemical properties of surfactants and their cytotoxicity in complex models. More importantly, our data suggest that, prior to in vivo tests, a complete understanding of surfactant cytotoxicity or irritancy potential requires a combination of cellular and tissue models. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. A first-in-human clinical study of a new SP-B and SP-C enriched synthetic surfactant (CHF5633) in preterm babies with respiratory distress syndrome. (United States)

    Sweet, David G; Turner, Mark A; Straňák, Zbyněk; Plavka, Richard; Clarke, Paul; Stenson, Ben J; Singer, Dominique; Goelz, Rangmar; Fabbri, Laura; Varoli, Guido; Piccinno, Annalisa; Santoro, Debora; Speer, Christian P


    CHF5633 (Chiesi Farmaceutici S.p.A., Parma, Italy) is the first fully synthetic surfactant enriched by peptide analogues of two human surfactant proteins. We planned to assess safety and tolerability of CHF5633 and explore preliminary efficacy. Multicentre cohort study. Forty infants from 27 +0 to 33 +6 weeks gestation with respiratory distress syndrome requiring fraction of inspired oxygen (FiO 2 ) ≥0.35 were treated with a single dose of CHF5633 within 48 hours after birth. The first 20 received 100 mg/kg and the second 20 received 200 mg/kg. Adverse events (AEs) and adverse drug reactions (ADRs) were monitored with complications of prematurity considered AEs if occurring after dosing. Systemic absorption and immunogenicity were assessed. Efficacy was assessed by change in FiO 2 after dosing and need for poractant-alfa rescue. Rapid and sustained improvements in FiO 2 were observed in 39 (98%) infants. One responded neither to CHF5633 nor two poractant-alfa doses. A total of 79 AEs were experienced by 19 infants in the 100 mg/kg cohort and 53 AEs by 20 infants in the 200 mg/kg cohort. Most AEs were expected complications of prematurity. Two unrelated serious AEs occurred in the second cohort. One infant died of necrotising enterocolitis and another developed viral bronchiolitis after discharge. The single ADR was an episode of transient endotracheal tube obstruction following a 200 mg/kg dose. Neither systemic absorption, nor antibody development to either peptide was detected. Both CHF5633 doses were well tolerated and showed promising clinical efficacy profile. These encouraging data provide a basis for ongoing randomised controlled trials. NCT01651637. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  20. Treatment with exogenous surfactant stimulates endogenous surfactant synthesis in premature infants with respiratory distress syndrome

    NARCIS (Netherlands)

    Bunt, JEH; Carnielli, VP; Janssen, DJ; Wattimena, JLD; Hop, WC; Sauer, PJ; Zimmermann, LJI


    Objective: Treatment of preterm infants with respiratory distress syndrome (RDS) with exogenous surfactant has greatly improved clinical outcome. Some infants require multiple doses, and it has not been studied whether these large amounts of exogenous surfactant disturb endogenous surfactant

  1. Chemistry and technology of surfactants

    National Research Council Canada - National Science Library

    Farn, Richard J


    ... 2.3.1 Micelles and critical micelle concentration 2.3.2 Aggregate structures and shapes 2.4 Adsorption of surfactants at surfaces 2.4.1 Adsorption at liquid- gas and liquid- liquid interfaces 2.4....

  2. Nonionic polymers reverse inactivation of surfactant by meconium and other substances. (United States)

    William Taeusch, H; Lu, K W; Goerke, J; Clements, J A


    A variety of substances including human meconium have been found to affect adversely the surface tension-lowering activity of pulmonary surfactants, and this effect may be important in the pathogenesis of a number of human diseases. To find whether inactivation of surfactant could be prevented or reduced by nonionic polymers, we added dextrans, polyethylene glycols (PEGs), or polyvinylpyrrolidones (PVPs) of various molecular weights to pulmonary surfactants. One to 3% human meconium or other inactivating substances were then added to the mixtures, which were tested in a modified pulsating bubble surfactometer. Polymers (3.3-500 kD) in 1-10% concentrations enhanced the ability of a commercial surfactant replacement (Survanta) to lower the minimum surface tension in the presence of meconium, serum, or lysophosphatidylcholine. Similar effects were seen when polymers were added after mixing of surfactant and meconium or other inhibitors, indicating that polymers are capable of reversing the inactivation. Results from rat experiments indicate that total lung capacity is increased when PEG is first added to the Survanta, then mixed with meconium and instilled into the lungs. We postulate that polymers separate meconium-surfactant complexes, permitting surfactant components better access to the air-liquid interface. Taeusch HW, Lu KW, Goerke J, Clements JA. Nonionic polymers reverse inactivation of surfactant by meconium and other substances.

  3. Biomimicry of surfactant protein C. (United States)

    Brown, Nathan J; Johansson, Jan; Barron, Annelise E


    Since the widespread use of exogenous lung surfactant to treat neonatal respiratory distress syndrome, premature infant survival and respiratory morbidity have dramatically improved. Despite the effectiveness of the animal-derived surfactant preparations, there still remain some concerns and difficulties associated with their use. This has prompted investigation into the creation of synthetic surfactant preparations. However, to date, no clinically used synthetic formulation is as effective as the natural material. This is largely because the previous synthetic formulations lacked analogues of the hydrophobic proteins of the lung surfactant system, SP-B and SP-C, which are critical functional constituents. As a result, recent investigation has turned toward the development of a new generation of synthetic, biomimetic surfactants that contain synthetic phospholipids along with a mimic of the hydrophobic protein portion of lung surfactant. In this Account, we detail our efforts in creating accurate mimics of SP-C for use in a synthetic surfactant replacement therapy. Despite SP-C's seemingly simple structure, the predominantly helical protein is extraordinarily challenging to work with given its extreme hydrophobicity and structural instability, which greatly complicates the creation of an effective SP-C analogue. Drawing inspiration from Nature, two promising biomimetic approaches have led to the creation of rationally designed biopolymers that recapitulate many of SP-C's molecular features. The first approach utilizes detailed SP-C structure-activity relationships and amino acid folding propensities to create a peptide-based analogue, SP-C33. In SP-C33, the problematic and metastable polyvaline helix is replaced with a structurally stable polyleucine helix and includes a well-placed positive charge to prevent aggregation. SP-C33 is structurally stable and eliminates the association propensity of the native protein. The second approach follows the same design

  4. Current Issues and Challenges in the Use of Aerosolized Surfactant for Respiratory Distress Syndrome in the Newborns

    Directory of Open Access Journals (Sweden)

    Dion Darius Samsudin


    Full Text Available BACKGROUND: Surfactant replacement therapy is a recognized treatment for respiratory distress syndrome (RDS in the newborns. Over the past 30 years, human and animal trials have been performed regarding administration of aerosolized surfactant to the injured lung, however the result has been unsatisfactory when compared with instilled surfactant delivery via endotracheal tube (ETT. This review aims to investigate the current issues, challenges and future recommendation of aerosolized surfactant therapy. CONTENT: Five randomized clinical trials in humans and 13 animal trials met the inclusion criteria and were reviewed. Most animal trials agree that this method of treatment is feasible. However, human trials presented conflicting results, and generally showed it to be ineffective. When compared with surfactant delivery via ETT, aerosolized surfactant is less effective in improving respiratory function. SUMMARY: The current data from human trials does not support the implementation of aerosolized surfactant therapy to treat newborns with RDS. Further research is necessary to improve nebulization, delivery, distribution and deposition in the lung, to investigate aerosolized surfactant delivery via ETT and to determine the appropriate dose. KEYWORDS: surfactant, aerosol, prematurity, respiratory distress syndrome.

  5. Synthesis of carbohydrate-based surfactants (United States)

    Pemberton, Jeanne E.; Polt, Robin L.; Maier, Raina M.


    The present invention provides carbohydrate-based surfactants and methods for producing the same. Methods for producing carbohydrate-based surfactants include using a glycosylation promoter to link a carbohydrate or its derivative to a hydrophobic compound.

  6. Fungal growth on anion surfactant medium. (United States)

    Hamada, Nobuo; Abe, Niichiro


    Before the present study, no fungi using anion surfactant as a nutrient had been identified, although some fungi were known to use nonion surfactant. Washing water collected from 63 washing machines was inoculated onto 0.1% LAS (Sodium dodecyl benzenesulfonate) anion surfactant media to identify fungi that can feed on anion-surfactant. Small dark colonies of fungi were found on several of the Petri-dishes from 12 days after inoculation. These were identified as Cladophialophora boppii and Exophiala spinifera using morphological features and rDNA data. A number of the isolates of C. boppii specifically were recognized as using anion surfactant as a nutrient. The growth characteristics of the two fungal species were examined on surfactant media of three kinds. Apart from anion surfactant, the fungi were also able to grow on nonion surfactant and on soap. The application of these fungi for environmental cleansing after detergent pollution is also discussed.

  7. Surfactant therapy restores gas exchange in lung injury due to paraquat intoxication in rats

    NARCIS (Netherlands)

    K.L. So; E. de Buijzer; D.A.M.P.J. Gommers (Diederik); U. Kaisers; P.J.J. van Genderen (Perry); B.F. Lachmann (Burkhard)


    textabstractParaquat is a weed killer which causes often fatal lung damage in humans and other animals. There is evidence that the pulmonary surfactant system is involved in the pathophysiology of respiratory failure after paraquat intoxication and, therefore, the

  8. Dissolution of anionic surfactant mesophases. (United States)

    Poulos, Andreas S; Jones, Christopher S; Cabral, João T


    Linear and circular solvent penetration experiments are used to study the dissolution of anionic SLE3S surfactant mesophases in water. We show that a lamellar (Lα) phase in contact with water will transit through a series of cubic, hexagonal, and micellar phase bands with sharp interfaces identified from their optical textures. In both linear and circular geometries, the kinetics of front propagation and eventual dissolution are well described by diffusive penetration of water, and a simple model applies to both geometries, with a different effective diffusion coefficient for water Df as the only fitting parameter. Finally, we show a surprising variation of dissolution rates with initial surfactant concentration that can be well explained by assuming that the driving force for solvent penetration is the osmotic pressure difference between neat water and the aqueous fraction of the mesophase that is highly concentrated in surfactant counterions.

  9. Cationic surfactants as the hydrolytic micellar catalysts


    Janošcová, Petra


    Cationic surfactants as the hydrolytic micellar catalysts Petra Janošcová The effectiveness of hydrolytic cleavage of the pesticide fenitrothionin cationic surfactants micellar media has been tested. All used surfactants increased the rate of fenitrothionhydrolysis, which was the evidence of micellar catalysis. For some surfactants decreases has been evident at the highest rate of hydrolysis concentrations. It has been the result of a phenomenon called the effect of empty micelles. High hydro...

  10. Surfactant adsorption to soil components and soils

    NARCIS (Netherlands)

    Ishiguro, Munehide; Koopal, Luuk K.


    Soils are complex and widely varying mixtures of organic matter and inorganic materials; adsorption of surfactants to soils is therefore related to the soil composition. We first discuss the properties of surfactants, including the critical micelle concentration (CMC) and surfactant adsorption on

  11. In vitro surfactant structure-toxicity relationships: implications for surfactant use in sexually transmitted infection prophylaxis and contraception.

    Directory of Open Access Journals (Sweden)

    Ângela S Inácio

    Full Text Available BACKGROUND: The need for woman-controlled, cheap, safe, effective, easy-to-use and easy-to-store topical applications for prophylaxis against sexually transmitted infections (STIs makes surfactant-containing formulations an interesting option that requires a more fundamental knowledge concerning surfactant toxicology and structure-activity relationships. METHODOLOGY/PRINCIPAL FINDINGS: We report in vitro effects of surfactant concentration, exposure time and structure on the viability of mammalian cell types typically encountered in the vagina, namely, fully polarized and confluent epithelial cells, confluent but non-polarized epithelial-like cells, dendritic cells, and human sperm. Representatives of the different families of commercially available surfactants--nonionic (Triton X-100 and monolaurin, zwitterionic (DDPS, anionic (SDS, and cationic (C(nTAB (n = 10 to 16, C(12PB, and C(12BZK--were examined. Triton X-100, monolaurin, DDPS and SDS were toxic to all cell types at concentrations around their critical micelle concentration (CMC suggesting a non-selective mode of action involving cell membrane destabilization and/or destruction. All cationic surfactants were toxic at concentrations far below their CMC and showed significant differences in their toxicity toward polarized as compared with non-polarized cells. Their toxicity was also dependent on the chemical nature of the polar head group. Our results suggest an intracellular locus of action for cationic surfactants and show that their structure-activity relationships could be profitably exploited for STI prophylaxis in vaginal gel formulations. The therapeutic indices comparing polarized epithelial cell toxicity to sperm toxicity for all surfactants examined, except C(12PB and C(12BZK, does not justify their use as contraceptive agents. C(12PB and C(12BZK are shown to have a narrow therapeutic index recommending caution in their use in contraceptive formulations. CONCLUSIONS

  12. Mobilization of arsenic from contaminated sediment by anionic and nonionic surfactants. (United States)

    Liang, Chuan; Peng, Xianjia


    The increasing manufacture of surfactants and their wide application in industry, agriculture and household detergents have resulted in large amounts of surfactant residuals being discharged into water and distributed into sediment. Surfactants have the potential to enhance arsenic mobility, leading to risks to the environment and even human beings. In this study, batch and column experiments were conducted to investigate arsenic mobilization from contaminated sediment by the commercial anionic surfactants sodium dodecylbenzenesulfonate (SDBS), sodium dodecyl sulfate (SDS), sodium laureth sulfate (AES) and nonionic surfactants phenyl-polyethylene glycol (Triton X-100) and polyethylene glycol sorbitan monooleate (Tween-80). The ability of surfactants to mobilize arsenic followed the order AES>SDBS>SDS≈Triton X-100>Tween 80. Arsenic mobilization by AES and Triton X-100 increased greatly with the increase of surfactant concentration and pH, while arsenic release by SDBS, SDS and Tween-80 slightly increased. The divalent ion Ca2+ caused greater reduction of arsenic mobilization than Na+. Sequential extraction experiments showed that the main fraction of arsenic mobilized was the specifically adsorbed fraction. Solid phase extraction showed that arsenate (As(V)) was the main species mobilized by surfactants, accounting for 65.05%-77.68% of the total mobilized arsenic. The mobilization of arsenic was positively correlated with the mobilization of iron species. The main fraction of mobilized arsenic was the dissolved fraction, accounting for 70% of total mobilized arsenic. Copyright © 2016. Published by Elsevier B.V.


    A demonstration of surfactant-enhanced aquifer remediation was conducted during the spring of 1999 at Marine Corps Base, Camp LeJeune, NC. A PCE-DNAPL zone was identified and delineated by extensive soil sampling in 1997, and was further characteized by a partitioning interwell t...

  14. Lipoteichoic acid induces surfactant protein-A biosynthesis in human alveolar type II epithelial cells through activating the MEK1/2-ERK1/2-NF-κB pathway

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    Liu Feng-Lin


    Full Text Available Abstract Background Lipoteichoic acid (LTA, a gram-positive bacterial outer membrane component, can cause septic shock. Our previous studies showed that the gram-negative endotoxin, lipopolysaccharide (LPS, could induce surfactant protein-A (SP-A production in human alveolar epithelial (A549 cells. Objectives In this study, we further evaluated the effect of LTA on SP-A biosynthesis and its possible signal-transducing mechanisms. Methods A549 cells were exposed to LTA. Levels of SP-A, nuclear factor (NF-κB, extracellular signal-regulated kinase 1/2 (ERK1/2, and mitogen-activated/extracellular signal-regulated kinase kinase (MEK1 were determined. Results Exposure of A549 cells to 10, 30, and 50 μg/ml LTA for 24 h did not affect cell viability. Meanwhile, when exposed to 30 μg/ml LTA for 1, 6, and 24 h, the biosynthesis of SP-A mRNA and protein in A549 cells significantly increased. As to the mechanism, LTA enhanced cytosolic and nuclear NF-κB levels in time-dependent manners. Pretreatment with BAY 11–7082, an inhibitor of NF-κB activation, significantly inhibited LTA-induced SP-A mRNA expression. Sequentially, LTA time-dependently augmented phosphorylation of ERK1/2. In addition, levels of phosphorylated MEK1 were augmented following treatment with LTA. Conclusions Therefore, this study showed that LTA can increase SP-A synthesis in human alveolar type II epithelial cells through sequentially activating the MEK1-ERK1/2-NF-κB-dependent pathway.

  15. Aerosol delivery of synthetic lung surfactant

    Directory of Open Access Journals (Sweden)

    Frans J. Walther


    Full Text Available Background. Nasal continuous positive airway pressure (nCPAP is a widely accepted technique of non-invasive respiratory support in premature infants with respiratory distress syndrome due to lack of lung surfactant. If this approach fails, the next step is often intubation, mechanical ventilation (MV and intratracheal instillation of clinical lung surfactant.Objective. To investigate whether aerosol delivery of advanced synthetic lung surfactant, consisting of peptide mimics of surfactant proteins B and C (SP-B and SP-C and synthetic lipids, during nCPAP improves lung function in surfactant-deficient rabbits.Methods. Experimental synthetic lung surfactants were produced by formulating 3% Super Mini-B peptide (SMB surfactant, a highly surface active SP-B mimic, and a combination of 1.5% SMB and 1.5% of the SP-C mimic SP-Css ion-lock 1 (BC surfactant, with a synthetic lipid mixture. After testing aerosol generation using a vibrating membrane nebulizer and aerosol conditioning (particle size, surfactant composition and surface activity, we investigated the effects of aerosol delivery of synthetic SMB and BC surfactant preparations on oxygenation and lung compliance in saline-lavaged, surfactant-deficient rabbits, supported with either nCPAP or MV.Results. Particle size distribution of the surfactant aerosols was within the 1–3 µm distribution range and surfactant activity was not affected by aerosolization. At a dose equivalent to clinical surfactant therapy in premature infants (100 mg/kg, aerosol delivery of both synthetic surfactant preparations led to a quick and clinically relevant improvement in oxygenation and lung compliance in the rabbits. Lung function recovered to a greater extent in rabbits supported with MV than with nCPAP. BC surfactant outperformed SMB surfactant in improving lung function and was associated with higher phospholipid values in bronchoalveolar lavage fluid; these findings were irrespective of the type of ventilatory

  16. Surfactant gene polymorphisms and interstitial lung diseases

    Directory of Open Access Journals (Sweden)

    Pantelidis Panagiotis


    Full Text Available Abstract Pulmonary surfactant is a complex mixture of phospholipids and proteins, which is present in the alveolar lining fluid and is essential for normal lung function. Alterations in surfactant composition have been reported in several interstitial lung diseases (ILDs. Furthermore, a mutation in the surfactant protein C gene that results in complete absence of the protein has been shown to be associated with familial ILD. The role of surfactant in lung disease is therefore drawing increasing attention following the elucidation of the genetic basis underlying its surface expression and the proof of surfactant abnormalities in ILD.

  17. The late administration of surfactant

    African Journals Online (AJOL)

    Arterial/alveolar oxygen ratio following administration of surfactant. Hours After Dosing. The outcome of infants receiving delayed SRT was good. The mean duration of ventilation of surviving infants was. 7,9 ± 4,3 days. Oxygen therapy post ventilation was required for a mean of 5,7 ± 4,5 days and infants were hospitalised ...

  18. Interactions of surfactants with lipid membranes. (United States)

    Heerklotz, Heiko


    Surfactants are surface-active, amphiphilic compounds that are water-soluble in the micro- to millimolar range, and self-assemble to form micelles or other aggregates above a critical concentration. This definition comprises synthetic detergents as well as amphiphilic peptides and lipopeptides, bile salts and many other compounds. This paper reviews the biophysics of the interactions of surfactants with membranes of insoluble, naturally occurring lipids. It discusses structural, thermodynamic and kinetic aspects of membrane-water partitioning, changes in membrane properties induced by surfactants, membrane solubilisation to micelles and other phases formed by lipid-surfactant systems. Each section defines and derives key parameters, mentions experimental methods for their measurement and compiles and discusses published data. Additionally, a brief overview is given of surfactant-like effects in biological systems, technical applications of surfactants that involve membrane interactions, and surfactant-based protocols to study biological membranes.

  19. Separation and preconcentration of riboflavin from human plasma using polythionine coated magnetite/hydroxyapatite nanocomposite prior to analysis by surfactant-enhanced fluorimetry (United States)

    Farzin, Leila; Shamsipur, Mojtaba


    The exploration of novel adsorption properties of conductive polymers based on hybridization with biocompatible nanomaterials receives an increasing interest. In this regard, hydroxyapatite (HA) bioceramic is of critical importance mainly owing to its facile synthesis, high surface area, economic and low toxicity in biological environments. In this work, we first prepared and characterized a magnetite/hydroxyapatite (Fe3O4/HA) nanocomposite using the bio-waste chicken eggshell via an attractive green way that involved low cost and irrespective of toxicity. Then, polythionine as a novel class of conductive polymers was in situ coated on the synthesized magnetic bioceramic for the separation and preconcentration of riboflavin (vitamin B2) in human plasma before its fluorimetric determination. Considering the putative role of riboflavin in protecting against cancer and cardiovascular diseases, it is essential to evaluate this vitamin in biological fluids. The described method possesses a linear range of 0.75-262.5 μg L- 1 (R2 = 0.9985) and a detection limit of 0.20 μg L- 1 (signal-to-noise ratio of 3). The relative standard deviations (RSDs) for single-sorbent repeatability and sorbent-to-sorbent reproducibility were less than 4.0% and 7.6% (n = 5), respectively. The respective enrichment factor and extraction recovery of the method found to be 35.7 and 98.4%. The analytical performance of method for riboflavin was characterized by good consistency of the results with those obtained by the enzyme-linked immunosorbent assay (ELISA) conventional method (p-value of human subjects and is addressed to clinical laboratories.

  20. Surfactant protein D is proatherogenic in mice

    DEFF Research Database (Denmark)

    Sorensen, Grith L; Madsen, Jens; Kejling, Karin


    Surfactant protein D (SP-D) is an important innate immune defense molecule that mediates clearance of pathogens and modulates the inflammatory response. Moreover, SP-D is involved in lipid homeostasis, and pulmonary accumulation of phospholipids has previously been observed in SP-D-deficient (Spd......-/-) mice. Atherogenesis involves both inflammation and lipid deposition, and we investigated the role of SP-D in the development of atherosclerosis. SP-D synthesis was localized to vascular endothelial cells. Atherosclerotic lesion areas were 5.6-fold smaller in the aortic roots in Spd-/- mice compared...... with wild-type C57BL/6N mice on an atherogenic diet. HDL cholesterol (HDL-C) was significantly elevated in Spd-/- mice. Treatment of Spd-/- mice with a recombinant fragment of human SP-D resulted in decreases of HDL-C (21%) as well as total cholesterol (26%), and LDL cholesterol (28%). Plasma TNF...

  1. Surfactants in tribology, v.3

    CERN Document Server

    Biresaw, Girma


    The manufacture and use of almost every consumer and industrial product rely on application of advanced knowledge in surface science and tribology. These two disciplines are of critical importance in major economic sectors, such as mining, agriculture, manufacturing (including metals, plastics, wood, computers, MEMS, NEMS, appliances), construction, transportation, and medical instruments, transplants, and diagnostic devices. An up-to-date reference with contributions by experts in surface science and tribology, Surfactants in Tribology, Volume 3 discusses some of the underlying tribological a

  2. Combined effects of polymers and KL(4) peptide on surface activity of pulmonary surfactant lipids. (United States)

    Lu, Karen W; Taeusch, H William


    Addition of ionic and nonionic polymers can improve the function of therapeutic surfactants in vitro and in vivo, especially under conditions that tend to inhibit surfactant activity. Since surfactant proteins also act to reduce surfactant inhibition, we studied the relative effects of a synthetic peptide (that mimics some of the properties of a surfactant protein), polymers, and their combination on function of surfactant phospholipid activity in vitro. We evaluated surface activity after adding polymers-polyethylene glycol or hyaluronan-to a lipid mixture with or without the synthetic peptide, sinapultide (KL(4)). Using a pulsating bubble surfactometer, we measured peptide/polymer effects separately or combined at two peptide concentrations. Phospholipid mixtures, with or without KL(4) or polymers, all demonstrated good surface activity. With serum present as an inhibiting agent, adding either concentration of KL(4) reduced inhibition. Mixtures containing the higher concentration of KL(4) required higher concentrations of serum for inhibition to occur. Adding either polymer to mixtures with KL(4) further decreased susceptibility to inhibition (required higher serum concentrations). In the presence of serum, high molecular weight hyaluronan with KL(4) at 0.4 mg/ml improved surface activity to a greater degree than 0.8 mg/ml KL(4) without polymer. If the beneficial effects of adding polymer to KL(4)-lipid mixtures are also borne out in the treatment of experimental lung injury, these peptide-polymer surfactant combinations may eventually prove useful in the treatment of some forms of acute lung injury in humans.

  3. Antibacterial Activity, in Vitro Cytotoxicity, and Cell Cycle Arrest of Gemini Quaternary Ammonium Surfactants. (United States)

    Zhang, Shanshan; Ding, Shiping; Yu, Jing; Chen, Xuerui; Lei, Qunfang; Fang, Wenjun


    Twelve gemini quaternary ammonium surfactants have been employed to evaluate the antibacterial activity and in vitro cytotoxicity. The antibacterial effects of the gemini surfactants are performed on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) with minimum inhibitory concentrations (MIC) ranging from 2.8 to 167.7 μM. Scanning electron microscopy (SEM) analysis results show that these surfactants interact with the bacterial cell membrane, disrupt the integrity of the membrane, and consequently kill the bacteria. The data recorded on C6 glioma and HEK293 human kidney cell lines using an MTT assay exhibit low half inhibitory concentrations (IC50). The influences of the gemini surfactants on the cell morphology, the cell migration ability, and the cell cycle are observed through hematoxylin-eosin (HE) staining, cell wound healing assay, and flow cytometric analyses, respectively. Both the values of MIC and IC50 decrease against the growth of the alkyl chain length of the gemini surfactants with the same spacer group. In the case of surfactants 12-s-12, the MICs and IC50s are found to decrease slightly with the spacer chain length changing from 2 to 8 and again to increase at higher spacer length (s = 10-12). All of the gemini surfactants show great antibacterial activity and cytotoxicity, and they might exhibit potential applications in medical fields.

  4. Surfactant transport on viscous bilayers (United States)

    Matar, Omar; Craster, Richard; Warner, Mark


    We model the external delivery of surfactant to pulmonary airways, an integral part of Surfactant Replacement Therapy (SRT), a method of treatment of Respiratory Distress Syndrome in neonates. We examine the spreading dynamics of insoluble surfactant by Marangoni stresses along the mucus-perciliary liquid bilayers that line the inside of airways. The bilayer is modelled as a thin highly viscous mucus surface film (mucus) overlying a much less viscous perciliary liquid layer (PCL); this is appropriate for small airways. By exploiting this large viscosity constrast, a variant of standard lubrication theory is adopted wherein terms, which would have otherwise been neglected in the lubrication approximation, are promoted in order to model correctly the presence of the mucus. Inclusion of van der Waals forces in the model permit the study of the effect of this mucus 'skin' on the possibility of bilayer rupture, a potential cause of failure of SRT. We find that increasing the viscosity contrast and initial mucus layer thickness delays the onset of rupture, while increasing the relative significance of Marangoni stresses leads to more marked thinning and rapid bilayer rupture [1]. [1] O. K. Matar, R. V. Craster and M. R. Warner, submitted to J. Fluid Mech. (2001).

  5. Hydrodynamic size of DNA/cationic gemini surfactant complex as a function of surfactant structure. (United States)

    Devínsky, Ferdinand; Pisárcik, Martin; Lacko, Ivan


    The present study deals with the determination of hydrodynamic size of DNA/cationic gemini surfactant complex in sodium bromide solution using the dynamic light scattering method. Cationic gemini surfactants with polymethylene spacer of variable length were used for the interaction with DNA. The scattering experiments were performed at constant DNA and sodium bromide concentrations and variable surfactant concentration in the premicellar and micellar regions as a function of surfactant spacer length. It was found that the DNA conformation strongly depends on the polymethylene spacer length as well as on the surfactant concentration relative to the surfactant critical micelle concentration. Gemini surfactant molecules with 4 methylene groups in the spacer were found to be the least efficient DNA compacting agent in the region above the surfactant cmc. Gemini molecules with the shortest spacer length (2 methylene groups) and the longest spacer length (8 methylene groups) investigated showed the most efficient DNA compaction ability.

  6. Surfactant inhibition in acute respiratory failure : consequences for exogenous surfactant therapy

    NARCIS (Netherlands)

    E.P. Eijking (Eric)


    textabstractThe neonatal respiratory distress syndrome (RDS) is characterized by immaturity of the lung, resulting in relative or absolute absence of pulmonary surfactant. Worldwide, neonates suffering from RDS have been treated successfully with exogenous surfactant preparations. Currently,

  7. Perfluorinated surfactants in surface and drinking waters. (United States)

    Skutlarek, Dirk; Exner, Martin; Färber, Harald


    In this paper recent results are provided of an investigation on the discovery of 12 perfluorinated surfactants (PS) in different surface and drinking waters (Skutlarek et al. 2006 a, Skutlarek et al. 2006 b). In the last years, many studies have reported ubiquitous distribution of this group of perfluorinated chemicals, especially perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in the environment, particularly in wildlife animal and human samples (Giesy and Kannan 2001, Houde et al. 2006, Prevedouros et al. 2006). Perfluorinated surfactants (e.g. PFOS and PFOA) have shown different potentials for reproductory interference and carcinogenity in animal experiments as well as partly long half-lives in humans (Guruge et al. 2006, FSA UK 2006a, FSA UK 2006b, 3M 2005, OECD 2002, Yao and Zhong 2005). They possess compound-dependent extreme recalcitrance against microbiological and chemical degradation and, in addition, they show variable potentials for bioaccumulation in animals and humans (Houde et al. 2006). Surface and drinking water samples were collected from different sampling sites: Surface waters: samples taken from the rivers Rhine, Ruhr, Moehne and some of their tributaries. Further samples were taken from the Rhine-Herne-Canal and the Wesel-Datteln-Canal. Drinking waters: samples taken in public buildings of the Rhine-Ruhr area. After sample clean-up and concentration by solid-phase extraction, the perfluorinated surfactants were determined using HPLC-MS/MS. All measured concentrations (sum of seven mainly detected components) in the Rhine river and its main tributaries (mouths) were determined below 100 ng/L. The Ruhr river (tributary of the Rhine) showed the highest concentration (94 ng/L), but with a completely different pattern of components (PFOA as major component), as compared with the other tributaries and the Rhine river. Further investigations along the Ruhr river showed remarkably high concentrations of PS in the upper reaches of

  8. Acute Pathophysiological Effects of Intratracheal Instillation of Budesonide and Exogenous Surfactant in a Neonatal Surfactant-depleted Piglet Model

    Directory of Open Access Journals (Sweden)

    Chia-Feng Yang


    Conclusions: Intratracheal instillation of surfactant or surfactant plus budesonide can improve oxygenation and pulmonary histologic outcome in neonatal surfactant-depleted lungs. The additional use of budesonide does not disturb the function of the exogenous surfactant. Intratracheal administration of a corticosteroid combined with surfactant may be an effective method for alleviating local pulmonary inflammation in severe RDS.

  9. Surfactant inhibition in acute respiratory failure : consequences for exogenous surfactant therapy


    Eijking, Eric


    textabstractThe neonatal respiratory distress syndrome (RDS) is characterized by immaturity of the lung, resulting in relative or absolute absence of pulmonary surfactant. Worldwide, neonates suffering from RDS have been treated successfully with exogenous surfactant preparations. Currently, exogenous surfactant administration has been accepted as a valuable treatment for this syndrome. Nevertheless, many questions on exogenous surfactant treatment remain unanswered. It has been observed that...

  10. Influence of surfactant on gas bubble stability. (United States)

    Hanwright, Jennifer; Zhou, James; Evans, Geoffrey M; Galvin, Kevin P


    Gas-bubble stability is achieved either by a reduction in the Laplace pressure or by a reduction in the permeability of the gas-liquid interface. Although insoluble surfactants have been shown definitively in many studies to lower the permeability of the gas-liquid interface and hence increase the resistance to interfacial mass transfer, remarkably little work has been done on the effects of soluble surfactants. An experimental system was developed to measure the effect of the soluble surfactant dodecyl trimethylammonium bromide on the desorption and absorption of carbon dioxide gas through a quiescent planar interface. The desorption experiments conformed to the model of non-steady-state molecular diffusion. The absorption experiments, however, produced an unexpected mass transfer mechanism, with surface renewal, probably because of instability in the density gradient formed by the carbon dioxide. In general, the soluble surfactant produced no measurable reduction in the rate of interfacial mass transfer for desorption or absorption. This finding is consistent with the conclusion of Caskey and Barlage that soluble surfactants produce a significantly lower resistance to interfacial mass transfer than do insoluble surfactants. The dynamic adsorption and desorption of the surfactant molecules at the gas-liquid interface creates short-term vacancies, which presumably permit the unrestricted transfer of the gas molecules through the interface. This surfactant exchange does not occur for insoluble surfactants. Gas bubbles formed in the presence of a high concentration of soluble surfactant were observed to dissolve completely, while those formed in the presence of the insoluble surfactant stearic acid did not dissolve easily, and persisted for very long periods. The interfacial concentration of stearic acid rises during bubble dissolution, as it is insoluble, and must eventually achieve full monolayer coverage and a state of compression, lowering the permeability of the

  11. Surfactant Therapy of ALI and ARDS (United States)

    Raghavendran, K; Willson, D; Notter, RH


    This article examines exogenous lung surfactant replacement therapy and its utility in mitigating clinical acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS). Biophysical research has documented that lung surfactant dysfunction can be reversed or mitigated by increasing surfactant concentration, and multiple studies in animals with ALI/ARDS have shown that respiratory function and pulmonary mechanics in vivo can be improved by exogenous surfactant administration. Exogenous surfactant therapy is a routine intervention in neonatal intensive care, and is life-saving in preventing or treating the neonatal respiratory distress syndrome (NRDS) in premature infants. In applications relevant for lung injury-related respiratory failure and ALI/ARDS, surfactant therapy has been shown to be beneficial in term infants with pneumonia and meconium aspiration lung injury, and in children up to age 21 with direct pulmonary forms of ALI/ARDS. However, extension of exogenous surfactant therapy to adults with respiratory failure and clinical ALI/ARDS remains a challenge. Coverage here reviews clinical studies of surfactant therapy in pediatric and adult patients with ALI/ARDS, particularly focusing on its potential advantages in patients with direct pulmonary forms of these syndromes. Also discussed is the rationale for mechanism-based therapies utilizing exogenous surfactant in combination with agents targeting other aspects of the multifaceted pathophysiology of inflammatory lung injury. Additional factors affecting the efficacy of exogenous surfactant therapy in ALI/ARDS are also described, including the difficulty of effectively delivering surfactants to injured lungs and the existence of activity differences between clinical surfactant drugs. PMID:21742216

  12. Surfactant-enhanced cellulose nanocrystal Pickering emulsions. (United States)

    Hu, Zhen; Ballinger, Sarah; Pelton, Robert; Cranston, Emily D


    The effect of surfactants on the properties of Pickering emulsions stabilized by cellulose nanocrystals (CNCs) was investigated. Electrophoretic mobility, interfacial tension, confocal microscopy and three-phase contact angle measurements were used to elucidate the interactions between anionic CNCs and cationic alkyl ammonium surfactants didecyldimethylammonium bromide (DMAB) and cetyltrimethylammonium bromide (CTAB). Both surfactants were found to adsorb onto CNCs with concentration-dependent morphology. At low concentrations, individual surfactant molecules adsorbed with alkyl tails pointing outward leading to hydrophobic CNCs. At higher concentrations, above the surfactant's apparent critical micelle concentration, surfactant aggregate morphologies on CNCs were inferred and the hydrophobicity of CNCs decreased. DMAB, which has two alkyl tails, rendered the CNCs more hydrophobic than CTAB which has only a single alkyl tail, at all surfactant concentrations. The change in CNC wettability from surfactant adsorption was directly linked to emulsion properties; adding surfactant increased the emulsion stability, decreased the droplet size, and controlled the internal phase of CNC Pickering emulsions. More specifically, a double transitional phase inversion, from oil-in-water to water-in-oil and back to oil-in-water, was observed for emulsions with CNCs and increasing amounts of DMAB (the more hydrophobic surfactant). With CNCs and CTAB, no phase inversion was induced. This work represents the first report of CNC Pickering emulsions with surfactants as well as the first CNC Pickering emulsions that can be phase inverted. The ability to surface modify CNCs in situ and tailor emulsions by adding surfactants may extend the potential of CNCs to new liquid formulations and extruded/spray-dried materials. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Surfactant nebulisation : lung function, surfactant distribution and pulmonary blood flow distribution in lung lavaged rabbits

    NARCIS (Netherlands)

    Dijk, Peter H.; Heikamp, A; Bambang Oetomo, Sidarto


    Objective: Surfactant nebulisation is a promising alternative to surfactant instillation in newborns with the respiratory distress syndrome. Although less surfactant is deposited in the lung, it improves gas exchange, probably due to a superior distribution. We hypothesize that a more uniform

  14. Solubilization of Hydrophobic Dyes in Surfactant Solutions

    Directory of Open Access Journals (Sweden)

    Ali Reza Tehrani-Bagha


    Full Text Available In this paper, the use of surfactants for solubilization of hydrophobic organic dyes (mainly solvent and disperse dyes has been reviewed. The effect of parameters such as the chemical structures of the surfactant and the dye, addition of salt and of polyelectrolytes, pH, and temperature on dye solubilization has been discussed. Surfactant self-assemble into micelles in aqueous solution and below the concentration where this occurs—the critical micelle concentration (CMC—there is no solubilization. Above the CMC, the amount of solubilized dye increases linearly with the increase in surfactant concentration. It is demonstrated that different surfactants work best for different dyes. In general, nonionic surfactants have higher solubilization power than anionic and cationic surfactants. It is likely that the reason for the good performance of nonionic surfactants is that they allow dyes to be accommodated not only in the inner, hydrocarbon part of the micelle but also in the headgroup shell. It is demonstrated that the location of a dye in a surfactant micelle can be assessed from the absorption spectrum of the dye-containing micellar solution.

  15. Analysis of the regulation of surfactant phosphatidylcholine metabolism using stable isotopes. (United States)

    Brandsma, Joost; Postle, Anthony D


    The pathways and mechanisms that regulate pulmonary surfactant synthesis, processing, secretion and catabolism have been extensively characterised using classical biochemical and analytical approaches. These have constructed a model, largely in experimental animals, for surfactant phospholipid metabolism in the alveolar epithelial cell whereby phospholipid synthesised on the endoplasmic reticulum is selectively transported to lamellar body storage vesicles, where it is subsequently processed before secretion into the alveolus. Surfactant phospholipid is a complex mixture of individual molecular species defined by the combination of esterified fatty acid groups and a comprehensive description of surfactant phospholipid metabolism requires consideration of the interactions between such molecular species. However, until recently, lipid analytical techniques have not kept pace with the considerable advances in understanding of the enzymology and molecular biology of surfactant metabolism. Refinements in electrospray ionisation mass spectrometry (ESI-MS) can now provide very sensitive platforms for the rapid characterisation of surfactant phospholipid composition in molecular detail. The combination of ESI-MS and administration of phospholipid substrates labelled with stable isotopes extends this analytical approach to the quantification of synthesis and turnover of individual molecular species of surfactant phospholipid. As this methodology does not involve radioactivity, it is ideally suited to application in clinical studies. This review will provide an overview of the metabolic processes that regulate the molecular specificity of surfactant phosphatidylcholine together with examples of how the application of stable isotope technologies in vivo has, for the first time, begun to explore regulation of the molecular specificity of surfactant synthesis in human subjects. Copyright © 2017 Elsevier GmbH. All rights reserved.

  16. Photoisomerization of merocyanine 540 in polymer–surfactant ...

    Indian Academy of Sciences (India)


    surfactant aggregate. 1. Introduction. Many biological and technological processes involve polymer-surfactant interaction 1–17. ... model' (figure 1), structure of the polymer-surfactant aggregate is like a necklace with .... group projected into bulk water.

  17. Hemolysis by surfactants--A review. (United States)

    Manaargadoo-Catin, Magalie; Ali-Cherif, Anaïs; Pougnas, Jean-Luc; Perrin, Catherine


    An overview of the use of surfactants for erythrocyte lysis and their cell membrane action mechanisms is given. Erythrocyte membrane characteristics and its association with the cell cytoskeleton are presented in order to complete understanding of the erythrocyte membrane distortion. Cell homeostasis disturbances caused by surfactants might induce changes starting from shape modification to cell lysis. Two main mechanisms are hypothesized in literature which are osmotic lysis and lysis by solubilization even if the boundary between them is not clearly defined. Another specific mechanism based on the formation of membrane pores is suggested in the particular case of saponins. The lytic potency of a surfactant is related to its affinity for the membrane and the modification of the lipid membrane curvature. This is to be related to the surfactant shape defined by its hydrophobic and hydrophilic moieties but also by experimental conditions. As a consequence, prediction of the hemolytic potency of a given surfactant is challenging. Several studies are focused on the relation between surfactant erythrolytic potency and their physico-chemical parameters such as the critical micellar concentration (CMC), the hydrophile-lipophile balance (HLB), the surfactant membrane/water partition coefficient (K) or the packing parameter (P). The CMC is one of the most important factors considered even if a lytic activity cut-off effect points out that the only consideration of CMC not enough predictive. The relation K.CMC must be considered in addition to the CMC to predict the surfactant lytic capacity within the same family of non ionic surfactant. Those surfactant structure/lytic activity studies demonstrate the requirement to take into account a combination of physico-chemical parameters to understand and foresee surfactant lytic potency. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. "SP-G", a putative new surfactant protein--tissue localization and 3D structure.

    Directory of Open Access Journals (Sweden)

    Felix Rausch

    Full Text Available Surfactant proteins (SP are well known from human lung. These proteins assist the formation of a monolayer of surface-active phospholipids at the liquid-air interface of the alveolar lining, play a major role in lowering the surface tension of interfaces, and have functions in innate and adaptive immune defense. During recent years it became obvious that SPs are also part of other tissues and fluids such as tear fluid, gingiva, saliva, the nasolacrimal system, and kidney. Recently, a putative new surfactant protein (SFTA2 or SP-G was identified, which has no sequence or structural identity to the already know surfactant proteins. In this work, computational chemistry and molecular-biological methods were combined to localize and characterize SP-G. With the help of a protein structure model, specific antibodies were obtained which allowed the detection of SP-G not only on mRNA but also on protein level. The localization of this protein in different human tissues, sequence based prediction tools for posttranslational modifications and molecular dynamic simulations reveal that SP-G has physicochemical properties similar to the already known surfactant proteins B and C. This includes also the possibility of interactions with lipid systems and with that, a potential surface-regulatory feature of SP-G. In conclusion, the results indicate SP-G as a new surfactant protein which represents an until now unknown surfactant protein class.

  19. Microwave corneosurfametry: a minute assessment of the skin compatibility of surfactant-containing products. (United States)

    Goffin, V; Piérard-Franchimont, C; Piérard, G E


    Surfactants may elicit several undesirable effects on the skin. The stratum corneum is one of the targets showing primary changes after a short contact with detergents. Corneosurfametry was introduced as an ex vivo bioassay to assess the interaction and compatibility of surfactants with human stratum corneum. The present work introduces a variant of the regular corneosurfametry test. Microwaving set at 750 W for 30 s was used to shorten the duration of the technical procedure and to allow the rating of neat surfactant-containing products. The color of samples (L.* and Chroma C*) was measured to derive the colorimetric index of mildness (CIM), the values of which rise from 0 to 70 with increasing surfactant mildness toward human stratum corneum. Data were compared with standard corneosurfametry performed at 20 and 40°C. Data indicate that increasing the temperature of the test solutions and microwaving alter the CIM values of most surfactants. Only the most gentle products are little affected. An overall good correlation exists between the regular and microwave corneosurfametry data. Microwave corneosurfametry is a new sensitive tool for predicting skin compatibility of surfactants.

  20. Structured fluids polymers, colloids, surfactants

    CERN Document Server

    Witten, Thomas A


    Over the last thirty years, the study of liquids containing polymers, surfactants, or colloidal particles has developed from a loose assembly of facts into a coherent discipline with substantial predictive power. These liquids expand our conception of what condensed matter can do. Such structured-fluid phenomena dominate the physical environment within living cells. This book teaches how to think of these fluids from a unified point of view showing the far-reaching effects ofthermal fluctuations in producing forces and motions. Keeping mathematics to a minimum, the book seeks the simplest expl

  1. Surfactants and submicron sea spray generation

    NARCIS (Netherlands)

    Sellegri, K.; O'Dowd, C.D.; Yoon, Y.J.; Jennings, S.G.; Leeuw, G. de


    Laboratory experiments have been carried out to elucidate the role of surfactants on the primary marine aerosol production of submicron marine aerosols. A synthetic surfactant SDS was used in conjunction with artificially generated seawater, and the resultant bubble-mediated aerosol produced was

  2. Hyaluronan decreases surfactant inactivation in vitro. (United States)

    Lu, Karen W; Goerke, Jon; Clements, John A; Taeusch, H William


    Hyaluronan (HA) is an anionic polymer and a constituent of alveolar fluid that can bind proteins, phospholipids, and water. Previous studies have established that nonionic polymers improve the surface activity of pulmonary surfactants by decreasing inactivation of surfactant. In this work, we investigate whether HA can also have beneficial effects when added to surfactants. We used a modified pulsating bubble surfactometer to measure mixtures of several commercially available pulmonary surfactants or native calf surfactant with and without serum inactivation. Surface properties such as equilibrium surface tension, minimum and maximum surface tensions on compression and expansion of a surface film, and degree of surface area reduction required to reach a surface tension of 10 mN/m were measured. In the presence of serum, addition of HA dramatically improved the surface activities of all four surfactants and in some cases in the absence of serum as well. These results indicate that HA reduces inactivation of surfactants caused by serum and add evidence that endogenous HAs may interact with alveolar surfactant under normal and abnormal conditions.

  3. Surfactant Adsorption: A Revised Physical Chemistry Lab (United States)

    Bresler, Marc R.; Hagen, John P.


    Many physical chemistry lab courses include an experiment in which students measure surface tension as a function of surfactant concentration. In the traditional experiment, the data are fit to the Gibbs isotherm to determine the molar area for the surfactant, and the critical micelle concentration is used to calculate the Gibbs energy of micelle…

  4. Surfactant effects on soil aggregate tensile strength (United States)

    Little is known regarding a soil aggregate's tensile strength response to surfactants that may be applied to alleviate soil water repellency. Two laboratory investigations were performed to determine surfactant effects on the tensile strength of 1) Ap horizons of nine wettable, agricultural soils co...

  5. Surfactant treatment before first breath for respiratory distress syndrome in preterm lambs: comparison of a peptide-containing synthetic lung surfactant with porcine-derived surfactant

    Directory of Open Access Journals (Sweden)

    van Zyl JM


    Full Text Available Johann M van Zyl,1 Johan Smith2 1Division of Pharmacology, Department of Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa; 2Department of Paediatrics and Child Health, Tygerberg Children's Hospital, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa Background: In a recent study utilizing a saline-lavaged adult rabbit model, we described a significant improvement in systemic oxygenation and pulmonary shunt after the instillation of a novel synthetic peptide-containing surfactant, Synsurf. Respiratory distress syndrome in the preterm lamb more closely resembles that of the human infant, as their blood gas, pH values, and lung mechanics deteriorate dramatically from birth despite ventilator support. Moreover, premature lambs have lungs which are mechanically unstable, with the advantage of being able to measure multiple variables over extended periods. Our objective in this study was to investigate if Synsurf leads to improved systemic oxygenation, lung mechanics, and histology in comparison to the commercially available porcine-derived lung surfactant Curosurf® when administered before first breath in a preterm lamb model. Materials and methods: A Cesarean section was performed under general anesthesia on 18 time-dated pregnant Dohne Merino ewes at 129–130 days gestation. The premature lambs were delivered and ventilated with an expiratory tidal volume of 6–8 mL/kg for the first 30 minutes and thereafter at 8–10 mL/kg. In a randomized controlled trial, the two surfactants tested were Synsurf and Curosurf®, both at a dose of 100 mg/kg phospholipids (1,2-dipalmitoyl-L-α-phosphatidylcholine; 90% in Synsurf, 40% in Curosurf®. A control group of animals was treated with normal saline. Measurements of physiological variables, blood gases, and lung mechanics were made before and after surfactant and saline replacement and at 15, 30, 45, 60, 90, 120, 180

  6. Exogenous Pulmonary Surfactant as a Vehicle for Antimicrobials: Assessment of Surfactant-Antibacterial Interactions In Vitro

    Directory of Open Access Journals (Sweden)

    Alexei Birkun


    Full Text Available Owing to its unique surface-active properties, an exogenous pulmonary surfactant may become a promising drug delivery agent, in particular, acting as a vehicle for antibiotics in topical treatment of pneumonia. The purpose of this study was to assess a mutual influence of natural surfactant preparation and three antibiotics (amikacin, cefepime, and colistimethate sodium in vitro and to identify appropriate combination(s for subsequent in vivo investigations of experimental surfactant/antibiotic mixtures. Influence of antibiotics on surface-active properties of exogenous surfactant was assessed using the modified Pattle method. Effects of exogenous surfactant on antibacterial activity of antimicrobials against Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa were evaluated using conventional microbiologic procedures. Addition of amikacin or cefepime to surfactant had no significant influence on surface-active properties of the latter. Obvious reduction of surface-active properties was confirmed for surfactant/colistimethate composition. When suspended with antibiotics, surfactant either had no impact on their antimicrobial activity (amikacin or exerted mild to moderate influence (reduction of cefepime bactericidal activity and increase of colistimethate bacteriostatic activity against S. aureus and P. aeruginosa. Considering favorable compatibility profile, the surfactant/amikacin combination is advisable for subsequent investigation of joint surfactant/antibacterial therapy in animals with bacterial pneumonia.

  7. Surfactant protein C in canine pulmonary fibrosis. (United States)

    Eriksson, M; von Euler, H; Ekman, E; Nordling, K; Häggström, J; Johansson, J


    Canine pulmonary fibrosis (CPF) occurs most commonly in West Highland White Terriers. The differing incidences of CPF among dog breeds suggest that genetic factors contribute to its pathophysiology. Pulmonary fibrosis in humans is associated with mutations in the gene coding for lung surfactant protein C (SP-C) (SFTPC). To investigate the histopathologic changes and SP-C composition and genetic structure in dogs with CPF. Five dogs with PF, 2 dogs with other lung diseases, and 3 healthy dogs. Lung tissue from dogs with clinically suspected CPF and 5 control cases was analyzed histopathologically. Bronchoalveolar lavage fluid (BALF) collected postmortem from 3 terriers with histopathologically confirmed pulmonary fibrosis and the 5 controls were analyzed by Western blots, and the exons of SFTPC were sequenced for 2 dogs with PF and 1 dog with other lung disease. SP-C could not be detected in BALF of 1 dog with PF, although SP-B was present. A mutation was detected in SFTPC exon 5 of this dog. From 2 dogs with PF and in all 5 control dogs SP-B and SP-C were detected in BALF. Taken together, the results indicate that canine and human lung fibrosis share histopathologic features and that analysis of SP-C and its gene in a larger set of dogs with PF is warranted.

  8. The influence of lung surfactant liquid crystalline nanostructures on respiratory drug delivery. (United States)

    Das, Shyamal C; Stewart, Peter J


    The respiratory route increasingly has been used for both local and systemic drug delivery. Although drug is absorbed rapidly after respiratory delivery, the role of lung surfactant in drug delivery is not well understood. The human lung contains only around 15mL of surface lining fluid spread over ∼100m2 surface. The fluid contains lung surfactant at a concentration of 8-24mg/kg/body weight; the lung surfactant which is lipo-protein in nature can form different liquid crystalline nanostructures. After a brief overview of the anatomy of respiratory system, the review has focused on the current understanding of lung surface lining fluid, lung surfactants and their composition and possible self-assembled nanostructures. The role of lung surfactant in drug delivery and drug dissolution has been briefly considered. Lung surfactant may form different liquid crystalline phases which can have an active role in drug delivery. The hypotheses developed in this review focuses on the potential roles of surface epithelial fluid containing liquid crystalline nanostructures in defining the dissolution mechanism and rate. The hypotheses also focus an understanding how liquid crystalline nanostructures can be used to control dissolution rate and how the nanostructures might be changed to influence delivery and induce toxicity. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Development of a Synthetic Surfactant Using a Surfactant Protein-C Peptide Analog: In Vitro Studies of Surface Physical Properties. (United States)

    Bae, Chong Woo; Chung, Sung Hoon; Choi, Yong Sung


    Pulmonary surfactant (PS) replacement has been the gold standard therapy for neonatal respiratory distress syndrome; however, almost all commercial PSs contain animal proteins. We prepared a synthetic PS by using a human surfactant protein (SP) analog and evaluated its in vitro properties. A peptide sequence (CPVHLKRLLLLLLLLLLLLLLLL) of human SP-C was chosen to develop the peptide analog (SPa-C). The new synthetic SP-C PS (sSP-C PS) was synthesized from SPa-C, dipalmitoyl phosphatidylcholine, phosphatidyl glycerol, and palmitic acid. Physical properties of the sSP-C PS were evaluated by measuring the maximum and minimum surface tensions (STs), surfactant spreading, and adsorption rate. In addition, we recorded an ST-area diagram. The data obtained on sSP-C PS were subsequently compared with those of purified natural bovine surfactant (PNBS), and the commercial product, Surfacten®. The sSP-C PS and Surfacten® were found to have maximum ST values of 32-33 mN/m, whereas that of PNBS was much lower at 19 mN/m. The minimum ST values of all three products were less than 10 mN/m. The values that were measured for the equilibrium ST of rapidly spreading sSP-C PS, Surfacten®, and PNBS were 27, 27, and 24 mN/m, respectively. The surface adsorptions were found to be the same for all three PSs (20 mN/m). ST-area diagrams of sSP-C PS and Surfacten® revealed similar properties. In an in vitro experiment, the physical properties exhibited by sSP-C PS were similar to those of Surfacten®. Further study is required to evaluate the in vivo efficacy.

  10. Changes in hydration of the stratum corneum are the most suitable indicator to evaluate the irritation of surfactants on the skin. (United States)

    Fujimura, T; Shimotoyodome, Y; Nishijima, T; Sugata, K; Taguchi, H; Moriwaki, S


    Irritancy levels of surfactants on human skin have not been clarified completely. The relationships between skin damage and changes of skin properties caused by various surfactants were investigated using non-invasive measurements. Aqueous solutions of seven kinds of anionic, non-ionic, and amphoteric surfactants were exposed to the inside of forearm skin of 20 human subjects in two separate studies using the cup method. Hydration of the stratum corneum (SC), transepidermal water loss (TEWL), pH, skin surface roughness, and contents of the SC were measured before and after one exposure and after five and nine consecutive exposures to various surfactants. The discontinuation ratio of subjects for testing in each surfactant was determined by skin irritation symptoms and was defined as the degree of skin damage. Significant changes were observed only in hydration, TEWL, and natural moisturizing factors (NMF) content in the SC following surfactant exposure. A significant correlation was observed between the discontinuation ratio of each surfactant and the changes of hydration, TEWL, and NMF. Especially, the change of SC hydration showed an excellent correlation with the discontinuation ratio both for single (r = 0.942, P surfactants, and therefore is the most suitable indicator to evaluate the irritation of surfactants on the skin. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Tunable, antibacterial activity of silicone polyether surfactants. (United States)

    Khan, Madiha F; Zepeda-Velazquez, Laura; Brook, Michael A


    Silicone surfactants are used in a variety of applications, however, limited data is available on the relationship between surfactant structure and biological activity. A series of seven nonionic, silicone polyether surfactants with known structures was tested for in vitro antibacterial activity against Escherichia coli BL21. The compounds varied in their hydrophobic head, comprised of branched silicone structures with 3-10 siloxane linkages and, in two cases, phenyl substitution, and hydrophilic tail of 8-44 poly(ethylene glycol) units. The surfactants were tested at three concentrations: below, at, and above their Critical Micelle Concentrations (CMC) against 5 concentrations of E. coli BL21 in a three-step assay comprised of a 14-24h turbidometric screen, a live-dead stain and viable colony counts. The bacterial concentration had little effect on antibacterial activity. For most of the surfactants, antibacterial activity was higher at concentrations above the CMC. Surfactants with smaller silicone head groups had as much as 4 times the bioactivity of surfactants with larger groups, with the smallest hydrophobe exhibiting potency equivalent to sodium dodecyl sulfate (SDS). Smaller PEG chains were similarly associated with higher potency. These data link lower micelle stability and enhanced permeability of smaller silicone head groups to antibacterial activity. The results demonstrate that simple manipulation of nonionic silicone polyether structure leads to significant changes in antibacterial activity. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. A study of surfactant-assisted waterflooding

    Energy Technology Data Exchange (ETDEWEB)

    Scamehorn, J F; Harwell, J H


    In surfactant-assisted waterflooding, a surfactant slug is injected into a reservoir, followed by a brine spacer, followed by second surfactant slug. The charge on the surfactant in the first slug has opposite sign to that in the second slug. When the two slugs mix in the reservoir, a precipitate or coacervate is formed which plugs the permeable region of the reservoir. Subsequently injected water or brine is forced through the low permeability region of the reservoir, increasing sweep efficiency of the waterflood, compared to a waterflood not using surfactants. In this part of the work, two major tasks are performed. First, core floods are performed with oil present to demonstrate the improvement in incremental oil production, as well as permeability modification. Second, a reservoir simulation model will be proposed to further delineate the optimum strategy for implementation of the surfactant-assisted waterflooding, as well as indicate the reservoir types for which it would be most effective. Surfactants utilized were sodium dodecyl sulfate and dodecyl pyridinium chloride. 44 refs., 17 figs., 3 tabs.

  13. Surfactants tailored by the class Actinobacteria

    Directory of Open Access Journals (Sweden)

    Johannes H Kügler


    Full Text Available Gloablly, the drive towards the establishment of a bio-based economy has resulted in an increased need for bio-based applications. This, in turn, has served as a driving force for the discovery and application of novel biosurfactants. The class Actinobacteria represents a vast group of microorganisms with the ability to produce a diverse range of secondary metabolites, including surfactants. Understanding the extensive nature of the biosurfactants produced by actinobacterial strains can assist in finding novel biosurfactants with new potential applications. This review therefore presents a comprehensive overview of the knowledge available on actinobacterial surfactants, the chemical structures that have been completely or partly elucidated, as well as the identity of the biosurfactant-producing strains. Producer strains of not yet elucidated compounds are discussed, as well as the original habitats of all the producer strains, which seems to indicate that biosurfactant production is environmentally driven. Methodology applied in the isolation, purification and structural elucidation of the different types of surface active compounds, as well as surfactant activity tests, are also discussed. Overall, actinobacterial surfactants can be summarized to include the dominantly occurring trehalose-comprising surfactants, other non-trehalose containing glycolipids, lipopeptides and the more rare actinobacterial surfactants. The lack of structural information on a large proportion of actinobacterial surfactants should be considered as a driving force to further explore the abundance and diversity of these compounds. This would allow for a better understanding of actinobacterial surface active compounds and their potential for biotechnological application.


    Directory of Open Access Journals (Sweden)

    František Kreps


    Full Text Available Microorganisms produce wide range of surfactants, generally called biosurfactants. These compounds are mainly divided according to their molecular weight, physico - chemical properties and mode of action. Saponins, plant surfactants, have properties of  soap and they are high foaming and therefore are used in cosmetic (shampoos, liquid soaps et cetera and food industry (sweeteners, food additives into the effervescents et cetera. Most of them are spread in plants of agriculture importance and some of them are basic segments in human food. They often occur in plants (in more then 100 species. Saponins can be find in vegetables as a soya, a bean, a lentil, a spinach, a tomato, a potato, a garlic, a onion. Today biosurfactants are mainly used in bioremediation but they can be utilized in many sectors of food industry. We have paid attention to some microbial and plant surfactants and their prospects of exploitation in this industry.doi:10.5219/170 

  15. Gemini surfactants from natural amino acids. (United States)

    Pérez, Lourdes; Pinazo, Aurora; Pons, Ramon; Infante, Mrosa


    In this review, we report the most important contributions in the structure, synthesis, physicochemical (surface adsorption, aggregation and phase behaviour) and biological properties (toxicity, antimicrobial activity and biodegradation) of Gemini natural amino acid-based surfactants, and some potential applications, with an emphasis on the use of these surfactants as non-viral delivery system agents. Gemini surfactants derived from basic (Arg, Lys), neutral (Ser, Ala, Sar), acid (Asp) and sulphur containing amino acids (Cys) as polar head groups, and Geminis with amino acids/peptides in the spacer chain are reviewed. © 2013.

  16. Mechanism of bacterial inactivation by cationic surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Pavlova, I.B.; Samoylenko, I.I.


    The mechanism of bacteriocidal action of the cationic surfactant dimethylbenzylammonium chloride was studied on exposure of Staphylococcus aureus, Streptococcus faecium, Bacillus subtilis and Escherichia coli to different concentrations of the agent and determinations of survival plots. The data showed that the surfactant was bacteriocidal for all the bacteria tested at a concentration of 0.0001%, but more efficient in the case of the gram positives. Electron microscopy showed considerable damage and dissarrangement of the cytoplasmic membrane, indicating that the killing mechanism involved this organelle. It appears that cationic surfactants may constitute effective disinfectant preparations. 9 references, 2 figures.

  17. Surfactants as Microbicides and Contraceptive Agents: A Systematic In Vitro Study (United States)

    Vieira, Otilia V.; Oberdoerfer, Daniel; Baptista, Marta; Santos, Manuel A. S.; Almeida, Luis; Ramalho-Santos, João; Vaz, Winchil L. C.


    Background The urgent need for cheap and easy-to-use protection against both unwanted pregnancies and sexually transmitted diseases has stimulated considerable interest in the use of surfactants as microbicides, anti-viral, and contraceptive agents in recent years. In the present study we report a systematic in vitro evaluation of the microbicidal, anti-viral and contraceptive potential of cationic, anionic, zwitterionic, and non-ionic surfactants. Methodology/Principal Findings Toxicity was evaluated in mammalian columnar epithelial (MDCK) cells, human sperm cells, Candida albicans, Escherichia coli, Pseudomonas aeruginosa, Neisseria gonorrhoeae, Streptococcus agalactiae and Enterococcus faecalis. The inhibition of adenovirus and lentivirus infection of MDCK cells was also tested. A homologous series of cationic surfactants, alkyl-N,N,N-trimethylammonium bromides (CnTAB), with varying alkyl chains were shown to be bactericidal and fungicidal at doses that were related to the surfactant critical micelle concentrations (CMC), all of them at concentrations significantly below the CMC. In general, bacteria were more susceptible to this surfactant group than C. albicans and this organism, in turn, was more susceptible than MDCK cells. This suggests that the CnTAB may be useful as vaginal disinfectants only in so far as bacterial and fungal infections are concerned. None of the surfactants examined, including those that have been used in pre-clinical studies, showed inhibition of adenovirus or lentivirus infection of MDCK cells or spermicidal activity at doses that were sub-toxic to MDCK cells. Conclusions/Significance The results of this study lead us to propose that systematic analysis of surfactant toxicity, such as we report in the present work, be made a mandatory pre-condition for the use of these substances in pre-clinical animal and/or human studies. PMID:18682796

  18. Surfactants as microbicides and contraceptive agents: a systematic in vitro study.

    Directory of Open Access Journals (Sweden)

    Otilia V Vieira

    Full Text Available BACKGROUND: The urgent need for cheap and easy-to-use protection against both unwanted pregnancies and sexually transmitted diseases has stimulated considerable interest in the use of surfactants as microbicides, anti-viral, and contraceptive agents in recent years. In the present study we report a systematic in vitro evaluation of the microbicidal, anti-viral and contraceptive potential of cationic, anionic, zwitterionic, and non-ionic surfactants. METHODOLOGY/PRINCIPAL FINDINGS: Toxicity was evaluated in mammalian columnar epithelial (MDCK cells, human sperm cells, Candida albicans, Escherichia coli, Pseudomonas aeruginosa, Neisseria gonorrhoeae, Streptococcus agalactiae and Enterococcus faecalis. The inhibition of adenovirus and lentivirus infection of MDCK cells was also tested. A homologous series of cationic surfactants, alkyl-N,N,N-trimethylammonium bromides (C(nTAB, with varying alkyl chains were shown to be bactericidal and fungicidal at doses that were related to the surfactant critical micelle concentrations (CMC, all of them at concentrations significantly below the CMC. In general, bacteria were more susceptible to this surfactant group than C. albicans and this organism, in turn, was more susceptible than MDCK cells. This suggests that the C(nTAB may be useful as vaginal disinfectants only in so far as bacterial and fungal infections are concerned. None of the surfactants examined, including those that have been used in pre-clinical studies, showed inhibition of adenovirus or lentivirus infection of MDCK cells or spermicidal activity at doses that were sub-toxic to MDCK cells. CONCLUSIONS/SIGNIFICANCE: The results of this study lead us to propose that systematic analysis of surfactant toxicity, such as we report in the present work, be made a mandatory pre-condition for the use of these substances in pre-clinical animal and/or human studies.

  19. Lung surfactant levels are regulated by Ig-Hepta/GPR116 by monitoring surfactant protein D.

    Directory of Open Access Journals (Sweden)

    Taku Fukuzawa

    Full Text Available Lung surfactant is a complex mixture of lipids and proteins, which is secreted from the alveolar type II epithelial cell and coats the surface of alveoli as a thin layer. It plays a crucial role in the prevention of alveolar collapse through its ability to reduce surface tension. Under normal conditions, surfactant homeostasis is maintained by balancing its release and the uptake by the type II cell for recycling and the internalization by alveolar macrophages for degradation. Little is known about how the surfactant pool is monitored and regulated. Here we show, by an analysis of gene-targeted mice exhibiting massive accumulation of surfactant, that Ig-Hepta/GPR116, an orphan receptor, is expressed on the type II cell and sensing the amount of surfactant by monitoring one of its protein components, surfactant protein D, and its deletion results in a pulmonary alveolar proteinosis and emphysema-like pathology. By a coexpression experiment with Sp-D and the extracellular region of Ig-Hepta/GPR116 followed by immunoprecipitation, we identified Sp-D as the ligand of Ig-Hepta/GPR116. Analyses of surfactant metabolism in Ig-Hepta(+/+ and Ig-Hepta(-/- mice by using radioactive tracers indicated that the Ig-Hepta/GPR116 signaling system exerts attenuating effects on (i balanced synthesis of surfactant lipids and proteins and (ii surfactant secretion, and (iii a stimulating effect on recycling (uptake in response to elevated levels of Sp-D in alveolar space.

  20. Aggregation of sulfosuccinate surfactants in water

    Energy Technology Data Exchange (ETDEWEB)

    Magid, L.J.; Daus, K.A.; Butler, P.D.; Quincy, R.B.


    The aggregation of sodium di-n-alkyl sulfosuccinates in water (H/sub 2/O and D/sub 2/O at 45/sup 0/C) has been investigated. A self-consistent picture of the dependence of sodium ion binding on surfactant concentration is obtained from emf measurements, conductimetry, and small-angle neutron scattering (SANS) measurements. The concentration dependence of the micellar agregation number for the sulfosuccinates and related double-tailed surfactants depends markedly on surfactant solubility. A sphere-to-disk transition in micellar shape, which might have been expected as a precursor to formation of a lamellar mesophase, was not observed as the surfactant concentration was increased. 8 figures, 2 tables.

  1. Enhanced Oil Recovery with Surfactant Flooding

    DEFF Research Database (Denmark)

    Sandersen, Sara Bülow

    behavior inside the reservoir can be manipulated by the injection of surfactants and co-surfactants, creating advantageous conditions in order to mobilize trapped oil. Correctly designed surfactant systems together with the crude oil can create microemulsions at the interface between crude oil and water...... at constant salinity (6.56 %), constant surfactant-alcohol ratio (SAR) but with varying water-oil ratios (WOR). At all temperatures it was very clear that the effect of pressure was significant. The system changed from the two phase region, Winsor II, to the three phase region, Winsor III, as pressure...... characterization of the two crude oils using gas chromatography and SARA analysis confirmed that the heavier components in the crude oils, (in the case of the Latin American crude oil), are correlated to the observed decrease of viscosity, where the viscosity decrease may be explained from change of the shape...

  2. Glyphosate: Surfactant herbicide poisoning - Is it mild?

    Directory of Open Access Journals (Sweden)

    K Venugopal


    Full Text Available Glyphosate Surfactant is a nonselective widely used herbicide in agriculture, forestry, industrial weed control, lawn, garden and aquatic environments. They have favorable toxicity with occupational and accidental exposures. The toxicity in humans is mucosal and gastrointestinal irritation, hypotension, metabolic acidosis, pulmonary insufficiency, and oliguria. Patient may appear asymptomatic for many hours before slowly lapse into a hypotensive, apparently nonhypovolaemic shock that can often ends fatally. We hereby report a case of a 25-year-old male patient who was admitted to our tertiary care hospital following suicidal consumption of around 250-300 ml of herbicide containing glyphosate (glypho; . Initially, gastric lavage done and the patient was managed with intubation and mechanical ventilation. He also developed acute renal failure, and renal function reverted to normal after four sittings of hemodialysis. Patient was successfully treated and discharged home. This case report emphasizes on timely systemic supportive measure as the sole method of treatment since this poison has no specific antidote.

  3. Evaluation of Surfactant Effects on Newborns


    N. Khalessi; K. Kamerani


    Introduction & Objective: One of the standard therapies in neonates with severe respiratory distress syndrome (RDS) is surfactant administration in early course of therapy that cause reduction in mortality, pneumothorax and need to mechanical ventilation. In this study that was carried out in Aliasghar Hospital NICU in 1994-1995 & 2001-2002, the goal was to compare two groups of neonates with severe RDS that had been ventilated in the first 24 hours but one group had received surfactant and ...

  4. Evaluation of Surfactant Effects on Newborns

    Directory of Open Access Journals (Sweden)

    N. Khalessi


    Full Text Available Introduction & Objective: One of the standard therapies in neonates with severe respiratory distress syndrome (RDS is surfactant administration in early course of therapy that cause reduction in mortality, pneumothorax and need to mechanical ventilation. In this study that was carried out in Aliasghar Hospital NICU in 1994-1995 & 2001-2002, the goal was to compare two groups of neonates with severe RDS that had been ventilated in the first 24 hours but one group had received surfactant and the other group (7 years ago was deprived of this substance. Materials & Methods: In our study, 36 neonates that received surfactant and 52 neonates with only mechanical ventilation therapy were compared. Data collected and analyzed using SPSS.Results: We found that mortality in patients with surfactant administration was significantly lower compared to the second group who did not receive surfactant. There were not any significant differences in incidences of HIV, pneumothorax, sepsis, and PDA and also course of hospitalization and need to ventilation between two groups. Conclusion: As a result, all of these findings reflect obligatory surfactant administration in sever RDS in NICU under observation of an educated expert.

  5. [Deficiency of surfactant protein: Case report]. (United States)

    Milet, María Beatriz; Mena N, Patricia; Pérez, Héctor I; Espinoza, Tatiana

    Congenital surfactant deficiency is a condition infrequently diagnosed in newborns. A clinical case is presented of surfactant protein B deficiency. A review is performed on the study, treatment and differential diagnosis of surfactant protein deficiencies and infant chronic interstitial lung disease. The case is presented of a term newborn that developed respiratory distress, recurrent pulmonary opacification, and a transient response to the administration of surfactant. Immunohistochemical and genetic studies confirmed the diagnosis of surfactant protein B deficiency. Pulmonary congenital anomalies require a high index of suspicion. Surfactant protein B deficiency is clinically progressive and fatal in the majority of the cases, similar to that of ATP binding cassette subfamily A member 3 (ABCA3) deficiency. Protein C deficiency is insidious and may present with a radiological pulmonary interstitial pattern. Due to the similarity in the histological pattern, genetic studies help to achieve greater certainty in the prognosis and the possibility of providing adequate genetic counselling. Copyright © 2016 Sociedad Chilena de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

  6. A class of mild surfactants that keep integral membrane proteins water-soluble for functional studies and crystallization (United States)

    Hovers, Jens; Potschies, Meike; Polidori, Ange; Pucci, Bernard; Raynal, Simon; Bonneté, Françoise; Serrano-Vega, Maria J.; Tate, Christopher G.; Picot, Daniel; Pierre, Yves; Popot, Jean-Luc; Nehmé, Rony; Bidet, Michel; Mus-Veteau, Isabelle; Bußkamp, Holger; Jung, Karl-Heinz; Marx, Andreas; Timmins, Peter A.; Welte, Wolfram


    Mixed protein-surfactant micelles are used for in vitro studies and 3D crystallization when solutions of pure, monodisperse integral membrane proteins are required. However, many membrane proteins undergo inactivation when transferred from the biomembrane into micelles of conventional surfactants with alkyl chains as hydrophobic moieties. Here we describe the development of surfactants with rigid, saturated or aromatic hydrocarbon groups as hydrophobic parts. Their stabilizing properties are demonstrated with three different integral membrane proteins. The temperature at which 50% of the binding sites for specific ligands are lost is used as a measure of stability and dodecyl-β-D-maltoside (“C12-b-M”) as a reference for conventional surfactants. One surfactant increased the stability of two different G protein-coupled receptors by approximately 10°C compared to C12-b-M. Another surfactant yielded a stabilization of the human Patched protein receptor by 13°C. In addition, one of the surfactants was successfully used to stabilize and crystallize the cytochrome b6f complex from Chlamydomonas reinhardtii. The structure was solved to the same resolution as previously reported in C12-b-M. PMID:21314479

  7. A new nano-engineered hierarchical membrane for concurrent removal of surfactant and oil from oil-in-water nanoemulsion (United States)

    Qin, Detao; Liu, Zhaoyang; Bai, Hongwei; Sun, Darren Delai; Song, Xiaoxiao


    Surfactant stabilized oil-in-water nanoemulsions pose a severe threat to both the environment and human health. Recent development of membrane filtration technology has enabled efficient oil removal from oil/water nanoemulsion, however, the concurrent removal of surfactant and oil remains unsolved because the existing filtration membranes still suffer from low surfactant removal rate and serious surfactant-induced fouling issue. In this study, to realize the concurrent removal of surfactant and oil from nanoemulsion, a novel hierarchically-structured membrane is designed with a nanostructured selective layer on top of a microstructured support layer. The physical and chemical properties of the overall membrane, including wettability, surface roughness, electric charge, thickness and structures, are delicately tailored through a nano-engineered fabrication process, that is, graphene oxide (GO) nanosheet assisted phase inversion coupled with surface functionalization. Compared with the membrane fabricated by conventional phase inversion, this novel membrane has four times higher water flux, significantly higher rejections of both oil (~99.9%) and surfactant (as high as 93.5%), and two thirds lower fouling ratio when treating surfactant stabilized oil-in-water nanoemulsion. Due to its excellent performances and facile fabrication process, this nano-engineered membrane is expected to have wide practical applications in the oil/water separation fields of environmental protection and water purification.

  8. Interactions of organic contaminants with mineral-adsorbed surfactants (United States)

    Zhu, L.; Chen, B.; Tao, S.; Chiou, C.T.


    Sorption of organic contaminants (phenol, p-nitrophenol, and naphthalene) to natural solids (soils and bentonite) with and without myristylpyridinium bromide (MPB) cationic surfactant was studied to provide novel insight to interactions of contaminants with the mineral-adsorbed surfactant. Contaminant sorption coefficients with mineral-adsorbed surfactants, Kss, show a strong dependence on surfactant loading in the solid. At low surfactant levels, the Kss values increased with increasing sorbed surfactant mass, reached a maximum, and then decreased with increasing surfactant loading. The Kss values for contaminants were always higher than respective partition coefficients with surfactant micelles (Kmc) and natural organic matter (Koc). At examined MPB concentrations in water the three organic contaminants showed little solubility enhancement by MPB. At low sorbed-surfactant levels, the resulting mineral-adsorbed surfactant via the cation-exchange process appears to form a thin organic film, which effectively "adsorbs" the contaminants, resulting in very high Kss values. At high surfactant levels, the sorbed surfactant on minerals appears to form a bulklike medium that behaves essentially as a partition phase (rather than an adsorptive surface), with the resulting Kss being significantly decreased and less dependent on the MPB loading. The results provide a reference to the use of surfactants for remediation of contaminated soils/sediments or groundwater in engineered surfactant-enhanced washing.

  9. Surfactant nebulization versus instillation during high frequency ventilation in surfactant-deficient rabbits

    NARCIS (Netherlands)

    Dijk, Peter H.; Heikamp, A; Bambang Oetomo, Sidarto


    Surfactant nebulization improves lung function at low alveolar doses of surfactant. However, efficiency of nebulization is low, and lung deposition seems to depend on lung aeration. High frequency ventilation (HFV) has been shown to improve lung aeration. We hypothesize that the combination of HFV

  10. Dilute Surfactant Methods for Carbonate Formations

    Energy Technology Data Exchange (ETDEWEB)

    Kishore K. Mohanty


    There are many fractured carbonate reservoirs in US (and the world) with light oil. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). The process of using dilute anionic surfactants in alkaline solutions has been investigated in this work for oil recovery from fractured oil-wet carbonate reservoirs both experimentally and numerically. This process is a surfactant-aided gravity drainage where surfactant diffuses into the matrix, lowers IFT and contact angle, which decrease capillary pressure and increase oil relative permeability enabling gravity to drain the oil up. Anionic surfactants have been identified which at dilute concentration of 0.05 wt% and optimal salinity can lower the interfacial tension and change the wettability of the calcite surface to intermediate/water-wet condition as well or better than the cationic surfactant DTAB with a West Texas crude oil. The force of adhesion in AFM of oil-wet regions changes after anionic surfactant treatment to values similar to those of water-wet regions. The AFM topography images showed that the oil-wetting material was removed from the surface by the anionic surfactant treatment. Adsorption studies indicate that the extent of adsorption for anionic surfactants on calcite minerals decreases with increase in pH and with decrease in salinity. Surfactant adsorption can be minimized in the presence of Na{sub 2}CO{sub 3}. Laboratory-scale surfactant brine imbibition experiments give high oil recovery (20-42% OOIP in 50 days; up to 60% in 200 days) for initially oil-wet cores through wettability alteration and IFT reduction. Small (<10%) initial gas saturation does not affect significantly the rate of oil recovery in the imbibition process, but larger gas saturation decreases the oil recovery rate. As the core permeability decreases, the rate of oil recovery reduces

  11. A Review on Progress in QSPR Studies for Surfactants (United States)

    Hu, Jiwei; Zhang, Xiaoyi; Wang, Zhengwu


    This paper presents a review on recent progress in quantitative structure-property relationship (QSPR) studies of surfactants and applications of various molecular descriptors. QSPR studies on critical micelle concentration (cmc) and surface tension (γ) of surfactants are introduced. Studies on charge distribution in ionic surfactants by quantum chemical calculations and its effects on the structures and properties of the colloids of surfactants are also reviewed. The trends of QSPR studies on cloud point (for nonionic surfactants), biodegradation potential and some other properties of surfactants are evaluated. PMID:20479997

  12. The modulation of haemolytic activity of non-ionic surfactants by oil ...

    African Journals Online (AJOL)

    In the present study, we report of our investigations into the ability of some commercial non-ionic surfactants to produce o/w microemulsions with different oils and water or phosphate buffered saline (PBS), their physicochemical properties and modulation of haemolytic activity on human erythrocytes. The compositions over ...

  13. Size influences the effect of hydrophobic nanoparticles on lung surfactant model systems

    NARCIS (Netherlands)

    Dwivedi, M.V.; Harishchandra, R.K.; Koshkina, O.; Maskos, M.; Galla, H.J.


    The alveolar lung surfactant (LS) is a complex lipid protein mixture that forms an interfacial monolayer reducing the surface tension to near zero values and thus preventing the lungs from collapse. Due to the expanding field of nanotechnology and the corresponding unavoidable exposure of human

  14. Microwave corneosurfametry and the short-duration dansyl chloride extraction test for rating concentrated irritant surfactants. (United States)

    Goffin, V; Piérard, G E


    There are ethical concerns to conduct in vivo tests in the animal and human to provide evidence that cosmetics and other topical products are safe. To compare two methods, namely the short-duration dansyl chloride extraction test and the microwave corneosurfametry bioassay, to test the irritation potential of concentrated surfactant systems. Five surfactants and water were tested using the in vivo test and the bioassay. A significant linear correlation was found between data yielded by the two procedures. The short-duration dansyl chloride extraction test and the microwave corneosurfametry bioassay provide similar information. The latter has the advantage of being safe.

  15. Automated flow system for sildenafil enrichment using surfactant coated solid-phase with fluorescence detection. (United States)

    Wang, Chien Chun; Sombra, Lorena; Fernández, Liliana


    In this work, Amberlite XAD-1180 resin is used for on-line surfactant-mediated pre-concentration of sildenafil as a prior step for its fluorescent detection. In order to activate the column for sildenafil pre-concentration, the cationic surfactant (hexadecyltrimethylammoniunm bromide, HTAB) is adsorbed onto the resin. In these conditions, sildenafil is retained by HTAB-resin and then it is eluted with ethanol and analyzed by spectrofluorimetry. Drug-surfactant association produces a considerable fluorescence enhancement, increasing considerably the sensitivity of detection. Therefore, sildenafil can be pre-concentrated and quantitatively determined, with a detection limit of 0.2 ng mL(-1). The proposed method was successfully applied to the analysis of bulk drug, human urine, tablets, and local herbal medicine. Validation processes were performed by recovering studies and statistical analysis with satisfactory results. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Solubilization and Interaction Studies of Bile Salts with Surfactants and Drugs: a Review. (United States)

    Malik, Nisar Ahmad


    In this review, bile salt, bile salt-surfactant, and bile salt-drug interactions and their solubilization studies are mainly focused. Usefulness of bile salts in digestion, absorption, and excretion of various compounds and their rare properties in ordering the shape and size of the micelles owing to the presence of hydrophobic and hydrophilic faces are taken into consideration while compiling this review. Bile salts as potential bio-surfactants to solubilize drugs of interest are also highlighted. This review will give an insight into the selection of drugs in different applications as their properties get modified by interaction with bile salts, thus influencing their solution behavior which, in turn, modifies the phase-forming behavior, microemulsion, and clouding phenomenon, besides solubilization. Finally, their future perspectives are taken into consideration to assess their possible uses as bio-surfactants without side effects to human beings.

  17. The Rebirth of Waste Cooking Oil to Novel Bio-based Surfactants (United States)

    Zhang, Qi-Qi; Cai, Bang-Xin; Xu, Wen-Jie; Gang, Hong-Ze; Liu, Jin-Feng; Yang, Shi-Zhong; Mu, Bo-Zhong


    Waste cooking oil (WCO) is a kind of non-edible oil with enormous quantities and its unreasonable dispose may generate negative impact on human life and environment. However, WCO is certainly a renewable feedstock of bio-based materials. To get the rebirth of WCO, we have established a facile and high-yield method to convert WCO to bio-based zwitterionic surfactants with excellent surface and interfacial properties. The interfacial tension between crude oil and water could reach ultra-low value as 0.0016 mN m−1 at a low dosage as 0.100 g L−1 of this bio-based surfactant without the aid of extra alkali, which shows a strong interfacial activity and the great potential application in many industrial fields, in particular, the application in enhanced oil recovery in oilfields in place of petroleum-based surfactants. PMID:25944301

  18. Syntheses of surfactants from oleochemical epoxides

    Directory of Open Access Journals (Sweden)

    Warwel Siegfried


    Full Text Available Sugar-based surfactants were obtained in good yields (up to 100% under mild conditions (70°C, methanol or mixtures of methanol and water by ring-opening of terminal epoxides with aminopolyols, derived from glucose. Reaction of N-methyl glucamine with epoxides from even-numbered C4-C18 alpha-olefins or from terminal unsaturated fatty acid methyl esters leads to linear products, while corresponding reactions with N-dodecyl glucamine or glucamine yield surfactants with different Y-structures. Products obtained by conversion of omega-epoxy fatty acid methyl esters were saponificated with NaOH or hydrolyzed enzymatically to sodium salts or free acids respectively, which are amphoteric surfactants. Studies of the surfactants at different pH-values demonstrate different surface active properties in aqueous solutions. Critical micelle concentrations (c.m.c. in a range between 2 and 500mg/l and surface tensions of 25-40mN/m were measured for several of the synthesized sugar-based surfactants. The ring-opening products are rather poor foamers, whereas some of the corresponding hydrobromides show good foaming properties.

  19. Recovering hydrocarbons with surfactants from lignin

    Energy Technology Data Exchange (ETDEWEB)

    Naae, D.G.; Whittington, L.E.; Ledoux, W.A.; Debons, F.E.


    This patent describes a method of recovering hydrocarbons from an underground hydrocarbon formation penetrated by at least one injection well and at least one production well, which comprises: injecting into the formation through an injection well a surfactant slug comprising about 0.1% to about 10% by weight of surfactants produced from lignin, the surfactants produced by placing lignin in contact with water, converting the lignin into low molecular weight lignin phenols by reducing the lignin in the presence of a reducing agent of carbon monoxide or hydrogen creating a reduction reaction mixture comprising oil soluble lignin phenols, the reduction occurring at a temperature greater than about 200/sup 0/C and a pressure greater than about 100 psi, recovering the oil soluble lignin phenols from the reduction mixture, and converting the lignin phenols into lignin surfactants by a reaction selected from the group consisting of alkoxylation, sulfonation, sulfation, aklylation, sulfomethylation, and alkoxysulfation; injecting into the formation through the injection well a drive fluid to push the surfactant slug towards a production well; and recovering hydrocarbons at the production well.

  20. Surfactant effects on SF6 hydrate formation. (United States)

    Lee, Bo Ram; Lee, Ju Dong; Lee, Hyun Ju; Ryu, Young Bok; Lee, Man Sig; Kim, Young Seok; Englezos, Peter; Kim, Myung Hyun; Kim, Yang Do


    Sulfur hexafluoride (SF(6)) has been widely used in a variety of industrial processes, but it is one of the most potent greenhouse gases. For this reason, it is necessary to separate or collect it from waste gas streams. One separation method is through hydrate crystal formation. In this study, SF(6) hydrate was formed in aqueous surfactant solutions of 0.00, 0.01, 0.05, 0.15 and 0.20 wt% to investigate the effects of surfactants on the hydrate formation rates. Three surfactants, Tween 20 (Tween), sodium dodecyl sulfate (SDS) and linear alkyl benzene sulfonate (LABS), were tested in a semi-batch stirred vessel at the constant temperature and pressures of 276.2 K and 0.78 MPa, respectively. All surfactants showed kinetic promoter behavior for SF(6) hydrate formation. It was also found that SF(6) hydrate formation proceeded in two stages with the second stage being the most rapid. In situ Raman spectroscopy analysis revealed that the increased gas consumption rate with the addition of surfactant was possibly due to the increased gas filling rate in the hydrate cavity.

  1. How nanobubbles lose stability: Effects of surfactants (United States)

    Xiao, Qianxiang; Liu, Yawei; Guo, Zhenjiang; Liu, Zhiping; Zhang, Xianren


    In contrast to stability theories of nanobubbles, the molecular mechanism of how nanobubbles lose stability is far from being understood. In this work, we try to interpret recent experimental observations that the addition of surfactants destabilizes nanobubbles with an unclear mechanism. Using molecular dynamics simulations, we identify two surfactant-induced molecular mechanisms for nanobubbles losing stability, either through depinning of a contact line or reducing vapor-liquid surface tension. One corresponds to the case with significant adsorption of surfactants on the substrates, which causes depinning of the nanobubble contact line and thus leads to nanobubble instability. The other stresses surfactant adsorption on the vapor-liquid interface of nanobubbles, especially for insoluble surfactants, which reduces the surface tension of the interface and leads to an irreversible liquid-to-vapor phase transition. Our finding can help improve our understanding in nanobubble stability, and the insight presented here has implications for surface nanobubbles involving with other amphiphilic molecules, such as proteins and contaminations.

  2. Fullerene surfactants and their use in polymer solar cells (United States)

    Jen, Kwan-Yue; Yip, Hin-Lap; Li, Chang-Zhi


    Fullerene surfactant compounds useful as interfacial layer in polymer solar cells to enhance solar cell efficiency. Polymer solar cell including a fullerene surfactant-containing interfacial layer intermediate cathode and active layer.

  3. Synthesis of mesoporous nano-hydroxyapatite by using zwitterions surfactant (United States)

    Mesoporous nano-hydroxyapatite (mn-HAP) was successfully synthesized via a novel micelle-templating method using lauryl dimethylaminoacetic acid as zwitterionic surfactant. The systematic use of such a surfactant in combination with microwave energy inputenables the precise contr...

  4. Polyelectrolyte surfactant aggregates and their deposition on macroscopic surfaces

    CERN Document Server

    Voisin, D


    Oppositely charged surfactant and polyelectrolyte are present in hair shampoos and conditioners, together with particles (e.g. anti-dandruff agents for scalp) and droplets (e.g. silicone oil for the hair). These are normally formulated at high surfactant concentrations, beyond the flocculation region for the polyelectrolyte concentration used. However, on dilution with water, during application, flocs are formed which carry the particles and droplets to the scalp and hair. The addition of an anionic surfactant to an aqueous solution of cationic polyelectrolyte, at a given concentration, can lead to the formation of polyelectrolyte-surfactant 'particles', in which the surfactant 'binds' to the polyelectrolyte. This occurs from the critical association concentration (CAC), up to the surfactant concentration corresponding to maximum binding. Within this range of surfactant concentrations, the surfactant bound to the polyelectrolyte is thought to associate to form what might be termed 'internal micelles'. Each po...

  5. Recent food applications of microbial surfactants. (United States)

    Nitschke, Marcia; Silva, Sumária Sousa E


    Owing to their natural origin and environmental compatibility, interest in microbial surfactants or biosurfactants has gained attention during last few years. These characteristics fulfill the demand of regulatory agencies and society to use more sustained and green chemicals. Microbial-derived surfactants can replace synthetic surfactants in a great variety of industrial applications as detergents, foaming, emulsifiers, solubilizers, and wetting agents. Change in the trend of consumers toward natural from synthetic additives and the increasing health and environmental concerns have created demand for new "green" additives in foods. Apart from their inherent surface-active properties, biosurfactants have shown antimicrobial and anti-biofilm activities against food pathogens; therefore, biosurfactants can be versatile additives or ingredients of food processing. These interesting applications will be discussed in this review.


    Directory of Open Access Journals (Sweden)

    Pirog T. P.


    Full Text Available The literature and own experimental data on the synthesis of microbial surfactants of different chemical nature (rhamnolipids, sophorolipids, manozylerythritollipids, lipopeptides at various waste (vegetable oil and fat, sugar, dairy industry, agriculture, forestry, biodiesel, as well as waste — fried vegetable oils are presented. Most suitable substrates for the synthesis of microbial surfactants are oil containing waste that, unlike, for example, lignocellulose, whey, technical glycerol do not require pre-treatment and purification. Replacing traditional substrates for the biosynthesis of surfactant with industrial waste will help to reduce the cost of technology by several times, dispose of unwanted waste, solve the problem of storage or disposal of large amounts of waste from the food industry, agricultural sector and companies that produce biodiesel, which spent large amount of energy and money for such needs

  7. Microstructure, morphology and lifetime of armored bubbles exposed to surfactants


    Subramaniam, Anand Bala; Mejean, Cecile; Abkarian, Manouk; Stone, Howard A.


    We report the behavior of particle-stabilized bubbles (armored bubbles) when exposed to various classes and concentrations of surfactants. The bubbles are non-spherical due to the jamming of the particles on the interface and are stable to dissolution prior to the addition of surfactant. We find that the dissolving bubbles exhibit distinct morphological, microstructural, and lifetime changes, which correlate with the concentration of surfactant employed. For low concentrations of surfactant a...

  8. Surfactant therapy in late preterm infants

    Directory of Open Access Journals (Sweden)

    Murat Yurdakök


    Full Text Available Late preterm (LPT neonates are at a high risk for respiratory distress soon after birth due to respiratory distress syndrome (RDS, transient tachypnea of the newborn, persistent pulmonary hypertension, and pneumonia along with an increased need for surfactant replacement therapy, continuous positive airway pressure, and ventilator support when compared with the term neonates. In the past, studies on outcomes of infants with respiratory distress have primarily focused on extremely premature infants, leading to a gap in knowledge and understanding of the developmental biology and mechanism of pulmonary diseases in LPT neonates. Surfactant deficiency is the most frequent etiology of RDS in very preterm and moderately preterm infants, while cesarean section and lung infection play major roles in RDS development in LPT infants. The clinical presentation and the response to surfactant therapy in LPT infants may be different than that seen in very preterm infants. Incidence of pneumonia and occurrence of pneumothorax are significantly higher in LPT and term infants. High rates of pneumonia in these infants may result in direct injury to the type II alveolar cells of the lung with decreasing synthesis, release, and processing of surfactant. Increased permeability of the alveolar capillary membrane to both fluid and solutes is known to result in entry of plasma proteins into the alveolar hypophase, further inhibiting the surface properties of surfactant. However, the oxygenation index value do not change dramatically after ventilation or surfactant administration in LPT infants with RDS compared to very preterm infants. These finding may indicate a different pathogenesis of RDS in late preterm and term infants. In conclusion, surfactant therapy may be of significant benefit in LPT infants with serious respiratory failure secondary to a number of insults. However, optimal timing and dose of administration are not so clear in this group. Additional

  9. The Inhibiting or Accelerating Effect of Different Surfactants on ...

    African Journals Online (AJOL)

    The course of differential capacity curves of the electric double layer at the mercury electrode/surfactant solution interface was described for three different surfactants from different groups. Using square-wave voltammetry (SWV) it was found that the surfactants had a varying effect on the kinetics of electroreduction of Zn2+ ...

  10. Surfactant phosphatidylcholine metabolism in preterm infants studied with stable isotopes

    NARCIS (Netherlands)

    J.E.H. Bunt (Jan Erik)


    textabstractAIM OF THE STUDIES 1. To develop and use a novel method to study surfactant metabolism in preterm and older infants. (chapters 3 and 4). 2. To study endogenous surfactant synthesis in relation to prenatal glucocorticosteroids. (chapters 5 and 6). 3. To study the influence of surfactant


    NARCIS (Netherlands)

    BRACKMAN, JC; ENGBERTS, JBFN; Herb, CA; Prudhomme, RK


    The influence of the chemical structure and charge of the surfactant on polymer-micelle interaction has been studied using various ionic and non-ionic surfactants, and surfactants of which the charge can be varied by (de)protonation. Octylthioglucoside, dodecyldimethylamine-oxide, alkylphosphates,

  12. Biophysical properties of protein-free, totally synthetic pulmonary surfactants, ALEC and Exosurf, in comparison with surfactant TA. (United States)

    Takahashi, A; Nemoto, T; Fujiwara, T


    An artificial pulmonary surfactant prepared from chloroform-methanol extract of bovine pulmonary surfactant (surfactant TA) has been shown to be effective in both the prevention and the treatment of respiratory distress syndrome in premature babies. Recently, two types of protein-free totally synthetic surfactants, artificial lung expanding compound (ALEC) and Exosurf, have been evaluated in clinical trials of surfactant therapy. Artificial lung expanding compound was used initially as a dry powder, but is now prepared as a crystalline suspension in saline at 4 degrees C. In this study we compared the biophysical properties of three different forms of ALEC (dry powder, crystalline suspension at 4 degrees C and 37 degrees C), Exosurf and surfactant TA (Surfacten) using a modified Wilhelmy surface balance and a pulsating bubble surfactometer. Surface activity of a crystalline suspension of ALEC in cold saline was no better than the dry powder of ALEC. Surfactant activity of ALEC was improved by addition of hydrophobic surfactant protein B and C (SP-B, SP-C) which are important constituents of surfactant TA. Surface properties of ALEC in any form and Exosurf were not superior to those of surfactant TA. These results suggest that a surfactant which contains SP-B and SP-C does not necessarily have to be dry or crystalline for an effective exogenous surfactant.

  13. Efficient Interfacially Driven Vehiculization of Corticosteroids by Pulmonary Surfactant. (United States)

    Hidalgo, Alberto; Salomone, Fabrizio; Fresno, Nieves; Orellana, Guillermo; Cruz, Antonio; Perez-Gil, Jesus


    Pulmonary surfactant is a crucial system to stabilize the respiratory air-liquid interface. Furthermore, pulmonary surfactant has been proposed as an effective method for targeting drugs to the lungs. However, few studies have examined in detail the mechanisms of incorporation of drugs into surfactant, the impact of the presence of drugs on pulmonary surfactant performance at the interface under physiologically meaningful conditions, or the ability of pulmonary surfactant to use the air-liquid interface to vehiculise drugs to long distances. This study focuses on the ability of pulmonary surfactant to interfacially vehiculize corticosteroids such as beclomethasone dipropionate (BDP) or Budesonide (BUD) as model drugs. The main objectives have been to (a) characterize the incorporation of corticosteroids into natural and synthetic surfactants, (b) evaluate whether the presence of corticosteroids affects surfactant functionality, and (c) determine whether surfactant preparations enable the efficient spreading and distribution of BDP and BUD along the air-liquid interface. We have compared the performance of a purified surfactant from porcine lungs and two clinical surfactants: Poractant alfa, a natural surfactant of animal origin extensively used to treat premature babies, and CHF5633, a new synthetic surfactant preparation currently under clinical trials. Both, natural and clinical surfactants spontaneously incorporated corticosteroids up to at least 10% by mass with respect to phospholipid content. The presence of the drugs did not interfere with their ability to efficiently adsorb into air-liquid interfaces and form surface active films able to reach and sustain very low surface tensions (<2 mN/m) under compression-expansion cycling mimicking breathing dynamics. Furthermore, the combination of clinical surfactant with corticosteroids efficiently promoted the active diffusion of the drug to long distances along the air-liquid interface. This effect could not be

  14. Gene targeting of the cysteine peptidase cathepsin H impairs lung surfactant in mice.

    Directory of Open Access Journals (Sweden)

    Frank Bühling

    Full Text Available BACKGROUND: The 11 human cysteine cathepsins are proteases mainly located in the endolysosomal compartment of all cells and within the exocytosis pathways of some secretory cell types. Cathepsin H (Ctsh has amino- and endopeptidase activities. In vitro studies have demonstrated Ctsh involvement in the processing and secretion of the pulmonary surfactant protein B (SP-B. Furthermore, Ctsh is highly expressed in the secretory organelles of alveolar type II pneumocytes where the surfactant proteins are processed. METHODOLOGY/PRINCIPAL FINDINGS: Hence, we generated Ctsh null mice by gene targeting in embryonic stem cells to investigate the role of this protease in surfactant processing in vivo. The targeting construct contains a ß-galactosidase (lacZ reporter enabling the visualisation of Ctsh expression sites. Ctsh-deficiency was verified by northern blot, western blot, and measurement of the Ctsh aminopeptidase activity. Ctsh(-/- mice show no gross phenotype and their development is normal without growth retardation. Broncho-alveolar lavage (BAL from Ctsh(-/- mice contained lower levels of SP-B indicating reduced SP-B secretion. The BAL phospholipid concentration was not different in Ctsh(+/+ and Ctsh(-/- mice, but measurement of surface tension by pulsating bubble surfactometry revealed an impairment of the tension reducing function of lung surfactant of Ctsh(-/- mice. CONCLUSIONS/SIGNIFICANCE: We conclude that cathepsin H is involved in the SP-B production and reduced SP-B levels impair the physical properties of the lung surfactant. However, Ctsh defiency does not reproduce the severe phenotype of SP-B deficient mice. Hence, other proteases of the secretory pathway of type II pneumocytes, i.e. cathepsins C or E, are still able to produce surfactant of sufficient quality in absence of Ctsh.

  15. Gene targeting of the cysteine peptidase cathepsin H impairs lung surfactant in mice. (United States)

    Bühling, Frank; Kouadio, Martin; Chwieralski, Caroline E; Kern, Ursula; Hohlfeld, Jens M; Klemm, Nicole; Friedrichs, Nicole; Roth, Wera; Deussing, Jan M; Peters, Christoph; Reinheckel, Thomas


    The 11 human cysteine cathepsins are proteases mainly located in the endolysosomal compartment of all cells and within the exocytosis pathways of some secretory cell types. Cathepsin H (Ctsh) has amino- and endopeptidase activities. In vitro studies have demonstrated Ctsh involvement in the processing and secretion of the pulmonary surfactant protein B (SP-B). Furthermore, Ctsh is highly expressed in the secretory organelles of alveolar type II pneumocytes where the surfactant proteins are processed. Hence, we generated Ctsh null mice by gene targeting in embryonic stem cells to investigate the role of this protease in surfactant processing in vivo. The targeting construct contains a ß-galactosidase (lacZ) reporter enabling the visualisation of Ctsh expression sites. Ctsh-deficiency was verified by northern blot, western blot, and measurement of the Ctsh aminopeptidase activity. Ctsh(-/-) mice show no gross phenotype and their development is normal without growth retardation. Broncho-alveolar lavage (BAL) from Ctsh(-/-) mice contained lower levels of SP-B indicating reduced SP-B secretion. The BAL phospholipid concentration was not different in Ctsh(+/+) and Ctsh(-/-) mice, but measurement of surface tension by pulsating bubble surfactometry revealed an impairment of the tension reducing function of lung surfactant of Ctsh(-/-) mice. We conclude that cathepsin H is involved in the SP-B production and reduced SP-B levels impair the physical properties of the lung surfactant. However, Ctsh defiency does not reproduce the severe phenotype of SP-B deficient mice. Hence, other proteases of the secretory pathway of type II pneumocytes, i.e. cathepsins C or E, are still able to produce surfactant of sufficient quality in absence of Ctsh.

  16. The interplay of lung surfactant proteins and lipids assimilates the macrophage clearance of nanoparticles.

    Directory of Open Access Journals (Sweden)

    Christian A Ruge

    Full Text Available The peripheral lungs are a potential entrance portal for nanoparticles into the human body due to their large surface area. The fact that nanoparticles can be deposited in the alveolar region of the lungs is of interest for pulmonary drug delivery strategies and is of equal importance for toxicological considerations. Therefore, a detailed understanding of nanoparticle interaction with the structures of this largest and most sensitive part of the lungs is important for both nanomedicine and nanotoxicology. Astonishingly, there is still little known about the bio-nano interactions that occur after nanoparticle deposition in the alveoli. In this study, we compared the effects of surfactant-associated protein A (SP-A and D (SP-D on the clearance of magnetite nanoparticles (mNP with either more hydrophilic (starch or hydrophobic (phosphatidylcholine surface modification by an alveolar macrophage (AM cell line (MH-S using flow cytometry and confocal microscopy. Both proteins enhanced the AM uptake of mNP compared with pristine nanoparticles; for the hydrophilic ST-mNP, this effect was strongest with SP-D, whereas for the hydrophobic PL-mNP it was most pronounced with SP-A. Using gel electrophoretic and dynamic light scattering methods, we were able to demonstrate that the observed cellular effects were related to protein adsorption and to protein-mediated interference with the colloidal stability. Next, we investigated the influence of various surfactant lipids on nanoparticle uptake by AM because lipids are the major surfactant component. Synthetic surfactant lipid and isolated native surfactant preparations significantly modulated the effects exerted by SP-A and SP-D, respectively, resulting in comparable levels of macrophage interaction for both hydrophilic and hydrophobic nanoparticles. Our findings suggest that because of the interplay of both surfactant lipids and proteins, the AM clearance of nanoparticles is essentially the same, regardless

  17. Pulmonary surfactant proteins and polymer combinations reduce surfactant inhibition by serum. (United States)

    Lu, Karen W; Pérez-Gil, Jesús; Echaide, Mercedes; Taeusch, H William


    Acute respiratory distress syndrome (ARDS) is an inflammatory condition that can be associated with capillary leak of serum into alveoli causing inactivation of surfactant. Resistance to inactivation is affected by types and concentrations of surfactant proteins, lipids, and polymers. Our aim was to investigate the effects of different combinations of these three components. A simple lipid mixture (DPPC/POPG) or a more complex lipid mixture (DPPC/POPC/POPG/cholesterol) was used. Native surfactant proteins SP-B and SP-C obtained from pig lung lavage were added either singly or combined at two concentrations. Also, non-ionic polymers polyethylene glycol and dextran and the anionic polymer hyaluronan were added either singly or in pairs with hyaluronan included. Non-ionic polymers work by different mechanisms than anionic polymers, thus the purpose of placing them together in the same surfactant mixture was to evaluate if the combination would show enhanced beneficial effects. The resulting surfactant mixtures were studied in the presence or absence of serum. A modified bubble surfactometer was used to evaluate surface activities. Mixtures that included both SP-B and SP-C plus hyaluronan and either dextran or polyethylene glycol were found to be the most resistant to inhibition by serum. These mixtures, as well as some with either SP-B or SP-C with combined polymers were as or more resistant to inactivation than native surfactant. These results suggest that improved formulations of lung surfactants are possible and may be useful in reducing some types of surfactant inactivation in treating lung injuries. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Pulmonary surfactant proteins and polymer combinations reduce surfactant inhibition by serum


    Lu, Karen W.; Pérez-Gil, Jesús; Echaide, Mercedes; Taeusch, H. William


    Acute respiratory distress syndrome (ARDS) is an inflammatory condition that can be associated with capillary leak of serum into alveoli causing inactivation of surfactant. Resistance to inactivation is affected by types and concentrations of surfactant proteins, lipids, and polymers. Our aim was to investigate the effects of different combinations of these three components. A simple lipid mixture (DPPC/POPG) or a more complex lipid mixture (DPPC/POPC/POPG/cholesterol) was used. Native surfac...

  19. Palm oil based surfactant products for petroleum industry (United States)

    Permadi, P.; Fitria, R.; Hambali, E.


    In petroleum production process, many problems causing reduced production are found. These include limited oil recovery, wax deposit, asphaltene deposit, sludge deposit, and emulsion problem. Petroleum-based surfactant has been used to overcome these problems. Therefore, innovation to solve these problems using surfactant containing natural materials deserves to be developed. Palm oil-based surfactant is one of the potential alternatives for this. Various types of derivative products of palm oil-based surfactant have been developed by SBRC IPB to be used in handling problems including surfactant flooding, well stimulation, asphaltene dissolver, well cleaning, and wax removal found in oil and gas industry.

  20. Thermally stable surfactants and compositions and methods of use thereof (United States)

    Chaiko, David J [Woodridge, IL


    There are provided novel thermally stable surfactants for use with fillers in the preparation of polymer composites and nanocomposites. Typically, surfactants of the invention are urethanes, ureas or esters of thiocarbamic acid having a hydrocarbyl group of from 10 to 50 carbons and optionally including an ionizable or charged group (e.g., carboxyl group or quaternary amine). Thus, there are provided surfactants having Formula I: ##STR00001## wherein the variables are as defined herein. Further provided are methods of making thermally stable surfactants and compositions, including composites and nanocomposites, using fillers coated with the surfactants.

  1. enhanced ultrafiltration at low surfactant concentrations

    African Journals Online (AJOL)


    Apr 24, 2006 ... Micellar-enhanced ultrafiltration (MEUF) of zinc ions (Zn2+) from aqueous solutions using single anionic surfactant sodium dodecyl sulphate (SDS) at low critical micelle concentrations (cmc) (0.2×cmc – 3×cmc) was investigated. When the initial. SDS concentration was below the cmc, unexpectedly high ...

  2. Surfactant protein D is proatherogenic in mice

    DEFF Research Database (Denmark)

    Sørensen, Grith Lykke; Madsen, Jens; Kejling, Karin


    Surfactant protein D (SP-D) is an important innate immune defense molecule that mediates clearance of pathogens and modulates the inflammatory response. Moreover, SP-D is involved in lipid homeostasis, and pulmonary accumulation of phospholipids has previously been observed in SP-D-deficient (Spd...


    Energy Technology Data Exchange (ETDEWEB)

    Kishore K. Mohanty


    There are many carbonate reservoirs in US (and the world) with light oil and fracture pressure below its minimum miscibility pressure (or reservoir may be naturally fractured). Many carbonate reservoirs are naturally fractured. Waterflooding is effective in fractured reservoirs, if the formation is water-wet. Many fractured carbonate reservoirs, however, are mixed-wet and recoveries with conventional methods are low (less than 10%). Thermal and miscible tertiary recovery techniques are not effective in these reservoirs. Surfactant flooding (or huff-n-puff) is the only hope, yet it was developed for sandstone reservoirs in the past. The goal of this research is to evaluate dilute (hence relatively inexpensive) surfactant methods for carbonate formations and identify conditions under which they can be effective. We have acquired field oil and core samples and field brine compositions from Marathon. We have conducted preliminary adsorption and wettability studies. Addition of Na{sub 2}CO{sub 3} decreases anionic surfactant adsorption on calcite surface. Receding contact angles increase with surfactant adsorption. Plans for the next quarter include conducting adsorption, phase behavior and wettability studies.

  4. Skin capacitance imaging and corneosurfametry. A comparative assessment of the impact of surfactants on stratum corneum. (United States)

    Xhauflaire-Uhoda, Emmanuelle; Loussouarn, Geneviève; Haubrechts, Christelle; Léger, Didier Saint; Piérard, Gérald E


    Silicon image sensor (SIS) technology was recently introduced as an innovative tool (SkinChip, L'Oréal) providing sensitive imaging of the skin capacitance. This method can detect discrete focal variations in skin surface hydration, and thus early discrete manifestations of skin irritation induced by surfactants. In the present in vivo study, 2 neat and diluted shampoos, and 5% and 10% sodium laurylsulfate solutions were tested on human skin. Each surfactant solution was gently rubbed on the skin using wet hair wicks mimicking the casual use of a shampoo on the scalp. Clinical and SIS evaluations were carried out. In addition, the same products were tested using the ex vivo corneosurfametry bioassay performed on human stratum corneum (SC) harvested by cyanoacrylate skin surface strippings. The colourimetric index of mildness (CIM) was measured on these samples. The product reactivity with the SC was recognized by darker skin capacitance images, and by both lowered SkinChip-generated values and lowered CIM values. The extent in changes varied according to the nature of the test products and their concentrations. The SkinChip image changes likely corresponded to the acute surfactant-induced water swelling of the corneocytes. Skin capacitance imaging and corneosurfametry allow to disclose discrete surfactant-induced alterations of corneocytes.

  5. Surfactant for pulmonary haemorrhage in neonates. (United States)

    Aziz, Abdul; Ohlsson, Arne


    In the 1960s and 1970s, pulmonary haemorrhage (PH) occurred mainly in full-term infants with pre-existing illness with an incidence of 1.3 per 1000 live births. Risk factors for PH included severity of illness, intrauterine growth restriction, patent ductus arteriosus (PDA), coagulopathy and the need for assisted ventilation. Presently, PH occurs in 3% to 5% of preterm ventilated infants with severe respiratory distress syndrome (RDS) who often have a PDA and have received surfactant. The cause of PH is thought to be due to rapid lowering of intrapulmonary pressure, which facilitates left to right shunting across a PDA and an increase in pulmonary blood flow. Retrospective case reports and one prospective uncontrolled study have shown promising results for surfactant in treating PH. To evaluate the effect of surfactant treatment compared to placebo or no intervention on mortality and morbidities in neonates with PH. For this update The Cochrane Library, Issue 2, 2012; MEDLINE; EMBASE; CINAHL;;; proceedings (2000 to 2011) of the Annual Meetings of the Pediatric Academic Societies (Abstracts2View) and Web of Science were searched on 8 February 2012. Randomised or quasi-randomised controlled trials that evaluated the effect of surfactant in the treatment of PH in intubated term or preterm (neonates with PH. Infants were included up to 44 weeks' postmenstrual age. The interventions studied were intratracheal instillation of surfactant (natural or synthetic, regardless of dose) versus placebo or no intervention. If studies were identified by the literature search, the planned analyses included risk ratio, risk difference, number needed to treat to benefit or to harm for dichotomous outcomes, and mean difference for continuous outcomes, with their 95% confidence intervals. A fixed-effect model would be used for meta-analyses. The risk of bias for included trials would be assessed. Heterogeneity tests, including the I(2) statistic

  6. Synthesis and properties evaluation of sulfobetaine surfactant with double hydroxyl (United States)

    Zhou, Ming; Luo, Gang; Zhang, Ze; Li, Sisi; Wang, Chengwen


    A series of sulfobetaine surfactants {N-[(3-alkoxy-2-hydroxyl)propoxy] ethyl-N,N-dimethyl-N-(2-hydroxyl)propyl sulfonate} ammonium chloride were synthesized with raw materials containing linear saturated alcohol, N,N-dimethylethanolamine, sodium 3-chloro-2-hydroxyl propane sulfonic acid and epichlorohydrin. The molecule structures of sulfobetaine surfactants were characterized by FTIR, 1HNMR and elemental analysis. Surface tension measurements can provide us information about the surface tension at the CMC (γCMC), pC20, Γmax and Amin. The pC20 values of sulfobetaine surfactants increase with the hydrophobic chain length increasing. Amin values of the surfactants decrease with increasing hydrophobic chain length from 10 to 14. The critical micelle concentration (CMC) and surface tension (γCMC) values of the sulfobetaine surfactants decrease with increasing hydrophobic chain length from 10 to 16. The lipophilicity of surfactant was enhanced with the increase of the carbon chain, however, the ability of anti-hard water was weakened. The minimum oil/water interfacial tension of four kinds of sulfobetaine surfactants is 10-2-10-3 mN/m magnitude, which indicates that the synthesized bis-hydroxy sulfobetaine surfactants have a great ability to reduce interfacial tension in the surfactant flooding system. The surface tension (γCMC) values of synthesized surfactants were lower compared with conventional anionic surfactant sodium dodecyl sulfonate.

  7. Comparative study of clinical pulmonary surfactants using atomic force microscopy (United States)

    Zhang, Hong; Fan, Qihui; Wang, Yi E.; Neal, Charles R.; Zuo, Yi Y.


    Clinical pulmonary surfactant is routinely used to treat premature newborns with respiratory distress syndrome, and has shown great potential in alleviating a number of neonatal and adult respiratory diseases. Despite extensive study of chemical composition, surface activity, and clinical performance of various surfactant preparations, a direct comparison of surfactant films is still lacking. In this study, we use atomic force microscopy to characterize and compare four animal-derived clinical surfactants currently used throughout the world, i.e., Survanta, Curosurf, Infasurf and BLES. These modified-natural surfactants are further compared to dipalmitoyl phosphatidylcholine (DPPC), a synthetic model surfactant of DPPC:palmitoyl-oleoyl phosphatidylglycerol (POPG) (7:3), and endogenous bovine natural surfactant. Atomic force microscopy reveals significant differences in the lateral structure and molecular organization of these surfactant preparations. These differences are discussed in terms of DPPC and cholesterol contents. We conclude that all animal-derived clinical surfactants assume a similar structure of multilayers of fluid phospholipids closely attached to an interfacial monolayer enriched in DPPC, at physiologically relevant surface pressures. This study provides the first comprehensive survey of the lateral structure of clinical surfactants at various surface pressures. It may have clinical implications on future application and development of surfactant preparations. PMID:21439262

  8. Surfactant Replacement Therapy Beyond Respiratory Distress Syndrome in Neonates. (United States)

    Jasani, Bonny; Kabra, Nandkishor; Nanavati, Ruchi


    Surfactant replacement therapy is an established modality of treatment in preterm neonates with respiratory distress syndrome. In addition, there are various neonatal respiratory disorders which are characterized by surfactant deficiency in which surfactant therapy can be a feasible and safe option. To collate the literature on the use of surfactant replacement therapy in neonates beyond respiratory distress syndrome and examine the evidence and newer developments. We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), MEDLINE, and EMBASE up to June 2015; and previous reviews, including cross-references, abstracts, and conference proceedings. Evidence supports surfactant administration via bolus route in neonates with meconium aspiration syndrome, but additional robust evidence is required before its adoption in clinical practice. There is limited evidence to support surfactant therapy in neonates with pneumonia, pulmonary hemorrhage and bronchopulmonary dysplasia. Large multicenter randomized trials are needed to cement or refute the role of surfactant therapy in these disorders.


    Energy Technology Data Exchange (ETDEWEB)

    George J. Hirasaki; Clarence A. Miller; Gary A. Pope; Richard E. Jackson


    Surfactant flooding has the potential to significantly increase recovery over that of conventional waterflooding. The availability of a large number of surfactant structures makes it possible to conduct a systematic study of the relation between surfactant structure and its efficacy for oil recovery. Also, the addition of an alkali such as sodium carbonate makes possible in situ generation of surfactant and significant reduction of surfactant adsorption. In addition to reduction of interfacial tension to ultra-low values, surfactants and alkali can be designed to alter wettability to enhance oil recovery. An alkaline surfactant process is designed to enhance spontaneous imbibition in fractured, oil-wet, carbonate formations. It is able to recover oil from dolomite core samples from which there was no oil recovery when placed in formation brine.

  10. Evolution of pulmonary surfactants for the treatment of neonatal respiratory distress syndrome and paediatric lung diseases. (United States)

    Mazela, Jan; Merritt, T Allen; Gadzinowski, Janusz; Sinha, Sunil


    This review documents the evolution of surfactant therapy, beginning with observations of surfactant deficiency in respiratory distress syndrome, the basis of exogenous surfactant treatment and the development of surfactant-containing novel peptides patterned after SP-B. We critically analyse the molecular interactions of surfactant proteins and phospholipids contributing to surfactant function. Peptide-containing surfactant provides clinical efficacy in the treatment of respiratory distress syndrome and offers promise for treating other lung diseases in infancy.

  11. Photo-Fenton degradation of non-ionic surfactant and its mixture with cationic or anionic surfactant. (United States)

    Ono, Erina; Tokumura, Masahiro; Kawase, Yoshinori


    The oxidative degradation of non-ionic surfactants by the photo-Fenton process has been examined. The photo-Fenton degradation kinetics of mixtures of non-ionic surfactant and other type surfactants has been also investigated since mixtures of non-ionic and ionic surfactants are commonly used to utilize their synergistic effects in many practices. Effects of operating parameters such as dosages of Fenton reagents (iron and hydrogen peroxide) and UV light intensity on the degradation of commercial non-ionic surfactant Sannonic SS-90 (polyoxyethylene alkyl ether) were studied. Although the dosages of the Fenton reagents increased the degradation rate up to the optimum dosages, further addition of the reagents could not enhance the degradation rate. Excess dosages of Fe and H(2)O(2) caused excess OH radicals which could be a scavenger of OH radicals and as a result could not enhance the degradation of the surfactant. The increase in UV light intensity resulting in the faster photo-Fenton process or the enhancement of OH radical formation rate led to the increase in degradation rate of non-ionic surfactant. Although the existence of the anionic surfactant (sodium dodecylbenzene sulphonate) would inhibit the degradation of the non-ionic surfactant due to the formation of complex with Fe ion, the existence of cationic surfactant (dodecyltrimethyl ammonium chloride) affected insignificantly the photo-Fenton degradation process of the non-ionic surfactant.

  12. An Overview of Pulmonary Surfactant in the Neonate: Genetics, Metabolism, and the Role of Surfactant in Health and Disease (United States)

    Nkadi, Paul O.; Merritt, T. Allen; Pillers, De-Ann M.


    Pulmonary surfactant is a complex mixture of phospholipids (PL) and proteins (SP) that reduce surface tension at the air-liquid interface of the alveolus. It is made up of about 70% to 80% PL, mainly dipalmitoylphosphatidylcholine (DPPC), 10% SP-A, B, C and D, and 10% neutral lipids, mainly cholesterol. Surfactant is synthesized, assembled, transported and secreted into the alveolus where it is degraded and then recycled. Metabolism of surfactant is slower in newborns, especially preterm, than in adults. Defective pulmonary surfactant metabolism results in respiratory distress with attendant morbidity and mortality. This occurs due to accelerated breakdown by oxidation, proteolytic degradation, inhibition or inherited defects of surfactant metabolism. Prenatal corticosteroids, surfactant replacement, whole lung lavage and lung transplantation have yielded results in managing some of these defects. Gene therapy could prove valuable in treating inherited defects of surfactant metabolism. PMID:19299177

  13. Surfactant for pulmonary hemorrhage in neonates. (United States)

    Aziz, Abdul; Ohlsson, Arne


    In the late 1960's and 1970's, pulmonary hemorrhage (PH) occurred mainly in full term infants with severe pre-existing illness. The incidence of PH was quoted as 1.3 per 1,000 live births. In the older medical literature, the risk factors associated with PH included the severity of the associated illness, intrauterine growth restriction, patent ductus arteriosus (PDA), coagulopathy, and the need for assisted ventilation. Presently, PH occurs mainly in preterm ventilated infants with severe respiratory distress syndrome (RDS) who often have a PDA and have received surfactant. Currently, PH complicates the hospital course of 3-5% of preterm infants with RDS. Although not clear, the cause of PH is thought to be due to a rapid lowering of intrapulmonary pressure, which facilitates left to right shunting across a patent ductus arteriosus and an increase in pulmonary blood flow. Retrospective case reports and one prospective uncontrolled study that used surfactant for PH in neonates have shown promising results in treating PH. To evaluate the effect of surfactant treatment compared to placebo or no intervention on mortality in neonates with pulmonary hemorrhage. In addition, the review will evaluate the effect of surfactant treatment on neonatal morbidities associated with PH compared to placebo or no intervention. The following databases were searched in January 2008: The Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 4, 2007) and MEDLINE from 1966 and EMBASE from 1980 to the time of the full review using the OVID interface. The proceedings of the Annual Meetings of the Pediatric Academic Societies and the European Society of Pediatric Research published in Pediatric Research or electronically on their web sites were searched from 1994 to the time of the full review. Science citation index (Web of Science) was searched for authors quoting key references of observational studies. Randomised or quasi-randomised controlled trials that

  14. Application of peptide gemini surfactants as novel solubilization surfactants for photosystems I and II of cyanobacteria. (United States)

    Koeda, Shuhei; Umezaki, Katsunari; Noji, Tomoyasu; Ikeda, Atsushi; Kawakami, Keisuke; Kondo, Masaharu; Yamamoto, Yasushi; Shen, Jian-Ren; Taga, Keijiro; Dewa, Takehisa; Ito, Shigeru; Nango, Mamoru; Tanaka, Toshiki; Mizuno, Toshihisa


    We designed novel peptide gemini surfactants (PG-surfactants), DKDKC12K and DKDKC12D, which can solubilize Photosystem I (PSI) of Thermosynecoccus elongatus and Photosystem II (PSII) of Thermosynecoccus vulcanus in an aqueous buffer solution. To assess the detailed effects of PG-surfactants on the original supramolecular membrane protein complexes and functions of PSI and PSII, we applied the surfactant exchange method to the isolated PSI and PSII. Spectroscopic properties, light-induced electron transfer activity, and dynamic light scattering measurements showed that PSI and PSII could be solubilized not only with retention of the original supramolecular protein complexes and functions but also without forming aggregates. Furthermore, measurement of the lifetime of light-induced charge-separation state in PSI revealed that both surfactants, especially DKDKC12D, displayed slight improvement against thermal denaturation below 60 °C compared with that using β-DDM. This degree of improvement in thermal resistance still seems low, implying that the peptide moieties did not interact directly with membrane protein surfaces. By conjugating an electron mediator such as methyl viologen (MV(2+)) to DKDKC12K (denoted MV-DKDKC12K), we obtained derivatives that can trap the generated reductive electrons from the light-irradiated PSI. After immobilization onto an indium tin oxide electrode, a cathodic photocurrent from the electrode to the PSI/MV-DKDKC12K conjugate was observed in response to the interval of light irradiation. These findings indicate that the PG-surfactants DKDKC12K and DKDKC12D provide not only a new class of solubilization surfactants but also insights into designing other derivatives that confer new functions on PSI and PSII.

  15. Surfactant Based Enhanced Oil Recovery and Foam Mobility Control

    Energy Technology Data Exchange (ETDEWEB)

    George J. Hirasaki; Clarence A. Miller


    Surfactant flooding has the potential to significantly increase recovery over that of conventional waterflooding. The availability of a large number of surfactant structures makes it possible to conduct a systematic study of the relation between surfactant structure and its efficacy for oil recovery. A mixture of two surfactants was found to be particularly effective for application in carbonate formations at low temperature. The mixture is single phase for higher salinity or calcium concentrations than that for either surfactant used alone. This makes it possible to inject the surfactant slug with polymer close to optimal conditions and yet be single phase. A formulation has been designed for a particular field application. It uses partially hydrolyzed polyacrylamide for mobility control. The addition of an alkali such as sodium carbonate makes possible in situ generation of naphthenic soap and significant reduction of synthetic surfactant adsorption. The design of the process to maximize the region of ultra-low IFT takes advantage of the observation that the ratio of soap to synthetic surfactant is a parameter in the conditions for optimal salinity. Even for a fixed ratio of soap to surfactant, the range of salinity for low IFT was wider than that reported for surfactant systems in the literature. Low temperature, forced displacement experiments in dolomite and silica sandpacks demonstrate that greater than 95% recovery of the waterflood remaining oil is possible with 0.2% surfactant concentration, 0.5 PV surfactant slug, with no alcohol. Compositional simulation of the displacement process demonstrates the role of soap/surfactant ratio on passage of the profile through the ultralow IFT region, the importance of a wide salinity range of low IFT, and the importance of the viscosity of the surfactant slug. Mobility control is essential for surfactant EOR. Foam is evaluated to improve the sweep efficiency of surfactant injected into fractured reservoirs as well as a

  16. A Combination of Short and Simple Surfactant Protein B and C Analogues as a New Synthetic Surfactant: In Vitro and Animal Experiments. (United States)

    Choi, Yong Sung; Chung, Sung Hoon; Bae, Chong Woo


    Pulmonary surfactants for preterm infants contain mostly animal-derived surfactant proteins (SPs), which are essential for lowering surface tension. We prepared artificial pulmonary surfactants using synthetic human SP analogs and performed in vitro and in vivo experiments. We synthesized peptide analogues that resemble human SP-B (RMLPQLVCRLVLRCSMD) and SP-C (CPVHLKRLLLLLLLLLLLLLLLL). Dipalmitoylphosphatidylcholine (DPPC), phosphatidylglycerol (PG), and palmitic acid (PA) were added and mixed in lyophilized to render powdered surfactant. Synsurf-1 was composed of DPPC:PG:PA:SP-B (75:25:10:3, w/w); Synsurf-2 was composed of DPPC:PG:PA:SP-C (75:25:10:3, w/w); and Synsurf-3 was composed of DPPC:PG:PA:SP-B:SP-C (75:25:10:3:3, w/w). We performed in vitro study to compare the physical characteristics using pulsating bubble surfactometer and modified Wilhelmy balance test. Surface spreading and adsorption test of the surfactant preparations were measured. In vivo test was performed using term and preterm rabbit pups. Pressure-volume curves were generated during the deflation phase. Histologic findings were examined. Pulsating bubble surfactometer readings revealed following minimum and maximum surface tension (mN/m) at 5 minutes: Surfacten® (5.5±0.4, 32.8±1.6), Synsurf-1 (16.7±0.6, 28.7±1.5), Synsurf-2 (7.9±1.0, 33.1±1.6), and Synsurf-3 (7.1±0.8, 34.5±1.0). Surface spreading rates were as follows: Surfacten® (27 mN/m), Synsurf-1 (43 mN/m), Synsurf-2 (27 mN/m), and Synsurf-3 (27 mN/m). Surface adsorption rate results were as follows: Surfacten® (28 mN/m), Synsurf-1 (35 mN/m), Synsurf-2 (29 mN/m), and Synsurf-3 (27 mN/m). The deflation curves were best for Synsurf-3; those for Synsurf-2 were better than those for Surfacten®. Synsurf-1 was the worst surfactant preparation. Microscopic examination showed the largest aerated area of the alveoli in the Synsurf-3 group, followed by Synsurf-1 and Surfacten®; Synsurf-2 was the smallest. Synsurf-3 containing both SP

  17. Pulmonary surfactant adsorption is increased by hyaluronan or polyethylene glycol. (United States)

    Taeusch, H William; Dybbro, Eric; Lu, Karen W


    In acute lung injuries, inactivating agents may interfere with transfer (adsorption) of pulmonary surfactants to the interface between air and the aqueous layer that coats the interior of alveoli. Some ionic and nonionic polymers reduce surfactant inactivation in vitro and in vivo. In this study, we tested directly whether an ionic polymer, hyaluronan, or a nonionic polymer, polyethylene glycol, enhanced adsorption of a surfactant used clinically. We used three different methods of measuring adsorption in vitro: a modified pulsating bubble surfactometer; a King/Clements device; and a spreading trough. In addition we measured the effects of both polymers on surfactant turbidity, using this assay as a nonspecific index of aggregation. We found that both hyaluronan and polyethylene glycol significantly increased the rate and degree of surfactant material adsorbed to the surface in all three assays. Hyaluronan was effective in lower concentrations (20-fold) than polyethylene glycol and, unlike polyethylene glycol, hyaluronan did not increase apparent aggregation of surfactant. Surfactant adsorption in the presence of serum was also enhanced by both polymers regardless of whether hyaluronan or polyethylene glycol was included with serum in the subphase or added to the surfactant applied to the surface. Therefore, endogenous polymers in the alveolar subphase, or exogenous polymers added to surfactant used as therapy, may both be important for reducing inactivation of surfactant that occurs with various lung injuries.


    Pirog, T P; Beregova, K A; Savenko, I V; Shevchuk, T A; Iutynska, G O


    To study the effect of Nocardia vaccinii IMV B-7405 surfactants on some bacteria (including pathogens of genera Proteus, Staphylococcus, Enterobacter), yeast of Candida species and fungi (Aspergillus niger R-3, Fusarium culmorum T-7). The antimi- crobial properties of surfactant were determined in suspension culture by Koch method and also by index of the minimum inhibitory concentration. Surfactants were extracted from supernatant of cultural liquid by mixture of chloroform and methanol (2:1). It is shown that the antimicrobial properties of N. vaccinii IMV B-7405 surfactant depended on the degree of purification (supernatant, solution of surfactant), concentration and exposure. Survival of Escherichia coli IEM-1 and Bacillus subtilis BT-2 (both vegetative cells and spores) after treatment for 1-2 hours with surfactants solution and the supernatant (the surfactant concentration 21 µg/ml) was 3-28%. Minimum inhibitory concentrations of N. vaccinii IMV B-7405 surfactants on studied bacteria, yeast and micromycetes were 11.5-85.0; 11.5-22.5 and 165.0-325.0 µ/ml respectively. Minimum inhibitory concentrations of N. vaccinii IMV B-7405 surfactants are comparable to those of the known microbial surfactants. The possibility of using the supernatant of culture liquid as an effective antimicrobial agent noticeably simplifies and reduces the cost of the technology of its obtaining.


    Energy Technology Data Exchange (ETDEWEB)

    George J. Hirasaki; Clarence A. Miller; Gary A. Pope; Richard E. Jackson


    Surfactant flooding has the potential to significantly increase recovery over that of conventional waterflooding. The availability of a large number of surfactants makes it possible to conduct a systematic study of the relation between surfactant structure and its efficacy for oil recovery. Also, the addition of an alkali such as sodium carbonate makes possible in situ generation of surfactant and significant reduction of surfactant adsorption. In addition to reduction of interfacial tension to ultra-low values, surfactants and alkali can be designed to alter wettability to enhance oil recovery. An alkaline surfactant process is designed to enhance spontaneous imbibition in fractured, oil-wet, carbonate formations. It is able to recover oil from dolomite core samples from which there was no oil recovery when placed in formation brine. Mobility control is essential for surfactant EOR. Foam is evaluted to improve the sweep efficiency of surfactant injected into fractured reservoirs. UTCHEM is a reservoir simulator specially designed for surfactant EOR. A dual-porosity version is demonstrated as a potential scale-up tool for fractured reservoirs.

  20. Next Generation Surfactants for Improved Chemical Flooding Technology

    Energy Technology Data Exchange (ETDEWEB)

    Laura Wesson; Prapas Lohateeraparp; Jeffrey Harwell; Bor-Jier Shiau


    The principle objective of this project was to characterize and test current and next generation high performance surfactants for improved chemical flooding technology, focused on reservoirs in the Pennsylvanian-aged (Penn) sands. In order to meet this objective the characteristic curvatures (Cc) of twenty-eight anionic surfactants selected for evaluation for use in chemical flooding formulations were determined. The Cc values ranged from -6.90 to 2.55 with the majority having negative values. Crude oil samples from nine Penn sand reservoirs were analyzed for several properties pertinent to surfactant formulation for EOR application. These properties included equivalent alkane carbon numbers, total acid numbers, and viscosity. The brine samples from these same reservoirs were analyzed for several cations and for total dissolved solids. Surfactant formulations were successfully developed for eight reservoirs by the end of the project period. These formulations were comprised of a tertiary mixture of anionic surfactants. The identities of these surfactants are considered proprietary, but suffice to say the surfactants in each mixture were comprised of varying chemical structures. In addition to the successful development of surfactant formulations for EOR, there were also two successful single-well field tests conducted. There are many aspects that must be considered in the development and implementation of effective surfactant formulations. Taking into account these other aspects, there were four additional studies conducted during this project. These studies focused on the effect of the stability of surfactant formulations in the presence of polymers with an associated examination of polymer rheology, the effect of the presence of iron complexes in the brine on surfactant stability, the potential use of sacrificial agents in order to minimize the loss of surfactant to adsorption, and the effect of electrolytes on surfactant adsorption. In these last four studies

  1. Deleted in Malignant Brain Tumors 1 (DMBT1 is present in hyaline membranes and modulates surface tension of surfactant

    Directory of Open Access Journals (Sweden)

    Griese Matthias


    Full Text Available Abstract Background Deleted in Malignant Brain Tumors 1 (DMBT1 is a secreted scavenger receptor cysteine-rich protein that binds various bacteria and is thought to participate in innate pulmonary host defense. We hypothesized that pulmonary DMBT1 could contribute to respiratory distress syndrome in neonates by modulating surfactant function. Methods DMBT1 expression was studied by immunohistochemistry and mRNA in situ hybridization in post-mortem lungs of preterm and full-term neonates with pulmonary hyaline membranes. The effect of human recombinant DMBT1 on the function of bovine and porcine surfactant was measured by a capillary surfactometer. DMBT1-levels in tracheal aspirates of ventilated preterm and term infants were determined by ELISA. Results Pulmonary DMBT1 was localized in hyaline membranes during respiratory distress syndrome. In vitro addition of human recombinant DMBT1 to the surfactants increased surface tension in a dose-dependent manner. The DMBT1-mediated effect was reverted by the addition of calcium depending on the surfactant preparation. Conclusion Our data showed pulmonary DMBT1 expression in hyaline membranes during respiratory distress syndrome and demonstrated that DMBT1 increases lung surface tension in vitro. This raises the possibility that DMBT1 could antagonize surfactant supplementation in respiratory distress syndrome and could represent a candidate target molecule for therapeutic intervention in neonatal lung disease.

  2. Deleted in Malignant Brain Tumors 1 (DMBT1) is present in hyaline membranes and modulates surface tension of surfactant (United States)

    Müller, Hanna; End, Caroline; Renner, Marcus; Helmke, Burkhard M; Gassler, Nikolaus; Weiss, Christel; Hartl, Dominik; Griese, Matthias; Hafner, Mathias; Poustka, Annemarie; Mollenhauer, Jan; Poeschl, Johannes


    Background Deleted in Malignant Brain Tumors 1 (DMBT1) is a secreted scavenger receptor cysteine-rich protein that binds various bacteria and is thought to participate in innate pulmonary host defense. We hypothesized that pulmonary DMBT1 could contribute to respiratory distress syndrome in neonates by modulating surfactant function. Methods DMBT1 expression was studied by immunohistochemistry and mRNA in situ hybridization in post-mortem lungs of preterm and full-term neonates with pulmonary hyaline membranes. The effect of human recombinant DMBT1 on the function of bovine and porcine surfactant was measured by a capillary surfactometer. DMBT1-levels in tracheal aspirates of ventilated preterm and term infants were determined by ELISA. Results Pulmonary DMBT1 was localized in hyaline membranes during respiratory distress syndrome. In vitro addition of human recombinant DMBT1 to the surfactants increased surface tension in a dose-dependent manner. The DMBT1-mediated effect was reverted by the addition of calcium depending on the surfactant preparation. Conclusion Our data showed pulmonary DMBT1 expression in hyaline membranes during respiratory distress syndrome and demonstrated that DMBT1 increases lung surface tension in vitro. This raises the possibility that DMBT1 could antagonize surfactant supplementation in respiratory distress syndrome and could represent a candidate target molecule for therapeutic intervention in neonatal lung disease. PMID:17908325

  3. Denaturation of proteins by surfactants studied by the Taylor dispersion analysis. (United States)

    Jelińska, Aldona; Zagożdżon, Anna; Górecki, Marcin; Wisniewska, Agnieszka; Frelek, Jadwiga; Holyst, Robert


    We showed that the Taylor Dispersion Analysis (TDA) is a fast and easy to use method for the study of denaturation proteins. We applied TDA to study denaturation of β-lactoglobulin, transferrin, and human insulin by anionic surfactant sodium dodecyl sulfate (SDS). A series of measurements at constant protein concentration (for transferrin was 1.9 x 10-5 M, for β- lactoglobulin was 7.6 x 10-5 M, and for insulin was 1.2 x 10-4 M) and varying SDS concentrations were carried out in the phosphate-buffered saline (PBS). The structural changes were analyzed based on the diffusion coefficients of the complexes formed at various surfactant concentrations. The concentration of surfactant was varied in the range from 1.2 x 10-4 M to 8.7 x 10-2 M. We determined the minimum concentration of the surfactant necessary to change the native conformation of the proteins. The minimal concentration of SDS for β-lactoglobulin and transferrin was 4.3 x 10-4 M and for insulin 2.3 x 10-4 M. To evaluate the TDA as a novel method for studying denaturation of proteins we also applied other methods i.e. electronic circular dichroism (ECD) and dynamic light scattering (DLS) to study the same phenomenon. The results obtained using these methods were in agreement with the results from TDA.

  4. Monitoring of phenolic compounds and surfactants in water of Ganga Canal, Haridwar (India) (United States)

    Seth, Richa; Singh, Prashant; Mohan, Manindra; Singh, Rakesh; Aswal, Ravinder Singh


    The Ganga Canal emerging out from Ganga River has great ritual importance among pilgrims and tourists at Haridwar, Uttarakhand, India. The Canal is being polluted due to mass bathing, washing, disposal of sewage, industrial waste and these human activities are deteriorating its water quality. To determine the impact of these activities, Ganga Canal water quality at five sites between Haridwar and Roorkee namely Pantdweep, Har Ki Pauri, Singhdwar, Piran Kaliyar and Old Bridge, Roorkee has been analyzed for organic pollutants phenolic compounds and surfactants, which have rarely been assessed and reported so far. The results of analysis show that phenolic compounds are not present in water samples of selected five sites during bi-monthly monitoring from January 2012 to November 2012. The Har Ki Pauri, Singhdwar, Piran Kaliyar and Old Bridge, Roorkee sites have been detected with surfactant concentrations (1.18, 1.63, 3.2 and 2.5 mg/l) more than permissible limit (1.00 mg/l). Also at most of the sites, surfactants' concentration crossed the desirable limit of BIS during the period of analysis. This distribution of surfactants in water has potential risk for skin diseases and cancer and requires regular monitoring with appropriate measures.

  5. Denaturation of proteins by surfactants studied by the Taylor dispersion analysis.

    Directory of Open Access Journals (Sweden)

    Aldona Jelińska

    Full Text Available We showed that the Taylor Dispersion Analysis (TDA is a fast and easy to use method for the study of denaturation proteins. We applied TDA to study denaturation of β-lactoglobulin, transferrin, and human insulin by anionic surfactant sodium dodecyl sulfate (SDS. A series of measurements at constant protein concentration (for transferrin was 1.9 x 10-5 M, for β- lactoglobulin was 7.6 x 10-5 M, and for insulin was 1.2 x 10-4 M and varying SDS concentrations were carried out in the phosphate-buffered saline (PBS. The structural changes were analyzed based on the diffusion coefficients of the complexes formed at various surfactant concentrations. The concentration of surfactant was varied in the range from 1.2 x 10-4 M to 8.7 x 10-2 M. We determined the minimum concentration of the surfactant necessary to change the native conformation of the proteins. The minimal concentration of SDS for β-lactoglobulin and transferrin was 4.3 x 10-4 M and for insulin 2.3 x 10-4 M. To evaluate the TDA as a novel method for studying denaturation of proteins we also applied other methods i.e. electronic circular dichroism (ECD and dynamic light scattering (DLS to study the same phenomenon. The results obtained using these methods were in agreement with the results from TDA.

  6. Surfactant protein B inhibits secretory phospholipase A2 hydrolysis of surfactant phospholipids (United States)

    Grier, Bonnie L.; Waite, B. Moseley; Veldhuizen, Ruud A.; Possmayer, Fred; Yao, Li-Juan; Seeds, Michael C.


    Hydrolysis of surfactant phospholipids (PL) by secretory phospholipases A2 (sPLA2) contributes to surfactant damage in inflammatory airway diseases such as acute lung injury/acute respiratory distress syndrome. We and others have reported that each sPLA2 exhibits specificity in hydrolyzing different PLs in pulmonary surfactant and that the presence of hydrophilic surfactant protein A (SP-A) alters sPLA2-mediated hydrolysis. This report tests the hypothesis that hydrophobic SP-B also inhibits sPLA2-mediated surfactant hydrolysis. Three surfactant preparations were used containing varied amounts of SP-B and radiolabeled tracers of phosphatidylcholine (PC) or phosphatidylglycerol (PG): 1) washed ovine surfactant (OS) (pre- and postorganic extraction) compared with Survanta (protein poor), 2) Survanta supplemented with purified bovine SP-B (1–5%, wt/wt), and 3) a mixture of dipalmitoylphosphatidylcholine (DPPC), 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC), and 1-palmitoyl-2-oleoyl-phosphatidylglycerol (POPG) (DPPC:POPC:POPG, 40:40:20) prepared as vesicles and monomolecular films in the presence or absence of SP-B. Hydrolysis of PG and PC by Group IB sPLA2 (PLA2G1A) was significantly lower in the extracted OS, which contains SP-B, compared with Survanta (P = 0.005), which is SP-B poor. Hydrolysis of PG and PC in nonextracted OS, which contains all SPs, was lower than both Survanta and extracted OS. When Survanta was supplemented with 1% SP-B, PG and PC hydrolysis by PLA2G1B was significantly lower (P hydrolysis by both PLA2G1B and Group IIA sPLA2 (PLA2G2A). In films, PLA2G1B hydrolyzed surfactant PL monolayers at surface pressures ≤30 mN/m (P hydrolysis can occur. These results suggest the hydrophobic SP, SP-B, protects alveolar surfactant PL from hydrolysis mediated by multiple sPLA2 in both vesicles (alveolar subphase) and monomolecular films (air-liquid interface). PMID:22037357

  7. Microemulsion-based lycopene extraction: Effect of surfactants, co-surfactants and pretreatments. (United States)

    Amiri-Rigi, Atefeh; Abbasi, Soleiman


    Lycopene is a potent antioxidant that has received extensive attention recently. Due to the challenges encountered with current methods of lycopene extraction using hazardous solvents, industry calls for a greener, safer and more efficient process. The main purpose of present study was application of microemulsion technique to extract lycopene from tomato pomace. In this respect, the effect of eight different surfactants, four different co-surfactants, and ultrasound and enzyme pretreatments on lycopene extraction efficiency was examined. Experimental results revealed that application of combined ultrasound and enzyme pretreatments, saponin as a natural surfactant, and glycerol as a co-surfactant, in the bicontinuous region of microemulsion was the optimal experimental conditions resulting in a microemulsion containing 409.68±0.68 μg/glycopene. The high lycopene concentration achieved, indicates that microemulsion technique, using a low-cost natural surfactant could be promising for a simple and safe separation of lycopene from tomato pomace and possibly from tomato industrial wastes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Hydrogels of sodium alginate in cationic surfactants: Surfactant dependent modulation of encapsulation/release toward Ibuprofen. (United States)

    Jabeen, Suraya; Chat, Oyais Ahmad; Maswal, Masrat; Ashraf, Uzma; Rather, Ghulam Mohammad; Dar, Aijaz Ahmad


    The interaction of cetyltrimethylammoium bromide (CTAB) and its gemini homologue (butanediyl-1,4-bis (dimethylcetylammonium bromide), 16-4-16 with biocompatible polymer sodium alginate (SA) has been investigated in aqueous medium. Addition of K2CO3 influences viscoelastic properties of surfactant impregnated SA via competition between electrostatic and hydrophobic interactions. Viscosity of these polymer-surfactant systems increases with increase in concentration of K2CO3, and a cryogel is formed at about 0.5M K2CO3 concentration. The thermal stability of gel (5% SA+0.5M K2CO3) decreases with increase in surfactant concentration, a minimum is observed with increase in 16-4-16 concentration. The impact of surfactant addition on the alginate structure vis-à-vis its drug loading capability and release thereof was studied using Ibuprofen (IBU) as the model drug. The hydrogel with 16-4-16 exhibits higher IBU encapsulation and faster release in comparison to the one containing CTAB. This higher encapsulation-cum-faster release capability has been related to micelle mediated solubilization and greater porosity of the hydrogel with gemini surfactant. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. The effect of postadded ethylene glycol surfactants on DNA-cationic surfactant/water mesophases. (United States)

    Leal, Cecilia; Bilalov, Azat; Lindman, Björn


    The addition of amphiphiles grafted with polyethylene glycol units to constructs of DNA-amphiphiles is of most relevance for applications demanding colloidal stability. In this work, we study the self-assembly behavior of a true ternary mixture comprising (i) an electroneutral complex of DNA and a cationic surfactant (dodecyltrimethylammonium, DTA), (ii) water, and (iii) nonionic surfactant (dodecyl tetraethylene glycol, C12EO4; and dodecyl octaethylene glycol, C12EO8). The phase diagrams of the two systems: DNA-DTA/C12EO4/water and DNA-DTA/C12EO8/water were carried out using 2H NMR, and small-angle X-ray scattering (SAXS). In both mixtures, the DNA-DTA complex incorporates the postadded nonionic surfactant and large liquid crystalline regions were found. The supramolecular assemblies evolve from a 2D hexagonal structure of the normal type to a lamellar phase as the content of nonionic surfactant is increased. The effect of ethylene glycol unit size in the phase behavior is discussed. We suggest that when longer ethylene glycol units (C12EO8 vs C12EO4) are used, the DNA-DTA aggregate gets saturated with the nonionic surfactant and there exists a coexistence of a fully swollen mesophase phase of C12EO8 alone presumably of the normal hexagonal type with the lamellar and hexagonal phases of DNA-DTA/C12EO8/water.

  10. Topological transformation of a surfactant bilayer

    DEFF Research Database (Denmark)

    Le, T.D.; Olsson, U.; Mortensen, K.


    Surfactant lamellar phases are often complicated by the formation of multilamellar (onions) under shear, which can originate simply by shaking the sample. A systematic study has been performed on the C10E3-D2O system in which different bilayer structures under a steady shear flow were investigate......>(b), in the transformation from onion to plane to multiply connected bilayer structure as a function of temperature. (C) 2000 Elsevier Science B.V. All rights reserved.......Surfactant lamellar phases are often complicated by the formation of multilamellar (onions) under shear, which can originate simply by shaking the sample. A systematic study has been performed on the C10E3-D2O system in which different bilayer structures under a steady shear flow were investigated...

  11. Surfactant protein D in newborn infants

    DEFF Research Database (Denmark)

    Dahl, Marianne; Juvonen, Pekka Olavi; Holmskov, Uffe


    Surfactant protein D (SP-D) is a collectin that plays an important role in the innate immune system. The role of SP-D in the metabolism of surfactant is as yet quite unclear. The aims of this study were to establish normal values of SP-D in the umbilical cord blood and capillary blood of mature...... was measured by enzyme-linked immunosorbent assay. The median concentration of SP-D in umbilical cord blood was 392.1 ng/mL and was found to be influenced by maternal smoking and labor. The median concentration of SP-D in capillary blood was 777.5 ng/mL and was found to be influenced by the mode of delivery...

  12. Negative electrospray ionisation of fluorotelomer alcohols (FTOH) and FTOH-derived acrylate surfactants by liquid chromatography coupled to accurate (tandem) mass spectrometry

    DEFF Research Database (Denmark)

    Trier, Xenia; Christensen, Jan H.; Niessen, Wilfried M. A.

    Fluorotelomer alcohols (FTOHs) are used to synthesize fluorinated surfactants, which form bioaccumulative perfluorinated degradation products, which are toxic to humans and the environment. To facilitate screening for FTOH-derived surfactants by LC-ESI–-MS, we identified product ions of FTOHs, an......, and propose FTOH fragmentation pathways on two MS instruments. By extraction of FTOH basepeak ions from accurate mass spectra, homologues series of peaks showed up in an industrial blend of FTOH-derived fluoroacrylates used in food paper packaging....

  13. Molecular dynamics of surfactant protein C

    DEFF Research Database (Denmark)

    Ramírez, Eunice; Santana, Alberto; Cruz, Anthony


    Surfactant protein C (SP-C) is a membrane-associated protein essential for normal respiration. It has been found that the alpha-helix form of SP-C can undergo, under certain conditions, a transformation from an alpha-helix to a beta-strand conformation that closely resembles amyloid fibrils, which...... occurs at the amino terminal, and despite this unfolding, no transition from alpha-helix to beta-strand was observed....

  14. Probing Nanoscale Thermal Transport in Surfactant Solutions (United States)

    Cao, Fangyu; Liu, Ying; Xu, Jiajun; He, Yadong; Hammouda, B.; Qiao, Rui; Yang, Bao


    Surfactant solutions typically feature tunable nanoscale, internal structures. Although rarely utilized, they can be a powerful platform for probing thermal transport in nanoscale domains and across interfaces with nanometer-size radius. Here, we examine the structure and thermal transport in solution of AOT (Dioctyl sodium sulfosuccinate) in n-octane liquids using small-angle neutron scattering, thermal conductivity measurements, and molecular dynamics simulations. We report the first experimental observation of a minimum thermal conductivity occurring at the critical micelle concentration (CMC): the thermal conductivity of the surfactant solution decreases as AOT is added till the onset of micellization but increases as more AOT is added. The decrease of thermal conductivity with AOT loading in solutions in which AOT molecules are dispersed as monomers suggests that even the interfaces between individual oleophobic headgroup of AOT molecules and their surrounding non-polar octane molecules can hinder heat transfer. The increase of thermal conductivity with AOT loading after the onset of micellization indicates that the thermal transport in the core of AOT micelles and across the surfactant-oil interfaces, both of which span only a few nanometers, are efficient.

  15. Influence of metacide - surfactant complexes on agricultural crops

    Directory of Open Access Journals (Sweden)

    Orynkul Esimova


    Full Text Available The complexes based on surfactants and polyhexamethyleneguanidine hydrochloride (metacide are important for agriculture. This paper considers compositions of known bactericidal metacide with different surfactants: anionic surfactant sodium dodecylsulphate (DDSNa and nonionic surfactant Tween 80 (monooleate of oxyethylenated anhydrosorbitols. The effect of individual components and associates of metacide and surfactants on productivity and infection of cereals was studied. According to the study, the highest productivity and infection rate were shown by the associate of metacide and Tween-80. At concentration of Tween-80 in aqueous solution equal to 0.001% in combination with metacide, efficiency was 98% at 0% infection. The surface tension and the wetting of metacide, DDSNa, Tween-80, and associates of metacide with surfactants were studied. In comparison with individual components, metacide-DDSNa and metacide-Tween-80 associates have higher surface activity.

  16. Gemini imidazolium surfactants: synthesis and their biophysiochemical study. (United States)

    Kamboj, Raman; Singh, Sukhprit; Bhadani, Avinash; Kataria, Hardeep; Kaur, Gurcharan


    New gemini imidazolium surfactants 9-13 have been synthesized by a regioselective epoxy ring-opening reaction under solvent-free conditions. The surface properties of these new gemini surfactants were evaluated by surface tension and conductivity measurements. These surfactants have been found to have low critical micelle concentration (cmc) values as compared to other categories of gemini cationic surfactants and also showed the tendency to form premicellar aggregates in solution at sufficiently low concentration below their cmc values. The thermal degradation of these surfactants was determined by thermograviometry analysis (TGA). These new cationic surfactants have a good DNA binding capability as determined by agarose gel electrophoresis and ethidium bromide exclusion experiments. They have also been found to have low cytotoxicity by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay on the C6 glioma cell line.

  17. Restoring pulmonary surfactant membranes and films at the respiratory surface. (United States)

    Echaide, Mercedes; Autilio, Chiara; Arroyo, Raquel; Perez-Gil, Jesus


    Pulmonary surfactant is a complex of lipids and proteins assembled and secreted by the alveolar epithelium into the thin layer of fluid coating the respiratory surface of lungs. There, surfactant forms interfacial films at the air-water interface, reducing dramatically surface tension and thus stabilizing the air-exposed interface to prevent alveolar collapse along respiratory mechanics. The absence or deficiency of surfactant produces severe lung pathologies. This review describes some of the most important surfactant-related pathologies, which are a cause of high morbidity and mortality in neonates and adults. The review also updates current therapeutic approaches pursuing restoration of surfactant operative films in diseased lungs, mainly through supplementation with exogenous clinical surfactant preparations. This article is part of a Special Issue entitled: Membrane Lipid Therapy: Drugs Targeting Biomembranes edited by Pablo V. Escribá. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. [Pulmonary surfactant homeostasis associated genetic abnormalities and lung diseases]. (United States)

    Jiang, Xiaojing; Sun, Xiuzhu; Du, Weihua; Hao, Haisheng; Zhao, Xueming; Wang, Dong; Zhu, Huabin; Liu, Yan


    Pulmonary surfactant (PS) is synthesized and secreted by alveolar epithelial type II (AEII) cells, which is a complex compound formed by proteins and lipids. Surfactant participates in a range of physiological processes such as reducing the surface tension, keeping the balance of alveolar fluid, maintaining normal alveolar morphology and conducting host defense. Genetic disorders of the surfactant homeostasis genes may result in lack of surfactant or cytotoxicity, and lead to multiple lung diseases in neonates, children and adults, including neonatal respiratory distress syndrome, interstitial pneumonia, pulmonary alveolar proteinosis, and pulmonary fibrosis. This paper has provided a review for the functions and processes of pulmonary surfactant metabolism, as well as the connection between disorders of surfactant homeostasis genes and lung diseases.

  19. A disorder of surfactant metabolism without identified genetic mutations


    Montella, Silvia; Vece, Timothy J.; Langston, Claire; Carrera, Paola; Nogee, Lawrence M.; Hamvas, Aaron; Manna, Angelo; Cervasio, Mara; Santamaria, Francesca


    Background Surfactant metabolism disorders may result in diffuse lung disease in children. Case presentation We report a 3-years-old boy with dry cough, progressive hypoxemia, dyspnea and bilateral ground glass opacities at chest high-resolution computed tomography (HRCT) who had no variants in genes encoding surfactant proteins or transcription factors. Lung histology strongly suggested an abnormality of surfactant protein. A 7-month course of pulse intravenous high-dose methylprednisolone p...

  20. Surfactant development for enhanced oil recover. Final report

    Energy Technology Data Exchange (ETDEWEB)



    The general objective of the project is to develop novel surfactants for tertiary recovery of light oil at elevated temperatures and high brine concentrations. Specific objectives are: to design, synthesize and characterize new surfactants capable of forming microemulsions of high stability at high temperatures and high salinity; to select microemulsions that will yield optimum efficiency and effectiveness in oil solubilization; to characterize the physico-chemical properties of selected microemulsion; to correlate surfactant efficacy with physico-chemical variables of selected reservoirs.

  1. Surfactant Based Enhanced Oil Recovery and Foam Mobility Control

    Energy Technology Data Exchange (ETDEWEB)

    George J. Hirasaki; Clarence A. Miller; Gary A. Pope


    Surfactant flooding has the potential to significantly increase recovery over that of conventional waterflooding. The availability of a large number of surfactant structures makes it possible to conduct a systematic study of the relation between surfactant structure and its efficacy for oil recovery. A combination of two surfactants was found to be particularly effective for application in carbonate formations at low temperature. A formulation has been designed for a particular field application. The addition of an alkali such as sodium carbonate makes possible in situ generation of surfactant and significant reduction of surfactant adsorption. In addition to reduction of interfacial tension to ultra-low values, surfactants and alkali can be designed to alter wettability to enhance oil recovery. The design of the process to maximize the region of ultra-low IFT is more challenging since the ratio of soap to synthetic surfactant is a parameter in the conditions for optimal salinity. Compositional simulation of the displacement process demonstrates the interdependence of the various components for oil recovery. An alkaline surfactant process is designed to enhance spontaneous imbibition in fractured, oil-wet, carbonate formations. It is able to recover oil from dolomite core samples from which there was no oil recovery when placed in formation brine. Mobility control is essential for surfactant EOR. Foam is evaluated to improve the sweep efficiency of surfactant injected into fractured reservoirs. UTCHEM is a reservoir simulator specially designed for surfactant EOR. It has been modified to represent the effects of a change in wettability. Simulated case studies demonstrate the effects of wettability.

  2. PLUNC is a novel airway surfactant protein with anti-biofilm activity.

    Directory of Open Access Journals (Sweden)

    Lokesh Gakhar


    Full Text Available The PLUNC ("Palate, lung, nasal epithelium clone" protein is an abundant secretory product of epithelia present throughout the conducting airways of humans and other mammals, which is evolutionarily related to the lipid transfer/lipopolysaccharide binding protein (LT/LBP family. Two members of this family--the bactericidal/permeability increasing protein (BPI and the lipopolysaccharide binding protein (LBP--are innate immune molecules with recognized roles in sensing and responding to Gram negative bacteria, leading many to propose that PLUNC may play a host defense role in the human airways.Based on its marked hydrophobicity, we hypothesized that PLUNC may be an airway surfactant. We found that purified recombinant human PLUNC greatly enhanced the ability of aqueous solutions to spread on a hydrophobic surface. Furthermore, we discovered that PLUNC significantly reduced surface tension at the air-liquid interface in aqueous solutions, indicating novel and biologically relevant surfactant properties. Of note, surface tensions achieved by adding PLUNC to solutions are very similar to measurements of the surface tension in tracheobronchial secretions from humans and animal models. Because surfactants of microbial origin can disperse matrix-encased bacterial clusters known as biofilms [1], we hypothesized that PLUNC may also have anti-biofilm activity. We found that, at a physiologically relevant concentration, PLUNC inhibited biofilm formation by the airway pathogen Pseudomonas aeruginosa in an in vitro model.Our data suggest that the PLUNC protein contributes to the surfactant properties of airway secretions, and that this activity may interfere with biofilm formation by an airway pathogen.

  3. The Pulmonary Surfactant: Impact of Tobacco Smoke and Related Compounds on Surfactant and Lung Development

    Directory of Open Access Journals (Sweden)

    Scott J Elliott


    Full Text Available Abstract Cigarette smoking, one of the most pervasive habits in society, presents many well established health risks. While lung cancer is probably the most common and well documented disease associated with tobacco exposure, it is becoming clear from recent research that many other diseases are causally related to smoking. Whether from direct smoking or inhaling environmental tobacco smoke (ETS, termed secondhand smoke, the cells of the respiratory tissues and the lining pulmonary surfactant are the first body tissues to be directly exposed to the many thousands of toxic chemicals in tobacco. Considering the vast surface area of the lung and the extreme attenuation of the blood-air barrier, it is not surprising that this organ is the primary route for exposure, not just to smoke but to most environmental contaminants. Recent research has shown that the pulmonary surfactant, a complex mixture of phospholipids and proteins, is the first site of defense against particulates or gas components of smoke. However, it is not clear what effect smoke has on the surfactant. Most studies have demonstrated that smoking reduces bronchoalveolar lavage phospholipid levels. Some components of smoke also appear to have a direct detergent-like effect on the surfactant while others appear to alter cycling or secretion. Ultimately these effects are reflected in changes in the dynamics of the surfactant system and, clinically in changes in lung mechanics. Similarly, exposure of the developing fetal lung through maternal smoking results in postnatal alterations in lung mechanics and higher incidents of wheezing and coughing. Direct exposure of developing lung to nicotine induces changes suggestive of fetal stress. Furthermore, identification of nicotinic receptors in fetal lung airways and corresponding increases in airway connective tissue support a possible involvement of nicotine in postnatal asthma development. Finally, at the level of the alveoli of the lung

  4. Infrared investigation of organo-montmorillonites prepared from different surfactants (United States)

    Ma, Yuehong; Zhu, Jianxi; He, Hongping; Yuan, Peng; Shen, Wei; Liu, Dong


    In this paper, a series of organoclays were prepared from montmorillonites with different CEC and surfactants with different alkyl chain numbers and chain length. Then, FTIR spectroscopy using ATR, DRIFT and KBr pressed disk techniques was used to characterize the local environments of surfactant and host clays in various surfactants modified montmorillonites under wet and dry states. The present study demonstrates that the alkyl chain length and chain number have significant influences on the local environment of the intercalated surfactants. Also, this study indicates that the surface property of the resulting organoclays is affected by the loading and configuration of the intercalated surfactants. In wet state, more gauche conformers are introduced into the alkyl chains in the organoclays with low surfactant loading, evidenced by the shift of CH 2 vibration to higher frequency. Meanwhile, in the case of the organo-montmorillonites with high surfactant loading, the interaction between the surfactant and silicate surface results in a re-arrangement of SiO 4 tetrahedral sheets and a splitting of Si-O stretching vibration. The KBr pressed disk technique is suitable to probe the conformational ordering of the confined amine chains and the reflectance spectroscopy with ATR and/or DRIFT technique is more suitable to probe the water in organoclays. These findings are of high importance to the preparation of organoclays with proper surfactants and investigation of the microstructure of the resulting organoclays using suitable techniques.

  5. Pulmonary surfactant surface tension influences alveolar capillary shape and oxygenation. (United States)

    Ikegami, Machiko; Weaver, Timothy E; Grant, Shawn N; Whitsett, Jeffrey A


    Alveolar capillaries are located in close proximity to the alveolar epithelium and beneath the surfactant film. We hypothesized that the shape of alveolar capillaries and accompanying oxygenation are influenced by surfactant surface tension in the alveolus. To prove our hypothesis, surfactant surface tension was regulated by conditional expression of surfactant protein (SP)-B in Sftpb(-/-) mice, thereby inhibiting surface tension-lowering properties of surfactant in vivo within 24 hours after depletion of Sftpb. Minimum surface tension of isolated surfactant was increased and oxygen saturation was significantly reduced after 2 days of SP-B deficiency in association with deformation of alveolar capillaries. Intravascularly injected 3.2-mum-diameter microbeads through jugular vein were retained within narrowed pulmonary capillaries after reduction of SP-B. Ultrastructure studies demonstrated that the capillary protrusion typical of the normal alveolar-capillary unit was reduced in size, consistent with altered pulmonary blood flow. Pulmonary hypertension and intrapulmonary shunting are commonly associated with surfactant deficiency and dysfunction in neonates and adults with respiratory distress syndromes. Increased surfactant surface tension caused by reduction in SP-B induced narrowing of alveolar capillaries and oxygen desaturation, demonstrating an important role of surface tension-lowering properties of surfactant in the regulation of pulmonary vascular perfusion.

  6. Surfactant-induced core/shell phase equilibrium in hydrogels. (United States)

    Gernandt, J; Hansson, P


    The formation of core/shell structures in hydrogels upon interaction with surfactants is a well-known phenomenon, but whether they are equilibrium states or not is still under debate. This paper presents an equilibrium theory of phase coexistence in hydrogels meant to answer the question of the stability of core/shell separation. The theory suggests that core/shell separation caused by surfactants can indeed be thermodynamically stable if the amount of added surfactant is not too large, but that the exact phase behaviour is governed by both the volume and concentration of the added surfactant solution.

  7. Inactivation of Herpes Simplex Viruses by Nonionic Surfactants (United States)

    Asculai, Samuel S.; Weis, Margaret T.; Rancourt, Martha W.; Kupferberg, A. B.


    Nonionic surface-active agents possessing ether or amide linkages between the hydrophillic and hydrophobic portions of the molecule rapidly inactivated the infectivity of herpes simplex viruses. The activity stemmed from the ability of nonionic surfactants to dissolve lipid-containing membranes. This was confirmed by observing surfactant destruction of mammalian cell plasma membranes and herpes simplex virus envelopes. Proprietary vaginal contraceptive formulations containing nonionic surfactants also inactivated herpes simplex virus infectivity. This observation suggests that nonionic surfactants in appropriate formulation could effectively prevent herpes simplex virus transmission. Images PMID:208460

  8. Pulmonary Surfactant Function in Alveoli and Conducting Airways

    Directory of Open Access Journals (Sweden)

    Goran Enhorning


    Full Text Available Surface tension plays a very important role in aeration of the neonate's lungs. Pulmonary surfactant, which is inadequate in the premature infant, modifies surface tension during the act of breathing and is necessary for maintenance of alveolar stability. These facts led to the development of the concept that it might be possible to treat the premature infant by supplementing the infant's inadequate surfactant supply. In addition to maintaining alveolar stability, pulmonary surfactant might also be of vital importance for maintenance of small airway patency. Various conditions, most importantly asthma, might be the reason for a surfactant dysfunction to develop. This in turn might cause airway resistance to increase.

  9. Surfactant alteration and replacement in acute respiratory distress syndrome

    Directory of Open Access Journals (Sweden)

    Walmrath Dieter


    Full Text Available Abstract The acute respiratory distress syndrome (ARDS is a frequent, life-threatening disease in which a marked increase in alveolar surface tension has been repeatedly observed. It is caused by factors including a lack of surface-active compounds, changes in the phospholipid, fatty acid, neutral lipid, and surfactant apoprotein composition, imbalance of the extracellular surfactant subtype distribution, inhibition of surfactant function by plasma protein leakage, incorporation of surfactant phospholipids and apoproteins into polymerizing fibrin, and damage/inhibition of surfactant compounds by inflammatory mediators. There is now good evidence that these surfactant abnormalities promote alveolar instability and collapse and, consequently, loss of compliance and the profound gas exchange abnormalities seen in ARDS. An acute improvement of gas exchange properties together with a far-reaching restoration of surfactant properties was encountered in recently performed pilot studies. Here we summarize what is known about the kind and severity of surfactant changes occuring in ARDS, the contribution of these changes to lung failure, and the role of surfactant administration for therapy of ARDS.

  10. Recent clinical trials of surfactant treatment for neonates. (United States)

    Halliday, Henry L


    To search for recent clinical trials of neonatal surfactant treatment and report their findings. Recent was defined as published between 2000 and 2005. An online search on PubMed was made on 30th December 2005 using the following terms: surfactant treatment, clinical trials and neonate, with limits of years 2000 to 2005 and age - newborn from birth to 1 month. Randomised clinical trials (RCTs) and systematic reviews of RCTs were prioritised and studies in children and animals were excluded from further analysis. 175 papers were found in this search. Only about half of these papers were directly related to some aspect of surfactant treatment and of these just over one-half were either RCTs or systematic reviews of RCTs. Of the 34 RCTs of surfactant treatment, 3 were excluded as they involved children or animals rather than neonates. Twenty-nine trials studied preterm babies with respiratory distress syndrome (RDS) and 2 were for meconium aspiration syndrome (MAS) in term infants. The median sample sizes of these studies were RDS (92, range 19-1,361) and MAS (42, range 22-61). Eighteen of the RDS trials compared two or more surfactant preparations, the most frequently studied being Curosurf and Survanta but altogether 11 different surfactants were compared. These new RCTs need to be analysed by meta-analyses in systematic reviews. Twelve systematic reviews were found and these demonstrated the superiority of prophylactic over selective use of surfactant in babies surfactant and the absence of an increase in long-term developmental sequelae. Surfactant for MAS may reduce the severity of respiratory illness and the need for extracorporeal membrane oxygenation. Of the non-randomised trials' novel delivery methods, failure to use evidence-based guidelines and the benefit of surfactant for babies Surfactant remains one of the most effective and safest interventions in neonatology. Prophylactic natural surfactant seems to be the most evidence-based treatment for babies

  11. Altered surfactant homeostasis and recurrent respiratory failure secondary to TTF-1 nuclear targeting defect (United States)


    Background Mutations of genes affecting surfactant homeostasis, such as SFTPB, SFTPC and ABCA3, lead to diffuse lung disease in neonates and children. Haploinsufficiency of NKX2.1, the gene encoding the thyroid transcription factor-1 (TTF-1) - critical for lung, thyroid and central nervous system morphogenesis and function - causes a rare form of progressive respiratory failure designated brain-lung-thyroid syndrome. Molecular mechanisms involved in this syndrome are heterogeneous and poorly explored. We report a novel TTF-1 molecular defect causing recurrent respiratory failure episodes in an infant. Methods The subject was an infant with severe neonatal respiratory distress syndrome followed by recurrent respiratory failure episodes, hypopituitarism and neurological abnormalities. Lung histology and ultrastructure were assessed by surgical biopsy. Surfactant-related genes were studied by direct genomic DNA sequencing and array chromatine genomic hybridization (aCGH). Surfactant protein expression in lung tissue was analyzed by confocal immunofluorescence microscopy. For kinetics studies, surfactant protein B and disaturated phosphatidylcholine (DSPC) were isolated from serial tracheal aspirates after intravenous administration of stable isotope-labeled 2H2O and 13C-leucine; fractional synthetic rate was derived from gas chromatography/mass spectrometry 2H and 13C enrichment curves. Six intubated infants with no primary lung disease were used as controls. Results Lung biopsy showed desquamative interstitial pneumonitis and lamellar body abnormalities suggestive of genetic surfactant deficiency. Genetic studies identified a heterozygous ABCA3 mutation, L941P, previously unreported. No SFTPB, SFTPC or NKX2.1 mutations or deletions were found. However, immunofluorescence studies showed TTF-1 prevalently expressed in type II cell cytoplasm instead of nucleus, indicating defective nuclear targeting. This pattern has not been reported in human and was not found in two

  12. Altered surfactant homeostasis and recurrent respiratory failure secondary to TTF-1 nuclear targeting defect

    Directory of Open Access Journals (Sweden)

    Carnielli Virgilio P


    Full Text Available Abstract Background Mutations of genes affecting surfactant homeostasis, such as SFTPB, SFTPC and ABCA3, lead to diffuse lung disease in neonates and children. Haploinsufficiency of NKX2.1, the gene encoding the thyroid transcription factor-1 (TTF-1 - critical for lung, thyroid and central nervous system morphogenesis and function - causes a rare form of progressive respiratory failure designated brain-lung-thyroid syndrome. Molecular mechanisms involved in this syndrome are heterogeneous and poorly explored. We report a novel TTF-1 molecular defect causing recurrent respiratory failure episodes in an infant. Methods The subject was an infant with severe neonatal respiratory distress syndrome followed by recurrent respiratory failure episodes, hypopituitarism and neurological abnormalities. Lung histology and ultrastructure were assessed by surgical biopsy. Surfactant-related genes were studied by direct genomic DNA sequencing and array chromatine genomic hybridization (aCGH. Surfactant protein expression in lung tissue was analyzed by confocal immunofluorescence microscopy. For kinetics studies, surfactant protein B and disaturated phosphatidylcholine (DSPC were isolated from serial tracheal aspirates after intravenous administration of stable isotope-labeled 2H2O and 13C-leucine; fractional synthetic rate was derived from gas chromatography/mass spectrometry 2H and 13C enrichment curves. Six intubated infants with no primary lung disease were used as controls. Results Lung biopsy showed desquamative interstitial pneumonitis and lamellar body abnormalities suggestive of genetic surfactant deficiency. Genetic studies identified a heterozygous ABCA3 mutation, L941P, previously unreported. No SFTPB, SFTPC or NKX2.1 mutations or deletions were found. However, immunofluorescence studies showed TTF-1 prevalently expressed in type II cell cytoplasm instead of nucleus, indicating defective nuclear targeting. This pattern has not been reported in human


    The relative environmental toxicities of synthetic and biogenic surfactants used in oil spill remediation efforts are not well understood. Acute and chronic toxicities of three synthetic surfactants and three microbially produced surfactants were determined and compared in this s...

  14. C-reactive protein increases membrane fluidity and distorts lipid lateral organization of pulmonary surfactant. Protective role of surfactant protein A

    DEFF Research Database (Denmark)

    Saenz, Alejandra; Lopez-Sanchez, Almudena; Mojica-Lazaro, Jonas


    The purpose of this study was to investigate how surfactant membranes can be perturbed by C-reactive protein (CRP) and whether surfactant protein A (SP-A) might overcome CRP-induced surfactant membrane alterations. The effect of CRP on surfactant surface adsorption was evaluated in vivo after int...

  15. Respiratory tract infections in diabetic and non-diabetic individuals are linked with serum surfactant protein-D. (United States)

    Jawed, Shireen; Saeed, Marium; Parveen, Naila


    To find out the rate of respiratory tract infections in diabetic and non-diabetic individuals and their relation with surfactant protein D. The cross-sectional study was conducted at Dow University of Health Sciences, Karachi, from September 2011 to April 2012, and comprised subjects of both genders between ages of 30 and 60 years. The subjects were divided into four groups: diabetic obese, non-diabetic obese, diabetic non-obese, and non-diabetic-non-obese. A structured questionnaire was used to collect information about respiratory tract infections. Serum surfactant protein D levels were analysed using human surfactant protein D enzyme-linked immunosorbent assay kit. Statistical analysis was performed using SPSS 16. Of the 90 subjects, there were 20(22.2%) diabetic obese, 30(33.3%) non-diabetic obese, 10(11.1%) diabetic non-obese, and 30(33.3%) non-diabetic-non-obese. The overall mean age was 36.6±103 years. Among the diabetic obese, 15(75%) had respiratory tract infections which was higher than the other study groups, and patients having respiratory tract infections had lower surfactant protein D levels than those who did not have infections (p=0.01). Diabetic obese subjects had greater rate of recurrent respiratory tract infections and had lower concentration of serum surfactant protein D compared to subjects without respiratory tract infections.

  16. The study of The study of the influence of temperature on surfactants – polyethylene glycol layers The study of the influence of temperature on surfactants – polyethylene glycol layers on liquid-gas interface liquid-gas interfacethe influence of temperature on surfactants – polyethylene glycol layers on liquid-gas interfaceThe study of the influence of temperature on surfactants – polyethylene glycol layers on liquid-gas interface

    Directory of Open Access Journals (Sweden)

    Seryk Boloshaan


    Full Text Available The surface tension of compositions consisting of nonionic polyethylene glycol and surface active substances of different nature and influence of temperatures on properties of their adsorption layers were studied. To be taken into account the basics of classical chemical thermodynamics and colloidal chemistry, the thermodynamic parameters were determined for the adsorption of glycol, cetyl pyridinium bromide, Tween- 80 and sodium dodecyl sulfate. Adsorption speed was valuated By Kinetic curves of a liquid /gas interfaces. As a surfactants were taken the anionic surfactant – sodium dodecylsulphate, cationic surfactant cetylpyridinium bromide and nonionic Tween-80. The reason of using nonionic polyethyleneglycol as polymer is that the polymer is not toxic, biodegradable and it has no harm to the human body. That is why they are largely used in food industry, pharmaceutics, cosmetics and household chemical products.

  17. Unveiling the Molecular Structure of Pulmonary Surfactant Corona on Nanoparticles. (United States)

    Hu, Qinglin; Bai, Xuan; Hu, Guoqing; Zuo, Yi Y


    The growing risk of human exposure to airborne nanoparticles (NPs) causes a general concern on the biosafety of nanotechnology. Inhaled NPs can deposit in the deep lung at which they interact with the pulmonary surfactant (PS). Despite the increasing study of nano-bio interactions, detailed molecular mechanisms by which inhaled NPs interact with the natural PS system remain unclear. Using coarse-grained molecular dynamics simulation, we studied the interaction between NPs and the PS system in the alveolar fluid. It was found that regardless of different physicochemical properties, upon contacting the PS, both silver and polystyrene NPs are immediately coated with a biomolecular corona that consists of both lipids and proteins. Structure and molecular conformation of the PS corona depend on the hydrophobicity of the pristine NPs. Quantitative analysis revealed that lipid composition of the corona formed on different NPs is relatively conserved and is similar to that of the bulk phase PS. However, relative abundance of the surfactant-associated proteins, SP-A, SP-B, and SP-C, is notably affected by the hydrophobicity of the NP. The PS corona provides the NPs with a physicochemical barrier against the environment, equalizes the hydrophobicity of the pristine NPs, and may enhance biorecognition of the NPs. These modifications in physicochemical properties may play a crucial role in affecting the biological identity of the NPs and hence alter their subsequent interactions with cells and other biological entities. Our results suggest that all studies of inhalation nanotoxicology or NP-based pulmonary drug delivery should consider the influence of the PS corona.

  18. Nucleate pool boiling heat transfer in aqueous surfactant solutions (United States)

    Wasekar, Vivek Mahadeorao

    Saturated, nucleate pool boiling in aqueous surfactant solutions is investigated experimentally. Also, the role of Marangoni convection, driven both by temperature and surfactant concentration gradients at the vapor-liquid interface of a nucleating bubble is computationally explored. Experimental measurements of dynamic and equilibrium sigma using the maximum bubble pressure method indicate dynamic sigma to be higher than the corresponding equilibrium value, both at room and elevated temperatures. Also, nonionic surfactants (Triton X-100, Triton X-305) show larger sigma depression than anionic surfactants (SDS, SLES), and a normalized representation of their dynamic adsorption isotherms is shown to be helpful in generalizing the surfactant effectiveness to reduce surface tension. The dynamic sigma has a primary role in the modification of bubble dynamics and associated heat transfer, and is dictated by the adsorption kinetics of the surfactant molecules at boiling temperatures. In general, an enhancement in heat transfer is observed, which is characterized by an early incipience and an optimum boiling performance at or around the critical micelle concentration of the surfactant. The optimum performances, typically in the fully developed boiling regime ( q''w > 100 kW/m2), show a reverse trend with respect to surfactant molecular weights M, i.e., higher molecular weight additives promote lower enhancement. Normalized boiling performance using the respective solution's dynamic sigma correlates heat transfer coefficient by M-0.5 for anionics and M 0 for nonionics. This has been shown to be brought about by the surfactant concentration and its interfacial activity in a concentration sublayer around the growing vapor bubble, which governs the bubble growth behavior through the mechanism of dynamic sigma. The ionic nature of the surfactant influences the thickness and molecular makeup of the enveloping sublayer, thereby affecting the bubble dynamics and boiling heat

  19. Enantioselectivity of vesicle-forming chiral surfactants in capillary electrophoresis. Role of the surfactant headgroup structure. (United States)

    Mohanty, Ashok; Dey, Joykrishna


    Two vesicle-forming single-tailed amino acid derivatized surfactants sodium N-[4-n-dodecyloxybenzoyl]-L-leucinate (SDLL) and sodium N-[4-n-dodecyloxybenzoyl]-L-isoleucinate (SDLIL) have been synthesized and used as pseudo-stationary phase in micellar electrokinetic chromatography to evaluate the role of steric factor of amino acid headgroup and hydrophobic/hydrophilic interactions for enantiomeric separations. The aggregation behavior of the surfactants has been studied in aqueous buffered solution using surface tension and fluorescence probe techniques. Results of these studies have suggested formation of vesicles in aqueous solutions. Microenvironment of the vesicle, which determines the depth of penetration of the analytes into vesicle was determined by fluorescence probe technique using pyrene, N-phenyl-1-naphthylamine (NPN), and 1,6-diphenyl-1,3,5-hexatriene (DPH) as probe molecules. Atropisomeric compounds (+/-)-1,1'-bi-2-naphthol (BOH), (+/-)-1,1'-binaphthyl-2,2'-diamine (BDA), (+/-)-1,1'-binaphthyl-2,2'-diylhydrogen phosphate (BNP) and Tröger's base (TB) and chiral compound benzoin (BZN) has been enantioseparated. The separations were optimized with respect to surfactant concentration, pH, and borate buffer concentration. SDLL was found to provide better resolution for BOH, BNP, and BZN. On the other hand, SDLIL offers better resolution for BDA. The chromatographic results have been discussed in the light of the aggregation behavior of the surfactants and the interaction of the solutes with the vesicles.

  20. Intratracheal budesonide supplementation in addition to surfactant improves pulmonary outcome in surfactant-depleted newborn piglets. (United States)

    Yang, Chia-Feng; Lin, Chih-Hsueh; Chiou, Shr-Yun; Yang, Yi-Chiang; Tsao, Pei-Chen; Lee, Yu-Sheng; Soong, Wen-Jue; Jeng, Mei-Jy


    Severe respiratory distress syndrome (RDS) is still a major cause of mortality and morbidity in premature infants. The combined use of intratracheal corticosteroid and surfactant in severe RDS, which bypasses the systemic circulation, may not only help recruit the lungs but also alleviates pulmonary inflammation without an increase in systemic adverse effects. Twelve newborn piglets received repeated pulmonary saline lavage to create surfactant-depleted lungs that mimic neonatal RDS, and then were randomly grouped into a control group (standard intratracheal instillation of surfactant-Survanta 100 mg/kg); and a budesonide (Bude) group (intratracheal instillation with the mixed suspension of Budesonide 0.25 mg/kg and Survanta 100 mg/kg). Blood samples were examined, and the observation period was 24 hr. The results showed that oxygenation was significantly better in Bude group compared to the control group over time (P = 0.016). The proinflammatory cytokines tumor necrosis factor-α and interleukin-1 β showed a reduced trend in the Bude group, but was not significantly different from the control group (P > 0.05). Comparing the histological lung injury scores, the Bude group had a significantly lower score than the control group at both dependent and non-dependent sites (P surfactant seems to results in a sustained improvement in pulmonary outcome over 24 hr. Copyright © 2012 Wiley Periodicals, Inc.

  1. Enhanced oil recovery with modified nonionic surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Capelle, A.; Littmann, W.


    Practically all work on chemical flooding, both in the laboratory and in the field, has been focused on petroleum sulphonates. However, as soon as the concentration of electrolyes, especially of divalent ions, exceeds a critical value, the use of this class of anionic surfactants becomes troublesome. Some of the difficulties may be overcome by the use of additives, preferably ether sulphates or ether sulphonates. Hence, the favourable properties of nonionic substances, such as excellent stability to electrolytes, have been combined with those of anionics, and thus the so-called modified nonionics are available for chemical flooding. These products offer the possibility of chemical adaption to the reservoir conditions, are very stable toward electrolytes, and their solubility does not depend on the temperature. The latter is a drawback of nonionic products (cloud point). The modified nonionics are essentially anionics based on ethene oxide derivatives of alcohols or alkylphenols, with subsequent incorporation of sulphate, sulphonate, carboxyl or phosphate groups. On the basis of the reservoir conditions, crude oil properties, and reservoir water, various processes have been screened for enhanced oil recovery in the Velebit reservoir. It was decided to simultaneously inject modified nonionic surfactants and polymers. In part of the reservoir, this process will be tested in two stages in a line drive with several injection wells and production wells. The total area is about 20,000 m/sup 3/. The first stage involves water flooding of about half the area, in order to collect additional data on the reservoir. During the second stage, simultaneous injection of surfactants and polymers will take place. The reservoir is described, and possible EOR processes, the flooding concept and selection of chemicals are discussed.

  2. Neonatal varicella pneumonia, surfactant replacement therapy

    Directory of Open Access Journals (Sweden)

    Mousa Ahmadpour-kacho


    Full Text Available Background: Chickenpox is a very contagious viral disease that caused by varicella-zoster virus, which appears in the first week of life secondary to transplacental transmission of infection from the affected mother. When mother catches the disease five days before and up to two days after the delivery, the chance of varicella in neonate in first week of life is 17%. A generalized papulovesicular lesion is the most common clinical feature. Respiratory involvement may lead to giant cell pneumonia and respiratory failure. The mortality rate is up to 30% in the case of no treatment, often due to pneumonia. Treatment includes hospitalization, isolation and administration of intravenous acyclovir. The aim of this case report is to introduce the exogenous surfactant replacement therapy after intubation and mechanical ventilation for respiratory failure in neonatal chickenpox pneumonia and respiratory distress. Case Presentation: A seven-day-old neonate boy was admitted to the Neonatal Intensive Care Unit at Amirkola Children’s Hospital, Babol, north of Iran, with generalized papulovesicular lesions and respiratory distress. His mother has had a history of Varicella 4 days before delivery. He was isolated and given supportive care, intravenous acyclovir and antibiotics. On the second day, he was intubated and connected to mechanical ventilator due to severe pneumonia and respiratory failure. Because of sever pulmonary involvement evidenced by Chest X-Ray and high ventilators set-up requirement, intratracheal surfactant was administered in two doses separated by 12 hours. He was discharged after 14 days without any complication with good general condition. Conclusion: Exogenous surfactant replacement therapy can be useful as an adjunctive therapy for the treatment of respiratory failure due to neonatal chickenpox.

  3. Porcine lung surfactant protein B gene (SFTPB)

    DEFF Research Database (Denmark)

    Cirera Salicio, Susanna; Fredholm, Merete


    The porcine surfactant protein B (SFTPB) is a single copy gene on chromosome 3. Three different cDNAs for the SFTPB have been isolated and sequenced. Nucleotide sequence comparison revealed six nonsynonymous single nucleotide polymorphisms (SNPs), four synonymous SNPs and an in-frame deletion of 69...... bp in the region coding for the active protein. Northern analysis showed lung-specific expression of three different isoforms of the SFTPB transcript. The expression level for the SFTPB gene is low in 50 days-old fetus and it increases during lung development. Quantitative real-time polymerase chain...

  4. The Krafft temperature of surfactant solutions

    Directory of Open Access Journals (Sweden)

    Manojlović Jelena Ž.


    Full Text Available Our main motivation to revisit the solution properties of cetyltrimethylammonium bromide is related to the clear requirement for better control of the adsorption parameters to form uniform self-assembled monolayers on muscovite mica substrates. To readily monitor the temporal evolution of structural details in cetyltrimethylammonium bromide solutions, we realized a rather simple conductivity experiment. Conductivity measurements were carried out as a function of temperature, to look closer into the Krafft temperature behavior of this surfactant. We measured the electrical conductivity of different concentrations of aqueous cetyltrimethylammonium bromide solutions, below and above the critical micells concentration.

  5. Size separation of analytes using monomeric surfactants (United States)

    Yeung, Edward S.; Wei, Wei


    A sieving medium for use in the separation of analytes in a sample containing at least one such analyte comprises a monomeric non-ionic surfactant of the of the general formula, B-A, wherein A is a hydrophilic moiety and B is a hydrophobic moiety, present in a solvent at a concentration forming a self-assembled micelle configuration under selected conditions and having an aggregation number providing an equivalent weight capable of effecting the size separation of the sample solution so as to resolve a target analyte(s) in a solution containing the same, the size separation taking place in a chromatography or electrophoresis separation system.

  6. A liquid CO2-compatible hydrocarbon surfactant: experiment and modelling

    NARCIS (Netherlands)

    Banerjee, S.; Kleijn, J.M.; Cohen Stuart, M.A.; Leermakers, F.A.M.


    Surfactants soluble in liquid CO2 are rare and knowledge on interfacial and self-assembly behaviour is fragmented. We found that polyoxyethylene (5) isooctylphenyl ether is interfacially active at the water–liquid CO2 interface. Water–liquid CO2 interfacial tension was measured at various surfactant

  7. The Effect of Surfactants on Gas-Liquid Pipe Flows

    NARCIS (Netherlands)

    Van Nimwegen, A.T.


    Liquid loading is a major problem in the natural gas industry, in which gas production is limited by the accumulation of liquids in the well tubing. Liquid loading can be prevented by the injection of surfactants at the bottom of the well. The surfactants cause the liquid in the well to foam,

  8. Surfactants attenuate gas embolism-induced thrombin production. (United States)

    Eckmann, David M; Diamond, Scott L


    There are no pharmacologic strategies to prevent embolism bubble-induced blood clot formation. The authors conducted experiments to measure thrombin production in sheared whole blood in the presence and absence of bubbles and three surface-active compounds. Blood samples were obtained from six volunteers seven times. The thrombin-specific substrate Boc-VPR-MCA was added to citrated blood diluted with HEPES-buffered saline. Experimental groups were as follows: sparging (air microbubble embolization) with surfactant present; sparging alone; surfactant alone; and neither surfactant nor sparging. The surfactants were Dow Corning Antifoam 1510US, Perftoran, and Pluronic F-127. Blood was sheared by a cone-plate viscometer at 100 and 500 s-1 for 5, 10, and 20 min at 37 degrees C, pipetted into excess stop buffer, and evaluated fluorimetrically. Mean values of fluorescence intensity +/- SDs for each group were compared using ANOVA. Differences were considered significant at P Surfactant addition without sparging did not change thrombin production (P > 0.05). Surfactants attenuated thrombin production in sparged samples 31.8-70.9% (P Surfactants added before sparging attenuate thrombin production. Surfactants may have a clinical application to attenuate gas embolism-induced clotting.

  9. Binding of alkylpyridinium chloride surfactants to sodium polystyrene sulfonate

    NARCIS (Netherlands)

    Ishiguro, M.; Koopal, L.K.


    Binding of cationic surfactants to anionic polymers is well studied. However, the surfactant binding characteristics at very low concentration near the start of binding and at high concentration, where charge compensation may Occur. are less well known. Therefore, the binding characteristics of

  10. Effects of surfactants on size and structure of amylose nanoparticles ...

    Indian Academy of Sciences (India)

    The present work investigated the influence of surfactants on size and structure of amylose nanoparticles (ANPs) prepared through precipitation. ANPs were fabricated using absolute ethanol containing surfactants (Tween80, Span80 and mixtures of Tween80 and Span80 with ratios of 25/75, 50/50 and 75/25, respectively) ...

  11. New Y-shaped surfactants from renewable resources. (United States)

    Ali, Tammar Hussein; Hussen, Rusnah Syahila Duali; Heidelberg, Thorsten


    A series of sugar-based surfactants, involving a single hydrophobic chain (C12) and two side-by-side arranged head groups, was prepared form simple glucose precursors. All surfactants were highly water soluble and exhibited exclusively micellar assemblies. This behavior makes them interesting candidates for oil in water emulsifiers. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Interaction of photosensitive surfactant with DNA and poly acrylic acid (United States)

    Zakrevskyy, Yuriy; Cywinski, Piotr; Cywinska, Magdalena; Paasche, Jens; Lomadze, Nino; Reich, Oliver; Löhmannsröben, Hans-Gerd; Santer, Svetlana


    In this paper, we investigate interactions and phase transitions in polyelectrolyte-surfactant complexes formed between a cationic azobenzene-containing surfactant and two types of polyelectrolytes: natural (DNA) or synthetic (PAA: poly acrylic acid). The construction of a phase diagram allowed distancing between four major phases: extended coil conformation, colloidally stable compacted globules, colloidal instability range, and surfactant-stabilized compact state. Investigation on the complexes' properties in different phases and under irradiation with UV light provides information about the role of the surfactant's hydrophobic trans isomers both in the formation and destruction of DNA and PAA globules as well as in their colloidal stabilization. The trans isomer shows much stronger affinity to the polyelectrolytes than the hydrophilic cis counterpart. There is no need for complete compensation of the polyelectrolyte charges to reach the complete compaction. On contrary to the findings previously reported in the literature, we demonstrate - for the first time - complete polyelectrolyte compaction which occurs already at 20% of DNA (and at 50% of PAA) charge compensation. The trans isomer plays the main role in the compaction. The aggregation between azobenzene units in the photosensitive surfactant is a driving force of this process. The decompaction can be realized during UV light irradiation and is strongly influenced by the interplay between surfactant-surfactant and surfactant-DNA interactions in the compacted globules.

  13. Adsorption and intercalation of anionic surfactants onto layered ...

    Indian Academy of Sciences (India)


    Abstract. Layered double hydroxides (LDH) with brucite like structure was modified with various anionic surfactants containing sulfonate, carboxyl, phosphonate and sulfate end group through ion-exchange method. XRD reports indicated that the sulfonate group containing surfactants led to an adsorption process whereas.

  14. Effects of surfactants on size and structure of amylose nanoparticles ...

    Indian Academy of Sciences (India)

    Abstract. The present work investigated the influence of surfactants on size and structure of amylose nanoparticles (ANPs) prepared through precipitation. ANPs were fabricated using absolute ethanol containing surfactants (Tween80, Span80 and mixtures of Tween80 and Span80 with ratios of 25/75, 50/50 and 75/25, ...

  15. Effect of exogenous surfactant on total respiratory system compliance.


    Milner, A D; Vyas, H; Hopkin, I E


    We measured total respiratory system compliance (Crs) before and after instilling 25 mg artificial surfactant in 1 ml saline down the endotracheal tube of preterm babies requiring resuscitation at birth, and compared results with data from 6 similar babies receiving saline only. Surfactant did not produce a significant improvement in Crs.

  16. The Inhibiting or Accelerating Effect of Different Surfactants on ...

    African Journals Online (AJOL)


    surfactants had a varying effect on the kinetics of electroreduction of Zn2+ ions. Simple relationships were presented ... drastic influence on the rate of an electrode reaction, either in a decelerating or an accelerating sense. ... surfactant concentrations were lower than their critical micellar point (CMC). 2. Experimental. 2.1.

  17. Phase Behavior of Laundry Surfactants in Polar Solvents

    NARCIS (Netherlands)

    Stuart, Marc C.A.; Pas, John C. van de; Engberts, Jan B.F.N.


    Laundry surfactants are usually mixtures of ionic and nonionic detergents that exhibit a complex phase behavior. Here the ternary phase behavior of an isotropic and a liquid crystalline (LC) surfactant mixture has been examined in water/solvent systems. The size of the LC area in the ternary phase

  18. Small-angle neutron scattering studies of nonionic surfactant: Effect ...

    Indian Academy of Sciences (India)

    concentration of sugar. The structure of micelles is almost independent of the different types of sugars used. Keywords. Small-angle neutron scattering; nonionic surfactant; micellar aggregation number. PACS Nos 61.12.Ex; 82.70.Uv. 1. Introduction. Surfactant molecules self assemble into aggregates in aqueous solution to ...

  19. Adsorption and intercalation of anionic surfactants onto layered ...

    Indian Academy of Sciences (India)

    Layered double hydroxides (LDH) with brucite like structure was modified with various anionic surfactants containing sulfonate, carboxyl, phosphonate and sulfate end group through ion-exchange method. XRD reports indicated that the sulfonate group containing surfactants led to an adsorption process whereas the sulfate ...

  20. Defluorination of drinking water using surfactant modified zeolites ...

    African Journals Online (AJOL)

    Defluorination of drinking water using surfactant modified zeolites. ... Owingto the arid nature of these localities, the inhabitants (who are mainly peasant farmers), relymore on groundwater sources for their drinking water. With the strenuous ... Keywords: characterization, defluoridation, groundwater, surfactant, zeolites ...

  1. Polymeric surfactants for enhanced oil recovery : A review

    NARCIS (Netherlands)

    Raffa, Patrizio; Broekhuis, Antonius A.; Picchioni, Francesco

    Chemical enhanced oil recovery (EOR) is surely a topic of interest, as conventional oil resources become more scarce and the necessity of exploiting heavy and unconventional oils increases. EOR methods based on polymer flooding, surfactant-polymer flooding and alkali-surfactant-polymer flooding are

  2. Use of natural surfactant in an infant with aspiration syndrome. (United States)

    Bisceglia, M; Verre, M; Tancioni, F; Piccirillo, M; Corapi, U P; Barozzi, E; Vulcano, S


    The remarkable effectiveness of surfactant in neonatology suggested its use also in adults as well as in children on the basis of the pulmonary pathophysiology. We describe a case of an 18 month-old child affected by acute respiratory distress syndrome (ARDS) due to asphyxy by gastric juice inhalation, successfully treated with porcine surfactant (Curosurf) associated with ventilatory therapy.

  3. Competitive adsorption: a physical model for lung surfactant inactivation. (United States)

    Fernsler, Jonathan G; Zasadzinski, Joseph A


    Charged, surface-active serum proteins can severely reduce or eliminate the adsorption of lung surfactant from the subphase to the alveolar air-liquid interface via a kinetically controlled competitive adsorption process. The decreased surfactant concentration at the interface leads to higher surface tensions during the compression of the interface during breathing. The correspondence between the factors governing colloid stability and competitive adsorption is validated via a new method of measuring surfactant and serum protein adsorption rates to the air-water interface, using quantitative Brewster angle microscopy (BAM). Competitive adsorption from a 10 mg/mL albumin subphase prevents the adsorption of lung surfactant from even high subphase concentrations due to the fast diffusion of the water-soluble proteins to the interface. The formation of an albumin film causes an electrostatic and steric barrier to subsequent surfactant adsorption, which can destroy the necessary properties of functional lung surfactant: low surface tension during compression and rapid respreading after film collapse. Surfactant inactivation is at least partially due to decreased surfactant adsorption; such decreased adsorption due to the presence of serum proteins may play a role in the development and severity of acute respiratory distress syndrome.

  4. Animal derived surfactant extract versus protein free synthetic surfactant for the prevention and treatment of respiratory distress syndrome. (United States)

    Ardell, Stephanie; Pfister, Robert H; Soll, Roger


    A wide variety of surfactant preparations have been developed and tested including synthetic surfactants and surfactants derived from animal sources. Although clinical trials have demonstrated that both synthetic surfactant and animal derived surfactant preparations are effective, comparison in animal models has suggested that there may be greater efficacy of animal derived surfactant products, perhaps due to the protein content of animal derived surfactant. To compare the effect of animal derived surfactant to protein free synthetic surfactant preparations in preterm infants at risk for or having respiratory distress syndrome (RDS). Searches were updated of the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library (2014), PubMed, CINAHL and EMBASE (1975 through November 2014). All languages were included. Randomized controlled trials comparing administration of protein free synthetic surfactants to administration of animal derived surfactant extracts in preterm infants at risk for or having respiratory distress syndrome were considered for this review. Data collection and analysis were conducted according to the standards of the Cochrane Neonatal Review Group. Fifteen trials met the inclusion criteria. The meta-analysis showed that the use of animal derived surfactant rather than protein free synthetic surfactant resulted in a significant reduction in the risk of pneumothorax [typical relative risk (RR) 0.65, 95% CI 0.55 to 0.77; typical risk difference (RD) -0.04, 95% CI -0.06 to -0.02; number needed to treat to benefit (NNTB) 25; 11 studies, 5356 infants] and a marginal reduction in the risk of mortality (typical RR 0.89, 95% CI 0.79 to 0.99; typical RD -0.02, 95% CI -0.04 to -0.00; NNTB 50; 13 studies, 5413 infants).Animal derived surfactant was associated with an increase in the risk of necrotizing enterocolitis [typical RR 1.38, 95% CI 1.08 to 1.76; typical RD 0.02, 95% CI 0.01 to 0.04; number needed to treat to harm (NNTH) 50; 8

  5. Pulmonary Surfactants for Acute and Chronic Lung Diseases (Part II

    Directory of Open Access Journals (Sweden)

    O. A. Rozenberg


    Full Text Available Part 2 of the review considers the problem of surfactant therapy for acute respiratory distress syndrome (ARDS in adults and young and old children. It gives information on the results of surfactant therapy and prevention of ARDS in patients with severe concurrent trauma, inhalation injuries, complications due to complex expanded chest surgery, or severe pneumonias, including bilateral pneumonia in the presence of A/H1N1 influenza. There are data on the use of a surfactant in obstetric care and prevention of primary graft dysfunction during lung transplantation. The results of longterm use of surfactant therapy in Russia, suggesting that death rates from ARDS may be substantially reduced (to 20% are discussed. Examples of surfactant therapy for other noncritical lung diseases, such as permanent athelectasis, chronic obstructive pulmonary diseases, and asthma, as well tuberculosis, are also considered.

  6. Minimally Invasive Surfactant Therapy and Noninvasive Respiratory Support. (United States)

    Kribs, Angela


    Respiratory distress syndrome (RDS) caused by surfactant deficiency is major cause for neonatal mortality and short- and long-term morbidity of preterm infants. Continuous positive airway pressure and other modes of noninvasive respiratory support and intubation and positive pressure ventilation with surfactant therapy are efficient therapies for RDS. Because continuous positive airway pressure can fail in severe surfactant deficiency, and because traditional surfactant therapy requires intubation and positive pressure ventilation, this entails a risk of lung injury. Several strategies to combine noninvasive respiratory therapy with minimally invasive surfactant therapy have been described. Available data suggest that those strategies may improve outcome of premature infants with RDS. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Animal-derived surfactant treatment of respiratory distress syndrome in premature neonates: a review. (United States)

    Fujii, Alan M; Carillo, Marie


    Exogenous surfactant treatment of premature infants with respiratory distress syndrome (RDS) has been the standard of care for the past two decades. There are many studies comparing various surfactant preparations. Data are clear that the synthetic surfactants without surfactant proteins are inferior to animal-derived surfactant preparations. Less compelling are the data regarding the relative efficacy of the various animal-derived surfactants available, but a pattern has evolved favoring surfactant preparations with higher concentrations of phospholipids and surfactant proteins. A higher initial dose of phospholipids may also be important, especially for preterm infants less than 32 weeks of gestation. Development has begun of new synthetic surfactants with surfactant protein analogs or recombinant surfactant proteins, which are not yet available in the United States. Synthetic surfactants hold the possibility of surfactant treatments without potential animal-born infectious agents or animal proteins that could induce an immune response in fragile premature infants with multiple medical problems. The goal of this review is to assess the comparison of available animal-derived surfactants and what is known of their comparison. with the newer synthetic surfactants. In addition, the possible direct and indirect effects of surfactant administration on regional blood flow are discussed, with their potential relationship to the volume of surfactant administered.

  8. Tidal volume delivery during surfactant administration in the delivery room. (United States)

    Schmölzer, Georg M; Kamlin, C Omar F; Dawson, Jennifer A; Morley, Colin J; Davis, Peter G


    Reduced mortality for infants born at less than 30 weeks’ gestation after prophylactic surfactant administration has led many to advocate routine intubation and administration of surfactant in all infants at risk of respiratory distress syndrome. However, surfactant administration is associated with adverse events including bradycardia, changes in cerebral blood flow and endotracheal tube obstruction. The aim of this study was to analyse respiratory function immediately before and after surfactant administration in the delivery room. We reviewed video recordings of the initial resuscitation in the delivery room of infants born at less than 32 weeks’ gestation between February 2007 and March 2010. Positive pressure ventilation was delivered with either a Neopuff T-piece or self-inflating bag. Respiratory parameters were recorded with a respiratory function monitor (RFM). Each RFM recording was analysed for 30 s before and 2 min after surfactant administration. Of 230 infants recorded during the study period 16 infants received surfactant in the delivery room. Their mean (standard deviation, SD) gestation and birth weight were 25 (1) weeks and 757 (249) g, respectively. Complete airway obstruction was seen in 4/16 (25%) infants. The median (interquartile range, IQR) duration of this obstruction was 16 (8–27) s. The median (IQR) expired tidal volume before surfactant delivery was 8.0 (5.2–11.2) mL/kg compared to 4.6 (4.1–7.3) mL/kg (p = 0.03) after surfactant administration. Substantial tidal volume changes occur before, during and after surfactant administration in the delivery room. Complete airway obstruction is common. Monitoring respiratory function during this procedure may help to assess the delivered tidal volume and airway pressures after surfactant treatment.

  9. Investigations into surfactant/gas hydrate relationship

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, Rudy; Zhang, Guochang; Dearman, Jennifer; Woods, Charles [Swalm School of Chemical Engineering, Mississippi State University, Mississippi State, MS 39762 (United States)


    Gas hydrates have unique physical properties portending useful industrial applications of gas storage, gas separation, or water desalination. When gas hydrates were found in the early 1990s to occur naturally and abundantly in seafloors, three other primary interests and concerns emerged: potential new energy source, climate threat from their greenhouse gases, and seafloor instabilities. This paper presents research showing how anionic synthetic surfactants helped develop an industrial gas hydrate storage process for natural gas and how naturally-occurring in-situ anionic biosurfactants influence the formation and placement of gas hydrates in ocean sediments. The catalytic effects, mechanisms, and surface specificities imparted by synthetic surfactants in the gas storage process and imparted by biosurfactants in porous media are discussed. The Bacillus subtilis bacterium that is indigenous to gas hydrate mounds in the Gulf of Mexico was cultured in the laboratory. Its biosurfactant was separated and found to catalyze gas hydrates in porous media. The experiments indicate that seafloor-biosurfactants can be produced rapidly in-situ to achieve threshold concentrations whereby hydrates are promoted. The biosurfactants accumulate and promote hydrate formation on specific mineral surfaces such as sodium montmorillonite. (author)

  10. Reversal of multidrug resistance by surfactants. (United States)

    Woodcock, D. M.; Linsenmeyer, M. E.; Chojnowski, G.; Kriegler, A. B.; Nink, V.; Webster, L. K.; Sawyer, W. H.


    Cremophor EL, a pharmacologically inactive solubilising agent, has been shown to reverse multidrug resistance (MDR). Using flow cytometric evaluation of equilibrium intracellular levels of daunorubicin (DNR), we found that eight other surface active agents will also reverse MDR. All the active detergents contain polyethoxylated moieties but have no similarities in their hydrophobic components. The properties of three polyethoxylated surfactants that showed the lowest toxicities, Cremophor, Tween 80 and Solutol HS15, were examined in more detail. The concentrations of Tween 80 and Solutol required to reverse DNR exclusion were 10-fold lower than for Cremophor. However while concentrations greater than or equal to 1:10(2) of the former two surfactants resulted in breakdown of cells, even 1:10 of Cremophor did not lyse cells. Studies of the effects of Cremophor on the uptake and efflux of DNR in normal and MDR cell types showed that Cremophor increases intracellular DNR primarily by locking the rapid efflux from the cells. This blockage of drug efflux may be mediated by a substantial alteration in the fluidity of cell membranes induced by Cremophor, as shown by decreased fluorescence anisotropy of a membrane probe. Consistent with these data, coinjection of adriamycin plus Cremophor into mice carrying a multidrug resistant P388 transplantable tumour significantly increased the survival time of the mice compared with adriamycin treatment alone. PMID:1637678

  11. Surfactant secretion and clearance in the newborn

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, P.A.; Wright, J.R.; Clements, J.A. (Univ. of California, San Francisco (USA))


    Pregnant rabbits (30 days) were injected intravenously with (3H)choline 8 h before delivery. The fetuses were delivered, and lung lavage and lamellar body phospholipids (PL) were analyzed. Some newborns also received radioactively labeled surfactant intratracheally on delivery and were permitted to breathe. With time, intratracheal label decreased in lavage and appeared in the lamellar body fraction, and intravenous label accumulated in both pools. Using a tracer analysis for non-steady state, we calculated surfactant secretion and clearance rates for the newborn period. Before birth, both rates rose slightly from 1.8 micrograms PL.g body wt-1.h-1 at 6 h before birth to 7.3 at birth. Immediately after birth, secretion rate rose to 37.7 micrograms PL.g body wt-1.h-1. Between 1.5 and 2 h after birth it fell to a minimum of 1.8 micrograms PL.g body wt-1.h-1 and then rose slowly to 6.0 at 12 h. After birth, clearance rate increased less than secretion rate (maximum 24.7 micrograms PL.g body wt-1.h-1 shortly after birth) then followed the same pattern but did not balance secretion rate in the 1st day.

  12. Identification of phases of various oil, surfactant/ co-surfactants and water system by ternary phase diagram. (United States)

    Syed, Haroon K; Peh, Kok K


    The objective of this study was to select appropriate surfactants or blends of surfactants and oil to study the ternary phase diagram behavior and identify various phases obtained from the oil and surfactant/surfactant mixture combinations of different HLB. The phases include conventional emulsion, gel/viscous and transparent/translucent microemulsion. Pseudoternary phase diagrams of water, oil and S/Smix of various HLB values range of 9.65-15 were constructed by using water titration method at room temperature. Visual analysis, conductivity and dye dilution test (methylene blue) were performed after each addition and mixing of water, to identify phases as microemulsion, o/w or w/o emulsion (turbid/milky) and transparent gel/turbid viscous. High gel or viscous area was obtained with Tween 80 and surfactant mixture of Tween 80 and Span 80 with all oils. The results indicated that non-ionic surfactants and PG of different HLB values exhibited different pseudoternary phase diagram characteristics but no microemulsions originated from mineral and olive oils. The w/o emulsion occupied a large area in the ternary phase triangle when HLB value of the surfactant/Smix decreased. The o/w emulsion area was large with increasing HLB value of surfactant/Smix.

  13. A Noninvasive Surfactant Adsorption Test Predicting the Need for Surfactant Therapy in Preterm Infants Treated with Continuous Positive Airway Pressure. (United States)

    Autilio, Chiara; Echaide, Mercedes; Benachi, Alexandra; Marfaing-Koka, Anne; Capoluongo, Ettore D; Pérez-Gil, Jesús; De Luca, Daniele


    To determine the diagnostic accuracy of the surfactant adsorption test (SAT) as a predictor for the need for surfactant replacement therapy in neonates with respiratory distress syndrome (RDS). Amniotic fluid samples were collected from 41 preterm neonates with RDS treated with continuous positive airway pressure (CPAP) and 15 healthy control term neonates. Purified porcine surfactant served as a further control. Lamellar bodies and lung ultrasound score were also measured in a subset of the neonates treated with CPAP. Surfactant was administered according to the European guidelines, and clinical data were collected prospectively. Surfactant activity was measured as adsorption at the air/liquid interface and given in relative fluorescent units (RFU). Surfactant activity differed among native porcine surfactant (median, 4863 RFU; IQR, 4405-5081 RFU), healthy term neonates (median, 2680 RFU; IQR, 2069-3050 RFU), and preterm neonates with RDS (median, 442 RFU; IQR, 92-920 RFU; P neonates who failed CPAP had lower surfactant activity compared with those who did not fail CPAP (median, 92 RFU; IQR, 0-315 RFU vs 749 RFU; IQR, 360-974 RFU; P = .0002). Differences between groups were more evident beyond 20-30 minutes of fluorescence; the 30-minute time point showed the highest area under the curve (0.84; P Surfactant activity at 30 minutes was significantly correlated with lamellar bodies (r = 0.51, P = .006) and lung ultrasound score (r = -0.39, P = .013). This technique has the potential to be developed into a fast, simple-to-interpret clinical test. The SAT can reliably identify preterm infants with subsequent CPAP failure and shows promise as a screening test for surfactant replacement in preterm neonates. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Filtration of Pathogenic Parasites Using Surfactant-Modified Zeolites (United States)

    Lehner, T.; Schulze-Makuch, D.; Bowman, R.


    Migration of pathogenic microorganisms, specifically Cryptosporidium parvum and Giardia lamblia, in groundwater due to sewage effluent and mismanaged wastewater has become an increased concern for human health in many regions. Cryptosporididosis and Giardiasis produces moderate to severe intestinal illness for many weeks and is a serious threat for immunodeficient persons. Previous studies by Schulze-Makuch et al. (2002) indicated that surfactant-modified zeolites (SMZ) removed all of the bacteria and most viruses in laboratory experiments. This study focuses on the efficiency of the SMZ to prevent migration of the protozoan spores in groundwater. Adsorption of the spores involves interactions between the surface properties of the spores and the SMZ. The efficiency of removal is tested simulating natural conditions. Laboratory experiments are conducted in a plexiglass model aquifer and pathogen removal is measured by taking water samples from strategically placed piezometers in the model. Since C. parvum and G. lamblia are hazardous to humans and move primarily in spore state through groundwater, polystyrene microspheres of similar sizes and Bacillus subtilis, a sporulating bacterium, are used as analogues for the protozoa. Preliminary results show a significant decrease in concentration of the B. subtilis spores down-gradient of the barrier.

  15. UV-vis spectra as an alternative to the Lowry method for quantify hair damage induced by surfactants. (United States)

    Pires-Oliveira, Rafael; Joekes, Inés


    It is well known that long term use of shampoo causes damage to human hair. Although the Lowry method has been widely used to quantify hair damage, it is unsuitable to determine this in the presence of some surfactants and there is no other method proposed in literature. In this work, a different method is used to investigate and compare the hair damage induced by four types of surfactants (including three commercial-grade surfactants) and water. Hair samples were immersed in aqueous solution of surfactants under conditions that resemble a shower (38 °C, constant shaking). These solutions become colored with time of contact with hair and its UV-vis spectra were recorded. For comparison, the amount of extracted proteins from hair by sodium dodecyl sulfate (SDS) and by water were estimated by the Lowry method. Additionally, non-pigmented vs. pigmented hair and also sepia melanin were used to understand the washing solution color and their spectra. The results presented herein show that hair degradation is mostly caused by the extraction of proteins, cuticle fragments and melanin granules from hair fiber. It was found that the intensity of solution color varies with the charge density of the surfactants. Furthermore, the intensity of solution color can be correlated to the amount of proteins quantified by the Lowry method as well as to the degree of hair damage. UV-vis spectrum of hair washing solutions is a simple and straightforward method to quantify and compare hair damages induced by different commercial surfactants. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. The effect of co-surfactant-modified micelles on chiral separations in EKC. (United States)

    Kojtari, Adeline B; Guetschow, Erik D; Foley, Joe P


    The use of chiral pseudostationary phases in EKC provides high efficiencies and excellent resolution for enantiomeric separations. The chiral pseudostationary phases of interest in this study are alcohol-modified ("swollen") micelles, in which a co-surfactant (medium chain-length alcohol) is added with the surfactant. In this study, the chiral surfactant, dodecoxycarbonylvaline (DDCV), along with the co-surfactant, 2-hexanol, has been prepared as swollen micelle in order to investigate the chiral separation of enantiomeric pairs. Three sets of experiments were investigated in which swollen micelle systems contained: chiral surfactant and racemic co-surfactant; chiral surfactant and chiral co-surfactant; and phase ratio increases, in which both chiral surfactant and chiral co-surfactant were employed. In the first two sets of experiments, co-surfactant concentration was held constant and the surfactant concentration was increased. In the third set of experiments, both surfactant and chiral surfactant concentrations were increased proportionally. The chromatographic figures of merit for each enantiomeric pair were investigated and compared with various chiral aggregate systems. In swollen micelle compositions using constant racemic 2-hexanol concentration, when DDCV concentration increased, enantioselectivity and resolution increased; whereas, efficiency remained constant for most of the test compounds. Compositions using constant S-2-hexanol concentration reached a maximum in all chromatographic figures of merit when DDCV concentration was increased from 2 to 3%. An increase in both surfactant and co-surfactant concentrations led to noisy baselines and chiral aggregates that were generally unstable in solution.

  17. Is surfactant a promising additive drug in ALI/ARDS-patients?

    NARCIS (Netherlands)

    Schultz, MJ; Kesecioglu, J

    The rationale for surfactant replacement therapy in patients with acute respiratory distress syndrome (ARDS) is to restore the normal composition of the surfactant system, as well as to overcome ongoing inactivation of present surfactant. Indeed, surfactant replacement therapy call normalize the

  18. Is surfactant a promising additive drug in ALI/ARDS-patients?

    NARCIS (Netherlands)

    Schultz, Marcus J.; Kesecioglu, Jozef


    The rationale for surfactant replacement therapy in patients with acute respiratory distress syndrome (ARDS) is to restore the normal composition of the surfactant system, as well as to overcome ongoing inactivation of present surfactant. Indeed, surfactant replacement therapy call normalize the

  19. Preparation and evaluation of sulphonamide nonionic surfactants

    Directory of Open Access Journals (Sweden)

    Ahmed, M. H. M.


    Full Text Available Alkyl (octyl, decyl and dodecyl; C8,C10 and C12 benzene sulphonyl chloride was used in the preparation of a novel series of nonionic surfactants (IV-VIa-c, (VII-IX a-c and (X-XIIa-c. The preparations were completed by reacting each alkyl (C8,C10 and C12 benzene sulphonyl chloride with ethanolamine to give (I-III respectively. The resulting products were reacted separately with ethylene oxide in the presence of different (base KOH, Lewis acid SnCl4 and k10 clay catalysts to produce different moles of nonionic surfactants (5, 7 and 9 in sequence corresponding to (IV-VIa-c, (VII-IX a-c and (X-XIIa-c respectively. The chemical structures of prepared nonionic surfactants were elucidated by IR and 1HNMR spectra. The surface activity, biodegradability and biological activities of the prepared compounds were investigated. The obtained data show that these compounds have good surface and biological activities as well as reasonable biodegradability properties.Cloruros de sulfonilbenceno alquilados (octil, decil, dodecil; C8, C10 y C12 fueron usados en la preparación de una nueva serie de surfactantes no iónicos (IV-VIa-c, (VII-IX a-c and (X-XIIa-c. Las preparaciones fueron completadas por reacción de cada cloruro de sulfonilbenceno alquilado (C8, C10 y C12 con etanolamina para dar los compuestos (IIII, respectivamente. Los anteriores productos reaccionaron separadamente con óxido de etileno en presencia de diferentes catalizadores (la base KOH, el ácido de Lewis SnCl4 y la arcilla k10 para producir secuencialmente diferentes surfactantes no iónicos con distintos moles de óxido de etileno (5, 7 y 9: (IV-VIa-c, (VII-IXa-c and (X-XIIa-c, respectivamente. La estructura química de los surfactantes no iónicos preparados fueron elucidadas mediante sus espectros de IR y 1H RMN. Las propiedades tensoactivas, biodegradabilidad y actividad biológica de los compuestos preparados fueron investigados. Los datos obtenidos muestran que estos compuestos tienen

  20. Surfactant reduction in embolism bubble adhesion and endothelial damage. (United States)

    Suzuki, Akira; Armstead, Stephen C; Eckmann, David M


    Surfactants may reduce the adhesion force holding bubbles to the vessel wall in gas embolism. The authors measured bubble adhesion force using excised microvessels. They assessed endothelial damage by measuring vessel reactivity and with microscopy. Microbubbles injected into arterioles resided for 5, 10, or 30 min, with intact or damaged endothelium. Perfusion was with rat serum alone (control) or with 1% Perftoran (OJSC SPC Perftoran, Moscow, Russia) or 1% Pluronic F-127 (Molecular Probes, Eugene, OR) added. Pressure across the bubble, bubble length, and bubble diameter were measured, and adhesion force per unit surface area, K = deltaPD/4 l, was calculated. Vessel reactivity was assessed using topical application of phenylephrine and acetylcholine. With the endothelium intact, K was higher in controls than with Perftoran at 10 and 30 min or Pluronic F-127 at 10 min (P surfactant added after air perfusion to damage the endothelium, K was lower (P surfactant in the perfusate before air perfusion, K was lower at 10 and 30 min for Perftoran and at 10 min for Pluronic F-127 than for controls (P surfactant exposure than in either surfactant group (P Surfactants reduced bubble adhesion force and preserved basic endothelial structure and vasodilatory function despite attempts to damage the endothelium. Surfactants seem to protect the endothelium from mechanically induced injury in addition to decreasing bubble adhesion forces.

  1. Optimization of metalworking fluid microemulsion surfactant concentrations for microfiltration recycling. (United States)

    Zhao, Fu; Clarens, Andres; Skerlos, Steven J


    Microfiltration can be used as a recycling technology to increase metalworking fluid (MWF) life span, decrease procurement and disposal costs, and reduce occupational health risks and environmental impacts. The cost-effectiveness of the process can be increased by minimizing fouling interactions between MWFs and membranes. This paper reports on the development of a microfiltration model that establishes governing relationships between MWF surfactant system characteristics and microfiltration recycling performance. The model, which is based on surfactant adsorption/desorption kinetics, queueing theory, and coalescence kinetics of emulsion droplets, is verified experimentally. An analysis of the model and supporting experimental evidence indicates that the selection of surfactant systems minimally adsorb to membranes and lead to a high activation energy of coalescence results in a higher MWF flux through microfiltration membranes. The model also yields mathematical equations that express the optimal concentrations of anionic and nonionic surfactants with which microfiltration flux is maximized for a given combination of oil type, oil concentration, and surfactant types. Optimal MWF formulations are demonstrated for a petroleum oil MWF using a disulfonate/ ethoxylated alcohol surfactant package and for several vegetable oil MWFs using a disulfonate/ethoxylated glyceryl ester surfactant package. The optimization leads to flux increases ranging from 300 to 800% without impact on manufacturing performance. It is further shown that MWF reformulation efforts directed toward increasing microfiltration flux can have the beneficial effect of increasing MWF robustness to deterioration and flux decline in the presence of elevated concentrations of hardwater ions.

  2. Surfactants in microbiology and biotechnology: Part 2. Application aspects. (United States)

    Singh, Ajay; Van Hamme, Jonathan D; Ward, Owen P


    Surfactants are amphiphilic compounds which can reduce surface and interfacial tensions by accumulating at the interface of immiscible fluids and increase the solubility, mobility, bioavailability and subsequent biodegradation of hydrophobic or insoluble organic compounds. Chemically synthesized surfactants are commonly used in the petroleum, food and pharmaceutical industries as emulsifiers and wetting agents. Biosurfactants produced by some microorganisms are becoming important biotechnology products for industrial and medical applications due to their specific modes of action, low toxicity, relative ease of preparation and widespread applicability. They can be used as emulsifiers, de-emulsifiers, wetting and foaming agents, functional food ingredients and as detergents in petroleum, petrochemicals, environmental management, agrochemicals, foods and beverages, cosmetics and pharmaceuticals, and in the mining and metallurgical industries. Addition of a surfactant of chemical or biological origin accelerates or sometimes inhibits the bioremediation of pollutants. Surfactants also play an important role in enhanced oil recovery by increasing the apparent solubility of petroleum components and effectively reducing the interfacial tensions of oil and water in situ. However, the effects of surfactants on bioremediation cannot be predicted in the absence of empirical evidence because surfactants sometimes stimulate bioremediation and sometimes inhibit it. For medical applications, biosurfactants are useful as antimicrobial agents and immunomodulatory molecules. Beneficial applications of chemical surfactants and biosurfactants in various industries are discussed in this review.

  3. Photosensitive microgels containing azobenzene surfactants of different charges. (United States)

    Schimka, Selina; Lomadze, Nino; Rabe, Maren; Kopyshev, Alexey; Lehmann, Maren; von Klitzing, Regine; Rumyantsev, Artem M; Kramarenko, Elena Yu; Santer, Svetlana


    We report on light sensitive microgel particles that can change their volume reversibly in response to illumination with light of different wavelengths. To make the anionic microgels photosensitive we add surfactants with a positively charged polyamine head group and an azobenzene containing tail. Upon illumination, azobenzene undergoes a reversible photo-isomerization reaction from a trans- to a cis-state accompanied by a change in the hydrophobicity of the surfactant. Depending on the isomerization state, the surfactant molecules are either accommodated within the microgel (trans-state) resulting in its shrinkage or desorbed back into water (cis-isomer) letting the microgel swell. We have studied three surfactants differing in the number of amino groups, so that the number of charges of the surfactant head varies between 1 and 3. We have found experimentally and theoretically that the surfactant concentration needed for microgel compaction increases with decreasing number of charges of the head group. Utilization of polyamine azobenzene containing surfactants for the light triggered remote control of the microgel size opens up a possibility for applications of light responsive microgels as drug carriers in biology and medicine.

  4. The Pulmonary Surfactant: Impact of Tobacco Smoke and Related Compounds on Surfactant and Lung Development


    Scott, J Elliott


    Cigarette smoking, one of the most pervasive habits in society, presents many well established health risks. While lung cancer is probably the most common and well documented disease associated with tobacco exposure, it is becoming clear from recent research that many other diseases are causally related to smoking. Whether from direct smoking or inhaling environmental tobacco smoke (ETS), termed secondhand smoke, the cells of the respiratory tissues and the lining pulmonary surfactant are the...

  5. Novel fluorinated gemini surfactants with γ-butyrolactone segments. (United States)

    Kawase, Tokuzo; Okada, Kazuyuki; Oida, Tatsuo


    In this work, novel γ-butyrolactone-type monomeric and dimeric (gemini) surfactants with a semifluoroalkyl group [Rf- (CH2)3-; Rf = C4F9, C6F13, C8F17] as the hydrophobic group were successfully synthesized. Dimethyl malonate was dimerized or connected using Br(CH2)sBr (s = 0, 1, 2, 3) to give tetraesters, and they were bis-allylated. Radical addition of fluoroalkyl using Rf-I and an initiator, i.e., 2,2'-azobisisobutyronitrile for C4F9 or di-t-butyl peroxide for C6F13 and C8F17, was perform at high temperature, with prolonged heating, to obtain bis(semifluoroalkyl)-dilactone diesters. These dilactone diesters were hydrolyzed using KOH/EtOH followed by decarboxylation in AcOH to afford γ-butyrolactonetype gemini surfactants. Common 1 + 1 semifluoroalkyl lactone surfactants were synthesized using the same method. Their surfactant properties [critical micelle concentration (CMC), γCMC, pC20, ΓCMC, and AG] were investigated by measuring the surface tension of the γ-hydroxybutyrate form prepared in aqueous tetrabutylammonium hydroxide solution. As expected, the CMC values of the gemini surfactants were more than one order of magnitude smaller than those of the corresponding 1 + 1 surfactants. Other properties also showed the excellent ability of the gemini structure to reduce the surface tension. These surfactants were easily and quantitatively recovered by acidification. The monomeric surfactant was recovered in the γ-hydroxybutyric acid form, and the gemini surfactant as a mixture of γ-butyrolactone and γ-hydroxybutyric acid forms.

  6. Gemini ester quat surfactants and their biological activity. (United States)

    Łuczyński, Jacek; Frąckowiak, Renata; Włoch, Aleksandra; Kleszczyńska, Halina; Witek, Stanisław


    Cationic gemini surfactants are an important class of surface-active compounds that exhibit much higher surface activity than their monomeric counterparts. This type of compound architecture lends itself to the compound being easily adsorbed at interfaces and interacting with the cellular membranes of microorganisms. Conventional cationic surfactants have high chemical stability but poor chemical and biological degradability. One of the main approaches to the design of readily biodegradable and environmentally friendly surfactants involves inserting a bond with limited stability into the surfactant molecule to give a cleavable surfactant. The best-known example of such a compound is the family of ester quats, which are cationic surfactants with a labile ester bond inserted into the molecule. As part of this study, a series of gemini ester quat surfactants were synthesized and assayed for their biological activity. Their hemolytic activity and changes in the fluidity and packing order of the lipid polar heads were used as the measures of their biological activity. A clear correlation between the hemolytic activity of the tested compounds and their alkyl chain length was established. It was found that the compounds with a long hydrocarbon chain showed higher activity. Moreover, the compounds with greater spacing between their alkyl chains were more active. This proves that they incorporate more easily into the lipid bilayer of the erythrocyte membrane and affect its properties to a greater extent. A better understanding of the process of cell lysis by surfactants and of their biological activity may assist in developing surfactants with enhanced selectivity and in widening their range of application.

  7. Surfactant selection for a liquid foam-bed photobioreactor. (United States)

    Janoska, Agnes; Vázquez, María; Janssen, Marcel; Wijffels, René H; Cuaresma, María; Vílchez, Carlos


    A novel liquid foam-bed photobioreactor has been shown to hold potential as an innovative technology for microalgae production. In this study, a foam stabilizing agent has been selected which fits the requirements of use in a liquid foam-bed photobioreactor. Four criteria were used for an optimal surfactant: the surfactant should have good foaming properties, should not be rapidly biodegradable, should drag up microalgae in the foam formed, and it should not be toxic for microalgae. Ten different surfactants (nonionic, cationic, and anionic) and two microalgae genera (Chlorella and Scenedesmus) were compared on the above-mentioned criteria. The comparison showed the following facts. Firstly, poloxameric surfactants (Pluronic F68 and Pluronic P84) have acceptable foaming properties described by intermediate foam stability and liquid holdup and small bubble size. Secondly, the natural surfactants (BSA and Saponin) and Tween 20 were easily biodegraded by bacteria within 3 days. Thirdly, for all surfactants tested the microalgae concentration is reduced in the foam phase compared to the liquid phase with exception of the cationic surfactant CTAB. Lastly, only BSA, Saponin, Tween 20, and the two Pluronics were not toxic at concentrations of 10 CMC or higher. The findings of this study indicate that the Pluronics (F68 and P84) are the best surfactants regarding the above-mentioned criteria. Since Pluronic F68 performed slightly better, this surfactant is recommended for application in a liquid foam-bed photobioreactor. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 2018. © 2018 American Institute of Chemical Engineers.

  8. Surfactant replacement therapy for preterm and term neonates with respiratory distress. (United States)

    Polin, Richard A; Carlo, Waldemar A


    Respiratory failure secondary to surfactant deficiency is a major cause of morbidity and mortality in preterm infants. Surfactant therapy substantially reduces mortality and respiratory morbidity for this population. Secondary surfactant deficiency also contributes to acute respiratory morbidity in late-preterm and term neonates with meconium aspiration syndrome, pneumonia/sepsis, and perhaps pulmonary hemorrhage; surfactant replacement may be beneficial for these infants. This statement summarizes the evidence regarding indications, administration, formulations, and outcomes for surfactant-replacement therapy. The clinical strategy of intubation, surfactant administration, and extubation to continuous positive airway pressure and the effect of continuous positive airway pressure on outcomes and surfactant use in preterm infants are also reviewed.

  9. Analysis of the structure and surfactant activity of novel formulations containing exogenous pulmonary surfactant and glucocorticoids. (United States)

    Cimato, Alejandra; Hoyos Obando, Andres; Facorro, Graciela; Martínez Sarrasague, María


    Exogenous pulmonary surfactant (EPS) could be used as carrier of glucocorticoids (GCs) in therapy for respiratory diseases. We formulated novel combination drug products containing bovine EPS and one GC (10wt%): beclomethasone (Be), budesonide (Bu) or fluticasone (Flu), and studied the GCs action on the surface activity and biophysical properties of EPS. Subtype ratio was evaluated by phospholipid determination; surface tension (ST) with a pulsating bubble surfactometer and conformational changes by Electron Spin Resonance (ESR). GCs were incorporated into EPS in more than 80%. None of them generated disaggregation of surfactant, only Bu was found in the light subtype. Bu and Be caused minimal changes in fluidity on polar region of bilayers, but these changes were not enough to inactivate the surfactant. Flu did not significantly alter any biophysical properties or surface activity. These novel combination EPS-GC products might be a promising strategy in the therapy of pulmonary diseases as the incorporation of the GCs tested did not cause detrimental effects on EPS functionality. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Effect of a soluble surfactant on a finite sized bubble motion in a blood vessel (United States)

    Swaminathan, T. N.; Mukundakrishnan, K.; Ayyaswamy, P. S.; Eckmann, D. M.


    We present detailed results for the motion of a finite sized gas bubble in a blood vessel. The bubble (dispersed phase) size is taken to be such as to nearly occlude the vessel. The bulk medium is treated as a shear thinning Casson fluid and contains a soluble surfactant that adsorbs and desorbs from the interface. Three different vessel sizes, corresponding to a small artery, a large arteriole, and a small arteriole, in normal humans, are considered. The hematocrit (volume fraction of RBCs) has been taken to be 0.45. For arteriolar flow, where relevant, the Fahraeus-Lindqvist effect is taken into account. Bubble motion cause temporal and spatial gradients of shear stress at the cell surface lining the vessel wall as the bubble approaches the cell, moves over it and passes it by. Rapid reversals occur in the sign of the shear stress imparted to the cell surface during this motion. Shear stress gradients together with sign reversals are associated with a recirculation vortex at the rear of the moving bubble. The presence of the surfactant reduces the level of the shear stress gradients imparted to the cell surface as compared to an equivalent surfactant-free system. Our numerical results for bubble shapes and wall shear stresses may help explain phenomena observed in experimental studies related to gas embolism, a significant problem in cardiac surgery and decompression sickness. PMID:20305744

  11. Application of maximum bubble pressure surface tensiometer to study protein-surfactant interactions. (United States)

    Dixit, Nitin; Zeng, David L; Kalonia, Devendra S


    Binding of a surfactant to proteins can affect their physicochemical stability and solubility in a formulation. The extent of the effect depends on the binding stoichiometry. In this study, we have utilized the technique of maximum bubble pressure surface tensiometry to characterize the binding between human serum albumin (HSA) and surfactants (sodium dodecyl sulfate (SDS) and polysorbate 80) by dynamic surface tension measurements. Results show that two classes of binding sites are present in HSA for SDS, 5 primary binding sites with high binding affinity (K(a)=5.38×10(5) M(-1)) and 12 secondary binding sites with low affinity (K(a)=6.7×10(4) M(-1)). The binding is high affinity and limited capacity due to both, ionic and hydrophobic interactions between HSA and SDS. For polysorbate 80, the binding does not follow the Scatchard plot, and is low affinity and high capacity, indicating that polysorbate 80 interacts with HSA through hydrophobic interactions. The results show that maximal bubble pressure surface tensiometry is a fast and convenient technique to determine the concentration of free and bound surfactants in the presence of proteins. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Characterization of colloidal gas aphron suspensions generated from plant-based natural surfactant solutions

    Energy Technology Data Exchange (ETDEWEB)

    Kommalapati, R.R.; Valsaraj, K.T.; Constant, W.D. [Louisiana State Univ., Baton Rouge, LA (United States)] [and others


    Colloidal gas aphron (CGA) suspensions generated using commercial surfactants are found to have great potential in the remediation of contaminated soils and waste streams. A plant-based natural surfactant solution prepared from the fruit pericarps of Sapindus mukorossi was used in this study to generate CGA suspensions. The CGA suspensions generated from this surfactant solution have size distributions similar to those of commercial surfactants. The stability of the CGA suspensions generated with natural surfactant solutions was observed to be higher than those generated using synthetic surfactants. However, the quality or the gas fraction of the suspensions is lower for a natural surfactant solution than that for commercial surfactants. The crude solution of natural surfactant prepared using simple water extraction contains saponins, the essential surface-active agent, and many other extraneous natural organic compounds. Yet, the CGA suspensions prepared from the crude solution seem to be comparable to those generated using synthetic surfactants in size distribution and stability.

  13. Surfactant mobility in nanoporous glass films. (United States)

    Kim, Taek-Soo; Mackie, Katherine; Zhong, Qiping; Peterson, Maria; Konno, Tomohisa; Dauskardt, Reinhold H


    Polymer molecules when physically confined at nanometer length scales diffuse nonclassically and very differently depending on their molecular weight and the nature of the confinement. Long polymers that exhibit "snakelike" reptation based mobility in melts may diffuse faster in confined nanometer sized cylinders with pore diameter d approximately 15 nm, and short polymers subject to Rouse dynamics have shown signatures of reptation and slower diffusion when confined in nanoporous glass with d approximately 4 nm. However, the mobility of short polymers with radii of gyration similar to a smaller pore diameter (d reptation based diffusion in the nanoscopic pore confinements. Such reptation mobility in agreement with theoretical predictions is not even observed in reptating polymer melts due to fluctuations of the entanglement pathway. The fixed pathways in the interconnected nanoporous films provide ideal nanoscale environments to explore mobility of confined molecules, and the results have implications for a number of technologies where nanoporous materials are in contact with surfactant molecules.

  14. Functionally polymerized surfactant vesicles: synthesis and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Tundo, P.; Kippenberger, D.J.; Klahn, P.L.; Prieto, N.E.; Fendler, J.H.


    Bis(2-(10-undecenoyloxycarbony bromide, bis(2-(10-undecenoyloxycarbony (2-hydroxyethyl)methylammonium bromide, bis(2-(10-undecenoyloxycarbony acid, bis(2-(10-undecenoyloxycarbony allylbis(2-dodecanoyloxycarbon bromide, and dimethyl-n-hexadecyl (10-(p-vin decyl)ammonium bromide have been synthesized. The predominantly single compartment bilayer vesicles formed from these surfactants could be polymerized either by exposure to ultraviolet irradiation or by the use of azoisobutyronitrile as an initiator. The presence of vesicles (unpolymerized and polymeric) has been demonstrated by electron micrography, H/sup 1/ NMR, gel filtration, phase transition, turbidity changes, substrate entrapment, and permeability. Polymerized vesicles are considerably more stable and less permeable and have reduced rates of turbidity changes compared to their unpolymerized counterparts. 19 references.

  15. Effect of surfactant on the evolution of bubble motion


    Antonnikova Aleksandra; Usanina Anna


    Results of an experimental study of the process of ascent of a single bubble of air in the presence of a surfactant are presented. An empirical dependence for drag coefficient of the bubble that emerges in a liquid containing a surfactant in the region of small Reynolds numbers has been obtained. Theoretical studies of the effect of surfactants on the velocity of motion of a bubble in a nonstationary regime have been carried out. A theoretical analysis of the effect of nonstationary forces on...

  16. Effect of surfactant on the evolution of bubble motion

    Directory of Open Access Journals (Sweden)

    Antonnikova Aleksandra


    Full Text Available Results of an experimental study of the process of ascent of a single bubble of air in the presence of a surfactant are presented. An empirical dependence for drag coefficient of the bubble that emerges in a liquid containing a surfactant in the region of small Reynolds numbers has been obtained. Theoretical studies of the effect of surfactants on the velocity of motion of a bubble in a nonstationary regime have been carried out. A theoretical analysis of the effect of nonstationary forces on the dynamics of bubble rising in the nonstationary regime has been conducted.

  17. Photocatalytic degradation of anionic surfactant using zinc oxide nanoparticles (United States)

    Giahi, M.; Habibi, S.; Toutounchi, S.; Khavei, M.


    In this paper the photocatalytic degradation of anionic surfactant LABS was studied by a batch process using ZnO nanoparticles with diameter size of 20 nm catalyst on irradiation with UV light and their behavior comparatively examined with respect to ZnO commercial powder. The effect of parameters such as initial surfactant concentration, initial solution pH has been studied. Also degradation at LABS in the presence of an electron acceptor like potassium peroxydisulfate and effect of anion presence on surfactant degradation has been systematically investigated. The obtained result demonstrated a high photocatalytic activity of nanosize semiconducting particles.

  18. Amino acid–based surfactants: New antimicrobial agents. (United States)

    Pinazo, A; Manresa, M A; Marques, A M; Bustelo, M; Espuny, M J; Pérez, L


    The rapid increase of drug resistant bacteria makes necessary the development of new antimicrobial agents. Synthetic amino acid-based surfactants constitute a promising alternative to conventional antimicrobial compounds given that they can be prepared from renewable raw materials. In this review, we discuss the structural features that promote antimicrobial activity of amino acid-based surfactants. Monocatenary, dicatenary and gemini surfactants that contain different amino acids on the polar head and show activity against bacteria are revised. The synthesis and basic physico-chemical properties have also been included.

  19. Key interactions of surfactants in therapeutic protein formulations: A review. (United States)

    Khan, Tarik A; Mahler, Hanns-Christian; Kishore, Ravuri S K


    Proteins as amphiphilic, surface-active macromolecules, demonstrate substantial interfacial activity, which causes considerable impact on their multifarious applications. A commonly adapted measure to prevent interfacial damage to proteins is the use of nonionic surfactants. Particularly in biotherapeutic formulations, the use of nonionic surfactants is ubiquitous in order to prevent the impact of interfacial stress on drug product stability. The scope of this review is to convey the current understanding of interactions of nonionic surfactants with proteins both at the interface and in solution, with specific focus to their effects on biotherapeutic formulations. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Synthesis of Branch Fluorinated Cationic Surfactant and Surface Properties

    Directory of Open Access Journals (Sweden)

    Hongke Wu


    Full Text Available A novel fluorinated quaternary ammonium salt cationic surfactant N,N,N-trimethyl-2-[[4-[[3,4,4,4-tetrafluoro-2-[1,2,2,2-tetrafluoro-1-(trifluoromethylethyl]-1,3-bis(tri-fluoromethyl-1-buten-1-yl]oxy]-benzoyl]amino]-iodide (FQAS was synthesized successfully, and its structure was characterized by FTIR, 1H-NMR, 19F-NMR, and MS. The surface activities of FQAS and the effect of temperature, electrolyte, and combination with hydrocarbon surfactant were investigated. The results showed that FQAS exhibited excellent surface activity and combination with hydrocarbon surfactant.

  1. Cold pearl surfactant-based blends. (United States)

    Crombie, R L


    Pearlizing agents have been used for many years in cosmetic formulations to add a pearlescent effect. Cold pearl surfactant-based blends are mixtures of glycol stearates and surfactants which can be blended in the cold into a wide range of personal-care formulations to create a pearlescent lustre effect. Under controlled manufacturing conditions constant viscosities and crystalline characteristics can be obtained. The development of these blends has been driven by efforts to improve the economics of adding solid pearlizing agents directly into a hot mix formulation. This paper summarizes the history of pearlizers, describes their advantages and physical chemistry of the manufacturing process. Finally some suggestions for applications are given. Les agents nacrants sont utilises depuis de nombreuses annees dans les formulations cosmetiques pour ajouter un effet nacre. Les melanges a froid a base de tensioactif nacre sont des melanges de stearates de glycol et de tensioactifs qui peuvent etre melanges a froid dans une large gamme de formulations d'hygiene personnelle pour creer un effet de lustre nacre. On peut obtenir des viscosites et des proprietes cristallines constantes avec des conditions de fabrication maitrisees. Le developpement de ces melanges a ete porte par les efforts pour ameliorer les couts de l'ajout d'agents nacrants solides directement dans une formulation melangee de l'ajout d'agents nacrants solides directement dans une formulation melangee a chaud. Cet article resume l'histoire des agents nacrants, decrit leurs avantages et al physico-chimie du procede de fabrication. On emet a la fin cetaines suggestions d'applications.

  2. Vesicles from pH-regulated reversible gemini amino-acid surfactants as nanocapsules for delivery. (United States)

    Lv, Jing; Qiao, Weihong; Li, Zongshi


    Reversible transition from micelles to vesicles by regulating pH were realized by gemini amino-acid surfactants N,N'-dialkyl-N,N'-diacetate ethylenediamine. Measurement results of ζ-potential at different pH and DLS at varying solvents revealed that the protonation between H(+) and double NCH2COO(-) groups (generating NH(+)CH2COO(-)), expressed as pKa1 and pKa2, is the key driving force to control the aggregation behaviors of gemini surfactant molecule. Effect of pH on the bilayer structure was studied in detail by using steady-state fluorescence spectroscopy of hydrophobic pyrene and Coumarin 153 (C153) respectively and fluorescence resonance energy transfer (FRET) from C153 to Rhodamine 6G (R6G). Various pH-regulated and pH-reversible self-assemblies were obtained in one surfactant system. Vitamin D3 was encapsulated in vesicle bilayers to form nano-VD3-capsules as VD3 supplement agent for health care products. By using the electrostatic attraction between Ca(2+) and double -COO(-) groups, nano-VD3-capsules with Ca(2+) coated outermost layers were prepared as a formulation for VD3 and calcium co-supplement agent. DLS and TEM were performed to check stability and morphology of the nano-capsules. It is concluded that the pH-regulated gemini amino-acid surfactants can be used to construct colloidal systems for delivering hydrophobic drugs or nutritions without lipids at human physiological pH level. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Surfactant-induced flow compromises determination of air-water interfacial areas by surfactant miscible-displacement. (United States)

    Costanza-Robinson, Molly S; Henry, Eric J


    Surfactant miscible-displacement (SMD) column experiments are used to measure air-water interfacial area (AI) in unsaturated porous media, a property that influences solute transport and phase-partitioning. The conventional SMD experiment results in surface tension gradients that can cause water redistribution and/or net drainage of water from the system ("surfactant-induced flow"), violating theoretical foundations of the method. Nevertheless, the SMD technique is still used, and some suggest that experimental observations of surfactant-induced flow represent an artifact of improper control of boundary conditions. In this work, we used numerical modeling, for which boundary conditions can be perfectly controlled, to evaluate this suggestion. We also examined the magnitude of surfactant-induced flow and its impact on AI measurement during multiple SMD flow scenarios. Simulations of the conventional SMD experiment showed substantial surfactant-induced flow and consequent drainage of water from the column (e.g., from 75% to 55% SW) and increases in actual AI of up to 43%. Neither horizontal column orientation nor alternative boundary conditions resolved surfactant-induced flow issues. Even for simulated flow scenarios that avoided surfactant-induced drainage of the column, substantial surfactant-induced internal water redistribution occurred and was sufficient to alter surfactant transport, resulting in up to 23% overestimation of AI. Depending on the specific simulated flow scenario and data analysis assumptions used, estimated AI varied by nearly 40% and deviated up to 36% from the system's initial AI. We recommend methods for AI determination that avoid generation of surface-tension gradients and urge caution when relying on absolute AI values measured via SMD. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Surfactant nebulisation prevents the adverse effects of surfactant therapy on blood pressure and cerebral blood flow in rabbits with severe respiratory failure

    NARCIS (Netherlands)

    Dijk, Peter H.; Heikamp, A; Bambang Oetomo, Sidarto


    Objective: Surfactant replacement therapy for the neonatal respiratory distress syndrome has shown beneficial effects on lung function and survival. Recently, rapid fluctuations of haemodynamics and cerebral perfusion following surfactant instillation have beer, described and an association with the

  5. Infrared spectroscopy of organoclays synthesized with the surfactant octadecyltrimethylammonium bromide (United States)

    Xi, Yunfei; Ding, Zhe; He, Hongping; Frost, Ray L.


    Infrared (IR) spectroscopy using a smart endurance single bounce diamond attenuated total reflection (ATR) cell has been used to study the changes in the spectra of the surfactant octadecyltrimethylammonium (ODTMA) bromide upon intercalation into a sodium montmorillonite. The wavenumbers of bands attributed to CH-stretching and CH-bending vibrations, in general, decrease as the concentration of the surfactant measured in terms of the cation exchange capacity (CEC) up to 1.0 CEC. After this point, the bands increase approaching a value the same as that of the surfactant. Significant changes occur in the HCH deformation modes of the methyl groups of the surfactant. These changes are attributed to the methyl groups locking into the siloxane (SiO) surface of the montmorillonite. Such a concept is supported by changes in the SiO-stretching bands of the montmorillonite siloxane surface.

  6. Surfactant-assisted sacrificial template-mediated synthesis ...

    Indian Academy of Sciences (India)

    The precursor and products were characterized by powder X-ray diffraction, fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopyand photoluminescence studies. Influence of surfactant and solvents on morphology and ...

  7. Effect of surfactant addition on removal of microbubbles using ultrasound. (United States)

    Kobayashi, Daisuke; Hayashida, Yoshiyuki; Sano, Kazuki; Terasaka, Koichi


    It is difficult to control the bubble in a liquid by the external operation, because the behavior of the bubble is controlled in buoyancy and flow of liquid. On the other hand, microbubbles, whose diameter is several decades μm, stably disperse in static liquid because of their small buoyancy and electrical repulsion. When an ultrasound, whose frequency was 2.4 MHz, was irradiated, the milky white microbubbles suspended solution became rapidly clear. In this study, the effects of surfactant addition on the removal of microbubbles from a liquid in an ultrasonic field were investigated. The efficiency of removal of microbubbles decreased with surfactant addition. Surfactant type influenced the size of agglomerated microbubbles, and the efficiency of removal of microbubbles changed. The surface of microbubble was modified by surfactant adsorption, and the steric inhibition influenced the removal of microbubbles. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. The adsorption of surfactant at the amorphous polymer solution interface

    CERN Document Server

    Gilchrist, V A


    Adsorption of surfactants onto amorphous polymers at the solid-solution interface is of direct relevance to many industrial sectors ranging from food, pharmaceuticals, paints, paper and photographic colour films. Although it is widely accepted that surfactants play the underpinning role in these applications, little is currently understood about the interactions between surfactants and polymeric materials at the molecular level. This lack of progress is mainly due to the inability of most existing techniques in probing this type of structural information at the wet interface. Specular neutron reflection (SNR) is a recently developed technique capable of detecting structural information with resolution down to a few angstroms (A). When combined with deuterium labeling, it is possible to distinguish the surfactant from the polymeric species at the interface. The aim of this work is to explore the appropriate experimental approach that utilizes the potential of neutron reflection to unravel molecular information...

  9. Effect of ionic surfactants on bauxite residues suspensions viscosity. (United States)

    Clifton, M; Nguyen, T; Frost, Ray


    Measurement of the rheological property of bauxite residue sample received from an Australian alumina refinery, treated with a number of cationic and anionic surfactant in laboratory has been carried out using a Brookfield viscometer for the assessment of the effect of surfactants on the residue viscosity. Sodium laurate, prepared with an excess of sodium hydroxide, was found to be effective while direct addition of anionic surfactants (lauric acid and sodium laureth sulphate) and cationic (cetyl trimethyl ammonium bromide) produce only moderate effect on the red mud suspension apparent viscosity at 65 degrees C. The experimental data appear to confirm the crucial role of the cation sodium in the process of adsorption of anionic surfactants on the flocculated red mud particles.

  10. Nonlinear vibrational spectroscopy of surfactants at liquid interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, Paulo B. [Univ. of California, Berkeley, CA (United States)


    Surfactants are widely used to modify physical and chemical properties of interfaces. They play an important role in many technological problems. Surfactant monolayer are also of great scientific interest because they are two-dimensional systems that may exhibit a very rich phase transition behavior and can also be considered as a model system for biological interfaces. In this Thesis, we use a second-order nonlinear optical technique (Sum-Frequency Generation - SFG) to obtain vibrational spectra of surfactant monolayer at Iiquidhapor and solid/liquid interfaces. The technique has several advantages: it is intrinsically surface-specific, can be applied to buried interfaces, has submonolayer sensitivity and is remarkably sensitive to the confirmational order of surfactant monolayers.

  11. Tunable Oleo-Furan Surfactants by Acylation of Renewable Furans

    Energy Technology Data Exchange (ETDEWEB)

    Park, Dae Sung; Joseph, Kristeen E.; Koehle, Maura; Krumm, Christoph; Ren, Limin; Damen, Jonathan N.; Shete, Meera H.; Lee, Han Seung; Zuo, Xiaobing; Lee, Byeongdu; Fan, Wei; Vlachos, Dionisios G.; Lobo, Raul F.; Tsapatsis, Michael; Dauenhauer, Paul J.


    An important advance in fluid surface control was the amphiphilic surfactant comprised of coupled molecular structures (i.e. hydrophilic and hydrophobic) to reduce surface tension between two distinct fluid phases. However, implementation of simple surfactants has been hindered by the broad range of applications in water containing alkaline earth metals (i.e. hard water), which disrupt surfactant function and require extensive use of undesirable and expensive chelating additives. Here we show that sugar-derived furans can be linked with triglyceride-derived fatty acid chains via Friedel-Crafts acylation within single layer (SPP) zeolite catalysts. These alkylfuran surfactants independently suppress the effects of hard water while simultaneously permitting broad tunability of size, structure, and function, which can be optimized for superior capability for forming micelles and solubilizing in water.

  12. Surfactants and the attachment of Pseudomonas aeruginosa to ...

    African Journals Online (AJOL)

    2-phenylidole (DAPI) staining, scanning electron microscopy (SEM) and spectrophotometry for their efficacy in preventing adhesion and removing Ps. Aeruginosa attached to 3CR12 stainless steel coupons and glass. All the surfactants tested ...

  13. Experimental study on thermophoresis of colloids in aqueous surfactant solutions (United States)

    Dong, Ruo-Yu; Zhou, Yi; Yang, Chun; Cao, Bing-Yang


    Thermophoresis refers to the motion of particles under a temperature gradient and it is one of the particle manipulation techniques. Regarding the thermophoresis of particles in liquid media, however, many open questions still remain, especially the role of the interfacial effect. This work reports on a systematic experimental investigation of surfactant effects, especially the induced interfacial effect, on the thermophoresis of colloids in aqueous solutions via a microfluidic approach. Two kinds of commonly used surfactants, sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB), are selected and the results show that from relatively large concentrations, the two surfactants can greatly enhance the thermophilic mobilities. Specifically, it is found that the colloid-water interfaces modified with more polar end groups can potentially lead to a stronger thermophilic tendency. Due to the complex effects of surfactants, further theoretical model development is needed to quantitatively describe the dependence of thermophoresis on the interface characteristics.

  14. (NLC-Effect of Surfactant Concentration on the Formulation Properties

    Directory of Open Access Journals (Sweden)

    Akram Pezeshki


    Conclusion: This study suggests that surfactant significantly influences the final product properties. Our findings may pave the way of researchers to focus on fortifying the beverages with various lipophilic nutraceuticals.

  15. Controlled release of estradiol solubilized in carbopol/surfactant aggregates. (United States)

    Barreiro-Iglesias, Rafael; Alvarez-Lorenzo, Carmen; Concheiro, Angel


    The potential of carbopol/surfactant dispersions as solubilizing and controlled release systems of estradiol (a poorly water-soluble drug) was evaluated. The solubilization of estradiol in the dispersions of Carbopol 934 (0.25%) and Pluronic F-127, Tween 80, sodium dodecylsulfate (SDS), or benzalkonium chloride (BkCl) was assessed, by differential scanning calorimetry (DSC) of films obtained by desiccation, as a decrease in estradiol melting temperature and enthalpy. The amounts of estradiol solubilized in carbopol/SDS and carbopol/Tween 80 aqueous dispersions were considerably greater (solubilization capacity: 1.3 and 9 times greater) than in the surfactant alone solutions and up to 100 times greater than in water. High aggregates/water equilibrium partition coefficients of estradiol in carbopol/SDS (1768 M(-1)) and carbopol/Tween 80 (14114 M(-1)) dispersions were found. Carbopol/(1%) SDS/(25 mg/dl) estradiol and carbopol/(0.1%) Tween 80/(5 mg/dl) estradiol dispersions had a pH of around 4, were easy flowing, and showed sustained release for at least 1 week. Estradiol diffusion coefficients were greater when the receptor medium was 0.3-1.0% SDS solution than when it was iso-osmotic NaCl solution or pH 7.5 phosphate buffer. At this pH, a viscoelastic gel is formed on the donor side of the membrane and the drug diffusion slowed down. When the receptor medium contains a surfactant, estradiol release seems to happen as a direct exchange between the carbopol/surfactant aggregates and the receptor surfactant micelles. If no surfactant is in the receptor fluid, estradiol/surfactant complexes migrate towards the receptor. Despite the low viscosity of these dispersions, estradiol diffusion coefficients were in the same order of magnitude as those obtained with a commercially available neutralized ethanol/water carbopol gel of estradiol (60 mg/dl). When the receptor medium had no surfactant, the low affinity of estradiol for water prevented drug diffusion from the

  16. Novel Surfactants and Their Applications, Including Mustard Decontamination (United States)


    34, Td forc(cHr)ttf (vnzl"", l;" The synthesis of surfactant 22 was included in the Progress Report for August 1,2004 to July 31, 2005, but its...reaction with pyrophosphoric acid. Then 66 gave shamrock surfactant 60 upon reaction with two equivalents of sodium hydroxide. 48/" HBr H"C) HO(CH2

  17. Surfactant properties differentially influence intravascular gas embolism mechanics. (United States)

    Swaminathan, T N; Ayyaswamy, P S; Eckmann, D M


    Gas bubble motion in a blood vessel causes temporal and spatial gradients of shear stress at the cell surface lining the vessel wall as the bubble approaches the cell, moves over it and passes it by. Rapid reversals occur in the sign of the shear stress imparted to the cell surface during this motion. These may result in injury to the cell. The presence of a soluble surfactant in the bulk medium reduces the level of the shear stress gradients imparted to the cell surface as compared to an equivalent surfactant-free system and is an important therapeutic aid. This is particularly true for a very small vessel. In this study, we analyze various physical and chemical properties of any given soluble surfactant to ascertain the relative significance of the property of the surfactant on the reduction in the level of the shear stress gradients imparted to the cell surface in such a vessel. While adsorption, desorption, and maximum possible monolayer interface surfactant concentration significantly impact the shear stress levels, physical properties such as the bulk or surface diffusivity do not appear to have large effects. At a given diameter, surfactants with k(a)/(k(d)d>O(10)⁻⁵ and Γ(∞)/C(0)d>9.5 x 10⁻⁴ are noted to be preferable from the point of view of an increased gap size between the bubble and vessel wall, and a corresponding reduction in the shear stress level imparted to an endothelial cell. The shear stress characteristics of nearly occluding bubbles, in contrast with smaller sized bubbles under identical conditions, are most affected by the introduction of a surfactant in regard to shear stress levels. These observations could form a basis for choosing surfactants in treating gas embolism related illnesses.

  18. A comparative study of mechanisms of surfactant inhibition. (United States)

    Gunasekara, Lasantha; Schoel, W Michael; Schürch, Samuel; Amrein, Matthias W


    Pulmonary surfactant spreads to the hydrated air-lung interface and reduces the surface tension to a very small value. This function fails in acute respiratory distress syndrome (ARDS) and the surface tension stays high. Dysfunction has been attributed to competition for the air-lung interface between plasma proteins and surfactant or, alternatively, to ARDS-specific alterations of the molecular profile of surfactant. Here, we compared the two mechanisms in vitro, to assess their potential role in causing respiratory distress. Albumin and fibrinogen exposure at or above blood level concentrations served as the models for testing competitive adsorption. An elevated level of cholesterol was chosen as a known adverse change in the molecular profile of surfactant in ARDS. Bovine lipid extract surfactant (BLES) was spread from a small bolus of a concentrated suspension (27 mg/ml) to the air-water interface in a captive bubble surfactometer (CBS) and the bubble volume was cyclically reduced and increased to assess surface activity of the spread material. Concentrations of inhibitors and the concentration and spreading method of pulmonary surfactant were chosen in an attempt to reproduce the exposure of surfactant to inhibitors in the lung. Under these conditions, neither serum albumin nor fibrinogen was persistently inhibitory and normal near-zero minimum surface tension values were obtained after a small number of cycles. In contrast, inhibition by an increased level of cholesterol persisted even after extensive cycling. These results suggest that in ARDS, competitive adsorption may not sufficiently explain high surface tension, and that disruption of the surfactant film needs to be given causal consideration.

  19. Nanoparticle decoration with surfactants: Molecular interactions, assembly, and applications (United States)

    Heinz, Hendrik; Pramanik, Chandrani; Heinz, Ozge; Ding, Yifu; Mishra, Ratan K.; Marchon, Delphine; Flatt, Robert J.; Estrela-Lopis, Irina; Llop, Jordi; Moya, Sergio; Ziolo, Ronald F.


    Nanostructures of diverse chemical nature are used as biomarkers, therapeutics, catalysts, and structural reinforcements. The decoration with surfactants has a long history and is essential to introduce specific functions. The definition of surfactants in this review is very broad, following its lexical meaning ;surface active agents;, and therefore includes traditional alkyl modifiers, biological ligands, polymers, and other surface active molecules. The review systematically covers covalent and non-covalent interactions of such surfactants with various types of nanomaterials, including metals, oxides, layered materials, and polymers as well as their applications. The major themes are (i) molecular recognition and noncovalent assembly mechanisms of surfactants on the nanoparticle and nanocrystal surfaces, (ii) covalent grafting techniques and multi-step surface modification, (iii) dispersion properties and surface reactions, (iv) the use of surfactants to influence crystal growth, as well as (v) the incorporation of biorecognition and other material-targeting functionality. For the diverse materials classes, similarities and differences in surfactant assembly, function, as well as materials performance in specific applications are described in a comparative way. Major factors that lead to differentiation are the surface energy, surface chemistry and pH sensitivity, as well as the degree of surface regularity and defects in the nanoparticle cores and in the surfactant shell. The review covers a broad range of surface modifications and applications in biological recognition and therapeutics, sensors, nanomaterials for catalysis, energy conversion and storage, the dispersion properties of nanoparticles in structural composites and cement, as well as purification systems and classical detergents. Design principles for surfactants to optimize the performance of specific nanostructures are discussed. The review concludes with challenges and opportunities.

  20. Structural studies of lamellar surfactant systems under shear

    DEFF Research Database (Denmark)

    Mortensen, K.


    Recent experimental studies on concentrated surfactant systems are reviewed. Particular attention is focused on the transformation from planar lamellar sheets to multilamellar vesicles. It is discussed whether both of these states are thermodynamic stable, or if the MLV is an artifact of shear...... induced factors. Recent studies includes the dependence on shear, and dependence on salt and cosurfactants, and thereby related lamellar defects. The review include moreover the demonstration that polymeric amphiphiles dramatically enhance the quality of classical surfactants. (C) 2001 Elsevier Science...

  1. Use of surfactants to control island size and density (United States)

    Merrell, Jason; Liu, Feng; Stringfellow, Gerald B.


    Methods of controlling island size and density on an OMVPE growth film may comprise adding a surfactant at a critical concentration level, allowing a growth phase for a first period of time, and ending the growth phase when desired island size and density are achieved. For example, the island size and density of an OMVPE grown InGaN thin film may be controlled by adding an antimony surfactant at a critical concentration level.

  2. European perspective on less invasive surfactant administration-a survey. (United States)

    Klotz, Daniel; Porcaro, Ugo; Fleck, Thilo; Fuchs, Hans


    Less invasive surfactant administration or minimally invasive surfactant therapy (LISA/MIST) has been proposed for the administration of surfactant in preterm infants without intubation. The aim of our survey was to assess the rate of utilization, premedication as well as technique and equipment used for LISA/MIST. Furthermore, attitudes and experiences in regard to indications, side effects, and efficacy should be assessed. An online-based survey was sent to 324 neonatologists from different centers within 37 European countries between December 2015 and March 2016. Of those 165 who responded (response rate 51%), 86 (52%) were using LISA/MIST. It is regarded the standard procedure for surfactant administration by 41%, with a wide variation in personal views on patient selection in terms of indication, appropriate gestational and postnatal age. Policies concerning premedication, devices, and technique of LISA/MIST differed widely. Side effects like surfactant reflux, bradycardia, and hypoxia were observed by 77% of neonatologists. Of neonatologists inexperienced in LISA/MIST, 89% would consider utilizing it in the future. Perceived efficacy of LISA/MIST was high (52%) to medium (33%). The use of LISA/MIST within Europe is widespread. There is a wide variation concerning all aspects of LISA in daily clinical routine and different views on when and how LISA should be performed. What is Known: • Noninvasive surfactant administration has been the subject of randomized controlled trials and has found its way into clinical routine. What is New: • Noninvasive surfactant administration techniques are widely applied in European neonatal units. • There is a wide variety of equipment used and techniques applied for less invasive surfactant delivery as well as different views on the indications and perceived efficacy of this intervention.

  3. Effects of Surfactants on the Rate of Chemical Reactions

    Directory of Open Access Journals (Sweden)

    B. Samiey


    Full Text Available Surfactants are self-assembled compounds that depend on their structure and electric charge can interact as monomer or micelle with other compounds (substrates. These interactions which may catalyze or inhibit the reaction rates are studied with pseudophase, cooperativity, and stoichiometric (classical models. In this review, we discuss applying these models to study surfactant-substrate interactions and their effects on Diels-Alder, redox, photochemical, decomposition, enzymatic, isomerization, ligand exchange, radical, and nucleophilic reactions.

  4. Competitive Adsorption: A Physical Model for Lung Surfactant Inactivation


    Fernsler, Jonathan G.; Zasadzinski, Joseph A.


    Charged, surface-active serum proteins can severely reduce or eliminate the adsorption of lung surfactant from the subphase to the alveolar air-liquid interface via a kinetically controlled competitive adsorption process. The decreased surfactant concentration at the interface leads to higher surface tensions during the compression of the interface during breathing. The correspondence between the factors governing colloid stability and competitive adsorption is validated via a new method of m...

  5. Optimizing the use of surfactants and water with foams: a comparison between soapy solutions and foams for sebum detergency (United States)

    Restagno, Frederic; Valois, Pauline; Petit, Pauline; Cazeneuve, Colette; Nicolas-Morgantini, Luc; Rio, Emmnauelle; Luengo, Gustavo

    Human sebum is excreted at the skin surface by the sebaceous glands. Surfactants are the core ingredients of shampoos and other cosmetics to eliminate the excess of sebum as detergency is the classical mechanism used for hair cleaning.. In this study, we add a precise amount of sebum on different hair. We developed a new protocol to measure the cleaning efficiency of surfactant solutions and foams made with the same surfactant solutions based on a spectroscopic method. More precisely, we add a well-controlled amount of colored sebum, we clean the hair with our test foam or solution and we remove completely the unwashed sebum. The sebum remaining after washing is quantified by visible spectroscopy. We tested either classical detergents such as SLES at different concentrations or white egg. The studies were performed on natural or bleached hair. In all the studied case, it was not possible to observe any difference in the cleaning efficiency between the bulk solutions and the foams made from the solutions. This study could allow to develop new shampoos formulations or dispensers in order to replace washing solutions by foams that could have the same cleaning efficiency with a lower amount of surfactants; diminishing the water rinsing needs during application.

  6. Anomalous behavior during leveling of thin coating layers with surfactant (United States)

    Schwartz, L. W.; Cairncross, R. A.; Weidner, D. E.


    Our recently-published linear analysis [Schwartz et al., Langmuir 11, 3690 (1995)] demonstrated that an initially rippled thin layer of Newtonian liquid with uniformly distributed surfactant may level in unexpected ways. While the presence of surfactant will, in general, slow the rate of leveling compared to that of a perfectly clean system, there was shown to exist a realistic parameter range where increasing, rather than reducing, the amount of surfactant present will hasten leveling. Here, for the two-dimensional problem, we investigate the importance of nonlinearity though numerical solution of (i) the unsteady lubrication form of the evolution equations with surfactant, and (ii) finite-element solution of the exact governing equations for slow viscous flow. Confirmation of the linear results is demonstrated and quantitative discrepancy only appears for large-amplitude and short-wavelength ripples. Surface tension gradient driven flow explains the anomalies; for moderate surfactants, the surface quickly `hardens,' leading to a decay rate of one-quarter of the clean-surface rate, while for weak surfactants, leveling proceeds to a plateau level which decays much slower than the hard-surface result.

  7. Influence of residual surfactants on DNAPL characterization using partitioning tracers (United States)

    Cho, Jaehyun; Annable, Michael D.; Rao, P. Suresh C.


    The partitioning tracer technique is among the DNAPL source-zone characterization methods being evaluated, while surfactant in-situ flushing is receiving attention as an innovative technology for enhanced source-zone cleanup. Here, we examine in batch and column experiments the magnitude of artifacts introduced in estimating DNAPL content when residual surfactants are present. The batch equilibrium tests, using residual surfactants ranging from 0.05 to 0.5 wt.%, showed that as the surfactant concentrations increased, the tracer partition coefficients decreased linearly for sodium hexadecyl diphenyl oxide disulfonate (DowFax 8390), increased linearly for polyoxyethylene (10) oleyl ether (Brij 97), and decreased slightly or exhibited no observable trend for sodium dihexyl sulfosuccinate (AMA 80). Results from column tests using clean sand with residual DowFax 8390 and Tetrachloroethylene (PCE) were consistent with those of batch tests. In the presence of DowFax 8390 (less than 0.5 wt.%), the PCE saturations were underestimated by up to 20%. Adsorbed surfactants on a loamy sand with positively charged oxides showed false indications of PCE saturation based on partitioning tracers in the absence of PCE. Using no surfactant (background soil) gave a false PCE saturation of 0.0004, while soil contacted by AMA 80, Brij 97, and DowFax 8390 gave false PCE saturations of 0.0024, 0.043, and 0.23, respectively.

  8. Splash Dynamics of Falling Surfactant-Laden Droplets (United States)

    Sulaiman, Nur; Buitrago, Lewis; Pereyra, Eduardo


    Splashing dynamics is a common issue in oil and gas separation technology. In this study, droplet impact of various surfactant concentrations onto solid and liquid surfaces is studied experimentally using a high-speed imaging analysis. Although this area has been widely studied in the past, there is still not a good understanding of the role of surfactant over droplet impact and characterization of resulting splash dynamics. The experiments are conducted using tap water laden with anionic surfactant. The effects of system parameters on a single droplet impingement such as surfactant concentration (no surfactant, below, at and above critical micelle concentration), parent drop diameter (2-5mm), impact velocity and type of impact surface (thin and deep pool) are investigated. Image analysis technique is shown to be an effective technique for identification of coalescence to splashing transition. In addition, daughter droplets size distributions are analyzed qualitatively in the events of splashing. As expected, it is observed that the formation of secondary droplets is affected by the surfactant concentration. A summary of findings will be discussed.

  9. Highly stable surfactant assisted polyaniline nanostructures with enhanced electroactivity (United States)

    Jamdegni, Monika; Kaur, Amarjeet


    Different nanostructures of Polyaniline(PANI) i.e. nanospheres, nanorods, nanofibers and layered structures have been successfully synthesized using varied concentration of anionic sodium dodecyl sulphate(SDS) and cationic Hexamethyltriammonium bromide (HTAB) by electrochemical method. Surfactant assisted morphology has been studied using FESEM. Incorporation of surfactants to the polymer matrix has been confirmed using FTIR spectroscopy. Electro activity and stability towards reversible redox activity was studied using cyclic voltammatry and chronoamperometry.The anionic surfactant severely enhances electroactivity and areal capacitance (3 Fcm-2) which was found to be two order higher than PANI film prepared without surfactant (0.039 Fcm-2), attributable to its additional doping effect. Immobilization of large surfactant molecule to polymer matrix inhibits its degradation due to nuleophilic attack ascribed to hydrophobic effect of surfactant. For PANI-SDS redox behavior remained almost same after 1000 reverse redox cycles while for PANI-HTAB we got only marginal changes.Our PANI-SDS samples are promising candidates for electro chromic applications.

  10. Natural and surfactant modified zeolites: A review of their applications for water remediation with a focus on surfactant desorption and toxicity towards microorganisms. (United States)

    Reeve, Peter J; Fallowfield, Howard J


    The objective of this review is to highlight the need for further investigation of microbial toxicity caused by desorption of surfactant from Surfactant Modified Zeolite (SMZ). SMZ is a low cost, versatile permeable reactive media which has the potential to treat multiple classes of contaminants. With this combination of characteristics, SMZ has significant potential to enhance water and wastewater treatment processes. Surfactant desorption has been identified as a potential issue for the ongoing usability of SMZ. Few studies have investigated the toxicity of surfactants used in zeolite modification towards microorganisms and fewer have drawn linkages between surfactant desorption and surfactant toxicity. This review provides an overview of natural zeolite chemistry, characteristics and practical applications. The chemistry of commonly used surfactants is outlined, along with the kinetics that drive their adsorption to the zeolite surface. Methodologies to characterise this surfactant loading are also described. Applications of SMZ in water remediation are highlighted, giving focus to applications which deal with biological pollutants and where microorganisms play a role in the remediation process. Studies that have identified surfactant desorption from SMZ are outlined. Finally, the toxicity of a commonly used cationic surfactant towards microorganisms is discussed. This review highlights the potential for surfactant to desorb from the zeolite surface and the need for further research into the toxicity of this desorbed surfactant towards microorganisms, including pathogens and environmental microbes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Mechanism of the immobilization of surfactants on polymeric surfaces by means of an argon plasma treatment: influence of the chemical structure of surfactant substrate

    NARCIS (Netherlands)

    Lens, J.P.; Lens, J.P.; Terlingen, J.G.A.; Terlingen, J.G.A.; Engbers, G.H.M.; Feijen, Jan


    In this article, a study on the mechanism of the immobilization of surfactants on polymeric surfaces by means of an argon plasma treatment is described. The unsaturated surfactant sodium 10-undecenoate [C11(:)] and the saturated surfactant sodium dodecanoate (C12) were immobilized on poly(ethylene)

  12. Influence of water concentrations on the phase transformation of a model surfactant/co-surfactant/water system (United States)

    Lunkad, Raju; Srivastava, Arpita; Debnath, Ananya


    The influence of water concentrations on phase transformations of a surfactant/co-surfactant/water system is investigated by using all atom molecular dynamics simulations. At higher water concentrations, where surfactant (behenyl trimethyl ammonium chloride, BTMAC) to co-surfactant (stearyl alcohol, SA) ratio is fixed, BTMAC and SA self-assemble into spherical micelles, which transform into strongly interdigitated one dimensional rippled lamellar phases upon decreasing water concentrations. Fragmentation or fusions of spherical micelles of different sizes are evident from the radial distribution functions at different temperatures. However, at lower water concentrations rippled lamellar phase transforms into an LβI phase upon heating. Our simulations reveal that the concentrations of water can influence available space around the head groups which couple with critical thickness to accommodate the packing fraction required for respective phases. This directs towards obtaining a controlling factor to design desired phases important for industrial and medical applications in the future.

  13. Compare severity of bronchopulmonary dysplasia in neonates with respiratory distress syndrome treated with surfactant to without surfactant. (United States)

    Chotigeat, Uraiwan; Ratchatanorravut, Sombat; Kanjanapattanakul, Wiboon


    The utilization of surfactant replacement therapy had been limited in treatment of respiratory distress syndrome (RDS) due to the high cost especially in developing countries. Nowadays, the National Health Insurance Policy has covered the cost of surfactant for the patients. Therefore, bronchopulmonary dysplasia (BPD) may be found increasing due to increased survival in patients with severe RDS. To compare immediate treatment outcome of severity of BPD and outcome after hospital discharge in neonates with RDS who were treated with or without surfactant. Retrospective cohort study. The data of 54 infants who developed BPD after RDS at Queen Sirikit National Institute of Child Health between January 1st, 2003 and December 31th, 2005 were kept in database format. The database was analyzed for difference between groups and the outcome of immediate treatment, severity of BPD and outcome after hospital discharge were compared. The study group was BPD cases from RDS treated with surfactant compared to control (BPD cases from RDS treated without surfactant) groups. Forty-three (80%) from fifty-four cases had completed data and were included into the present study. There was no statistically significant difference in maternal conditions and neonatal conditions between groups. Antenatal steroid was prescribed more often in RDS without surfactant group than surfactant group. The mean birth weight and gestational age in surfactant and without surfactant groups were 1,179.1 +/- 274.3 gm vs. 1,114.4 +/- 338.3 gm and 29 +/- 1.6 weeks vs. 29.2 +/- 2.7 weeks respectively, but no significant differences were observed between groups. To compare the severity of RDS, only 17.6% of moderate to severe RDS in the control group was found, whereas 100% was found in the study group. Moderate to severe BPD cases were found more often in the control group (70.6%) than in the study group (61.6%), but no statistically significant difference was shown. The immediate complications, e

  14. Effect of double-tailed surfactant architecture on the conformation, self-assembly, and processing in polypeptide-surfactant complexes. (United States)

    Junnila, Susanna; Hanski, Sirkku; Oakley, Richard J; Nummelin, Sami; Ruokolainen, Janne; Faul, Charl F J; Ikkala, Olli


    This work describes the solid-state conformational and structural properties of self-assembled polypeptide-surfactant complexes with double-tailed surfactants. Poly(L-lysine) was complexed with three dialkyl esters of phosphoric acid (i.e., phosphodiester surfactants), where the surfactant tail branching and length was varied to tune the supramolecular architecture in a facile way. After complexation with the branched surfactant bis(2-ethylhexyl) phosphate in an aqueous solution, the polypeptide chains adopted an alpha-helical conformation. These rod-like helices self-assembled into cylindrical phases with the amorphous alkyl tails pointing outward. In complexes with dioctyl phosphate and didodecyl phosphate, which have two linear n-octyl or n-dodecyl tails, respectively, the polypeptide formed antiparallel beta-sheets separated by alkyl layers, resulting in well-ordered lamellar self-assemblies. By heating, it was possible to trigger a partial opening of the beta-sheets and disruption of the lamellar phase. After repeated heating/cooling, all of these complexes also showed a glass transition between 37 and 50 degrees C. Organic solvent treatment and plasticization by overstoichiometric amount of surfactant led to structure modification in poly(L-lysine)-dioctyl phosphate complexes, PLL(diC8)(x) (x = 1.0-3.0). Here, the alpha-helical PLL is surrounded by the surfactants and these bottle-brush-like chains self-assemble in a hexagonal cylindrical morphology. As x is increased, the materials are clearly plasticized and the degree of ordering is improved: The stiff alpha-helical backbones in a softened surfactant matrix give rise to thermotropic liquid-crystalline phases. The complexes were examined by Fourier transform infrared spectroscopy, small- and wide-angle X-ray scattering, transmission electron microscopy, differential scanning calorimetry, polarized optical microscopy, and circular dichroism.

  15. Effects of Exogenous Surfactants on the Parameters of Blood Gas Composition in Neonatal Respiratory Distress Syndrome

    Directory of Open Access Journals (Sweden)

    S. A. Perepelitsa


    Full Text Available Objective: to study the effects of the surfactants Surfactant-BL and Curosurf on pulmonary oxygenizing properties in preterm neonatal infants with respiratory distress syndrome (RDS. The studies were performed in 81 preterm neonates with severe RDS. For the therapy of RDS, the exogenous surfactants Surfactant-BL and Curosurf were used in 52 and 29 children with RDS, respectively. The similarity of infants from both groups was statistically confirmed. Blood gas composition and artificial ventilation parameters were examined. Results. The administration of the exogenous surfactants Surfactant-BL and Curosurf normalized blood gas composition, enhanced alveolar ventilation, and improved pulmonary ventilation-perfusion relationships. The exogenous surfactants permit the performance of artificial ventilation when the values are close to the physiological ones. There were no significant differences in the effects on the surfactants on gas exchange parameters. Key words: respiratory distress syndrome, surfactant, artificial ventilation, mean airway pressure, blood gas composition.

  16. Impact of model perfumes on surfactant and mixed surfactant self-assembly. (United States)

    Penfold, J; Tucker, I; Green, A; Grainger, D; Jones, C; Ford, G; Roberts, C; Hubbard, J; Petkov, J; Thomas, R K; Grillo, I


    The impact of some model perfumes on surfactant self-assembly has been investigated, using small-angle neutron scattering. A range of different model perfumes, with differing degrees of hydrophilicity/hydrophobicity, have been explored, and in order of increasing hydrophobicity include phenyl ethanol (PE), rose oxide (RO), limonene (LM), linalool (LL), and dihydrogen mercenol (DHM). The effect of their solubilization on the nonionic surfactant micelles of dodecaethylene monododecyl ether (C12EO12) and on the mixed surfactant aggregates of C12EO12 and the cationic dialkyl chain surfactant dihexadecyl dimethyl ammonium bromide (DHDAB) has been quantified. For PE and LL the effect of their solubilization on the micelle, mixed micelle/lamellar and lamellar regimes of the C12EO12/DHDAB mixtures, has also been determined. For the C12EO12 and mixed DHDAB/C12EO12 micelles PE is solubilized predominantly at the hydrophilic/hydrophobic interface, whereas the more hydrophobic perfumes, from RO to DHM, are solubilized predominantly in the hydrophobic core of the micelles. For the C12EO12 micelles, with increasing perfume concentration, the more hydrophobic perfumes (RO to DHM) promote micellar growth. Relatively modest growth is observed for RO and LM, whereas substantial growth is observed for LL and DHM. In contrast, for the addition of PE the C12EO12 micelles remain as relatively small globular micelles, with no significant growth. For the C12EO12/DHDAB mixed micelles, the pattern of behavior with the addition of perfume is broadly similar, except that the micellar growth with increasing perfume concentration for the more hydrophobic perfumes is less pronounced. In the Lbeta (Lv) region of the DHDAB-rich C12EO12/DHDAB phase diagram, the addition of PE results in a less structured (less rigid) lamellar phase, and ultimately a shift toward a structure more consistent with a sponge or bicontinuous phase. In the mixed L1/Lbeta region of the phase diagram PE induces a slight

  17. Capillary electrophoresis investigation on equilibrium between polymer-related and surfactant-related species in aqueous polymer-surfactant solutions. (United States)

    Wu, Yefan; Chen, Miaomiao; Fang, Yun; Zhu, Meng


    It was inferred from aqueous solution behavior of nonionic polymers and anionic surfactants that the formation of charged polymer-bound surfactant micelle above critical aggregation concentration (cac) and the formation of free surfactant micelle beyond polymer saturation point (psp), but there was still a lack of direct experimental evidence for the considered equilibrium chemical species. Three modes of capillary electrophoresis are applied in this paper to study the complexation between nonionic polymers, polyvinylpyrrolidone (PVP) or polyethylene glycol (PEG), and sodium dodecylbenzenesulfonate (SDBS) by successfully distinguishing the imaginary charged polymer-bound SDBS micelle from nonionic polymer and SDBS molecule. Perhaps even more important, it is the action of SDBS as both a main surfactant and a UV probe that makes the free surfactant micelle emerged in electropherogram beyond psp, and thus makes it possible for the first time to provide the equilibrium relationship of the polymer-related and the surfactant-related species in the concentration regions divided into by cac and psp. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Structural characterization of human and bovine lung surfactant protein D

    DEFF Research Database (Denmark)

    Leth-Larsen, Rikke; Holmskov, U; Højrup, P


    . The heterogeneity in SP-D was caused mainly by a high number of post-translational modifications in the collagen-like region. Proline and lysine residues were partly hydroxylated and lysine residues were further O-glycosylated with the disaccharide galactose-glucose. A partly occupied N-linked glycosylation site...

  19. Use of surfactants for the remediation of contaminated soils: A review

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Xuhui, E-mail: [School of Resource and Environmental Science, Wuhan University, Wuhan 430072 (China); Jiang, Rui; Xiao, Wei [School of Resource and Environmental Science, Wuhan University, Wuhan 430072 (China); Yu, Jiaguo, E-mail: [State Key Laboratory of Advanced Technology for Material Synthesis and Processing, Wuhan University of Technology, Wuhan 430070 (China)


    Highlights: • The recent advances in use of surfactant for soil remediation are reviewed. • The mechanisms of surfactant-based soil remediation are discussed. • A review on the application of different types of surfactants is made. • The future research direction of surfactant-based technologies is suggested. - Abstract: Due to the great harm caused by soil contamination, there is an increasing interest to apply surfactants to the remediation of a variety of contaminated soils worldwide. This review article summarizes the findings of recent literatures regarding remediation of contaminated soils/sites using surfactants as an enhancing agent. For the surfactant-based remedial technologies, the adsorption behaviors of surfactants onto soil, the solubilizing capability of surfactants, and the toxicity and biocompatibility of surfactants are important considerations. Surfactants can enhance desorption of pollutants from soil, and promote bioremediation of organics by increasing bioavailability of pollutants. The removal of heavy metals and radionuclides from soils involves the mechanisms of dissolution, surfactant-associated complexation, and ionic exchange. In addition to the conventional ionic and nonionic surfactants, gemini surfactants and biosurfactants are also applied to soil remediation due to their benign features like lower critical micelle concentration (CMC) values and better biocompatibility. Mixed surfactant systems and combined use of surfactants with other additives are often adopted to improve the overall performance of soil washing solution for decontamination. Worldwide the field studies and full-scale remediation using surfactant-based technologies are yet limited, however, the already known cases reveal the good prospect of applying surfactant-based technologies to soil remediation.

  20. Self-Assembly of Nanoparticle Surfactants (United States)

    Lombardo, Michael T.

    Self-assembly utilizes non-covalent forces to organize smaller building blocks into larger, organized structures. Nanoparticles are one type of building block and have gained interest recently due to their unique optical and electrical properties which have proved useful in fields such as energy, catalysis, and advanced materials. There are several techniques currently used to self-assemble nanoparticles, each with its own set of benefits and drawbacks. Here, we address the limited number of techniques in non-polar solvents by introducing a method utilizing amphiphilic gold nanoparticles. Grafted polymer chains provide steric stabilization while small hydrophilic molecules induce assembly through short range attractive forces. The properties of these self-assembled structures are found to be dependent on the polymer and small molecules surface concentrations and chemistries. These particles act as nanoparticle surfactants and can effectively stabilize oil-water interfaces, such as in an emulsion. In addition to the work in organic solvent, similar amphiphilic particles in aqueous media are shown to effectively stabilize oil-in-water emulsions that show promise as photoacoustic/ultrasound theranostic agents.

  1. Alkyl-imidazolium glycosides: non-ionic-cationic hybrid surfactants from renewable resources. (United States)

    Salman, Abbas Abdulameer; Tabandeh, Mojtaba; Heidelberg, Thorsten; Hussen, Rusnah Syahila Duali; Ali, Hapipah Mohd


    A series of surfactants combining carbohydrate and imidazolium head groups were prepared and investigated on their assembly behavior. The presence of the imidazolium group dominated the interactions of the surfactants, leading to high CMCs and large molecular surface areas, reflected in curved rather than lamellar surfactant assemblies. The carbohydrate, on the other hand, stabilized molecular assemblies slightly and reduced the surface tension of surfactant solutions considerably. A comparative emulsion study discourages the use of pure alkyl imidazolium glycosides owing to reduced assembly stabilities compared with APGs. However, the surfactants are believed to have potential as component in carbohydrate based surfactant mixtures. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Surfactant and temperature effects on paraben transport through silicone membranes. (United States)

    Waters, Laura J; Dennis, Laura; Bibi, Aisha; Mitchell, John C


    This study investigates the effects of two surfactants (one anionic and one non-ionic) and controlled modifications in temperature (298-323K) on the permeation of two structurally similar compounds through a silicone membrane using a Franz diffusion cell system. In all cases the presence of an anionic surfactant, namely sodium dodecyl sulphate (SDS), reduced the permeation of both compounds (methylparaben and ethylparaben) over a period of 24h. The degree of permeation reduction was proportional to the concentration of surfactant with a maximum effect observed, with an average reduction of approximately 50%, at the highest surfactant concentration of 20mM. Differences were seen around the critical micelle concentration (CMC) of SDS implying the effect was partially connected with the favoured formation of micelles. In contrast, the presence of non-ionic surfactant (Brij 35) had no effect on the permeation of methylparaben or ethylparaben at any of the concentrations investigated, both above and below the CMC of the surfactant. From these findings the authors conclude that the specific effects of SDS are a consequence of ionic surfactant-silicone interactions retarding the movement of paraben through the membrane through indirect modifications to the surface of the membrane. As expected, an increase in experimental temperature appeared to enhance the permeation of both model compounds, a finding that is in agreement with previously reported data. Interestingly, in the majority of cases this effect was optimum at the second highest temperature studied (45°C) which suggests that permeation is a temperature-dependent phenomenon. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Cell-specific modulation of surfactant proteins by ambroxol treatment. (United States)

    Seifart, Carola; Clostermann, Ursula; Seifart, Ulf; Müller, Bernd; Vogelmeier, Claus; von Wichert, Peter; Fehrenbach, Heinz


    Ambroxol [trans-4-(2-amino-3,5-dibromobenzylamino)-cyclohexanole hydrochloride], a mucolytic agent, was postulated to provide surfactant stimulatory properties and was previously used to prevent surfactant deficiency. Currently, the underlying mechanisms are not exactly clear. Because surfactant homeostasis is regulated by surfactant-specific proteins (SP), we analyzed protein amount and mRNA expression in whole lung tissue, isolated type II pneumocytes and bronchoalveolar lavage of Sprague-Dawley rats treated with ambroxol i.p. (75 mg/kg body weight, twice a day [every 12 h]). The methods used included competitive polymerase chain reaction (RT-PCR), Northern blotting, Western immunoblotting, and immunohistochemistry. In isolated type II pneumocytes of ambroxol-treated animals, SP-C protein and mRNA content were increased, whereas SP-A, -B and -D protein, mRNA, and immunoreactivity remained unaffected. However, ambroxol treatment resulted in a significant increase of SP-B and in a decrease of SP-D in whole lung tissue with enhanced immunostaining for SP-B in Clara Cells. SP-A and SP-D were significantly decreased in BAL fluid of ambroxol-treated animals. The data suggest that surfactant protein expression is modulated in a cell-specific manner by ambroxol, as type II pneumocytes exhibited an increase in SP-C, whereas Clara cells exhibited an increase in the immunoreactivity for SP-B accounting for the increased SP-B content of whole lung tissue. The results indicate that ambroxol may exert its positive effects, observed in the treatment of diseases related to surfactant deficiency, via modulation of surfactant protein expression.

  4. Simulating pH titration of a single surfactant in ionic and nonionic surfactant micelles. (United States)

    Morrow, Brian H; Wang, Yuhang; Wallace, Jason A; Koenig, Peter H; Shen, Jana K


    Calculation of surfactant pK(a)'s in micelles is a challenging task using traditional electrostatic methods due to the lack of structural data and information regarding the effective dielectric constant. Here we test the implicit- and hybrid-solvent-based continuous constant pH molecular dynamics (CpHMD) methods for predicting the pK(a) shift of a lauric acid solubilized in three micelles: dodecyl sulfate (DS), dodecyltrimethylammonium (DTA), and dodecyltriethylene glycol ether (DE3). Both types of simulations are able to reproduce the observed positive pK(a) shifts for the anionic DS and nonionic DE3 micelles. However, for the cationic DTA micelle, the implicit-solvent simulation fails to predict the direction of the pK(a) shift, while the hybrid-solvent simulation, where conformational sampling is conducted in explicit solvent, is consistent with experiment, although the specific-ion effects remain to be accurately determined. Comparison between the implicit- and hybrid-solvent data shows that the latter gives a more realistic description of the conformational environment of the titrating probe. Surprisingly, in the DTA micelle, surfactants are only slightly attracted to the laurate ion, which diminishes the magnitude of the electrostatic stabilization, resulting in a positive pK(a) shift that cannot be explained by chemical intuition or other theoretical models. Our data underscores the importance of microscopic models and ionization-coupled conformational dynamics in quantitative prediction of the pK(a) shifts in micelles.

  5. Effect of surfactant counterion and organic modifier on the properties of surfactant vesicles in electrokinetic chromatography. (United States)

    Schuster, Stephanie A; Foley, Joe P


    Counterion and organic modifier are two parameters in EKC that can be varied in order to obtain improved solubility, selectivity, and efficiency. The effect of changing surfactant counterion and/or organic modifier on the chromatographic and electrophoretic properties of cetyltrimethylammonium bromide (CTAB)/sodium octyl sulfate (SOS) vesicles is examined in EKC. The vesicles are prepared in a 1:3.66 cationic/ anionic mole ratio for a total surfactant concentration of 69 mM. The cationic CTAB is replaced by cetyltrimethylammonium chloride (CTAC) and the first use of CTAC/SOS vesicles is reported. The mean diameter of the CTAC/SOS vesicles is 96 nm while that of the CTAB/SOS vesicles is 85 nm. A class I modifier (2-amino-1-butanol) and a class II modifier (acetonitrile) have similar effects on the EOF, elution range, methylene selectivity, and the efficiency of the CTAB/SOS vesicles and the CTAC/SOS vesicles. Upon addition of 10% ACN, there is roughly a 10-fold increase in the efficiency of heptanophenone, a model hydrophobic compound, compared to the efficiency using unmodified vesicles. Linear free energy relationship (LFER) analysis using the Abraham solvation model is employed to characterize solute-vesicle interactions. The results suggest that organic modifier-vesicle interactions depend somewhat on the counterion.

  6. Evolution of surfactant therapy for respiratory distress syndrome: past, present, and future. (United States)

    Sardesai, Smeeta; Biniwale, Manoj; Wertheimer, Fiona; Garingo, Arlene; Ramanathan, Rangasamy


    Respiratory distress syndrome (RDS) due to surfactant deficiency is the most common cause of respiratory failure in preterm infants. Tremendous progress has been made since the original description that surfactant deficiency is the major cause of RDS. Surfactant therapy has been extensively studied in preterm infants and has been shown to significantly decrease air leaks and neonatal and infant mortality. Synthetic and animal-derived surfactants from bovine as well as porcine origin have been evaluated in randomized controlled trials. Animal-derived surfactants generally result in faster weaning of respiratory support, shorter duration of invasive ventilation, and decreased mortality when compared to first- or second-generation of synthetic surfactants, but some of the second-generation synthetic surfactants are at least not inferior to the animal-derived surfactants. Using a higher initial dose of porcine derived surfactant may provide better outcomes when compared with using lower doses of bovine surfactants, likely, due to compositional difference and/or the dose. Third-generation synthetic surfactant containing peptide analogs of surfactant protein B and C are currently being studied. Less invasive intra-tracheal surfactant administration techniques in spontaneously breathing neonate receiving noninvasive ventilator support are also being evaluated. In the present era, prophylactic surfactant is not recommended as it may increase the risk of lung injury or death. In the future, surfactants may be used as vector to deliver steroids, or used in combination with molecules, such as, recombinant Club Cell Protein-10 (rhCC-10) to improve pulmonary outcomes. Also, noninvasive surfactant administration techniques, such as aerosolization or atomization of surfactant may play a greater role in the future.

  7. Surfactant uptake dynamics in mammalian cells elucidated with quantitative coherent anti-stokes Raman scattering microspectroscopy.

    Directory of Open Access Journals (Sweden)

    Masanari Okuno

    Full Text Available The mechanism of surfactant-induced cell lysis has been studied with quantitative coherent anti-Stokes Raman scattering (CARS microspectroscopy. The dynamics of surfactant molecules as well as intracellular biomolecules in living Chinese Hamster Lung (CHL cells has been examined for a low surfactant concentration (0.01 w%. By using an isotope labeled surfactant having CD bonds, surfactant uptake dynamics in living cells has been traced in detail. The simultaneous CARS imaging of the cell itself and the internalized surfactant has shown that the surfactant molecules is first accumulated inside a CHL cell followed by a sudden leak of cytosolic components such as proteins to the outside of the cell. This finding indicates that surfactant uptake occurs prior to the cell lysis, contrary to what has been believed: surface adsorption of surfactant molecules has been thought to occur first with subsequent disruption of cell membranes. Quantitative CARS microspectroscopy enables us to determine the molecular concentration of the surfactant molecules accumulated in a cell. We have also investigated the effect of a drug, nocodazole, on the surfactant uptake dynamics. As a result of the inhibition of tubulin polymerization by nocodazole, the surfactant uptake rate is significantly lowered. This fact suggests that intracellular membrane trafficking contributes to the surfactant uptake mechanism.

  8. Numerical approach for enhanced oil recovery with surfactant flooding

    Directory of Open Access Journals (Sweden)

    Sadegh Keshtkar


    Full Text Available The remained oil in the reservoir after conventional water-flooding processes, forms a dispersed phase in the form of oil drops which is trapped by capillary forces and is almost about 70% of the original oil in the place (OOIP. To reduce oil residual saturation in laboratory experiments and field projects, surfactant flooding is effective via decreasing the interfacial tension mobility ratio between oil and water phases. Estimation of the role of design variables, like chemical concentrations, partition coefficient and injection rate in different performance quantities, considering a heterogeneous and multiphase oil reservoir is a critical stage for optimal design. Increasing demand for oil production from water-flooded reservoirs has caused an increasing interest in surfactant-polymer (SP and alkali-surfactant-polymer (ASP. Modeling minimizes the risk of high cost of chemicals by improving our insight of process. In the present paper, a surfactant compositional flood model for a three-component (water, petroleum and surfactant, two phase (aqueous and oleic system is studied. A homogeneous, two-dimensional, isothermal reservoir with no free gas or alkali is assumed. The governing equations are in three categories: the continuity equations for the transport of each component, Darcy's equation for the transport of each phase and other auxiliary equations. The equations are solved by finite-differences using a procedure implicit in pressure and explicit in saturation. The validation of the model is achieved through comparing the modeling results with CMG simulators and Buckley–Leverett theory. The results of modeling showed good agreement with CMG results, and the comparison with Buckley–Leverett theory is explained according to different assumptions. After validation of the model, in order to investigate sensitivity analysis, the effects of system variables (partition coefficient, surface tension, oil viscosity and surface injection

  9. Ecotoxicological characterization of polyoxyethylene glycerol ester non-ionic surfactants and their mixtures with anionic and non-ionic surfactants. (United States)

    Ríos, Francisco; Fernández-Arteaga, Alejandro; Lechuga, Manuela; Fernández-Serrano, Mercedes


    This paper reports on a study that investigated the aquatic toxicity of new non-ionic surfactants derived from renewable raw materials, polyoxyethylene glycerol ester (PGE), and their binary mixtures with anionic and non-ionic surfactants. Toxicity of pure PGEs was determined using representative organisms from different trophic levels: luminescent bacteria (Vibrio fischeri), microalgae (Pseudokirchneriella subcapitata), and freshwater crustaceans (Daphnia magna). Relationships between toxicity and the structural parameters such as unit of ethylene oxide (EO) and hydrophilic-lipophilic balance (HLB) were evaluated. Critical micellar concentration (CMC) in the conditions of the toxicity test was also determined. It was found that the toxicity of the aqueous solutions of PGE decreased when the number of EO units in the molecule, HLB, and CMC increased. PGEs showed lower CMC in marine medium, and the toxicity to V. ficheri is lower when the CMC was higher. Given their non-polar nature, narcosis was expected to be the primary mode of toxic action of PGEs. For the mixture of surfactants, we observed that the mixtures with PGE that had the higher numbers of EO units were more toxic than the aqueous solutions of pure surfactants. Moreover, we found that concentration addition was the type of action more likely to occur for mixtures of PGE with lower numbers of EO units with non-ionic surfactants (alkylpolyglucoside and fatty alcohol ethoxylate), whereas for the mixture of PGE with lower EO units and anionic surfactant (ether carboxylic derivative), the most common response type was response addition. In case of mixtures involving amphoteric surfactants and PGEs with the higher numbers of EO units, no clear pattern with regard to the mixture toxicity response type could be observed.

  10. The unusual symmetric reopening effect induced by pulmonary surfactant. (United States)

    Yamaguchi, Eiichiro; Giannetti, Matthew J; Van Houten, Matthew J; Forouzan, Omid; Shevkoplyas, Sergey S; Gaver, Donald P


    This study investigates the stability of a finger of air as it propagates into a liquid-filled model of a liquid-filled model of a pulmonary bifurcation. We seek to elucidate the stability characteristics of the reopening of daughter airways, an event that may be important to the treatment of acute lung disease. To do so, we investigated the symmetry of reopening under conditions of nearly constant surface tension with 1) purified H2O or 2) an anionic surfactant (sodium dodecyl sulfate). Dynamic surface tension was investigated using pulmonary surfactant (Infasurf) with and without the presence of albumin. Flow visualization was accomplished using a microparticle image velocimetry (μ-PIV)/shadowgraph system through which we measured 1) the propagation velocity of the finger of air that reopens each daughter branch, and 2) the instantaneous and averaged velocity field of liquid phase surrounding the tip of the propagating bubble. Only pulmonary surfactant demonstrated the ability of maintaining a nearly symmetric propagation in the daughter channels, which is likely to lead to homogeneous airway reopening. In contrast, when pulmonary surfactant was inactivated by albumin or when the system was held at a nearly constant surface tension, reopening occurred asymmetrically. Our analysis suggests that Infasurf's dynamic surface tension qualities are important to stabilize the removal of liquid obstructions. This demonstrates a new important function of pulmonary surfactant for airway reopening of a multibranched network.

  11. Modification of shape oscillations of an attached bubble by surfactants

    Directory of Open Access Journals (Sweden)

    Tihon J.


    Full Text Available Surface-active agents (surfactants, e.g. washing agents strongly modifies properties of gas-liquid interface. We have carried out extensive experiments, in which we study effect of surfactants on the shape oscillations of a bubble, which is attached at a tip of a capillary. In the experiments, shape oscillations of a bubble are invoked by a motion of a capillary, to which the bubble is injected. Decaying oscillations are recorded and their frequency and damping are evaluated. By changing the excitation frequency, three lowest oscillation modes are studied. Experiments were repeated in aqueous solution of several surfactants (terpineol, SDS, CTAB, Triton X-100, Triton X-45 at various concentrations. Generally, these features are observed: Initially a surfactant addition leads to an increase of the oscillation frequency (though surface tension is decreasing; this effect can be attributed to the increasing interfacial elasticity. The decay time of oscillation is strongly decreasing, as a consequence of energy dissipation linked with Marangoni stresses. At a certain critical concentration, frequency decreases abruptly and the decay time passes by a minimum. With further addition of surfactant, frequency decreases, and the decay time slightly lengthens. Above critical micelle concentration, all these parameters stabilize. Interestingly, the critical concentration, at which frequency drop occurs, depends on mode order. This clearly shows that the frequency drop and minimum decay time are not a consequence of some abrupt change of interfacial properties, but are a consequence of some phenomena, which still need to be explained.

  12. Early Use of Surfactant-BL after Lung Transplantation

    Directory of Open Access Journals (Sweden)

    M. Sh. Khubutia


    Full Text Available Goal. To evaluate the clinical effect of early administration of surfactant-BL on pulmonary oxygenizing function and biomechanics in patients early after lung transplantation (LT. Materials and methods. Seven patients early after transplantation were administered with a surfactant-BL («Biosurf», St.-Petersburg, RF to prevent or treat primary lung transplant disfunction. Results and conclusions. Multiple endobronchial administration of surfactant-BL (0, 24, and 48 hours resulted in a progressive increase in the ratio of arterial oxygen partial pressure by an average of 94 mm Hg (p<0.05 to oxygen fraction in a respiratory mixture ( РаО2^Ю2 at 48 hours after the surgery and by an average 1.2-fold increase in dynamic thoracopulmonary compliance accompanied by a reduction in the magnitude of PLGD. Employed protocol of surfactant-BL administration was favorable for optimizing the biomechanical properties and oxygenizing function of the lung. The findings clearly demonstrate that the early administration of surfactant-BL after LT should benefit the comprehensive prevention and treatment of PLGD that complicates the early postoperative period after LT.

  13. Dynamics of Surfactant Liquid Plugs at Bifurcating Lung Airway Models (United States)

    Tavana, Hossein


    A surfactant liquid plug forms in the trachea during surfactant replacement therapy (SRT) of premature babies. Under air pressure, the plug propagates downstream and continuously divides into smaller daughter plugs at continuously branching lung airways. Propagating plugs deposit a thin film on airway walls to reduce surface tension and facilitate breathing. The effectiveness of SRT greatly depends on the final distribution of instilled surfactant within airways. To understand this process, we investigate dynamics of splitting of surfactant plugs in engineered bifurcating airway models. A liquid plug is instilled in the parent tube to propagate and split at the bifurcation. A split ratio, R, is defined as the ratio of daughter plug lengths in the top and bottom daughter airway tubes and studied as a function of the 3D orientation of airways and different flow conditions. For a given Capillary number (Ca), orienting airways farther away from a horizontal position reduced R due to the flow of a larger volume into the gravitationally favored daughter airway. At each orientation, R increased with 0.0005 < Ca < 0.05. This effect diminished by decrease in airways diameter. This approach will help elucidate surfactant distribution in airways and develop effective SRT strategies.

  14. Controlling block copolymer phase behavior using ionic surfactant

    Energy Technology Data Exchange (ETDEWEB)

    Ray, D.; Aswal, V. K. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085, India E-mail: (India)


    The phase behavior of poly(ethylene oxide)-poly(propylene oxide-poly(ethylene oxide) PEO-PPO-PEO triblock copolymer [P85 (EO{sub 26}PO{sub 39}EO{sub 26})] in presence of anionic surfactant sodium dodecyl sulfate (SDS) in aqueous solution as a function of temperature has been studied using dynamic light scattering (DLS) and small-angle neutron scattering (SANS). The measurements have been carried out for fixed concentrations (1 wt%) of block copolymer and surfactants. Each of the individual components (block copolymer and surfactant) and the nanoparticle–surfactant mixed system have been examined at varying temperature. The block copolymer P85 forms spherical micelles at room temperature whereas shows sphere-to-rod like micelle transition at higher temperatures. On the other hand, SDS surfactant forms ellipsoidal micelles over a wide temperature range. Interestingly, it is found that phase behavior of mixed micellar system (P85 + SDS) as a function of temperature is drastically different from that of P85, giving the control over the temperature-dependent phase behavior of block copolymers.

  15. Spatiotemporal measurement of surfactant distribution on gravity-capillary waves

    CERN Document Server

    Strickland, Stephen L; Daniels, Karen E


    Materials adsorbed to the surface of a fluid -- for instance, crude oil, biogenic slicks, or industrial/medical surfactants -- will move in response to surface waves. Due to the difficulty of non-invasive measurement of the spatial distribution of a molecular monolayer, little is known about the dynamics that couple the surface waves and the evolving density field. Here, we report measurements of the spatiotemporal dynamics of the density field of an insoluble surfactant driven by gravity-capillary waves in a shallow cylindrical container. Standing Faraday waves and traveling waves generated by the meniscus are superimposed to create a non-trivial surfactant density field. We measure both the height field of the surface using moir\\'e-imaging, and the density field of the surfactant via the fluorescence of NBD-tagged phosphatidylcholine, a lipid. Through phase-averaging stroboscopically-acquired images of the density field, we determine that the surfactant accumulates on the leading edge of the traveling menis...

  16. Polydiacetylene sensor interaction with food sanitizers and surfactants. (United States)

    Zhang, Yueyuan; Northcutt, Julie; Hanks, Tim; Miller, Ian; Pennington, Bill; Jelinek, Raz; Han, Inyee; Dawson, Paul


    Polydiacetylene (PDA) vesicles are of interest as biosensors, particularly for pathogenic bacteria. As part of a food monitoring system, interaction with food sanitizers/surfactants was investigated. PDA vesicles were prepared by inkjet-printing, photopolymerized and characterized by dynamic light scattering (DLS) and UV/Vis spectroscopy. The optical response of PDA vesicles at various concentrations verses a fixed sanitizer/surfactant concentration was determined using a two variable factorial design. Sanitizer/surfactant response at various concentrations over time was also measured. Results indicated that only Vigilquat and TritonX-100 interacted with PDA vesicles giving visible colour change out of 8 sanitizers/surfactants tested. PDA vesicle concentration, sanitizer/surfactant concentration, and time all had a significant (P<0.0001) effect on colour change. As they are highly sensitive to the presence of Vigilquat and TritonX-100, PDA sensors could be used to detect chemical residues as well as for detection of various contaminants in the food industry. Copyright © 2016. Published by Elsevier Ltd.

  17. Preparation and evaluation of some amide ether carboxylate surfactants

    Directory of Open Access Journals (Sweden)

    M.M.A. El-Sukkary


    Full Text Available A homologous series of new mild surfactants, namely: Alkyl amide ether carboxylates surfactants (AEC RCO–NHCH2CH2O (CH2CH2O6CH2COONa, were synthesized by esterification, amidation, ethoxylation and carboxymethylation reaction steps of fatty acids (Lauric, Myristic, palmitic, stearic, oleic or linoleic. The chemical structures of the prepared compounds were confirmed using different spectroscopic techniques, FTIR spectroscopy, mass spectra and HNMR. The surface properties including surface and interfacial tensions, foaming height, emulsification power, calcium ion stability, stability to hydrolysis and critical micelle concentration (cmc were determined. The study of their surface properties showed their stability in hard water and in acidic and alkaline media. These compounds have high calcium ion stability. The low foaming power could have an application in the dyeing auxiliary industry. The lower values of the interfacial tension values indicate the ability of using these surfactants in several applications as corrosion inhibitors and biocides. The data revealed various advantages and potentials as a main surfactant as well as co- surfactants.

  18. Surfactant selection for the remediation of solvent-contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Herrin, J. [Radian Corp., Salt Lake City, UT (United States); Schrab, G.; Dulaney, W. [Radian Corp., Austin, TX (United States); Kirchner, K. [Air Force, Hill AFB, UT (United States)


    Soil surfactant flushing is being considered for the remediation of contaminated soil at a Superfund Site at Hill Air Force Base (Hill AFB), Utah. Contamination at the site includes two pools of dense nonaqueous-phase liquid (DNAPL) near the location of previous disposal trenches. The DNAPL consists primarily of trichloroethene (TCE), with lesser amounts of other chlorinated solvents and oil and grease. The highly contaminated soils currently saturated with DNAPL are the most appropriate medium for the soil flushing technique. After extraction of the existing, mobile DNAPL, surfactants can be used to enhance the removal of residual contamination from the soils. A treatability study was conducted to evaluate the effectiveness of several types and concentrations of surfactants in enhancing the removal of TCE and other DNAPL contaminants from soil samples collected at the site, The laboratory studies included screening the selected surfactants for their effectiveness in solubilizing DNAPL. Batch tests were then conducted with the most effective surfactants to evaluate their ability to remove (through solubilization and mobilization) DNAPL constituents from the contaminated soils.

  19. Flow improvers for water injection based on surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Oskarsson, H.; Uneback, I.; Hellsten, M.


    In many cases it is desirable to increase the flow of injection water when an oil well deteriorates. It is very costly in offshore operation to lay down an additional water pipe to the injection site. Flow improvers for the injection water will thus be the most cost-effective way to increase the flow rate. During the last years water-soluble polymers have also been applied for this purpose. These drag-reducing polymers are however only slowly biodegraded which has been an incentive for the development of readily biodegradable surfactants as flow improvers for injection water. A combination of a zwitterionic and an anionic surfactant has been tested in a 5.5 inch, 700 m long flow loop containing sulphate brine with salinity similar to sea water. A drag reduction between 75 and 80% was achieved with 119 ppm in solution of the surfactant blend at an average velocity of 1.9 m/s and between 50 and 55% at 2.9 m/s. The surfactants in this formulation were also found to be readily biodegradable in sea water and low bio accumulating which means they have an improved environmental profile compared to the polymers used today. Due to the self-healing properties of the drag-reducing structures formed by surfactants, these may be added before the pump section - contrary to polymers which are permanently destroyed by high shear forces. (Author)

  20. [Adsorption of phenol chemicals by surfactant-modified zeolites]. (United States)

    Xie, Jie; Wang, Zhe; Wu, De-Yi; Li, Chun-Jie


    Two kinds of zeolites were prepared from fly ash and modified by surfactant subsequently. Surfactant-modified zeolites were studied for adsorption of phenol chemicals (phenol, p-chlorphenol, bisphenol A). It showed that the adsorption affinity of zeolite to phenol chemicals was significantly improved after surfactant modification. The adsorption isotherms of phenol chemicals were well fitted by the Langmuir isotherm. For the two surfactant-surfactant modified zeolites, the maximum adsorption amounts of phenol, p-chlorphenol, and bisphenol A calculated from the Langmuir equation were 37.7, 52.36, 90.9 mg x g(-1) and 10.7, 22.83, 56.8 mg x g(-1), respectively. When pH values of solutions were higher than the pK(a) values of phenol chemicals, the removal efficiencies were getting higher with the increase of pH values. The octanol/water partition coefficient (K(ow)) was also found to be an important factor affecting adsorption of phenol chemicals by the modified zeolites. Higher K(ow) value, which means the greater hydrophobicity of the chemicals, resulted in a higher removal.

  1. Critical Role of Arg/Lys343 in the Species-Dependent Recognition of Phosphatidylinositol by Plumonary Surfactant Protein D

    Energy Technology Data Exchange (ETDEWEB)

    Crouch,E.; McDonald, B.; Smith, K.; Roberts, M.; Mealy, T.; Seaton, B.; Head, J.


    Surfactant protein D (SP-D) plays important roles in lung host defense. However, it can also recognize specific host molecules and contributes to surfactant homeostasis. The major known surfactant-associated ligand is phosphatidylinositol (PI). Trimeric neck-carbohydrate recognition domains (NCRDs) of rat and human SP-D exhibited dose-dependent, calcium-dependent, and inositol-sensitive binding to solid-phase PI and to multilamellar PI liposomes. However, the rat protein exhibited a >5-fold higher affinity for solid-phase PI than the human NCRD. In addition, human dodecamers, but not full-length human trimers, efficiently coprecipitated with multilamellar PI liposomes in the presence of calcium. A human NCRD mutant resembling the rat and mouse proteins at position 343 (hR343K) showed much stronger binding to PI. A reciprocal rat mutant with arginine at the position of lysine 343 (rK343R) showed weak binding to PI, even weaker than that of the wild-type human protein. Crystal complexes of the human trimeric NCRD with myoinositol and inositol 1-phosphate showed binding of the equatorial OH groups of the cyclitol ring of the inositol to calcium at the carbohydrate binding site. Myoinositol binding occurred in two major orientations, while inositol 1-phosphate appeared primarily constrained to a single, different orientation. Our studies directly implicate the CRD in PI binding and reveal unexpected species differences in PI recognition that can be largely attributed to the side chain of residue 343. In addition, the studies indicate that oligomerization of trimeric subunits is an important determinant of recognition of PI by human SP-D.

  2. The melting of pulmonary surfactant monolayers. (United States)

    Yan, Wenfei; Biswas, Samares C; Laderas, Ted G; Hall, Stephen B


    Monomolecular films of phospholipids in the liquid-expanded (LE) phase after supercompression to high surface pressures (pi), well above the equilibrium surface pressure (pi(e)) at which fluid films collapse from the interface to form a three-dimensional bulk phase, and in the tilted-condensed (TC) phase both replicate the resistance to collapse that is characteristic of alveolar films in the lungs. To provide the basis for determining which film is present in the alveolus, we measured the melting characteristics of monolayers containing TC dipalmitoyl phosphatidylcholine (DPPC), as well as supercompressed 1-palmitoyl-2-oleoyl phosphatidylcholine and calf lung surfactant extract (CLSE). Films generated by appropriate manipulations on a captive bubble were heated from or =60 degrees C at different constant pi above pi(e). DPPC showed the abrupt expansion expected for the TC-LE phase transition, followed by the contraction produced by collapse. Supercompressed CLSE showed no evidence of the TC-LE expansion, arguing that supercompression did not simply convert the mixed lipid film to TC DPPC. For both DPPC and CLSE, the melting point, taken as the temperature at which collapse began, increased at higher pi, in contrast to 1-palmitoyl-2-oleoyl phosphatidylcholine, for which higher pi produced collapse at lower temperatures. For pi between 50 and 65 mN/m, DPPC melted at 48-55 degrees C, well above the main transition for bilayers at 41 degrees C. At each pi, CLSE melted at temperatures >10 degrees C lower. The distinct melting points for TC DPPC and supercompressed CLSE provide the basis by which the nature of the alveolar film might be determined from the temperature-dependence of pulmonary mechanics.

  3. Surfactant accumulation within the top foam layer due to rupture of external foam films. (United States)

    Dukhin, S S; Kovalchuk, V I; Aksenenko, E V; Miller, R


    The analysis of processes taking place in a steady pneumatic (dynamic) foam shows the possibility of different modes of surfactant accumulation within the top layers of bubbles due to rupture of external foam films. An increasing surfactant concentration within the top layers promotes the stabilisation of bubbles and the foam as a whole. Considering the balance of surfactant and water during the bursting of films it is possible to estimate the accumulated surfactant loss caused by a downwards flow through the Plateau borders of the subsurface bubble layer. This effect depends on the particular conditions, especially on the surfactant activity and concentration of the surfactant, water volume fraction in the foam and size of foam bubbles. The process of surfactant accumulation in the top foam bubble layer can be complicated due to the removal of part of the accumulated surfactant through transport with droplets spread out during bubble bursting.

  4. Inactivation of pulmonary surfactant due to serum-inhibited adsorption and reversal by hydrophilic polymers: experimental

    DEFF Research Database (Denmark)

    Taeusch, H William; de la Serna, Jorge Bernardino; Perez-Gil, Jesus


    increases in pi did not occur when surfactants were applied to subphases containing serum. Components of serum are surface active and adsorb reversibly to the interface increasing pi up to a concentration-dependent saturation value, pi(max). When surfactants were applied to subphases containing serum......The rate of change of surface pressure, pi, in a Langmuir trough following the deposition of surfactant suspensions on subphases containing serum, with or without polymers, is used to model a likely cause of surfactant inactivation in vivo: inhibition of surfactant adsorption due to competitive...... adsorption of surface active serum proteins. Aqueous suspensions of native porcine surfactant, organic extracts of native surfactant, and the clinical surfactants Curosurf, Infasurf, and Survanta spread on buffered subphases increase the surface pressure, pi, to approximately 40 mN/m within 2 min...

  5. Switchable Pickering emulsions stabilized by silica nanoparticles hydrophobized in situ with a conventional cationic surfactant. (United States)

    Zhu, Yue; Jiang, Jianzhong; Liu, Kaihong; Cui, Zhenggang; Binks, Bernard P


    A stable oil-in-water Pickering emulsion stabilized by negatively charged silica nanoparticles hydrophobized in situ with a trace amount of a conventional cationic surfactant can be rendered unstable on addition of an equimolar amount of an anionic surfactant. The emulsion can be subsequently restabilized by adding a similar trace amount of cationic surfactant along with rehomogenization. This destabilization-stabilization behavior can be cycled many times, demonstrating that the Pickering emulsion is switchable. The trigger is the stronger electrostatic interaction between the oppositely charged ionic surfactants compared with that between the cationic surfactant and the (initially) negatively charged particle surfaces. The cationic surfactant prefers to form ion pairs with the added anionic surfactant and thus desorbs from particle surfaces rendering them surface-inactive. This access to switchable Pickering emulsions is easier than those employing switchable surfactants, polymers, or surface-active particles, avoiding both the complicated synthesis and the stringent switching conditions.

  6. Surfactant phosphatidylcholine half-life and pool size measurements in premature baboons developing bronchopulmonary dysplasia

    NARCIS (Netherlands)

    D.J. Janssen; V.P. Carnielli (Virgilio); P.E. Cogo (Paola); S.R. Seidner; I.H.I. Luijendijk; J.L.D. Wattimena (Josias); A.H. Jobe (Alan); L.J.I. Zimmermann (Luc)


    textabstractBecause minimal information is available about surfactant metabolism in bronchopulmonary dysplasia, we measured half-lives and pool sizes of surfactant phosphatidylcholine in very preterm baboons recovering from respiratory distress syndrome and developing

  7. Phase behavior and oil recovery investigations using mixed and alkaline-enhanced surfactant systems

    Energy Technology Data Exchange (ETDEWEB)

    Llave, F.M.; Gall, B.L.; French, T.R.; Noll, L.A.; Munden, S.A.


    The results of an evaluation of different mixed surfactant and alkaline-enhanced surfactant systems for enhanced oil recovery are described. Several mixed surfactant systems have been studies to evaluate their oil recovery potential as well as improved adaptability to different ranges of salinity, divalent ion concentrations, and temperature. Several combinations of screening methods were used to help identify potential chemical formulations and determine conditions where particular chemical systems can be applied. The effects of different parameters on the behavior of the overall surfactant system were also studied. Several commercially available surfactants were tested as primary components in the mixtures used in the study. These surfactants were formulated with different secondary as well as tertiary components, including ethoxylated and non-ethoxylated sulfonates and sulfates. Improved salinity and hardness tolerance was achieved for some of these chemical systems. The salinity tolerance of these systems were found to be dependent on the molecular weight, surfactant type, and concentration of the surfactant components.

  8. Effects of anthropogenic surfactants on the conversion of marine dissolved organic carbon and microgels. (United States)

    Shiu, Ruei-Feng; Lee, Chon-Lin


    The possible impact of three types of anthropogenic surfactants on the ability of marine dissolved organic carbon (DOC) to form self-assembled microgels was evaluated. The behavior of existing native microgels was also examined in the presence of surfactants. These results reveal that the release of surfactants even at low concentrations into the aquatic environment could effectively hinder the self-assembly of DOC polymers. The extent of the size reduction had the following order: anionic, cationic, and non-ionic. Furthermore, charged surfactants can disrupt existing native microgels, converting large assemblies into smaller particles. One possible mechanisms is that surfactants are able to enhance the stability of DOC polymers and disrupt aggregates due to their surface charges and protein-denaturing activities. These findings suggest that the ecological system is altered by anthropogenic surfactants, and provide useful information for ecological assessments of different types of surfactants and raise warnings about surfactant applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Surfactant treatment before reperfusion improves the immediate function of lung transplants in rats

    NARCIS (Netherlands)

    Erasmus, ME; Petersen, AH; Hofstede, G; Haagsman, HP; Oetomo, SB; Prop, J

    An impaired function of alveolar surfactant can cause lung transplant dysfunction early after reperfusion. In this study it was investigated whether treatment with surfactant before reperfusion improves the immediate function of lung transplants and whether an improved transplant function was

  10. Treatment of acute respiratory distress syndrome in secondary surfactant deficiency in neonates

    Directory of Open Access Journals (Sweden)

    Heru Samudro


    Full Text Available In this report we present data of three premature infants who received 1 to 2 doses of surfactant for an acute respiratory deterioration and after initial surfactants treatment for RDS.

  11. Surfactant treatment in premature infants with Respiratory Distress Syndrome in Curacao

    NARCIS (Netherlands)

    Verhagen, AAE; Keli, SO; van der Meulen, GN; Wiersma, H; Arias, M; Angelista, IR; Muskiet, FD

    Surfactant replacement therapy for Respiratory Distress Syndrome (RDS) in premature neonates has been established as an effective treatment, although significant mortality and morbidity remain. In Curacao, surfactant became available as a therapeutic option in 1994. A retrospective cohort study was

  12. Surfactant/detergent titration analysis method and apparatus for machine working fluids, surfactant-containing wastewater and the like (United States)

    Smith, D.D.; Hiller, J.M.


    The present invention is an improved method and related apparatus for quantitatively analyzing machine working fluids and other aqueous compositions such as wastewater which contain various mixtures of cationic, neutral, and/or anionic surfactants, soluble soaps, and the like. The method utilizes a single-phase, non-aqueous, reactive titration composition containing water insoluble bismuth nitrate dissolved in glycerol for the titration reactant. The chemical reaction of the bismuth ion and glycerol with the surfactant in the test solutions results in formation of micelles, changes in micelle size, and the formation of insoluble bismuth soaps. These soaps are quantified by physical and chemical changes in the aqueous test solution. Both classical potentiometric analysis and turbidity measurements have been used as sensing techniques to determine the quantity of surfactant present in test solutions. This method is amenable to the analysis of various types of new, in-use, dirty or decomposed surfactants and detergents. It is a quick and efficient method utilizing a single-phase reaction without needing a separate extraction from the aqueous solution. It is adaptable to automated control with simple and reliable sensing methods. The method is applicable to a variety of compositions with concentrations from about 1% to about 10% weight. It is also applicable to the analysis of waste water containing surfactants with appropriate pre-treatments for concentration. 1 fig.

  13. The toxicity of cationic surfactant HDTMA-Br, desorbed from surfactant modified zeolite, towards faecal indicator and environmental microorganisms. (United States)

    Reeve, Peter J; Fallowfield, Howard J


    Surfactant Modified Zeolite (SMZ) represents a versatile, cost-effective permeable reactive material, capable of treating multiple classes of contaminants. The potential for HDTMA-Br, a cationic surfactant commonly used to modify zeolite, to desorb from the zeolite surface has been identified as a potential issue for the ongoing use of SMZ in water remediation contexts. This paper investigates the toxicity of HDTMA-Br towards enteric virus surrogates, F-RNA bacteriophage MS2 and E. coli, Bacillus subtilis, and soil microflora. The concentration of surfactant desorbing from SMZ was quantified through a bioassay using E. coli. Results showed HDTMA-Br concentrations of ≥10-5M were toxic to MS2, ≥10-4M were toxic to E. coli and ≥10-6M were toxic to B. subtilis. No toxic relationship was established between HDTMA-Br and soil microflora. Desorption of ≥10-4M of HDTMA-Br was shown for the two SMZ samples under the mixing conditions used. Effects of this surfactant on total soil microflora were ambiguous since no toxic relationship could be established, however, HDTMA-Br, at concentrations desorbing from SMZ, were shown to impact the soil bacterium B. subtilis. Further research is required to determine the effect of this surfactant on microbial populations and species diversity in soils. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Poloxamer-Decorated Polymer Nanoparticles for Lung Surfactant Compatibility

    DEFF Research Database (Denmark)

    Beck-Broichsitter, Moritz; Bohr, Adam; Ruge, Christian A


    (styrene) and poly(lactide) nanoparticle-induced lung surfactant inhibition could be related to the type and content of the applied poloxamer. Escalations of the adsorbed coating layer thickness (>3 nm) as well as concentration (brush- rather than mushroom-like conformation of poly(ethylene glycol), chain......Lung-delivered polymer nanoparticles provoked dysfunction of the essential lung surfactant system. A steric shielding of the nanoparticle surface with poloxamers could minimize the unwanted interference of polymer nanoparticles with the biophysical function of lung surfactant. The extent of poly......-associated proteins. Poloxamer-modified polymer nanoparticles represent a promising nanomedicine platform intended for respiratory delivery revealing negligible effects on the biophysical functionality of the lining layer present in the deep lungs....

  15. Modification of Deeply Buried Hydrophobic Interfaces by Ionic Surfactants

    Energy Technology Data Exchange (ETDEWEB)

    L Tamam; D Pontoni Z Sapir; S Yefet; S Sloutskin; B Ocko; H Reichert; M Deutsch


    Hydrophobicity, the spontaneous segregation of oil and water, can be modified by surfactants. The way this modification occurs is studied at the oil-water interface for a range of alkanes and two ionic surfactants. A liquid interfacial monolayer, consisting of a mixture of alkane molecules and surfactant tails, is found. Upon cooling, it freezes at T{sub s}, well above the alkane's bulk freezing temperature, T{sub b}. The monolayer's phase diagram, derived by surface tensiometry, is accounted for by a mixtures-based theory. The monolayer's structure is measured by high-energy X-ray reflectivity above and below T{sub s}. A solid-solid transition in the frozen monolayer, occurring approximately 3 C below T{sub s}, is discovered and tentatively suggested to be a rotator-to-crystal transition.

  16. Growth Mechanism of Gold Nanorods in Binary Surfactant System

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bo-Mi; Seo, Sun-Hwa; Joe, Ara; Shim, Kyu-Dong; Jang, Eue-Soon [Kumoh National Institute of Technology, Gumi (Korea, Republic of)


    In order to reveal the growth mechanism of gold nanorods (GNRs) in a binary surfactant system, we synthesized various GNRs by changing the concentration of the surfactants, AgNO{sub 3}, and HBr in the growth solution. We found that the benzyldime thylhexadecylammoniumchloride surfactant had weak interaction with the gold ions, but it could reduce the membrane fluidity. In addition, we could dramatically decrease the cetyltrimethylammonium bromide concentration required for GNR growth by adding an HBr solution. Notably, Ag{sup +} ions were necessary to break the symmetry of the seed crystals for GNR growth, but increasing the concentration of Ag{sup +} and Br{sup -} ions caused a decrease in the template size.

  17. Mathematical Modelling of Surfactant Self-assembly at Interfaces

    KAUST Repository

    Morgan, C. E.


    © 2015 Society for Industrial and Applied Mathematics. We present a mathematical model to describe the distribution of surfactant pairs in a multilayer structure beneath an adsorbed monolayer. A mesoscopic model comprising a set of ordinary differential equations that couple the rearrangement of surfactant within the multilayer to the surface adsorption kinetics is first derived. This model is then extended to the macroscopic scale by taking the continuum limit that exploits the typically large number of surfactant layers, which results in a novel third-order partial differential equation. The model is generalized to allow for the presence of two adsorbing boundaries, which results in an implicit free-boundary problem. The system predicts physically observed features in multilayer systems such as the initial formation of smaller lamellar structures and the typical number of layers that form in equilibrium.

  18. Effect of dynamic surfactant adsorption on emulsion stability. (United States)

    Urbina-Villalba, German


    The effect of dynamic surfactant adsorption on the stability of concentrated oil in water emulsions is studied. For this purpose, a modification of the standard Brownian dynamics algorithm (Ermak, D.; McCammon, J. A. J. Chem. Phys. 1978, 69, 1352) previously used to study the behavior of bitumen emulsions assuming instantaneous adsorption (Urbina-Villalba, G.; García-Sucre, M. Langmuir 2000, 16, 7975) was employed. In the present case, dynamic adsorption (DA) was accounted for through a time-dependent electrostatic repulsion between the drops, a function of the surfactant surface excess. The surface excess was allowed to evolve with time according to well-established analytical expressions which depend parametrically on the surfactant diffusion constant (Ds) and the total surfactant concentration (C). The investigation required appropriate incorporation of hydrodynamic interactions in concentrated systems. This was achieved through a novel methodology, which expresses the diffusion constant of each particle as a function of its local concentration and the shortest distance of separation between nearest neighbors. In model systems, the variation of the number of drops as a function of time was followed for different magnitudes of the apparent diffusion constant D(app) of the surfactant. For each of these values, the effect of C and the volume fraction of internal phase (phi) was considered. DA was found to influence emulsion stability appreciably at moderately high phi. In this case, the average collision time between drops is comparable to the time required for the occurrence of a substantial surfactant adsorption, but the interdrop separation is sufficiently large to prevent a considerable slowdown of particle movement due to hydrodynamic interactions.

  19. Inhaled Surfactant Therapy in Newborns in Artificial Lung Ventilation

    Directory of Open Access Journals (Sweden)

    S. A. Perepelitsa


    Full Text Available Objective: to evaluate the efficiency of inhaled surfactant therapy in neonatal infants with respiratory failure.Subjects and methods. The trial enrolled 13 premature neonatal infants; their mean gestational age was 31.8±2.8 weeks and the birth weight was 1825±600.9 g. They had a oneminute Apgar score of 4.3±1.4. All the neonates needed mechanical ventilation (MV atbirth because the leading clinical sign was respiratory failure caused by acute intranatal hypoxia, neonatal amniotic fluid aspiration, respiratory distress syndrome (RDS, and cerebral ischemia. Curosurf was injected in a dose of 174.7±21 mg/kg in the infants with neonatal RDS at 35 minutes of life. All the babies included in the study were noted to have severe disease and prolonged MV. After stabilization of their status, the neonates received combination therapy involving surfactantBL inhalation to reduce the duration of MV. The dose of the agent was 75 mg. Results. After surfactantBL inhalation, effective spontaneous respiration occurred in 69.2% of the newborn infants; successful extubation was carried out. The median duration ofMV after surfactant BL inhalation was 22 hours (4—68 hours. There were no reintubated cases after inhalation therapy. Following surfactantBL inhalation, 4 (30.8% patients remained to be on MV as a control regimen; 3 of them had highfre quency MV. SurfactantBL inhalation made it possible to change the respiratory support regimen and to reduce MV parame ters in these babies. 

  20. Structure and Dynamics of Nonionic Surfactant Aggregates in Layered Materials. (United States)

    Guégan, Régis; Veron, Emmanuel; Le Forestier, Lydie; Ogawa, Makoto; Cadars, Sylvian


    The aggregation of surfactants on solid surfaces as they are adsorbed from solution is the basis of numerous technological applications such as colloidal stabilization, ore flotation, and floor cleaning. The understanding of both the structure and the dynamics of surfactant aggregates applies to the development of alternative ways of preparing hybrid layered materials. For this purpose, we study the adsorption of the triethylene glycol mono n-decyl ether (C10E3) nonionic surfactant onto a synthetic montmorillonite (Mt), an aluminosilicate clay mineral for organoclay preparation with important applications in materials sciences, catalysis, wastewater treatment, or as drug delivery. The aggregation mechanisms follow those observed in an analogous natural Mt, with the condensation of C10E3 in a bilayer arrangement once the surfactant self-assembles in a lamellar phase beyond the critical micelle concentration, underlining the importance of the surfactant state in solution. Solid-state 1H nuclear magnetic resonance (NMR) at fast magic-angle spinning (MAS) and high magnetic field combined with1H-13C correlation experiments and different types of 13C NMR experiments selectively probes mobile or rigid moieties of C10E3 in three different aggregate organizations: (i) a lateral monolayer, (ii) a lateral bilayer, and (iii) a normal bilayer. High-resolution 1H{27Al} CP-1H-1H spin diffusion experiments shed light on the proximities and dynamics of the different fragments and fractions of the intercalated surfactant molecules with respect to the Mt surface. 23Na and 1H NMR measurements combined with complementary NMR data, at both molecular and nanometer scales, precisely pointed out the location of the C10E3 ethylene oxide hydrophilic group in close contact with the Mt surface interacting through ion-dipole or van der Waals interactions.

  1. Surfactant protein A and surfactant protein D variation in pulmonary disease

    DEFF Research Database (Denmark)

    Sørensen, Grith Lykke; Husby, Steffen; Holmskov, Uffe


    molecules present on immune cells leading to enhanced microbial clearance and modulation of inflammation. SP-A and SP-D also modulate the functions of cells of the adaptive immune system including dendritic cells and T cells. Studies on SP-A and SP-D polymorphisms and protein levels in bronchoalveolar...... preferentially to sugars on a broad spectrum of pathogen surfaces and thereby facilitating immune functions including viral neutralization, clearance of bacteria, fungi and apoptotic and necrotic cells, modulation of allergic reactions, and resolution of inflammation. SP-A and SP-D can interact with receptor......Surfactant proteins A (SP-A) and D (SP-D) have been implicated in pulmonary innate immunity. The proteins are host defense lectins, belonging to the collectin family which also includes mannan-binding lectin (MBL). SP-A and SP-D are pattern-recognition molecules with the lectin domains binding...

  2. Interaction of diazepam with surfactants. Spectrophotometric and spectrofluorometric study (United States)

    De La Guardia, M.; Rodilla, F.


    The interaction of diazepam with non-ionic, anionic and cationic surfactants has been studied spectrophotometrically and fluorometrically. It has been verified that the absorption spectrum of diazepam is not modified in micellar medium. However, a dramatic five-fold increase in fluorescence sensitivity is observed in the presence of sodium lauryl sulphate (SDS). The experimental conditions, temperature, pH and surfactant concentration have been optimized to improve the fluorometric determination of diazepam and a detection limit of 0,04 ppmhas been obtained.

  3. Expeditious Synthesis of Dianionic-Headed 4-Sulfoalkanoic Acid Surfactants. (United States)

    Jiang, Jianghui; Xu, Jiaxi


    4-Sulfoalkanoic acids are a class of important dianionic-headed surfactants. Various 4-sulfoalkanoic acids with straight C8, C10, C12, C14, C16, and C18 chains were synthesized expeditiously through the radical addition of methyl 2-((ethoxycarbonothioyl)thio)acetate to linear terminal olefins and subsequent oxidation with peroxyformic acid. This is a useful and convenient strategy for the synthesis of dianionic-headed surfactants with a carboxylic acid and sulfonic acid functionalities in the head group region.

  4. Circulating surfactant protein D is decreased in early rheumatoid arthritis

    DEFF Research Database (Denmark)

    Høgh, Silje Vermedal; Lindegaard, Hanne Merete; Sørensen, Grith Lykke


    Innate immune system abnormalities, e.g., mannan-binding lectin (MBL) genotype variants, have been demonstrated to modify the disease course of rheumatoid arthritis (RA). Surfactant protein D (SP-D) shares important structural and functional properties with MBL suggesting that SP-D may be an addi......Innate immune system abnormalities, e.g., mannan-binding lectin (MBL) genotype variants, have been demonstrated to modify the disease course of rheumatoid arthritis (RA). Surfactant protein D (SP-D) shares important structural and functional properties with MBL suggesting that SP-D may...

  5. Lung Surfactant and Its Use in Lung Diseases

    Directory of Open Access Journals (Sweden)

    O. A. Rosenberg


    Full Text Available The review considers the present views of lung surfactant (LS functions with emphasis on its protective and barrier properties and ability to maintain local and adaptive immunity. The composition of commercial LS formulations is analyzed. Data on qualitative and quantitative LS abnormalities are presented in various diseases in neonates and adults. The results of clinical trials of different LS formulations in the treatment of acute respiratory distress syndrome in adults are analyzed in detail. Recent data on the results of and prospects for surfactant therapy for bronchial asthma, chronic obstructive pulmonary disease and pulmonary tuberculosis are given. 

  6. Effects of a surfactant (FFD-6) on Scenedesmus morphology and growth under different nutrient conditions

    NARCIS (Netherlands)

    Lürling, M.F.L.L.W.


    Surfactants are man-made compounds that are meanwhile omnipresent in the environment, but environmental concentrations of surfactants are such that they are thought to have little risk for aquatic systems. The major anionic surfactants currently on the global market are linear alkylbenzene

  7. Contrast media inhibit exogenous surfactant therapy in rats with acute respiratory distress syndrome

    NARCIS (Netherlands)

    Kesecioglu, Jozef; Haitsma, Jack J.; Schultz, Marcus J.; den Heeten, Gerard J.; Lachmann, Burkhard


    AIM: To test the effects of various contrast media on the pulmonary surfactant system. MATERIAL AND METHODS: In a rat model of acute respiratory distress syndrome (ARDS) induced by lung lavage, the effects of surfactant suspended in saline were compared with surfactant suspended in the contrast

  8. Effect of surfactant types and their concentration on the structural characteristics of nanoclay (United States)

    Zawrah, M. F.; Khattab, R. M.; Saad, E. M.; Gado, R. A.


    A series of organo-modified nanoclays was synthesized using three different surfactants having different alkyl chain lengths and concentrations [0.5-5.0 cation exchange capacity (CEC)]. These surfactants were Ethanolamine (EA), Cetyltrimethylammoniumbromide (CTAB) and Tetraoctadecylammoniumbromide (TO). The obtained modified nanoclays were characterized by X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM) and compared with unmodified nanoclay. The results of XRD analysis indicated that the basal d-spacing has increased with increasing alkyl chain length and surfactant concentration. From the obtained microstructures of these organo-modified nanoclays, the mechanism of surfactant adsorption was proposed. At relatively low loading of surfactant, most of surfactant entered the spacing by an ion-exchange mechanism and is adsorbed onto the interlayer cation sites. When the concentration of the surfactant exceeds the CEC of clay, the surfactant molecules then adhere to the surface adsorbed surfactant. Some surfactants entered the interlayers, whereas the others were attached to the clay surface. When the concentration of surfactant increased further beyond 2.0 CEC, the surfactants might occupy the inter-particle space within the house-of-cards aggregate structure.


    Past results from surfactant-enhanced biodegradation studies have been equivocal because of inhibitory effects of the surfactants and a poor understanding of the characteristics of PAH-degrading microorganisms that make them responsive to surfactants. We have studied the minerali...

  10. Green synthesis of Au nanostructures at room temperature using biodegradable plant surfactants (United States)

    One-step green synthesis of gold (Au) nanostructures is described using naturally occurring biodegradable plant surfactants such as VeruSOL-3™ (mixture of d-limonene and plant-based surfactants), VeruSOL-10™, VeruSOL-11™ and VeruSOL-12™ (individual plant-based surfactants deri...

  11. Distribution of endotracheally instilled surfactant protein SP-C in lung-lavaged rabbits.

    NARCIS (Netherlands)

    Bambang Oetomo, Sidarto; de Leij, Louis; Curstedt, T; ter Haar, J G; Schoots, Coenraad; Wildevuur, Charles; Okken, Albert

    In lung-lavaged surfactant-deficient rabbits (n = 6) requiring artificial ventilation, porcine surfactant was instilled endotracheally. This resulted in improvement of lung function so that the animals could be weaned off artificial ventilation. The animals were killed 4 1/2 h after surfactant


    NARCIS (Netherlands)


    Newborn infants with respiratory distress who fail to respond to surfactant treatment receive a second dose of surfactant. The effect of this strategy on the distribution of surfactant to the lung is unknown. We therefore investigated the distribution of the first (100 mg/kg body weight) and second

  13. Modeling transport effects of perfluorinated and hydrocarbon surfactants in groundwater by using micellar liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, Rashad N. [Department of Chemistry and Center for Integrative Toxicology, Michigan State University, East Lansing, MI 48824-1322 (United States); McGuffin, Victoria L. [Department of Chemistry and Center for Integrative Toxicology, Michigan State University, East Lansing, MI 48824-1322 (United States)], E-mail:


    The effects of hydrocarbon and perfluorinated surfactants, above their critical micelle concentration (CMC), on the transport of neutral environmental pollutants are compared. Reversed-phase micellar liquid chromatography is used to model the groundwater system. The octadecylsilica stationary phase serves to simulate soil particles containing organic matter, whereas the aqueous surfactant mobile phases serve to simulate groundwater containing a surfactant at varying concentrations. Sodium dodecyl sulfate and lithium perfluorooctane sulfonate are used as representatives of the hydrocarbon and perfluorinated surfactants, respectively. Benzene, mono- and perhalogenated benzenes, and polycyclic aromatic hydrocarbons are used as models for environmental pollutants. Transport effects were elucidated from the retention factor, k, and the equilibrium constant per micelle, K{sub eq}, of the model pollutants in the individual surfactants. Based on k values, the transport of the model pollutants increased in both surfactant solutions in comparison to pure water. As the concentration of the surfactants increased, the transport of the pollutants increased as well. Notably, the K{sub eq} values of the pollutants in the perfluorinated surfactant were at least an order of magnitude less than those in the hydrocarbon surfactant. Overall, these results suggest that the presence of a perfluorinated surfactant, above its CMC, increases the transport of pollutants in a groundwater system. However, the perfluorinated surfactant exhibits a lesser transport effect than the hydrocarbon surfactant.

  14. Performance improvement of ionic surfactant flooding in carbonate rock samples by use of nanoparticles

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Ahmadi


    Full Text Available Abstract Various surfactants have been used in upstream petroleum processes like chemical flooding. Ultimately, the performance of these surfactants depends on their ability to reduce the interfacial tension between oil and water. The surfactant concentration in the aqueous solution decreases owing to the loss of the surfactant on the rock surface in the injection process. The main objective of this paper is to inhibit the surfactant loss by means of adding nanoparticles. Sodium dodecyl sulfate and silica nanoparticles were used as ionic surfactant and nanoparticles in our experiments, respectively. AEROSIL® 816 and AEROSIL® 200 are hydrophobic and hydrophilic nanoparticles. To determine the adsorption loss of the surfactant onto rock samples, a conductivity approach was used. Real carbonate rock samples were used as the solid phase in adsorption experiments. It should be noted that the rock samples were water wet. This paper describes how equilibrium adsorption was investigated by examining adsorption behavior in a system of carbonate sample (solid phase and surfactant solution (aqueous phase. The initial surfactant and nanoparticle concentrations were 500–5000 and 500–2000 ppm, respectively. The rate of surfactant losses was extremely dependent on the concentration of the surfactant in the system, and the adsorption of the surfactant decreased with an increase in the nanoparticle concentration. Also, the hydrophilic nanoparticles are more effective than the hydrophobic nanoparticles.

  15. Penetration of Sodium Hypochlorite Modified with Surfactants into Root Canal Dentin. (United States)

    Palazzi, Flavio; Blasi, Andrea; Mohammadi, Zahed; Del Fabbro, Massimo; Estrela, Carlos


    The aim of this study was to evaluate the effect of concentration, exposure time and temperature of sodium hypochlorite (NaOCl) added with surfactants on its penetration into dentinal tubules. Sixty-five extracted human permanent maxillary anterior teeth with single canals were prepared by ProTaper SX hand-operated instruments. The teeth were then sectioned perpendicular to the long axis. The crowns and apical thirds of all the teeth were removed. The remaining roots were processed into 4-mm-long blocks and stained overnight in crystal violet. One hundred and thirty stained blocks were further split into halves and treated by nine different types of NaOCl-based solutions. Three solutions were added with surfactants (Hypoclean, H6, Chlor-Xtra) and the others were regular hypochlorites at increasing concentrations (1%, 2%, 4%, 5.25%, dentin blocks were exposed to the solutions for 2, 5, and 20 min at 20 °C, 37 °C and 45 °C, respectively. The depth of NaOCl penetration was determined by bleaching of the stain and measured by light microscopy at 20x and 40x. Statistical comparisons were made by using a generalized linear model with Bonferroni's post-hoc correction. The shortest penetration (81±6.6 μm) was obtained after incubation in 1% NaOCl for 2 min at 20 °C; the highest penetration (376.3±3.8 μm) was obtained with Chlor-Xtra for 20 min at 45 °C. Varying NaOCl concentration produced a minimal effect while temperature and exposure time had a significant direct relationship with NaOCl penetration into dentinal tubules, especially those with lowered surface tension. The exposure time and temperature of sodium hypochlorite as well as the addition of surfactants may influence the penetration depth of irrigants into dentinal tubules.

  16. Surfactant therapy for bronchiolitis in critically ill infants. (United States)

    Jat, Kana R; Chawla, Deepak


    Bronchiolitis is one of the most frequent causes of respiratory failure in infants; some infants will require intensive care and mechanical ventilation. There is lack of evidence regarding effective treatment for bronchiolitis other than supportive care. Abnormalities of surfactant quantity or quality (or both) have been observed in severe cases of bronchiolitis. Exogenous surfactant administration appears to favourably change the haemodynamics of the lungs and may be a potentially promising therapy for severe bronchiolitis. This is an update of a review published in Issue 9, 2012. We did not identify any new studies for inclusion, and our conclusions remain unchanged. To evaluate the efficacy of exogenous surfactant administration (i.e. intratracheal administration of surfactant of any type (whether animal-derived or synthetic), at any dose and at any time after start of ventilation) compared to placebo, no intervention or standard care in reducing mortality and the duration of ventilation in infants and children with bronchiolitis requiring mechanical ventilation. We searched the Cochrane Central Register of Controlled Studies (CENTRAL; 2015, Issue 5) which contains the Cochrane Acute Respiratory Infections Group's Specialised Register; MEDLINE (1948 to June week 3, 2015); EMBASE (1974 to June 2015); CINAHL (1982 to June 2015); LILACS (1985 to June 2015); and Web of Science (1985 to June 2015). We considered prospective, randomised controlled trials (RCTs) and quasi-RCTs evaluating the effect of exogenous surfactant in infants and children with bronchiolitis requiring mechanical ventilation. Two review authors selected studies independently. We extracted the data using a predefined proforma, independently analysed the data, and performed meta-analyses. We included three small RCTs enrolling 79 participants. Two trials did not use a placebo in the control arms and the third trial used air placebo. Two included studies reported no mortality. We judged all three of

  17. Effect of surfactant and surfactant blends on pseudoternary phase diagram behavior of newly synthesized palm kernel oil esters

    Directory of Open Access Journals (Sweden)

    Mahdi ES


    Full Text Available Elrashid Saleh Mahdi1, Mohamed HF Sakeena1, Muthanna F Abdulkarim1, Ghassan Z Abdullah1,3, Munavvar Abdul Sattar2, Azmin Mohd Noor11Department of Pharmaceutical Technology, 2Department of Physiology, School of Pharmaceutical Sciences, Universiti Sains Malaysia, Minden, Penang, Malaysia; 3Department of Pharmaceutical Technology, International Medical University, Bukit Jalil, Kuala Lumpur, MalaysiaBackground: The purpose of this study was to select appropriate surfactants or blends of surfactants to study the ternary phase diagram behavior of newly introduced palm kernel oil esters.Methods: Nonionic surfactant blends of Tween® and Tween®/Span® series were screened based on their solubilization capacity with water for palm kernel oil esters. Tween® 80 and five blends of Tween® 80/Span® 80 and Tween® 80/Span® 85 in the hydrophilic-lipophilic balance (HLB value range of 10.7–14.0 were selected to study the phase diagram behavior of palm kernel oil esters using the water titration method at room temperature.Results: High solubilization capacity was obtained by Tween® 80 compared with other surfactants of Tween® series. High HLB blends of Tween® 80/Span® 85 and Tween® 80/Span® 80 at HLB 13.7 and 13.9, respectively, have better solubilization capacity compared with the lower HLB values of Tween® 80/Span® 80. All the selected blends of surfactants were formed as water-in-oil microemulsions, and other dispersion systems varied in size and geometrical layout in the triangles. The high solubilization capacity and larger areas of the water-in-oil microemulsion systems were due to the structural similarity between the lipophilic tail of Tween® 80 and the oleyl group of the palm kernel oil esters.Conclusion: This study suggests that the phase diagram behavior of palm kernel oil esters, water, and nonionic surfactants is not only affected by the HLB value, but also by the structural similarity between palm kernel oil esters and the surfactant

  18. Surfactant therapy of pulmonary conditions excluding those with primary surfactant deficiency and bronchoscopy as delivery method: an overview of Russian patents and publications. (United States)

    Jargin, Sergei V


    Preparations of pulmonary surfactant are used for the treatment of respiratory distress syndrome in a newborn. Their applicability as a method of routine for lung diseases beyond the neonatal period is questionable. Some publications from the former Soviet Union (SU) have reported on successful surfactant therapy of ARDS in children and adults as well as for inhalation injuries, pneumonia, and tuberculosis. Bronchoscopy was used and recommended as a method of surfactant delivery for ARDS, some types of pneumonia and tuberculosis. Manufacturing processes of surfactant preparations from bovine lung and amniotic fluid, described by Russian patents, and bronchoscopy as a delivery mode are discussed here. A concluding point is that some reports from the former SU about administration of exogenous surfactant in pulmonary conditions, excluding those with primary surfactant deficiency, are only partly confirmed by the international literature.

  19. Structural Variation in Polyoxomolybdate Hybrid Crystals Comprising Ionic-Liquid Surfactants

    Directory of Open Access Journals (Sweden)

    Takeru Ito


    Full Text Available Polyoxomolybdate inorganic-organic hybrid crystals were synthesized with 1-decyl-3-methylimidazolium and 1-dodecyl-3-methylimidazolium as ionic-liquid surfactants. Both hybrid crystals possessed alternate stacking of surfactant layers and octamolybdate (Mo8 monolayers, while the molecular structures of Mo8 were different depending on the surfactants and solvents employed for crystallization. Each Mo8 anion was connected by two sodium cations to form infinite one-dimensional chain. The surfactant chains in these crystals were arranged in a complicatedly bent manner, which will be induced by the weak C–H···O hydrogen bonds between the Mo8 anions and ionic-liquid surfactants.

  20. Study of interactions between hyaluronan and cationic surfactants by means of calorimetry, turbidimetry, potentiometry and conductometry. (United States)

    Krouská, J; Pekař, M; Klučáková, M; Šarac, B; Bešter-Rogač, M


    The thermodynamics of the micelle formation of the cationic surfactants tetradecyltrimethylammonium bromide (TTAB) and cetyltrimethylammonium bromide (CTAB) with and without the addition of hyaluronan of two molecular weights was studied in aqueous solution by titration calorimetry. Macroscopic phase separation, which was detected by calorimetry and also by conductometry, occurs when charges on the surfactant and hyaluronan are balanced. In contrast, turbidimetry and potentiometry showed hyaluronan-surfactant interactions at very low surfactant concentrations. The observed differences between systems prepared with CTAB and TTAB indicate that besides the electrostatic interactions, which probably predominate, hydrophobic effects also play a significant role in hyaluronan interactions with cationic surfactants. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. The effect of pressure on the phase behavior of surfactant systems: An experimental study

    DEFF Research Database (Denmark)

    Sandersen, Sara Bülow; Stenby, Erling Halfdan; von Solms, Nicolas


    Enhanced oil recovery is employed in many mature oil reservoirs to maintain or increase the reservoir recovery factor. In this context, surfactant flooding has recently gained interest again. Surfactant flooding is the injection of surfactants (and co-surfactants) into the reservoir, in order...... is influenced to an even greater extent. It was concluded that at certain compositions of the surfactant system (near to the phase boundary found at atmospheric pressure) the increase in pressure changed the phase behavior (for example causing the system to move from two phases to three or vice versa...

  2. Dynamic surface tension of natural surfactant extract under superimposed oscillations. (United States)

    Reddy, Prasika I; Al-Jumaily, Ahmed M; Bold, Geoff T


    Surfactant dysfunction plays a major role in respiratory distress syndrome (RDS). This research seeks to determine whether the use of natural surfactant, Curosurf™ (Cheisi Farmaceutici, Parma, Italy), accompanied with pressure oscillations at the level of the alveoli can reduce the surface tension in the lung, thereby making it easier for infants with RDS to maintain the required level of functional residual capacity (FRC) without collapse. To simulate the alveolar environment, dynamic surface tension measurements were performed on a modified pulsating bubble surfactometer (PBS) type device and showed that introducing superimposed oscillations about the tidal volume excursion between 10 and 70 Hz in a surfactant bubble lowers interfacial surface tension below values observed using tidal volume excursion alone. The specific mechanisms responsible for this improvement are yet to be established; however it is believed that one mechanism may be the rapid transient changes in the interfacial area increase the number of interfacial binding sites for surfactant molecules, increasing adsorption and diffusion to the interface, thereby decreasing interfacial surface tension. Existing mathematical models in the literature reproduce trends noticed in experiments in the range of breathing frequencies only. Thus, a modification is introduced to an existing model to both incorporate superimposed pressure oscillations and demonstrate that these may improve the dynamic surface tension in the alveoli. Copyright © 2010 Elsevier Ltd. All rights reserved.

  3. Adsorption and micellization of surfactants : comparison of theory and experiment

    NARCIS (Netherlands)

    Boehmer, M.


    The purpose of this thesis is to extend the knowledge of micellization and adsorption of surfactants in aqueous solutions or the solid /electrolyte interface. To this end experimental results for well defined systems have been compared with theoretical calculations.

    The theoretical

  4. Proteins and protein/surfactant mixtures at interfaces in motion

    NARCIS (Netherlands)

    Boerboom, F.J.G.


    The research described in this thesis covers a number of aspects of the relation between surface properties and foaming properties of proteins, low molecular surfactants and mixtures thereof. This work is the result of a question of the industrial partners if it is possible to understand

  5. Complex phase behavior in solvent-free nonionic surfactants

    DEFF Research Database (Denmark)

    Hillmyer, M.A.; Bates, F.S.; Almdal, K.


    was synthesized here. The general phase behavior in these materials resembles that of both higher molecular weight block copolymers and lower molecular weight nonionic surfactant solutions. Two of the block copolymers exhibited thermally induced order-order transitions and were studied in detail by small...

  6. The effect of electrolytes on emulsions stabilized by nonionic surfactants

    NARCIS (Netherlands)

    Boomgaard, van den A.


    The objective of this study was to investigate the effect of high electrolyte concentrations on the stability of oil-in-water- emulsions stabilized by nonionic surfactants.

    In chapter 1 several stability mechanisms are briefly outlined and the distinction between coalescence and

  7. NMR Investigation of Equilibrium Micelle of Two Head Surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Meong Soo; Nam, Ki Dae [School of Chemical Engineering, Chungbuk National University, Cheongju (Korea); Jeong, Hwan Kyeong [AMLCD Division Semiconductor Samsung Electronics, Chunan (Korea); Lee, Hyang Woo [Department of Cosmetology, Keochang Provincial College, Keochang (Korea)


    The two-headed surfactant, disodium 4-n-alkyl-3-sulfonato succinate, has been synthesized by the monoesterification of maleic anhydride and n-alkanol(C{sub 8} {approx} C{sub 12}) and addition of sodium bisulfite to the corresponding monoester. The equilibrium micellar properties formed by these aqueous compounds, and the conformations of the alkyl long chain length that comprised of the interior of micellar, have been investigated using a combination of 1-D NMR and homonuclear/heteronuclear 2-D NMR techniques. The cmc' and the aggregation numbers determined from the NMR experiments were in an agreement with previous results found in the literatures for other types of two-headed surfactant systems. The amphiphiles had high cmc' and low aggregation numbers compared to single-headed surfactants of a comparable chain length. All these results were attributed to the addition a second headgroup to a single-headed, single-tailed surfactant. 27 refs., 6 figs., 4 tabs.

  8. A study of polymer-surfactant interactions by neutron reflectivity

    CERN Document Server

    Warren, N


    surfactants and their relative levels of interaction with the polymer. The surface behaviour of these systems was observed to be in many ways more remarkable than that of the bulk solution. In the high total surfactant concentration range, once all polymer molecules were associated with bound micelles, the extent of adsorption at the air-liquid interface was found to be dominated largely, as might be expected, by the solution monomer concentrations of the two surfactants. Prior to this, however, adsorption was dominated by the presence of a very surface active polymer-SDS complex which gave rise to enhanced SDS adsorption and low surface tensions compared with those found in polymer-free systems. The origin of this effect, being the stabilisation of the adsorbed SDS monolayer due to a reduction in the inter-headgroup repulsions through screening, by the charged polymer segments, suggests that this may be a characteristic feature of systems continuing a polyelectrolyte and an oppositely charged surfactant. In ...

  9. Lung Surfactant-The Indispensable Component of Respiratory ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 10; Issue 8. Lung Surfactant - The Indispensable Component of Respiratory Mechanics. Shweta Saxena. Research News Volume 10 Issue 8 August 2005 pp 91-96. Fulltext. Click here to view fulltext PDF. Permanent link:

  10. A triblock fluorous surfactant as a specific gelator for perfluorocarbons. (United States)

    Gan, Jiaan; El Bakkari, Mounir; Belin, Colette; Margottin, Chrystèle; Godard, Pascale; Pozzo, Jean-Luc; Vincent, Jean-Marc


    The fluorinated double-tailed triblock surfactant 1-Na represents a new type of gelator for perfluorocarbons which can gelate at low concentration (1.5 wt%) both bromoperfluorooctane and perfluorodecalin, two of the most appealing perfluorinated fluids for pharmaceutical applications.

  11. Degradation of Surfactants in Hydroponic Wheat Root Zones (United States)

    Monje, Oscar; McCoy, Lashelle; Flanagan, Aisling

    Hygiene water recycling in recirculating hydroponic systems can be enhanced by plant roots by providing a substrate and root exudates for bacterial growth. However, reduced plant growth can occur during batch mode additions of high concentrations of surfactant. An analog hygiene water stream containing surfactants (Steol CS330, Mirataine CB) was added to a hydroponically-grown wheat plant root zone. The plants were grown at 700 mol mol-1 CO2, a photosynthetic photon flux of 300 mol m-2 s-1, and a planting density of 380 plants m-2. Volumetric oxygen mass transfer coefficients were determined using the fermentative/dynamic outgassing method to maintain adequate oxygen mass transfer rates in the root zone. This analysis suggested an optimal flow rate of the hydroponic solution of 5 L min-1. The hydroponic system was inoculated with biofilm from a bioreactor and rates of surfactant degradation were measured daily based on reduction in chemical oxygen demand (COD). The COD decreased from 400 to 100 mg L-1 after 2 days following batch addition of the analog hygiene water to the hydroponic system. Measurements of dissolved oxygen concentration and solution temperature suggest that the root zone was provided adequate aeration to meet both oxygen demands from plant and microbial respiration during the degradation of the surfactant. Results from this study show that hydroponic systems can be used to enhance rates of hygiene water processing.

  12. Hydrocarbon-degrading Bacteria Isolation and Surfactant Influence ...

    African Journals Online (AJOL)



    Aug 7, 2012 ... 1Department of Epidemiology, Medical Statistics and Environmental Health, Faculty of Public Health, College of. Medicine, University ... hydrocarbon degrading bacteria and to establish the effect of surfactants on the growth of organisms. ... They are released into the soil environment as industrial chemicals.

  13. Nonionic surfactant Brij35 effects on toluene biodegradation in a ...

    African Journals Online (AJOL)

    regarded as the most adequate biochemical reaction model. For the biochemical reaction process, the biochemical reaction rate was also inhibited at higher surfactant content and the degree of inhibitive effect was more pronounced at lower inlet concentration. The biochemical reaction rate was also inhibited at higher inlet ...

  14. The influence of nonionic surfactant Brij 30 on biodegradation of ...

    African Journals Online (AJOL)

    Zero-order kinetics with diffusion limitation was regarded as the most adequate biochemical reaction kinetic model. The microbial growth rate and biochemical reaction rate were inhibited at higher surfactant content and toluene inlet concentration. The degree of inhibitive effect was more pronounced at lower toluene inlet ...

  15. Genetic and environmental influences of surfactant protein D serum levels

    DEFF Research Database (Denmark)

    Sorensen, G.L.; Hjelmborg, J.V.; Kyvik, K.O.


    The collectin surfactant protein D (SP-D) is an important component of the pulmonary innate immune system, but SP-D is also present on extrapulmonary epithelial surfaces and in serum, where it has been used as a biomarker for pulmonary disease states. In this study, we investigate the mechanisms ...

  16. Effect of surfactants on the mechanical properties of acetaminophen ...

    African Journals Online (AJOL)

    The purpose of this study was to investigate the effect of non ionic surfactant on the mechanical properties of acetaminophen-wax matrix tablet and hence its implication on dissolution profile. Acetaminophen-wax matrix granules were prepared by melt granulation technique. This was formed by triturating acetaminophen ...

  17. Comparative insight into surfactants mediated amyloidogenesis of lysozyme. (United States)

    Chaturvedi, Sumit K; Khan, Javed M; Siddiqi, Mohammad K; Alam, Parvez; Khan, Rizwan H


    Electrostatic and hydrophobic interactions have an important role in the protein aggregation. In this study, we have investigated the effect of charge and hydrophobicity of oppositely charged surfactants i.e., anionic (AOT and SDS) and cationic (CTAB and DTAB) on hen egg white lysozyme at pH 9.0 and 13.0, respectively. We have employed various methods such as turbidity measurements, Rayleigh light scattering, ThT, Congo red and ANS dye binding assays, far-UV CD, atomic force microscopy, transmission electron and fluorescence microscopy. At lower molar ratio, both anionic and cationic surfactants promote amyloid fibril formation in lysozyme at pH 9.0 and 13.0, respectively. The aggregation was proportionally increased with respect to protein concentration and hydrophobicity of surfactant. The morphology of aggregates at both the pH was fibrillar in structure, as visualized by dye binding and microscopic imaging techniques. Initially, the interaction between surfactants and lysozyme was electrostatic and then hydrophobic as investigated by ITC. This study demonstrates the crucial role of charge and hydrophobicity during amyloid fibril formation. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Preparation of microemulsions with soybean oil-based surfactants (United States)

    Emulsions are widely applied in food, cosmeceutical and medicinal formulations. Smaller and highly stable droplets of emulsions are important for their application. This research reports that by using soybean oil-based surfactants, the higher stabilized oil-in-water emulsions were obtained via an ul...

  19. A PIV Study of Drop-interface Coalescence with Surfactants (United States)

    Weheliye, Weheliye Hashi; Dong, Teng; Angeli, Panagiota


    In this work, the coalescence of a drop with an aqueous-organic interface was studied by Particle Image Velocimetry (PIV). The effect of surfactants on the drop surface evolution, the vorticity field and the kinetic energy distribution in the drop during coalescence were investigated. The coalescence took place in an acrylic rectangular box with 79% glycerol solution at the bottom and Exxsol D80 oil above. The glycerol solution drop was generated through a nozzle fixed at 2cm above the aqueous/oil interface and was seeded with Rhodamine particles. The whole process was captured by a high-speed camera. Different mass ratios of non-ionic surfactant Span80 to oil were studied. The increase of surfactant concentration promoted deformation of the interface before the rupture of the trapped oil film. At the early stages after film rupture, two counter-rotating vortices appeared at the bottom of the drop which then travelled to the upper part. The propagation rates, as well as the intensities of the vortices decreased at high surfactant concentrations. At early stages, the kinetic energy was mainly distributed near the bottom part of the droplet, while at later stages it was distributed near the upper part of the droplet. Programme Grant MEMPHIS, Chinese Scholarship Council (CSC).

  20. The late administration of surfactant | Ballot | South African Medical ...

    African Journals Online (AJOL)

    Current recommendations for surfactant replacement therapy (SRT) in the treatment of hyaline membrane disease (HMD) are to administer the drug as soon as possible after starting ventilation in order to prevent ventilator lung damage. We present a review of 18 infants (gestational age 32,4 ± 1,9 weeks and birth weight 1 ...

  1. Packing states of multilamellar vesicles in a nonionic surfactant system

    DEFF Research Database (Denmark)

    Le, T.D.; Olsson, U.; Mortensen, K.


    under shear. Here, we focused only in the MLV region, L-alpha(*), of a temperature sensitive surfactant system (C12E4-water) to investigate the packing of multilamellar vesicles as a function of temperature under constant shear. Two sets of temperature scan experiments were performed in the L...

  2. Antibiotic and surfactant effects on lysine accumulation by Bacillus ...

    African Journals Online (AJOL)

    The effects of antibiotics and surfactants on lysine accumulation in the culture broth of three strains of Bacillus megaterium (B. megaterium SP 86, B. megaterium SP 76 and B. megaterium SP 14) were investigated. Lincomycin, neomycin and tetracycline stimulated lysine increase in B. megaterium SP 76 and B. megaterium ...

  3. Comprehensive study of tartrazine/cationic surfactant interaction. (United States)

    Shahir, Afshin Asadzadeh; Javadian, Soheila; Razavizadeh, Bi Bi Marzieh; Gharibi, Hussein


    Interaction of a food dye, tartrazine, with some cationic conventional and gemini surfactants, tetradecyltrimethylammonium bromide (TTAB), N,N'-ditetradecyl-N,N,N',N'-tetramethyl-N,N'-butanediyl-diammonium dibromide (14,4,14), and N,N'-didodecyl-N,N,N',N'-tetramethyl-N,N'-butanediyl-diammonium dibromide (12,4,12), were first investigated comprehensively employing conductometry, tensiometry, and UV-visible spectroscopy. Tartrazine was found to behave in the same manner as aromatic counterions. The formation of ion pairs reflected as a considerable increase of the surfactant efficiency in tensiometry plots and their stoichiometry were determined by Job's method of continuous variations. For the tartrazine/TTAB system, nonionic DS(3), ionic DS(2-), and/or DS(2)(-) ion pairs, their small premicelles, and tartrazine-rich micelles were constituted as well as dye-containing TTAB-rich micelles. Insoluble J-aggregates of DS(-) ion pairs and cylindrical surfactant-rich micelles were also formed in tartrazine/gemini surfactant systems and recognized by transmission electron microscopy. The zeta potential and the size of the aggregates were determined using dynamic light scattering and confirmed the suggested models for the processes happening in each system. Cyclic voltammetry was applied successfully to track all of these species using tartrazine's own reduction peak current for the first time.

  4. Effect of Surfactants on Plasmid DNA Stability and Release from ...

    African Journals Online (AJOL)

    ... diffusion mechanism was found to predominate in DNA release. Conclusion: The microspheres were non-toxic to the neuro-2a cells which suggest they can be potentially used in the gene therapy of neuronal diseases. Keywords: Surfactant, Gene therapy, Microspheres, Polylactic glycolide, Plasmid DNA, Supercoil index, ...

  5. Hydrocarbon-degrading bacteria isolation and surfactant influence ...

    African Journals Online (AJOL)

    This study was conducted based on the need to isolate hydrocarbon degrading bacteria and to establish the effect of surfactants on the growth of organisms. Ten organisms were isolated and classified into five genera based on their physiological, morphological and biochemical characteristics. These genera include ...

  6. Circulating surfactant protein D is decreased in systemic lupus erythematosus

    DEFF Research Database (Denmark)

    Hoegh, Silje Vermedal; Voss, Anne; Sorensen, Grith Lykke


    Objective. Deficiencies of innate immune molecules like mannan binding lectin (MBL) have been implicated in the pathogenesis of systemic lupus erythematosus (SLE). Surfactant protein D (SP-D) and MBL belong to the same family of innate immune molecules - the collectins, which share important...

  7. The cost and effectiveness of surfactant replacement therapy at ...

    African Journals Online (AJOL)

    therapy ms of. The cost and effectiveness of surfactant replacement therapy at Johannesburg. Hospital, November 1991. December 1992 v. A. Davies, D. E. Ballot, ..... neural d retinopa developm ventilate these, 69 backgro. Main o urban ba developm. Study infants d. Tygerber at 3-mon. Result significa and ges babies w.

  8. Early surfactant therapy and nasal continuous positive airways ...

    African Journals Online (AJOL)

    Objectives. To determine if the administration of porcine surfactant 100 mg/kg within 24 hours after birth, to infants with respiratory distress syndrome (RDS) receiving nasal continuous positive airways pressure (NCPAP) and inspired oxygen (FiO2) 0.3 - 0.4, decreased the need for mechanical ventilation (MV) during the first ...

  9. Pentanol as Co-Surfactant in Polypyrrole Actuators

    DEFF Research Database (Denmark)

    Bay, Lasse; West, Keld; Skaarup, Steen


    Conductin polymers have been investigated for the use as active component in polymer actuators. Addition of I-pentanol as co-surfactant to the polymerisation solution is shown to increase the reversible linear strain that can be achieved with polypyrrole films doped with dodecyl benzene sulfonate...

  10. The selection of infants for surfactant replacement therapy under ...

    African Journals Online (AJOL)

    surfactant, which is now regarded as standard therapy for. HMD in developed countries,'" is expensive. Regimens involving multiple dosing or prophylactic administration may add to the cost. In our neonatal intensive care unit (NICU), owing to financial constraints, infants below i 000 g birth weight are not routinely ventilated ...

  11. The study on magnetite particles coated with bilayer surfactants (United States)

    Wang, Xuman; Zhang, Caining; Wang, Xiaoliang; Gu, Hongchen


    Magnetite particles were prepared by co-precipitation, then sodium oleic (SO) and sodium dodecyl benzene sulfonate (SDBS) were applied as inner and outer surfactants, respectively. IR and TG were used to study the surface adsorption of SO and SDBS on magnetite particles. The experimental results demonstrated that SO molecules were linked to the magnetite particles through chemical bond and SDBS coated on the surface of magnetite particles covered with SO by means of Van der Waals attraction. Furthermore, based on the adsorption isotherms of surfactants on the magnetite particles and the dependence of Zeta potential of particles on the surfactants concentrations, the adsorption mechanisms of these two surfactants on the magnetite particles were studied. The isotherm adsorption model for SO on magnetite particles showed excellent correlation to Langmuir type and the adsorption equation was Γ=0.162c1+0.303c (25 °C), while that for SDBS on magnetite particles coated with SO showed excellent consistence with Freundlich type and the adsorption equation was Γ = 0.32 c0.475 (25 °C). In addition, the results demonstrated that both SO and SDBS formed monolayer adsorption on the surface of magnetite particles.

  12. Nonionic surfactant Brij35 effects on toluene biodegradation in a ...

    African Journals Online (AJOL)



    Oct 19, 2009 ... behaviors of hydrophobic toluene compounds in this composite bead biofilter. The effect of inlet concentration and surfactant content in this biofilter on the microbial growth rate and biochemical reaction rate are also studied. MATERIALS AND METHODS. Materials. Peat (industrial grade from KekkilaOyj, ...

  13. Parametric analysis of surfactant-aided imbibition in fractured carbonates. (United States)

    Adibhatla, B; Mohanty, K K


    Many carbonate oil reservoirs are oil-wet and fractured; waterflood recovery is very low. Dilute surfactant solution injection into the fractures can improve oil production from the matrix by altering the wettability of the rock to a water-wetting state. A 2D, two-phase, multicomponent, finite-volume, fully-implicit numerical simulator calibrated with our laboratory results is used to assess the sensitivity of the process to wettability alteration, IFT reduction, oil viscosity, surfactant diffusivity, matrix block dimensions, and permeability heterogeneity. Capillarity drives the oil production at the early stage, but gravity is the major driving force afterwards. Surfactants which alter the wettability to a water-wet regime give higher recovery rates for higher IFT systems. Surfactants which cannot alter wettability give higher recovery for lower IFT systems. As the wettability alteration increases the rate of oil recovery increases. Recovery rate decreases with permeability significantly for a low tension system, but only mildly for high tension systems. Increasing the block dimensions and increasing oil viscosity decreases the rate of oil recovery and is in accordance with the scaling group for a gravity driven process. Heterogeneous layers in a porous medium can increase or decrease the rate of oil recovery depending on the permeability and the aspect ratio of the matrix block.

  14. Competitive adsorption of nonionic surfactant and nonionic polymer on silica

    NARCIS (Netherlands)

    Postmus, B.R.; Leermakers, F.A.M.; Koopal, L.K.; Cohen Stuart, M.A.


    Competitive adsorption of the nonionic polymer poly(ethylene oxide) (PEO) and the nonionic surfactant of the type poly(ethylene oxide) alkyl ether from aqueous solutions on a silica surface is examined. From one-component solutions, both species readily adsorb onto silica and, in the bulk of mixed

  15. Evaluation and application of surfactants synthesized from asphalt components

    Directory of Open Access Journals (Sweden)

    E.R. Souaya


    Full Text Available The synthesis, characterization, surface activity and applications of nonionic surfactants derived from the asphalt components (maltenes M are presented. These compounds were synthesized by the sulfonation of (maltene, then the prepared maltene sulfonic acid (MS was reacted with hexadecylamine giving maltene sulfonamide product (A which undergoes an alkali-catalyzed ethoxylation at (135–150 °C. Several surfactants (M-10 to M-40 were formed with different ethylene oxide units (from 10 up to 40 and were characterized by molecular weight determinations, elemental analyses and FTIR analysis. Surface tension, as a function of concentration of the surfactants in the aqueous media, was measured at 25 °C. From these measurements, the critical micelle concentration (CMC, the maximum surface excess concentration (Гmax, Minimum area per molecule (Amin, effectiveness of surface reduction (ПCMC and the efficiency (pC20 were calculated. The prepared surfactants were applied as emulsifying agents for making asphalt emulsions. Storage stability, (Saybolt Furol viscosity, settlement (water content difference %, coating ability and water resistance were measured. The results indicated that M-20 (maltene sulfonamide ethoxylated with 20 units of ethylene oxides gives a maximum stability.

  16. Adsorption of a multicomponent rhamnolipid surfactant to soil

    NARCIS (Netherlands)

    Noordman, Wouter H.; Brusseau, Mark L.; Janssen, Dick B.


    The adsorption of rhamnolipid, a multicomponent biosurfactant with potential application in soil remediation, to two sandy soils was investigated using batch and column studies. The surfactant mixture contained six anionic components differing in lipid chain length and number of rhamnose moieties.

  17. Biomimetic oligosaccharide and peptide surfactant polymers designed for cardiovascular biomaterials (United States)

    Ruegsegger, Mark Andrew

    A common problem associated with cardiovascular devices is surface induced thrombosis initiated by the rapid, non-specific adsorption of plasma proteins onto the biomaterial surface. Control of the initial protein adsorption is crucial to achieve the desired longevity of the implanted biomaterial. The cell membrane glycocalyx acts as a non-thrombogenic interface through passive (dense oligosaccharide structures) and active (ligand/receptor interactions) mechanisms. This thesis is designed to investigate biomimicry of the cell glycocalyx to minimize non-specific protein adsorption and promote specific ligand/receptor interactions. Biomimetic macromolecules were designed through the molecular-scale engineering of polymer surfactants, utilizing a poly(vinyl amine) (PVAm) backbone to which hydrophilic (dextran, maltose, peptide) and hydrophobic alkyl (hexanoyl or hexanal) chains are simultaneously attached. The structure was controlled through the molar feed ratio of hydrophobic-to-hydrophilic groups, which also provided control of the solution and surface-active properties. To mimic passive properties, a series of oligomaltose surfactants were synthesized with increasing saccharide length (n = 2, 7, 15 where n is number of glucose units) to investigate the effect of coating height on protein adsorption. The surfactants were characterized by infra red (IR) and nuclear magnetic resonance (NMR) spectroscopies for structural properties and atomic force microscopy (AFM) and contact angle goniometry for surface activity. Protein adsorption under dynamic flow (5 dyn/cm2) was reduced by 85%--95% over the bare hydrophobic substrate; platelet adhesion dropped by ˜80% compared to glass. Peptide ligands were incorporated into the oligosaccharide surfactant to promote functional activity of the passive coating. The surfactants were synthesized to contain 0%, 25%, 50%, 75%, and 100% peptide ligand density and were stable on hydrophobic surfaces. The peptide surface density was

  18. Adherence of Pseudomonas aeruginosa onto surfactant-laden contact lenses. (United States)

    Mosuela, Reynalyn; Mustafa, Shelan; Gould, Simon; Hassanin, Hany; Alany, Raid G; ElShaer, Amr


    There is an immense research interest to utilise contact lens (CLs) as a popular platform for ocular drug delivery. However, CLs are the major predisposing factors of bacterial keratitis which is commonly caused by adhesion of microbes such as Pseudomonas aeruginosa and Staphylococcus epidermidis. The aim of the current study is to explore the effect of surfactants; Poloxamer 188, Polysorbate 80 and Tetronic ® 90R4 (at 0.25% - 3% v/v) on the characteristics of CLs and on the adhesion abilities of Pseudomonas aeruginosa to the lenses' surfaces. CLs were formulated using a hydrophilic monomer; 2-hydroxyethyl methacrylate (HEMA) together with silicone-based polymer such as Poly dimethyl siloxane (PDMS) or 3,3,3-trifluoropropylsilane (FSA) then lenses were polymerized under UV light. The formulated CLs with surfactants were found to have an increased equilibrium water content (EWC) due to hydrophilic moiety present in surfactants. A relationship was deduced between EWC and surface contact angle of lenses containing surfactants; where an increased EWC was associated with a decrease in contact angle reflecting a more hydrophilic surfaces of CLs. Apart from the 3% Polysorbate 80 (p Lenses with surfactants were found to have lower bacterial ATP concentration than lenses without surfactants. Poloxamer 188 in FSA lenses reduced bacterial adhesion from 4.22 × 10 -4  ± 1.30 × 10 -4 pM to 1.03 × 10 -4  ± 4.86 × 10 -5 pM, a reduction by 75.59% when compared to the control lenses (p = .002). Moreover, 1% Tetronic ® 90R4 in PDMS showed a reduction by 57.17% in ATP concentration. Polysorbate 80 in FSA exhibited the least bacterial adhesion with an average bacterial ATP concentration of 3.85 × 10 -5  ± 2.61 × 10 -5 pM; i.e 90.88% less bacterial ATP than control lenses (p = .001). Bioluminescence studies demonstrated a decrease in Pseudomonas aeruginosa adhesion to CLs containing surfactants without impairing the optical and

  19. Contact angles of surfactant solutions on heterogeneous surfaces. (United States)

    Milne, A J B; Elliott, J A W; Amirfazli, A


    Using Gibbs' adsorption equation and a literature isotherm, a new general model to predict the contact angle of surfactant solutions on (smooth or rough) chemically heterogeneous surfaces is constructed based on the Cassie equation. The model allows for adsorption at the liquid-vapor, solid-liquid, and solid-vapor interfaces. Solid-vapor adsorption is allowed in order to model the autophobic effect on hydrophilic surfaces. Using representative values for the coefficients which describe adsorption at each interface, model predictions for contact angles as a function of f parameters (area fractions) and surfactant concentration are made for heterogeneous surfaces made up of different materials. On smooth surfaces, the f parameters serve as weighting factors determining how to combine the effects of surfactant adsorption on each material to predict the behavior on the heterogeneous surface. Due to the non-linear nature of the model, the inclusion of a small amount of hydrophobic material has a greater effect on a predominantly hydrophilic material than vice versa, explaining the result seen in literature that a small amount of hydrophobic contamination (such as oil) significantly increases contact angle on a hydrophilic surface. The fact that even a small amount of heterogeneity can greatly change experimental results could lead to incorrect experimental conclusions about surfactant adsorption if a surface were wrongly assumed to be homogeneous. Model predictions rapidly become more complex as the number of differently wettable materials present on the surface increases. Also, an approximately equal weighting of different materials generally leads to more complex behaviors compared to heterogeneous surfaces composed largely of a single material. Rough heterogeneous surfaces follow previous results for surfactant wetting of rough homogeneous surfaces, leading to an amplification/attenuation of surfactant effects for penetrated/unpenetrated wetting, and further

  20. Maintained inspiratory activity during proportional assist ventilation in surfactant-depleted cats early after surfactant instillation: phrenic nerve and pulmonary stretch receptor activity

    Directory of Open Access Journals (Sweden)

    Schaller Peter


    Full Text Available Abstract Background Inspiratory activity is a prerequisite for successful application of patient triggered ventilation such as proportional assist ventilation (PAV. It has recently been reported that surfactant instillation increases the activity of slowly adapting pulmonary stretch receptors (PSRs followed by a shorter inspiratory time (Sindelar et al, J Appl Physiol, 2005 [Epub ahead of print]. Changes in lung mechanics, as observed in preterm infants with respiratory distress syndrome and after surfactant treatment, might therefore influence the inspiratory activity when applying PAV early after surfactant treatment. Objective To investigate the regulation of breathing and ventilatory response in surfactant-depleted young cats during PAV and during continuous positive airway pressure (CPAP early after surfactant instillation in relation to phrenic nerve activity (PNA and the activity of PSRs. Methods Seven anesthetized, endotracheally intubated young cats were exposed to periods of CPAP and PAV with the same end-expiratory pressure (0.2–0.5 kPa before and after lung lavage and after surfactant instillation. PAV was set to compensate for 75% of the lung elastic recoil. Results Tidal volume and respiratory rate were higher with lower PaCO2 and higher PaO2 during PAV than during CPAP both before and after surfactant instillation (p Conclusion PSR activity and the control of breathing are maintained during PAV in surfactant-depleted cats early after surfactant instillation, with a higher ventilatory response and a lower breathing effort than during CPAP.

  1. SP-A-enriched surfactant for treatment of rat lung transplants with SP-A deficiency after storage and reperfusion

    NARCIS (Netherlands)

    Erasmus, ME; Hofstede, GJH; Petersen, AH; Batenburg, JJ; Haagsman, HP; Oetomo, SB; Prop, J


    Background. The function of pulmonary surfactant is affected by lung transplantation, contributing to impaired lung transplant function. A decreased amount of surfactant protein-A (SP-A) after reperfusion is believed to contribute to the impaired surfactant function. Surfactant treatment has been

  2. Skin accumulation and penetration of a hydrophilic compound by a novel gemini surfactant, sodium dilauramidoglutamide lysine. (United States)

    Hikima, Tomohiro; Tamura, Yoshinaga; Yamawaki, Yukio; Yamamoto, Masashi; Tojo, Kakuji


    We investigated a novel peptide-based gemini amphiphilic compound, sodium dilauramidoglutamide lysine (DLGL), as a chemical enhancer for the skin penetration of l-ascorbic acid 2-glucoside (AAG). A three-dimensional cultured human skin product, TESTSKIN™ LSE-high (LSE-high), was used as a skin model. The penetration flux of AAG with DLGL and that obtained with sodium lauramidoglutamide (LG) as a conventional surfactant across LSE-high were increased by 12.56 and 69.29 times compared to the control, respectively. The ratio of AAG amount with DLGL in the skin (21.78% total dose) was significantly increased (pskin, resulting in enhanced AAG penetration flux. However, LG might create the pathways through the skin. We conclude that DLGL is a gemini surfactant that accumulates a hydrophilic compound in skin and enhances the penetration flux. DLGL may therefore be a novel addition agent for skin local therapy. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Removal of anionic contaminants by surfactant modified powdered activated carbon (SM-PAC) combined with ultrafiltration. (United States)

    Hong, Hye-Jin; Kim, Hojeong; Lee, You-Jin; Yang, Ji-Won


    A variety of inorganic contaminants may form toxic oxyanions in aqueous systems which pose significant hazard to human health and the ecosystem. In order to remove the oxyanions from aqueous stream effectively, surfactant-modified powdered activated carbon (SM-PAC) combined with ultrafiltration (UF) was proposed in this study. As the cationic surfactant, cetylpyridinium chloride (CPC), adsorbs on the surface of PAC, the zeta potential of PAC increases to +40 mV. Oxyanions such as chromate, ferricyanide and arsenate bind on SM-PAC by electrostatic interaction, then the contaminants bound with SM-PAC can be separated by UF membrane. 0.3 mM of chromate and ferricyanide are removed completely with 4.0 g/L of SM-PAC. In case of arsenate, the removal efficiency was lower than chromate and ferricyanide. It is considered that the competition occurs among anionic pollutants on the limited binding sites of SM-PAC and lower valence of arsenate results in the lower removal efficiency. High permeate flux is maintained during filtration. The spent SM-PAC was regenerated by the concentrated Cl(-) solutions. NaCl solution whose molar Cl(-) concentration is 1.4 times higher than the contaminants bound on SM-PAC was optimal for the regeneration. Regenerated SM-PAC exhibited similar adsorption capacity to fresh SM-PAC. SM-PAC combined with UF can effectively remove anionic contaminants. Moreover, the simple and efficient regeneration process is proposed.

  4. Colloidal stability of hydrophobic nanoparticles in ionic surfactant solutions: definition of the critical dispersion concentration. (United States)

    Dederichs, Thomas; Möller, Martin; Weichold, Oliver


    The dispersion stability diagrams of hydrophobic boehmite nanoparticles in aqueous n-alkyltrimethylammonium bromide solutions (alkyl chain lengths 10-16) were studied over a wide range of particle and surfactant concentrations. The surfactant molecules adsorb tail-on on the particle surface, which provides the colloidal stability through electrostatic repulsion. In the stable region of each diagram, bimodal particle size distributions (50 and 500 nm) are found at lower surfactant concentration, which give way to monomodal distributions (50 nm) at higher concentration. This deagglomeration is connected with the cmc of the surfactants and can be explained by a desorption of counterions from the self-assembled surfactant layer. The desorption is caused by changes in the counterion concentration upon micellization. At low particle concentrations, the transition from the intermediate to the stable region, that is, the disappearance of the precipitate, occurs at a constant surfactant concentration. This concentration is introduced as the "critical dispersion concentration" (cdc), this being the lowest required concentration of a surfactant that is necessary to disperse the hydrophobic particles. The logarithm of the cdc shows a linear dependence on the surfactant chain length, thus a cmc-analogous behavior. The ratio cdc/cmc decreases with increasing surfactant chain length, indicating that long-chain surfactants are more efficient in dispersing nanoparticles than are their lower homologues. The existence of a system-specific critical cdc/cmc ratio, beyond which stable dispersions cannot be obtained, is proposed, which explains the disability of short-chain surfactants to disperse colloids.

  5. Biophysical inhibition of synthetic vs. naturally-derived pulmonary surfactant preparations by polymeric nanoparticles. (United States)

    Beck-Broichsitter, Moritz; Ruppert, Clemens; Schmehl, Thomas; Günther, Andreas; Seeger, Werner


    Reasonable suspicion has accumulated that inhaled nano-scale particulate matter influences the biophysical function of the pulmonary surfactant system. Hence, it is evident to provide novel insights into the extent and mechanisms of nanoparticle-surfactant interactions in order to facilitate the fabrication of safe nanomedicines suitable for pulmonary applications. Negatively- and positively-charged poly(styrene) nanoparticles (diameters of ~100nm) served as model carriers. Nanoparticles were incubated with several synthetic and naturally-derived pulmonary surfactants to characterize the sensitivity of each preparation to biophysical inactivation. Changes in surface properties (i.e. adsorption and dynamic surface tension behavior) were monitored in a pulsating bubble surfactometer. Both nanoparticle formulations revealed a dose-dependent influence on the biophysical behavior of all investigated pulmonary surfactants. However, the surfactant sensitivity towards inhibition depended on both the carrier type, where negatively-charged nanoparticles showed increased inactivation potency compared to their positively-charged counterparts, and surfactant composition. Among the surfactants tested, synthetic mixtures (i.e. phospholipids, phospholipids supplemented with surfactant protein B, and Venticute®) were more susceptible to surface-activity inhibition as the more complex naturally-derived preparations (i.e. Alveofact® and large surfactant aggregates isolated from rabbit bronchoalveolar lavage fluid). Overall, nanoparticle characteristics and surfactant constitution both influence the extent of biophysical inhibition of pulmonary surfactants. © 2013.

  6. Influence of age on surfactant isolated from healthy horses maintained on pasture. (United States)

    Christmann, U; Hite, R D; Witonsky, S G; Elvinger, F; Werre, S R; Thatcher, C D; Tan, R H H; Buechner-Maxwell, V A


    Surfactant alterations are described in horses after exercise, anesthesia, and prolonged transport, in horses with recurrent airway obstruction, and in neonatal foals. The effect of horse age or bronchoalveolar lavage fluid (BALF) sample characteristics on surfactant is unknown. To evaluate surfactant phospholipid composition and function in healthy horses, and to investigate the influence of age and BALF sample characteristics on surfactant. Seventeen healthy horses 6-25 years of age maintained on pasture year-round. BALF was collected by standard procedures and was assessed for recovery volume, nucleated cell count (NCC), and cytology. Cell-free BALF was separated into crude surfactant pellet (CSP) and surfactant supernatant (Supe) by ultracentrifugation. Phospholipid and protein content were determined from both fractions. CSP phospholipid composition was analyzed by high-performance liquid chromatography with an evaporative light scatter detector. Surface tension of CSP was evaluated with a pulsating bubble surfactometer. Regression analysis was used to evaluate associations between age, BALF sample characteristics, and surfactant variables. Results and conclusions were derived from 15 horses. Increasing age was associated with decreased phospholipid content in CSP but not Supe. Age did not affect protein content of CSP or Supe, or surfactant phospholipid composition or function. Age-related surfactant changes were unaffected by BALF recovery percentage, NCC, and cytological profile. Older horses have decreased surfactant phospholipid content, which might be because of age-related pulmonary changes. Surfactant composition is unaffected by BALF sample characteristics at a BALF recovery percentage of at least 50%.

  7. Effect of sodium dodecyl sulfate surfactant on rheological properties of gellan gum hydrogels (United States)

    Mithra, K.; Khandai, Santripti; Jena, Sidhartha S.


    Rheological measurements on gellan gum hydrogels were carried out to investigate the effect of an anionic surfactant, sodium dodecyl sulfate (SDS) on hydrogel structure. The gel strength was found to be strongly correlated to surfactant concentration. Below the Critical Micellar Concentration (CMC), we observed an increase in gel strength with rise in surfactant concentration and a reverse trend is observed for surfactant concentration above CMC. The gel network structure is found to be highly elastic below CMC, while an aggregated network is observed at higher concentration of surfactant. With the addition of surfactant, sol to gel transition temperature of Gellan Gum is shifted to higher temperature, suggesting addition of surfactant promotesas well as stabilizes the helix formation.

  8. Essential Regulation of Lung Surfactant Homeostasis by the Orphan G Protein-Coupled Receptor GPR116

    Directory of Open Access Journals (Sweden)

    Mi Young Yang


    Full Text Available GPR116 is an orphan seven-pass transmembrane receptor whose function has been unclear. Global disruption of the Gpr116 gene in mice revealed an unexpected, critical role for this receptor in lung surfactant homeostasis, resulting in progressive accumulation of surfactant lipids and proteins in the alveolar space, labored breathing, and a reduced lifespan. GPR116 expression analysis, bone marrow transplantation studies, and characterization of conditional knockout mice revealed that GPR116 expression in ATII cells is required for maintaining normal surfactant levels. Aberrant packaging of surfactant proteins with lipids in the Gpr116 mutant mice resulted in compromised surfactant structure, function, uptake, and processing. Thus, GPR116 plays an indispensable role in lung surfactant homeostasis with important ramifications for the understanding and treatment of lung surfactant disorders.

  9. A review of shampoo surfactant technology: consumer benefits, raw materials and recent developments. (United States)

    Cornwell, P A


    Surfactants form the core of all shampoo formulations, and contribute to a wide range of different benefits, including cleansing, foaming, rheology control, skin mildness and the deposition of benefit agents to the hair and scalp. The purpose of this review was to assist the design of effective, modern, shampoo surfactant technologies. The mechanisms through which surfactants help deliver their effects are presented, along with the appraisal techniques through which surfactant options can be tested and screened for product development. The steps that should be taken to select the most appropriate blend of surfactants are described, and useful information on the most widely used surfactants is provided. The review concludes with an examination of recent developments in 'greener' surfactants, 'sulphate-free' technologies and structured liquid phases for novel sensory properties and for suspending benefit agents. © 2017 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  10. The surface activity of pulmonary surfactant from diving mammals. (United States)

    Miller, Natalie J; Daniels, Christopher B; Schürch, Samuel; Schoel, W Michael; Orgeig, Sandra


    Pinnipeds (seals and sea lions) have developed a specialised respiratory system to cope with living in a marine environment. They have a highly reinforced lung that can completely collapse and reinflate during diving without any apparent side effects. These animals may also have a specialised surfactant system to augment the morphological adaptations. The surface activity of surfactant from four species of pinniped (California sea lion, Northern elephant seal, Northern fur seal and Ringed seal) was measured using a captive bubble surfactometer (CBS), and compared to two terrestrial species (sheep and cow). The surfactant of Northern elephant seal, Northern fur seal and Ringed seal was unable to reduce surface tension (gamma) to normal levels after 5 min adsorption (61.2, 36.7, and 46.2 +/- 1.7 mN/m, respectively), but California sea lion was able to reach the levels of the cow and sheep (23.4 mN/m for California sea lion, 21.6 +/- 0.3 and 23.0 +/- 1.5 mN/m for cow and sheep, respectively). All pinnipeds were also unable to obtain the very low gamma(min) achieved by cow (1.4 +/- 0.1 mN/m) and sheep (1.5 +/- 0.4 mN/m). These results suggest that reducing surface tension to very low values is not the primary function of surfactant in pinnipeds as it is in terrestrial mammals, but that an anti-adhesive surfactant is more important to enable the lungs to reopen following collapse during deep diving.

  11. Recycling of surfactant template in mesoporous MCM-41 synthesis (United States)

    Lai, J. Y.; Twaiq, F.; Ngu, L. H.


    The recycling of surfactant template is investigated through the reuse of the surfactant template in the mesoporous MCM-41 synthesis process. In the synthesis of MCM-41, tetraethylorthosilicate (TEOS) solution in water was utilized as the silica source while hexadecyltrimethylammonium bromide (CTAB) solution in ethyl alcohol was used as a surfactant template. The synthesized gel is formed thoroughly by mixing the two solutions under acid conditions with a pH value of 0.5 for 1 hour and kept for crystallization for 48 hours. The as-synthesized MCM-41 powder is recovered by filtration while the filtrate (mother liquor) was then reused for the second synthesis cycle. The synthesis procedure was repeated till no further solid product was formed. The synthesized gel was not produced in the unifying solution in the fifth cycle of MCM-41 synthesis. The quality of the calcined MCM-41 powder produced in each synthesis cycle was evaluated by calculating the amount of MCM-41 produced and the surface area of the powder product. The result showed that 1.28, 0.37, 1.64, 1.90 and 0.037 g were obtained in the 1st, 2nd, 3rd, 4th and 5th synthesis cycle, respectively. The surface area of the powder produced was found to be 1170, 916, 728, and 508 m2/g for 1st, 2nd, 3rd and 4th respectively. The concentration of the surfactant template has reached value lower than the critical micelle concentration (CMC) and remained constant after the 4th cycle. There was no further formation of gel due to low availability in the interaction between silicate anions and surfactant cations when the amount of TEOS was fixed for every synthesis cycle.

  12. Solution Properties of Dissymmetric Sulfonate-type Anionic Gemini Surfactants. (United States)

    Yoshimura, Tomokazu; Akiba, Kazuki


    Dissymmetric and symmetric anionic gemini surfactants, N-alkyl-N'-alkyl-N,N'dipropanesulfonylethylenediamine (CmCnSul, where m and n represent alkyl chain lengths of m-n = 4-16, 6-14, 8-12, 10-10, and 12-12), were synthesized by two- or three-step reactions. Their physicochemical properties were characterized by equilibrium surface tension measurements, steady-state fluorescence spectroscopy of pyrene, and dynamic light scattering. The critical micelle concentration (CMC) of the dissymmetric surfactants C4C16Sul, C6C14Sul, and C8C12Sul was slightly lower than that of the symmetric surfactant C10C10Sul. The occupied area per molecule (A) of C8C12Sul was smaller than that of C10C10Sul, indicating that C8C12Sul has a high surface activity. However, the increase in the degree of dissymmetry from C8C12Sul to C6C14Sul and then to C4C16Sul resulted in high surface tension and large A. Based on the surface tension, the standard free energies of micellization (∆G°mic) and adsorption (∆G°ads), the efficiency of surface adsorption (pC20), and the effectiveness of surface adsorption (CMC/C20) were obtained. These parameters suggested that C8C12Sul formed micelles more readily than the other surfactants. The properties determined from the surface tension indicated that C8C12Sul's ability is intermediate between those of C10C10Sul and C12C12Sul. The pyrene fluorescence and dynamic light scattering results revealed that the micelle size depends on the longer of the two alkyl chains in dissymmetric surfactants.

  13. Scanning force microscopy at the air-water interface of an air bubble coated with pulmonary surfactant. (United States)

    Knebel, D; Sieber, M; Reichelt, R; Galla, H-J; Amrein, M


    To study the structure-function relationship of pulmonary surfactant under conditions close to nature, molecular films of a model system consisting of dipalmitoylphosphatidylcholine, dipalmitoylphosphatidylglycerol, and surfactant-associated protein C were prepared at the air-water interface of air bubbles about the size of human alveoli (diameter of 100 microm). The high mechanical stability as well as the absence of substantial film flow, inherent to small air bubbles, allowed for scanning force microscopy (SFM) directly at the air-water interface. The SFM topographical structure was correlated to the local distribution of fluorescent-labeled dipalmitoylphosphatidylcholine, as revealed from fluorescence light microscopy of the same bubbles. Although SFM has proven before to be exceptionally well suited to probe the structure of molecular films of pulmonary surfactant, the films so far had to be transferred onto a solid support from the air-water interface of a film balance, where they had been formed. This made them prone to artifacts imposed by the transfer. Moreover, the supported monolayers disallowed the direct observation of the structural dynamics associated with expansion and compression of the films as upon breathing. The current findings are compared in this respect to our earlier findings from films, transferred onto a solid support.

  14. Hydrolysis of Surfactants Containing Ester Bonds: Modulation of Reaction Kinetics and Important Aspects of Surfactant Self-Assembly (United States)

    Lundberg, Dan; Stjerndahl, Maria


    The effects of self-assembly on the hydrolysis kinetics of surfactants that contain ester bonds are discussed. A number of examples on how reaction rates and apparent reaction orders can be modulated by changes in the conditions, including an instance of apparent zero-order kinetics, are presented. Furthermore, it is shown that the examples on…

  15. Surfactant protein-B 121ins2 heterozygosity, reduced pulmonary function, and chronic obstructive pulmonary disease in smokers

    DEFF Research Database (Denmark)

    Bækvad-Hansen, Marie; Dahl, Morten; Tybjaerg-Hansen, Anne


    Hereditary surfactant protein-B deficiency is an autosomal recessive disorder that causes fatal respiratory distress syndrome in newborns. Seventy percent of the cases of hereditary surfactant protein-B deficiency are caused by homozygosity for the 121ins2 mutation in the surfactant protein-B gen....... Individuals heterozygous for this mutation have partial absence of surfactant protein-B and could be at risk of lung disease when exposed to additional risk factors for impaired surfactant function such as tobacco smoking....

  16. Glicerólise de óleo de peixe catalisada por lipase comercial de Rhizomucor miehei em meio com surfactante de grau alimentício Glycerolysis of fish oil catalyzed by a commercial lipase from Rhizomucor miehei in reaction media containing food grade surfactant

    Directory of Open Access Journals (Sweden)

    Joanna Silva Santos


    Full Text Available Omega-3 enriched partial acylglycerols are beneficial for human health. The aim of this study was to obtain monoacylglycerols (MAG and diacylglycerols (DAG by means of glycerolysis of fish oil catalyzed by a lipase from Rhizomucor miehei in the presence of food grade surfactants (Tween 65, 80 or 85. Glycerolysis was successful in the reaction media for all the tested surfactants, showing their potential for use as additives in such a system. The best results, however, were obtained for the reaction medium in the absence of surfactant whose peroxide value was the lowest after glycerolysis.

  17. Surfactant therapy for acute respiratory distress in infants

    Directory of Open Access Journals (Sweden)

    Corrado Moretti


    Full Text Available Acute respiratory distress syndrome (ARDS remains the primary indication for admission to paediatric intensive care units and accounts for significant mortality, morbidity and resource utilization. Respiratory infections, in particular pneumonia and severe bronchiolitis, are the most common causes of respiratory failure requiring mechanical ventilation in infants and children. This paper reviews the pathophysiology of ARDS and the management of paediatric patients with acute lung injury. Data indicate that adoption of a lung protective ventilation with low tidal volumes and of an open-lung ventilation strategy, characterized by sufficient positive end-expiratory pressure (PEEP to avoid atelectasis, provides the greatest likelihood of survival and minimizes lung injury. The relative benefits of strategies such as high frequency oscillatory ventilation (HFOV, inhaled nitric oxide (iNO, recruiting manoeuvres and prone position are also considered. Moreover this article examines exogenous lung surfactant replacement therapy and its efficacy in the treatment of paediatric ARDS. In infants and children with acute lung injury the endogenous surfactant system is not only deficient, as observed in preterm infants, but altered via a variety of other mechanisms like inhibition and dysfunction. All factors contribute to the altered physiology seen in ARDS. The role of exogenous surfactant in lung injury beyond the neonatal period is therefore more complex and its limited efficacy may be related to a number of factors, among them inadequacy of pharmaceutical surfactants, insufficient dosing or drug delivery, poor drug distribution or, simply, an inability of the drug to counteract the underlying pathophysiology of ARDS. Several trials have found no clinical benefit from various surfactant supplementation methods in adult patients with ARDS, however some studies have shown that this therapy can improve oxygenation and decrease mortality in some specific

  18. Meconium impairs pulmonary surfactant by a combined action of cholesterol and bile acids. (United States)

    Lopez-Rodriguez, Elena; Echaide, Mercedes; Cruz, Antonio; Taeusch, H William; Perez-Gil, Jesus


    Mechanisms for meconium-induced inactivation of pulmonary surfactant as part of the meconium aspiration syndrome in newborn infants, to our knowledge, are not clearly understood. Here we have studied the biophysical mechanisms of how meconium affects surface activity of pulmonary surfactant and whether the membrane-perturbing effects of meconium can be mimicked by exposure of surfactant to a mixture of bile acids and cholesterol. Surface activity of pulmonary surfactant complexes purified from animal lungs was analyzed in the absence and in the presence of meconium in standard surface balances and in a captive bubble surfactometer. We have also evaluated accumulation of surfactant at the air-liquid interface by what we believe to be a novel microtiter plate fluorescent assay, and the effect of meconium components on surfactant membrane fluidity using Laurdan fluorescence thermotropic profiles and differential scanning calorimetry thermograms. Rapid interfacial adsorption, low surface tension upon film compression, efficient film replenishment upon expansion, and thermotropic properties of surfactant complexes are all adversely affected by meconium, and, in a similar manner, they are affected by cholesterol/taurocholate mixtures but not by taurocholate alone. We conclude that inhibition of surfactant by meconium can be mimicked by a bile salt-promoted incorporation of excess cholesterol into surfactant complexes. These results highlight the potential pathogenic role of cholesterol-mobilizing agents as a crucial factor resulting in cholesterol induced alterations of structure and dynamics of surfactant membranes and films. Copyright © 2011 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  19. Role of cholesterol in the biophysical dysfunction of surfactant in ventilator-induced lung injury. (United States)

    Vockeroth, Dan; Gunasekara, Lasantha; Amrein, Matthias; Possmayer, Fred; Lewis, James F; Veldhuizen, Ruud A W


    Mechanical ventilation may lead to an impairment of the endogenous surfactant system, which is one of the mechanisms by which this intervention contributes to the progression of acute lung injury. The most extensively studied mechanism of surfactant dysfunction is serum protein inhibition. However, recent studies indicate that hydrophobic components of surfactant may also contribute. It was hypothesized that elevated levels of cholesterol significantly contribute to surfactant dysfunction in ventilation-induced lung injury. Sprague-Dawley rats (n = 30) were randomized to either high-tidal volume or low-tidal volume ventilation and monitored for 2 h. Subsequently, the lungs were lavaged, surfactant was isolated, and the biophysical properties of this isolated surfactant were analyzed on a captive bubble surfactometer with and without the removal of cholesterol using methyl-beta-cyclodextrin. The results showed lower oxygenation values in the high-tidal volume group during the last 30 min of ventilation compared with the low-tidal volume group. Surfactant obtained from the high-tidal volume animals had a significant impairment in function compared with material from the low-tidal volume group. Removal of cholesterol from the high-tidal volume group improved the ability of the surfactant to reduce the surface tension to low values. Subsequent reconstitution of high-cholesterol values led to an impairment in surface activity. It is concluded that increased levels of cholesterol associated with endogenous surfactant represent a major contributor to the inhibition of surfactant function in ventilation-induced lung injury.

  20. The role of surfactants on ethylcellulose oleogel structure and mechanical properties. (United States)

    Davidovich-Pinhas, M; Barbut, S; Marangoni, A G


    The effects of surfactant addition to ethyl-cellulose (EC) based oleogels were examined with respect to the chemical nature of the "head" and "tail" groups of the surfactant. Unique sigmoidal temperature dependent rheological behavior was observed upon surfactant addition, suggesting additional organized structure formation. Glycerol-based surfactant addition lead to greatest decrease in the sol-gel and gel-sol transition temperatures compared to sorbitan-based surfactants. This behavior can be attributed to the plasticizing nature of the small head group of glycerol compared to the larger head group of sorbitan surfactants. A significant increase in the penetration force of the gels was observed upon surfactant addition, suggesting possible surfactant-polymer interactions which stiffen the polymer network. Thermal analysis detected a reduction in both SMS and GMS crystallization peak temperature and enthalpy. In the case of GMS, two melting peaks were observed upon EC addition to the oil phase, suggesting EC/surfactant interactions. These results demonstrate the effects of surfactant head group structure on EC oleogel rheological properties. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Acute toxicity of anionic and non-ionic surfactants to aquatic organisms. (United States)

    Lechuga, M; Fernández-Serrano, M; Jurado, E; Núñez-Olea, J; Ríos, F


    The environmental risk of surfactants requires toxicity measurements. As different test organisms have different sensitivity to the toxics, it is necessary to establish the most appropriate organism to classify the surfactant as very toxic, toxic, harmful or safe, in order to establish the maximum permissible concentrations in aquatic ecosystems. We have determined the toxicity values of various anionic surfactants ether carboxylic derivatives using four test organisms: the freshwater crustacean Daphnia magna, the luminescent bacterium Vibrio fischeri, the microalgae Selenastrum capricornutum (freshwater algae) and Phaeodactylum tricornutum (seawater algae). In addition, in order to compare and classify the different families of surfactants, we have included a compilation of toxicity data of surfactants collected from literature. The results indicated that V. fischeri was more sensitive to the toxic effects of the surfactants than was D. magna or the microalgae, which was the least sensitive. This result shows that the most suitable toxicity assay for surfactants may be the one using V. fischeri. The toxicity data revealed considerable variation in toxicity responses with the structure of the surfactants regardless of the species tested. The toxicity data have been related to the structure of the surfactants, giving a mathematical relationship that helps to predict the toxic potential of a surfactant from its structure. Model-predicted toxicity agreed well with toxicity values reported in the literature for several surfactants previously studied. Predictive models of toxicity is a handy tool for providing a risk assessment that can be useful to establish the toxicity range for each surfactant and the different test organisms in order to select efficient surfactants with a lower impact on the aquatic environment. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Surfactant-enhanced release of carbaryl and ethion from two long-term contaminated soils. (United States)

    Ahmad, Riaz; Kookana, Rai S; Alston, Angus M


    The potential of five nonionic surfactants, Triton X-100, Brij35, Ethylan GE08, Ethylan CD127, and Ethylan CPG660 for enhancing release of carbaryl and ethion from two long-term contaminated soils was evaluated using the batch method. Incorporation of the surfactants into soils enhanced the release of both pesticides to various extents, which could be related to the type of pesticides and type and the amount of surfactants added. Release of ethion was dramatically enhanced by aqueous concentrations of surfactants above their critical micelle concentration values. This was attributed to solubility enhancement through incorporation of the highly hydrophobic compound within surfactant micelles. A concentration of 10 g L(-1) of various surfactants released >70% of the total ethion from the soil irrespective of the surfactant. For carbaryl, the surfactants were effective at low concentrations and dependence on concentration was lower than in the case of ethion. The ethylan surfactants (GE08, CD127, and CPG660) had a higher potential than Triton X-100 and Brij35 for releasing the pesticides. However, there was still a significant portion of carbaryl (11% of the total) and ethion (17% of the total) left in the soil. Our study also showed that there must be an optimal concentration of each surfactant to maximize the mass transfer of pesticides. At some threshold concentration level, additional surfactant started to inhibit the mass transfer of solute from the soil into the water. The results suggested that surfactants could help remediation of soils polluted by pesticides. The choice of surfactant should be made based on the properties of pesticides.

  3. The Role of Surfactant in Lung Disease and Host Defense against Pulmonary Infections (United States)

    Han, SeungHye


    Pulmonary surfactant is essential for life as it lines the alveoli to lower surface tension, thereby preventing atelectasis during breathing. Surfactant is enriched with a relatively unique phospholipid, termed dipalmitoylphosphatidylcholine, and four surfactant-associated proteins, SP-A, SP-B, SP-C, and SP-D. The hydrophobic proteins, SP-B and SP-C, together with dipalmitoylphosphatidylcholine, confer surface tension–lowering properties to the material. The more hydrophilic surfactant components, SP-A and SP-D, participate in pulmonary host defense and modify immune responses. Specifically, SP-A and SP-D bind and partake in the clearance of a variety of bacterial, fungal, and viral pathogens and can dampen antigen-induced immune function of effector cells. Emerging data also show immunosuppressive actions of some surfactant-associated lipids, such as phosphatidylglycerol. Conversely, microbial pathogens in preclinical models impair surfactant synthesis and secretion, and microbial proteinases degrade surfactant-associated proteins. Deficiencies of surfactant components are classically observed in the neonatal respiratory distress syndrome, where surfactant replacement therapies have been the mainstay of treatment. However, functional or compositional deficiencies of surfactant are also observed in a variety of acute and chronic lung disorders. Increased surfactant is seen in pulmonary alveolar proteinosis, a disorder characterized by a functional deficiency of the granulocyte-macrophage colony-stimulating factor receptor or development of granulocyte-macrophage colony-stimulating factor antibodies. Genetic polymorphisms of some surfactant proteins such as SP-C are linked to interstitial pulmonary fibrosis. Here, we briefly review the composition, antimicrobial properties, and relevance of pulmonary surfactant to lung disorders and present its therapeutic implications. PMID:25742123

  4. Polyelectrolyte-Surfactant Complexes: A New Class of Organogelators (United States)

    Cavicchi, Kevin; Liu, Yuqing; Guzman, Gustavo


    Polyelectrolyte-surfactant complexes (PE-SURFs) are a class of polymers generated by neutralizing a polyelectrolyte with an oppositely charged surfactant. It has been found that PE-SURFs composed of polystyrene sulfonate and long chain alkyl dimethyl amines act as good organogelators for a range of hydrophobic, organic solvents. Thermo-reversible organogels are formed by heating and cooling PE-SURF/solvent solutions. The gel transition temperature is influenced by the degree of polymerization, the length of the alkyl side-chain, the solubility parameter of the solvent, and the concentration of the gelator. Freeze-drying and scanning electron microscopy characterization of the resultant xerogels shows the formation of rod- and plate-like network morphologies depending on the system parameters. This behavior is consistent with gelation driven by the self-assembly of the amphiphilic PE-SURFs into micellar networks.

  5. Level-set simulations of soluble surfactant driven flows (United States)

    Cleret de Langavant, Charles; Guittet, Arthur; Theillard, Maxime; Temprano-Coleto, Fernando; Gibou, Frédéric


    We present an approach to simulate the diffusion, advection and adsorption-desorption of a material quantity defined on an interface in two and three spatial dimensions. We use a level-set approach to capture the interface motion and a Quad/Octree data structure to efficiently solve the equations describing the underlying physics. Coupling with a Navier-Stokes solver enables the study of the effect of soluble surfactants that locally modify the parameters of surface tension on different types of flows. The method is tested on several benchmarks and applied to three typical examples of flows in the presence of surfactant: a bubble in a shear flow, the well-known phenomenon of tears of wine, and the Landau-Levich coating problem.

  6. Aqueous behaviour of cationic surfactants containing a cleavable group. (United States)

    Samakande, Austin; Chaghi, Radhouane; Derrien, Gaelle; Charnay, Clarence; Hartmann, Patrice C


    The aggregation behaviour of two novel cationic RAFT agents (transfer surfactants); N,N-dimethyl-N-(4-(((phenylcarbonothioyl)thio)methyl)benzyl)ethanammonium bromide (PCDBAB) and N-(4-((((dodecylthio)-carbonothioyl)thio)methyl)benzyl)-N,N-dimethylethanammonium bromide (DCTBAB) in diluted solutions have been investigated by surface tension, conductimetry and microcalorimetry measurements. The thermodynamic parameters i.e. the critical micelle concentration (cmc), the degree of micelle ionization (alpha), the head group surface area (a 0), Delta H mic, Delta G mic and T Delta S mic are reported at 303 K. The thermodynamic parameters have been compared to those of the conventional surfactant cetyltrimethylammonium bromide (CTAB) in order to specify structural relationships. The obtained results have been discussed considering the hydrophobic behaviour of the S-C=S- linkage and the specific interactions that arise from the introduction of the benzene ring into the hydrophobic part.

  7. Removal of cesium ions from clays by cationic surfactant intercalation. (United States)

    Park, Chan Woo; Kim, Bo Hyun; Yang, Hee-Man; Seo, Bum-Kyoung; Moon, Jei-Kwon; Lee, Kune-Woo


    We propose a new approach to remediate cesium-contaminated clays based on intercalation of the cationic surfactant dodecyltrimethylammonium bromide (DTAB) into clay interlayers. Intercalation of DTAB was found to occur very rapidly and involved exchanging interlayer cations. The reaction yielded efficient cesium desorption (∼97%), including of a large amount of otherwise non-desorbable cesium ions by cation exchange with ammonium ions. In addition, the intercalation of DTAB afforded an expansion of the interlayers, and an enhanced desorption of Cs by cation exchange with ammonium ions even at low concentrations of DTAB. Finally, the residual intercalated surfactants were easily removed by a decomposition reaction with hydrogen peroxide in the presence of Cu 2+ /Fe 2+ catalysts. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Comparison of several ethanol productions using xylanase, inorganic salts, surfactant (United States)

    Wu, Yan; Lu, Jie; Yang, Rui-feng; Song, Wen-jing; Li, Hai-ming; Wang, Hai-song; Zhou, Jing-hui


    Liquid hot water (LHW) pretreatment is an effective and environmentally friendly method to produce bioethanol with lignocellulosic materials. Corn stover was pretreated with liquid hot water (LHW) and then subjected to semi-simultaneous saccharification and fermentation (S-SSF) to obtain high ethanol concentration and yield. The present study aimed to confirm the effect of several additives on the fermentation digestibility of unwashed WIS of corn stover pretreated with LHW. So we also investigated the process, such as enzyme addition, inorganic salts, surfactant and different loading Triton. Results show that high ethanol concentration is necessary to add xylanase in the stage of saccharification. The ethanol concentration increased mainly with magnesium ion on fermentation. Comparing with Tween 80, Span 80 and Polyethylene glycol, Triton is the best surfactant. In contrast to using xylanase and Triton respectively, optimization can make up the lack of stamina and improve effect of single inorganic salts.

  9. Green Cosmetic Surfactant from Rice: Characterization and Application

    Directory of Open Access Journals (Sweden)

    Ibrahim Hanno


    Full Text Available During recent years, microwave irradiation has been extensively used for performing green organic synthesis. The aim of this study was to synthesize, through a microwave-assisted irradiation process, a natural surfactant with O/W emulsifying properties. Our attention was focused on polyglycerol esters of fatty acids that are biocompatible and biodegradable non-ionic surfactants widely used in food and cosmetic products. The emulsifier was obtained using vegetable raw material from renewable sources: polyglycerol derived from vegetable glycerol and rice bran oil fatty acids. The natural emulsifier obtained was then characterized and evaluated for its emulsifying properties using different doses, oil phases, rheological additives, waxes, etc. The potential application in solar products, in comparison with other natural emulsifiers, was also evaluated.

  10. Surfactant assisted surface morphology and thermal properties of polythiophene composites (United States)

    Vijeth, H.; Niranjana, M.; Yesappa, L.; Chapi, Sharanappa; Raghu, S.; Ashokkumar, S. P.; Devendrappa, H.


    Conducting polythiophene (PTH)/aluminium oxide (Al2O3) composites was prepared with camphor sulphonic acid (CSA) as s anionic surfactant by means of in situ chemical oxidation polymerization. The morphology and material phase of PTH/Al2O3 (PTHA) composites were investigated by Field-Emission Scanning Electron Microscopy (FESEM) and Energy-dispersive X-ray spectroscopy (EDX). The FESEM image shows alter the size of grain and EDX results consistent with the presence of Al2O3 and CSA chemical composition. Thermal stability of composites was characterized using TGA/DSC, the results indicate that the PTP/Al2O3 composites have higher thermal stability than that of PTP and decompose at higher temperatures due to addition of anionic surfactant.

  11. Speckle patterns during the spreading of lung surfactant (United States)

    Llovera-González, Juan J.; Moreno-Yeras, Alfredo B.; Martínez-Muñoz, Diana M.; Ferreira, Marcia Zotti Justo; Shin Nishitani, Wagner; Almeida, Alexandre Barros; Alencar, Adriano M.; Muramatsu, Mikiya; Serra-Toledo, Rolando L.


    Pulmonary surfactant is a very important product in the medical treatment of the syndrome of insufficiency respiratory in neonates. The synthesis of this surfactant in labs need to optimize the rate of spreading in the alveolar interstitial liquid obtaining a monolayer of the phospholipids membrane base capable to maintains several of the dynamical properties of the respiratory system during breathing. The recover of theses mechanical properties has to be archived using the minimal quantities of product and with the optimal proteins composition (SP-B in special). In this paper we show our results of obtaining and process speckle pattern images of the spreading of phospholipids membrane composed the matrix of this product (DPPC) when physiologic interstitial liquid are presented.

  12. Congenital surfactant protein B deficiency - emphasis on imaging

    Energy Technology Data Exchange (ETDEWEB)

    Newman, B. [Dept. of Radiology, Children' s Hospital of Pittsburgh, PA (United States); Kuhn, J.P. [Dept. of Radiology, Buffalo Children' s Hospital, Buffalo, NY (United States); Kramer, S.S. [Dept. of Radiology, Children' s Hospital of Philadelphia, PA (United States); Carcillo, J.A. [Dept. of Pediatrics, Children' s Hospital of Pittsburgh, Pittsburgh, PA (United States)


    Background and objectives. Surfactant protein B deficiency has become increasingly recognized as a cause of severe prolonged respiratory distress. Little has been written about the imaging appearance and the role of imaging in diagnosis. Materials and methods. Three newborn infants with severe respiratory distress exhibited prolonged diffuse pulmonary opacification radiographically. Results. Diffuse ground-glass opacity and markedly prominent interlobular septa suggesting alveolar proteinosis were present on early thin-section chest computed tomographic (CT) images. Fibrotic changes with prominent interlobular septal thickening were present on a later CT. Surfactant protein B deficiency was confirmed by alveolar lavage and peripheral blood DNA analysis. Conclusion. Thin-section chest CT imaging contributes important information when this diagnosis is considered. (orig.)

  13. Shear-Induced Deformation of Surfactant Multilamellar Vesicles (United States)

    Pommella, Angelo; Caserta, Sergio; Guida, Vincenzo; Guido, Stefano


    Surfactant multilamellar vesicles (SMLVs) play a key role in the formulation of many industrial products, such as detergents, foodstuff, and cosmetics. In this Letter, we present the first quantitative investigation of the flow behavior of single SMLVs in a shearing parallel plate apparatus. We found that SMLVs are deformed and oriented by the action of shear flow while keeping constant volume and exhibit complex dynamic modes (i.e., tumbling, breathing, and tank treading). This behavior can be explained in terms of an excess area (as compared to a sphere of the same volume) and of microstructural defects, which were observed by 3D shape reconstruction through confocal microscopy. Furthermore, the deformation and orientation of SMLVs scale with radius R in analogy with emulsion droplets and elastic capsules (instead of R3, such as in unilamellar vesicles). A possible application of the physical insight provided by this Letter is in the rationale design of processing methods of surfactant-based systems.

  14. Surfactants enhance recovery of poorly soluble drugs during microdialysis sampling

    DEFF Research Database (Denmark)

    Koplin, Sebastian; Kumpugdee-Vollrath, Mont; Bauer-Brandl, Annette


    celecoxib, i.e. the fraction of drug, which is not associated with taurocholate surfactant micelles. In buffer, the measured concentrations matched the overall CXB concentrations. By the use of SDS-containing perfusates microdialysis sampling enabled reliable quantification of minute amounts of free CXB......Aim of this project was to investigate the applicability of a recently developed in vitro microdialysis-sampling approach in connection with a dissolution-/permeation (D/P) system, especially the impact of surfactants within the perfusion fluid. The D/P-system is based on side-by-side chambers......, separated by a barrier that simulates the intestinal barrier. Here, in contrast to conventional D/P-systems, the dissolution of the drug (donor chamber concentration) is followed by microdialysis sampling. This approach appears promising, because it is expected not to disturb the dynamic interplay between...

  15. HPMA copolymers as surfactants in the preparation of biocompatible nanoparticles for biomedical application. (United States)

    Kelsch, Annette; Tomcin, Stephanie; Rausch, Kristin; Barz, Matthias; Mailänder, Volker; Schmidt, Manfred; Landfester, Katharina; Zentel, Rudolf


    In this work we describe the application of amphiphilic N-(2-hydroxypropyl)methacrylamide (HPMA)-based copolymers as polymeric surfactants in miniemulsion techniques. HPMA-based copolymers with different ratios of HPMA (hydrophilic) to laurylmethacrylate (LMA; hydrophobic) units were synthesized by RAFT polymerization and postpolymerization modification. The amphiphilic polymers can act as detergents in both the miniemulsion polymerization of styrene and the miniemulsion process in combination with solvent evaporation, which was applied to polystyrene and polylactide. Under optimized conditions, monodisperse colloids can be prepared. The most promising results could be obtained by using the block copolymer with a ratio of 90/10. Preliminary cell uptake studies showed that polymer-stabilized nanoparticles have only minor unspecific cellular internalization in HeLa cells. Furthermore, cytotoxicity assays showed no particle-attributed toxicity. In addition, the copolymer-stabilized particles preserved the shape and size in human blood serum as demonstrated by dynamic light scattering.


    Energy Technology Data Exchange (ETDEWEB)

    Yulin Deng; Junyong Zhu


    Based on the fundamental understanding of ink removal and fiber loss mechanism in flotation deinking process, we developed this innovative technology using surfactant spray to improve the ink removal efficiency, reduce the water and fiber loss, reduce the chemical consumption and carry over in the flotation deinking. The innovative flotation deinking process uses a spray to deliver the frothing agent during flotation deinking to control several key process variables. The spray can control the foam stability and structure and modify the fluid dynamics to reduce the fibers entrapped in the froth layer. The froth formed at the top part of the flotation column will act as a physical filter to prevent the penetration of frothing agent into the pulp suspension to eliminate fiber contamination and unfavorable deinking surface chemistry modification due to surfactant adsorption on the fiber surface. Because of the filter effect, frothing agents will be better utilized. Under the sponsorships of the US Dept. of Energy (DOE) and the member companies of the Institute of Paper Science and Technology, we studied the chem-mechanical mechanism of surfactant spray for flotation deinking using different furnishes, chemicals, and flotation devices in the past four years. In the final year of the project, we successfully conducted mill trials at Abitibi-Consolidated, Inc., Snowflake paper recycling operation of 100% mixture of ONP/OMG. Results from laboratory, pilot-plant and mill trials indicated that surfactant spray technology can significantly reduce fiber loss in flotation deinking. It can be concluded that paper industry can profit greatly when this technology is commercialized in flotation deinking mills.

  17. Surfactant-free CO2-based microemulsion-like systems. (United States)

    Hankel, Robert F; Rojas, Paula E; Cano-Sarabia, Mary; Sala, Santi; Veciana, Jaume; Braeuer, Andreas; Ventosa, Nora


    The presence of water-rich and water-lean nanodomains in a transparent, pressurized "water-acetone-CO2" mixture was revealed by Raman spectroscopy. This nano-structured liquid can be classified as a surfactant-free microemulsion-like system and has the capacity to dissolve hydrophobic compounds, such as ibuprofen, in the presence of large amounts of water. This finding opens new opportunities in the fields of confined reactions and material templating.

  18. Making biogas desulphurisation more effective by using surfactants


    Petr Buryan


    This work, studying three surfactants, has proved that if they are added in an amount below 0.1 wt. % to the washing solution of the Fe-EDTA complex capturing hydrogen sulphide from biogas, it is possible to reduce the required amount of oxidation air regenerating washing solution up to four times. This can also lead to a significant reduction in the volumes of technological apparatuses, the washing medium, costs of chemical substances. The aim of this research is to ma...

  19. Three-dimensional model of surfactant replacement therapy. (United States)

    Filoche, Marcel; Tai, Cheng-Feng; Grotberg, James B


    Surfactant replacement therapy (SRT) involves instillation of a liquid-surfactant mixture directly into the lung airway tree. It is widely successful for treating surfactant deficiency in premature neonates who develop neonatal respiratory distress syndrome (NRDS). However, when applied to adults with acute respiratory distress syndrome (ARDS), early successes were followed by failures. This unexpected and puzzling situation is a vexing issue in the pulmonary community. A pressing question is whether the instilled surfactant mixture actually reaches the adult alveoli/acinus in therapeutic amounts. In this study, to our knowledge, we present the first mathematical model of SRT in a 3D lung structure to provide insight into answering this and other questions. The delivery is computed from fluid mechanical principals for 3D models of the lung airway tree for neonates and adults. A liquid plug propagates through the tree from forced inspiration. In two separate modeling steps, the plug deposits a coating film on the airway wall and then splits unevenly at the bifurcation due to gravity. The model generates 3D images of the resulting acinar distribution and calculates two global indexes, efficiency and homogeneity. Simulating published procedural methods, we show the neonatal lung is a well-mixed compartment, whereas the adult lung is not. The earlier, successful adult SRT studies show comparatively good index values implying adequate delivery. The later, failed studies used different protocols resulting in very low values of both indexes, consistent with inadequate acinar delivery. Reasons for these differences and the evolution of failure from success are outlined and potential remedies discussed.

  20. Spontaneous vesicle phase formation by pseudogemini surfactants in aqueous solutions. (United States)

    Sun, Nan; Shi, Lijuan; Lu, Fei; Xie, Shuting; Zheng, Liqiang


    The phase behavior of a kind of pseudogemini surfactant in aqueous solutions, formed by the mixture of sodium dodecyl benzene sulfonate (SDBS) and butane-1,4-bis (methylimidazolium bromide) ([mim-C4-mim]Br2) or butane-1,4-bis(methylpyrrolidinium bromide) ([mpy-C4-mpy]Br2) in a molar ratio of 2 : 1, is reported in the present work. When [mim-C4-mim]Br2 or [mpy-C4-mpy]Br2 is mixed with SDBS in aqueous solutions, one cationic [mim-C4-mim]Br2 or [mpy-C4-mpy]Br2 molecule "bridges" two SDBS molecules by noncovalent interactions (e.g. electrostatic, π-π stacking, and σ-π interactions), behaving like a pseudogemini surfactant. Vesicles can be formed by this kind of pseudogemini surfactant, determined by freeze-fracture transmission electron microscopy (FF-TEM) or cryogenic-transmission electron microscopy (cryo-TEM) and dynamic light scattering (DLS). The mixed system of sodium dodecyl sulfate (SDS) with [mim-C4-mim]Br2 or [mpy-C4-mpy]Br2 was also constructed, and only micelles were observed. We infer that a pseudogemini surfactant is formed under the synergic effect of electrostatic, π-π stacking, and σ-π interactions in the SDBS/[mim-C4-mim]Br2/H2O system, while electrostatic attraction and hydrophobic interactions may provide the directional force for vesicle formation in the SDBS/[mpy-C4-mpy]Br2/H2O system.

  1. Surfactant protein D in chornic obstructive pulmonary disease (COPD). (United States)

    Moreno, Dolores; Garcia, Alexis; Lema, Diego; De Sanctis, Juan B


    In the recent years, a large number of potential biomarkers for Chronic Obstructive Pulmonary Disease (COPD) have been described. One of the important biomarkers is Surfactant Protein D (SPD) since serum SPD levels have been associated with lung function or health status in patients with severe COPD. Several interesting evidences of the protein and gene polymorphisms have been described. The present review highlights the current literature, recent patents and, future prospects of this important collection.

  2. The influence of surfactant HLB and oil/surfactant ratio on the formation and properties of self-emulsifying pellets and microemulsion reconstitution. (United States)

    Matsaridou, Irini; Barmpalexis, Panagiotis; Salis, Andrea; Nikolakakis, Ioannis


    Self-emulsifying oil/surfactant mixtures can be incorporated into pellets that have the advantages of the oral administration of both microemulsions and a multiple-unit dosage form. The purpose of this work was to study the effects of surfactant hydrophilic-lipophilic balance (HLB) and oil/surfactant ratio on the formation and properties of self-emulsifying microcrystalline cellulose (MCC) pellets and microemulsion reconstitution. Triglycerides (C(8)-C(10)) was the oil and Cremophor ELP and RH grades and Solutol the surfactants. Pellets were prepared by extrusion/spheronization using microemulsions with fixed oil/surfactant content but with different water proportions to optimize size and shape parameters. Microemulsion reconstitution from pellets suspended in water was evaluated by turbidimetry and light scattering size analysis, and H-bonding interactions of surfactant with MCC from FT-IR spectra. It was found that water requirements for pelletization increased linearly with increasing HLB. Crushing load decreased and deformability increased with increasing oil/surfactant ratio. Incorporation of higher HLB surfactants enhanced H-bonding and resulted in faster and more extensive disintegration of MCC as fibrils. Reconstitution was greater at high oil/surfactant ratios and the droplet size of the reconstituted microemulsions was similar to that in the wetting microemulsions. The less hydrophilic ELP with a double bond in the fatty acid showed weaker H-bonding and greater microemulsion reconstitution. Purified ELP gave greater reconstitution than the unpurified grade. Thus, the work demonstrates that the choice of type and quantity of the surfactant used in the formulation of microemulsions containing pellets has an important influence on their production and performance.

  3. Surfactant toxicity in a case of (4-chloro-2-methylphenoxy) acetic acid herbicide intoxication. (United States)

    Hwang, I; Lee, J W; Kim, J S; Gil, H W; Song, H Y; Hong, S Y


    Self-poisoning with (4-chloro-2-methylphenoxy) acetic acid (MCPA) is a common reason for presentation to hospitals, especially in some Asian countries. We encountered a case of a 76-year-old woman who experienced unconsciousness, shock and respiratory failure after ingesting 100 mL MCPA herbicide. We determined whether the surfactant in the formulation was the chemical responsible for the toxic symptom in this patient. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell viability and lactate dehydrogenase (LDH) cytotoxicity assays were performed on human brain neuroblastoma SK-N-SH cells. The expressions of 84 genes in 9 categories that are implicated in cellular damage pathways were quantified using an RT(2) Profiler™ PCR array on a human neuronal cell line challenged with polyoxyethylene tridecyl ether (PTE). Pesticide intoxication institute in university hospital. Extracorporeal elimination with intravenous lipid emulsion. Cell viability and gene expression. In the MTT assay, MCPA only minimally decreased cell viability even at concentrations as high as 1 mM. Cells treated with 1-methoxy-2-propanol, dimethylamine and polypropylene glycol exhibited minimal decreases in viability, whilst the viability of cells challenged with PTE decreased dramatically; only 15.5% of cells survived after exposure to 1 µM PTE. Similarly, the results of the LDH cytotoxicity assay showed that MCPA had very low cytotoxicity, whilst cells treated with PTE showed incomparably higher LDH levels (p < 0.0001). PTE up-regulated the expressions of genes implicated in various cell damage pathways, particularly genes involved in the inflammatory pathway. The surfactant PTE was likely the chemical responsible for the toxic symptom in our patient. © The Author(s) 2014.

  4. Dependence of carbon nanotubes dispersion kinetics on surfactants (United States)

    Ramos, Erika; Pardo, Wilmer A.; Mir, Mònica; Samitier, Josep


    Carbon nanotubes (CNTs) have been the subject of many studies due to their unique structure and desirable properties. However, the ability to solubilize and separate single CNTs from the bundles they form is still a challenge that needs to be overcome in order to extend their applications in the field of Nanotechnology. Covalent interactions are designed to modify CNTs surface and so prevent agglomeration. Though, this method alters the structures and intrinsic properties of CNTs. In the present work, noncovalent approaches to functionalize and solubilize CNTs are studied in detail. A dispersion kinetic study was performed to characterize the ability of different type of surfactants (non-ionic, anionic, cationic and biopolymer) to unzip CNT bundles. The dispersion kinetic study performed depicts the distinct CNTs bundles unzipping behavior of the different type of surfactants and the results elucidate specific wavelengths in relation with the degree of CNT clustering, which provides new tools for a deeper understanding and characterization of CNTs. Small angle x-ray scattering and transmission electron microscopy results are in agreement with UV-vis-NIR observations, revealing perfectly monodispersed CNTs for the biopolymer and cationic surfactant.

  5. Microbiological Production of Surfactant from Agricultural Residuals for IOR Application

    Energy Technology Data Exchange (ETDEWEB)

    Bala, Greg Alan; Bruhn, Debby Fox; Fox, Sandra Lynn; Noah, Karl Scott; Thompson, David Neal


    Utilization of surfactants for improved oil recovery (IOR) is an accepted technique with high potential. However, technology application is frequently limited by cost. Biosurfactants (surface-active molecules produced by microorganisms) are not widely utilized in the petroleum industry due to high production costs associated with use of expensive substrates and inefficient product recovery methods. The economics of biosurfactant production could be significantly impacted through use of media optimization and application of inexpensive carbon substrates such as agricultural process residuals. Utilization of biosurfactants produced from agricultural residuals may 1) result in an economic advantage for surfactant production and technology application, and 2) convert a substantial agricultural waste stream to a value-added product for IOR. A biosurfactant with high potential for use is surfactin, a lipopeptide biosurfactant, produced by Bacillus subtilis. Reported here is the production and potential IOR utilization of surfactin produced by Bacillus subtilis (American Type Culture Collection (ATCC) 21332) from starch-based media. Production of surfactants from microbiological growth media based on simple sugars, chemically pure starch medium, simulated liquid and solid potato-process effluent media, a commercially prepared potato starch in mineral salts, and process effluent from a potato processor is discussed. Additionally, the effect of chemical and physical pretreatments on starchy feedstocks is discussed.

  6. Surfactant mediated slurry formulations for Ge CMP applications

    KAUST Repository

    Basim, G. Bahar


    In this study, slurry formulations in the presence of self-assembled surfactant structures were investigated for Ge/SiO2 CMP applications in the absence and presence of oxidizers. Both anionic (sodium dodecyl sulfate-SDS) and cationic (cetyl trimethyl ammonium bromide-C12TAB) micelles were used in the slurry formulations as a function of pH and oxidizer concentration. CMP performances of Ge and SiO2 wafers were evaluated in terms of material removal rates, selectivity and surface quality. The material removal rate responses were also assessed through AFM wear rate tests to obtain a faster response for preliminary analyses. The surfactant adsorption characteristics were studied through surface wettability responses of the Ge and SiO2 wafers through contact angle measurements. It was observed that the self-assembled surfactant structures can help obtain selectivity on the silica/germanium system at low concentrations of the oxidizer in the slurry. © 2013 Materials Research Society.

  7. Pulmonary surfactant and nanocarriers: Toxicity versus combined nanomedical applications. (United States)

    Hidalgo, Alberto; Cruz, Antonio; Pérez-Gil, Jesús


    Pulmonary surfactant is a membrane-based lipid-protein system essential for the process of breathing, which coats and stabilizes the whole respiratory surface and possesses exceptional biophysical properties. It constitutes the first barrier against the entry of pathogens and harmful particles in the alveolar region, extended through the lungs, but on the other hand, it can offer novel possibilities as a shuttle for the delivery of drugs and nanocarriers. The advances in nanotechnology are opening the doors to new diagnostic and therapeutic avenues, which are not accessible by means of the current approaches. In this context, the pulmonary route is called to become a powerful way of entry for innovative treatments based on nanotechnology. In this review, the anatomy of the respiratory system and its properties for drug entry are first revisited, as well as some current strategies that use the respiratory route for both local and peripheral action. Then, a brief overview is presented on what pulmonary surfactant is, how it works and why it could be used as a drug delivery vehicle. Finally, the review is closed with a description of the development of nanocarriers in the lung context and their interaction with endogenous and clinical pulmonary surfactants. This article is part of a Special Issue entitled: Membrane Lipid Therapy: Drugs Targeting Biomembranes edited by Pablo V. Escribá. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Free-surface entrainment into a rimming flow containing surfactants (United States)

    Thoroddsen, S. T.; Tan, Y.-K.


    We study experimentally the free-surface entrainment of tubes into a steady rimming flow formed inside a partially filled horizontally rotating cylinder. The liquid consists of a glycerin-water mixture containing surfactants (fatty acids). The phenomenon does not occur without the surfactants and the details are sensitive to their concentration. The entrainment of numerous closely spaced air tubes and/or surfactant columns can start intermittently along a two-dimensional stagnation line, but is usually associated with the appearance of an axially periodic vortex structure, the so-called shark teeth, which fixes the spanwise location of these tubes. The number of tubes is governed by the three-dimensional shape of the free surface, reducing from more than 10 to only two in each trough, as the rotation rate is increased. The tubes vary in diameter from 10-30 μm and can extend hundreds of diameters into the liquid layer before breaking up into a continuous stream of bubbles and/or drops. The tubes are driven through the stagnation line by the strong viscous shear and are stretched in the downstream direction. The entrainment starts when the Capillary number Ca=μωR/σ≃0.4.

  9. Alteration of biophysical activity of pulmonary surfactant by aluminosilicate nanoparticles. (United States)

    Kondej, Dorota; Sosnowski, Tomasz R


    The influence of five different types of aluminosilicate nanoparticles (NPs) on the dynamic surface activity of model pulmonary surfactant (PS) (Survanta) was studied experimentally using oscillating bubble tensiometry. Bentonite, halloysite and montmorillonite (MM) NPs, which are used as fillers of polymer composites, were characterized regarding the size distribution, morphology and surface area. Particle doses applied in the studies were estimated based on the inhalation rate and duration, taking into account the expected aerosol concentration and deposition efficiency after penetration of NPs into the alveolar region. The results indicate that aluminosilicate NPs at concentrations in the pulmonary liquid above 0.1 mg cm(-3) are capable of promoting alterations of the original dynamic biophysical activity of the PS. This effect is indicated by deviation of the minimum surface tension, stability index and the size of surface tension hysteresis. Such response is dependent on the type of NPs present in the system and is stronger when particle concentration increases. It is suggested that interactions between NPs and the PS must be related to the surfactant adsorption on the suspended particles, while in the case of surface-modified clay NPs the additional washout of surface-active components may be expected. It is speculated that observed changes in surface properties of the surfactant may be associated with undesired health effects following extensive inhalation of aluminosilicate NPs in the workplace.

  10. Micellization Behavior of Long-Chain Substituted Alkylguanidinium Surfactants

    Directory of Open Access Journals (Sweden)

    Roza Bouchal


    Full Text Available Surface activity and micelle formation of alkylguanidinium chlorides containing 10, 12, 14 and 16 carbon atoms in the hydrophobic tail were studied by combining conductivity and surface tension measurements with isothermal titration calorimetry. The purity of the resulting surfactants, their temperatures of Cr→LC and LC→I transitions, as well as their propensity of forming birefringent phases, were assessed based on the results of 1H and 13C NMR, differential scanning calorimetry (DSC, and polarizing microscopy studies. Whenever possible, the resulting values of Krafft temperature (TK, critical micelle concentration (CMC, minimum surface tension above the CMC, chloride counter-ion binding to the micelle, and the standard enthalpy of micelle formation per mole of surfactant (ΔmicH° were compared to those characterizing alkyltrimethylammonium chlorides or bromides with the same tail lengths. The value of TK ranged between 292 and 314 K and increased strongly with the increase in the chain length of the hydrophobic tail. Micellization was described as both entropy and enthalpy-driven. Based on the direct calorimetry measurements, the general trends in the CMC with the temperature, hydrophobic tail length, and NaCl addition were found to be similar to those of other types of cationic surfactants. The particularly exothermic character of micellization was ascribed to the hydrogen-binding capacity of the guanidinium head-group.

  11. Micellization Behavior of Long-Chain Substituted Alkylguanidinium Surfactants (United States)

    Bouchal, Roza; Hamel, Abdellah; Hesemann, Peter; In, Martin; Prelot, Bénédicte; Zajac, Jerzy


    Surface activity and micelle formation of alkylguanidinium chlorides containing 10, 12, 14 and 16 carbon atoms in the hydrophobic tail were studied by combining conductivity and surface tension measurements with isothermal titration calorimetry. The purity of the resulting surfactants, their temperatures of Cr→LC and LC→I transitions, as well as their propensity of forming birefringent phases, were assessed based on the results of 1H and 13C NMR, differential scanning calorimetry (DSC), and polarizing microscopy studies. Whenever possible, the resulting values of Krafft temperature (TK), critical micelle concentration (CMC), minimum surface tension above the CMC, chloride counter-ion binding to the micelle, and the standard enthalpy of micelle formation per mole of surfactant (ΔmicH°) were compared to those characterizing alkyltrimethylammonium chlorides or bromides with the same tail lengths. The value of TK ranged between 292 and 314 K and increased strongly with the increase in the chain length of the hydrophobic tail. Micellization was described as both entropy and enthalpy-driven. Based on the direct calorimetry measurements, the general trends in the CMC with the temperature, hydrophobic tail length, and NaCl addition were found to be similar to those of other types of cationic surfactants. The particularly exothermic character of micellization was ascribed to the hydrogen-binding capacity of the guanidinium head-group. PMID:26861309

  12. Flavonoid-surfactant interactions: A detailed physicochemical study (United States)

    Singh, Onkar; Kaur, Rajwinder; Mahajan, Rakesh Kumar


    The aim of this article is to study the interactions between flavonoids and surfactants with attention of finding the probable location of flavonoids in micellar media that can be used for controlling their antioxidant behavior. In present study, the micellar and interfacial behavior of twin tailed anionic surfactants viz. sodium bis(2-ethylhexyl)sulfosuccinate (AOT) and sodium bis(2-ethylhexyl)phosphate (NaDEHP) in the presence of two flavonoids, namely quercetin (QUE) and kaempferol (KFL) have been studied by surface tension measurements. UV-visible, fluorescence and differential pulse voltammetric (DPV) measurements have been employed to predict the probable location of flavonoids (QUE/KFL) within surfactant (AOT/NaDEHP) aggregates. Dynamic light scattering (DLS) measurements further confirmed the solubilization of QUE/KFL in AOT/NaDEHP aggregates deduced from increased hydrodynamic diameter (Dh) of aggregates in the presence of flavonoids. Both radical scavenging activity (RSA) and degradation rate constant (k) of flavonoids are found to be higher in NaDEHP micelles as compared to AOT micelles.

  13. Efficacy of glyphosate and five surfactants for controlling giant salvinia (United States)

    Fairchild, J.F.; Allert, A.L.; Riddle, J.S.; Gladwin, D.R.


    Giant salvinia (Salvinia molesta Mitchell) is a non-native, invasive aquatic fern that was recently introduced to the southern United States. The aggressive nature of the species has led to concerns over its potential adverse impacts to native plants, fish, and invertebrates. We conducted a study to determine the efficacy of glyphosate [isopropylamine salt of N-(phosphono-methyl)glycine] and several surfactants for control of giant salvinia. Studies were conducted over a 42-day period using static renewals (twice weekly) with 4% Hoagland's medium (10 mg/L N equivalent) in replicated 2-L containers. Five concentrations of glyphosate (0, 0.45, 0.91, 1.82, and 3.60% v:v) and five surfactants (0.25% concentration, v:v; Optima???, Kinetic???, Mon 0818???, Cygnet Plus???, and LI-700???) were applied with a pressurized sprayer as a single surface application in a fully nested experimental design. Untreated giant salvinia grew rapidly and exhibited an increase of 800% wet weight biomass over the 42-day test duration. Glyphosate, with and without surfactants, exhibited efficacy at concentrations as low as 0.45% of the commercial formulation. Glyphosate with Optima was the only mixture that resulted in complete mortality of plants with no regrowth.

  14. Lung surfactant function and composition in neonatal foals and adult horses. (United States)

    Christmann, Undine; Livesey, Leanda C; Taintor, Jennifer S; Waldridge, Bryan M; Schumacher, John; Grier, Bonnie L; Hite, R Duncan


    Lung surfactant function and composition are varied and adapted to the specific respiratory physiology of all mammalian species. Lung surfactant function and composition are different in neonatal foals as compared to adult horses. Six adult horses, 7 term foals (surfactant into crude surfactant pellets (CSP) and supernatant. Both fractions were analyzed for phospholipid and protein content with the Bartlett and bicinchoninic acid method, respectively. Phospholipid composition of the CSP was determined by using high-performance liquid chromatography with an evaporative light scatter detector. Surface tension of the CSP was measured with a pulsating bubble surfactometer. Results from term foals (surfactant in neonatal foals are significantly different compared to adult horses. These changes may influence biophysical and immunologic functions of surfactant.

  15. Effect of three representative surfactants on methane hydrate formation rate and induction time

    Directory of Open Access Journals (Sweden)

    Mostafa keshavarz Moraveji


    Full Text Available The effects of three types of surfactants on methane hydrate formation process were investigated. Three different classes of surfactants involving anionic (sodium dodecyl sulfonate, cationic (hexadecyl trimethyl ammonium bromide and non-ionic (poly oxy ethylene (40 octyl phenyl ether have been used. Thermodynamics of hydrate formation, formation rate, kinetic constants and induction time in the presence of surfactants with various concentrations were analyzed. Critical micelle concentrations (CMCs of these surfactants in water were determined by induction time measurements in various concentrations under methane hydrate formation conditions. The critical micelle concentration (CMC at the methane hydrate formation conditions for SDS, HTABr and TritonX-405 solutions were obtained at 450, 380 and 950 ppm, respectively. The experimental results indicated that hydrate formation rate increased with the use of surfactants for all concentrations and induction time decreased. It was found that for surfactants, CMC at hydrate formation conditions was less than CMC at ambient conditions.

  16. The Effect of Surfactants on the Diameter and Morphology of Electrospun Ultrafine Nanofiber

    Directory of Open Access Journals (Sweden)

    Jian-Yi Zheng


    Full Text Available Different surfactants are introduced to study the diameter and morphology transformation characteristics of electrospun nanofiber. Surfactants increase the net charge density and instability motion of charged jet. The instability motion provides a good way to stretch the charged jets into finer ones, by which the beaded structures are also prevented. Ultrafine nanofiber with average diameter less than 65 nm can be fabricated. The nanofiber diameter decreases with the increase of surfactant concentration in polymer solution. The nanofibers with anionic surfactant sodium dodecyl sulfate (SDS have the smallest diameter. The cationic surfactant hexadecyl trimethyl ammonium bromide (HTAB plays the best role to prevent the formation of beaded structures in nanofibers, and helps to increase the uniformity of electrospun nanofiber. The effects of surfactants on the nanofiber diameter and morphology have been studied, which would promote the industrial application of ultrafine polymeric nanofibers.

  17. Effect of curcumin on the binding of cationic, anionic and nonionic surfactants with myoglobin (United States)

    Mondal, Satyajit; Ghosh, Soumen


    Interaction of a globular protein, myoglobin and different surfactants has been studied in the absence and presence of curcumin in phosphate buffer at pH = 7.4 by UV-VIS spectrophotometry, fluorimetry and fluorescence polarization anisotropy methods. Results show that heme environment of myoglobin is changed by cationic cetyltrimethylammonium bromide (CTAB) and sodium N-dodecanoyl sarcosinate (SDDS). In the presence of curcumin, CTAB cannot change the heme; but SDDS can make change. Nonionic surfactant N-decanoyl-N-methylglucamine (Mega 10) cannot change the heme environment. Protein is unfolded by the surfactant. Curcumin can prevent the unfolding of protein in the low concentration region of ionic surfactants such as CTAB and SDDS. In nonionic surfactant media, curcumin accelerates the denaturation process. Due to myoglobin-curcumin complex formation, rotational motion of curcumin decreases in surfactant media and so anisotropy increases.

  18. Vesicle formation and stability in the surfactant sodium 4-(1'-heptylnonyl) benzenesulfonate

    Energy Technology Data Exchange (ETDEWEB)

    Franses, E.I.; Talmon, Y.; Scriven, L.E.; Davis, H.T.; Miller, W.G.


    Surfactants composed of a hydrophilic moiety covalently attached to the end of a hydrocarbon chain (e.g., sodium dodecyl sulfate), spontaneously form micelles, equilibrium aggregates, in solution if the surfactant concentration exceeds a critical value called the CMC. Naturally occurring double-tail surfactants (e.g., phospholipids) are not known to form micelles. Over a considerable range in surfactant concentration, 2 phases coexist in equilibrium: a hydrated, multilamellar (smectic) surfactant phase and an aqueous phase saturated with surfactant. In this report the preparation of vesicles, their direct, unstained visualization by electron microscopy, and investigation of their stability and structure by turbidimetry, conductimetry, light microscopy, densitometry, scanning calorimetry, and nuclear magnetic resonance spectroscopy are discussed. Dispersed liquid crystal was studied by the same means. For comparison, parallel studies on bovine lecithin are presented. From the results, it is concluded that these vesicles may be stable for many months, but eventually revert to multilamellar liquid crystals.

  19. Effect of alkyl length of cationic surfactants on desorption of Cs from contaminated clay

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bo Hyun; Park, Chan Woo; Yang, Hee Man; Seo, Bum Kyoung; Lee, Kune Woo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Park, So Jin [Chungnam National University, Daejeon (Korea, Republic of)


    In this study, desorption characteristics of Cs from clay according to the hydrophobic alkyl chain length of the cationic surfactant were investigated. Alkyltrimethylammonium bromide was used as a cationic surfactant, and the length of the hydrophobic alkyl chain of the cationic surfactant was varied from –octyl to –cetyl. The adsorbed amount of the cationic surfactant on montmorillonite increased with the length of the hydrophobic alkyl chain, and intercalation of the cationic surfactant into the clay interlayer increased the interlayer distances. The Cs removal efficiency was also enhanced with increasing alkyl chain length, and the cationic surfactant with the cetyl group showed a maximum Cs removal efficiency of 99±2.9%.

  20. Surfactant Protein-B 121ins2 Heterozygosity, Reduced Pulmonary Function and COPD in Smokers

    DEFF Research Database (Denmark)

    Bækvad-Hansen, Marie; Dahl, Morten; Tybjærg-Hansen, Anne


    protein-B gene. Individuals heterozygous for this mutation have partial absence of surfactant protein-B and could be at risk of lung disease when exposed to additional risk factors for impaired surfactant function such as tobacco smoking. OBJECTIVES: To test whether individuals heterozygous for the 121ins.......2-4.8) for spirometry defined COPD and of 2.2(1.0-5.1) for hospitalization due to COPD. Among never smokers, 121ins2 heterozygotes did not differ from wildtypes in lung function or risk of COPD. CONCLUSIONS: Surfactant protein-B 121ins2 heterozygosity is associated with reduced lung function and increased risk for COPD......RATIONALE: Hereditary surfactant protein-B deficiency is an autosomal recessive disorder that causes fatal respiratory distress syndrome in newborns. Seventy percent of the cases of hereditary surfactant protein-B deficiency are caused by homozygosity for the 121ins2 mutation in the surfactant...