LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 53

Search options

  1. Article ; Online: Evaluating the Impact of Hydrophobic Silicon Dioxide in the Interfacial Properties of Lung Surfactant Films.

    Guzmán, Eduardo / Santini, Eva / Ferrari, Michele / Liggieri, Libero / Ravera, Francesca

    Environmental science & technology

    2022  Volume 56, Issue 11, Page(s) 7308–7318

    Abstract: The interaction of hydrophobic silicon dioxide particles (fumed silicon dioxide), as model air pollutants, and Langmuir monolayers of a porcine lung surfactant extract has been studied in order to try to shed light on the physicochemical bases underlying ...

    Abstract The interaction of hydrophobic silicon dioxide particles (fumed silicon dioxide), as model air pollutants, and Langmuir monolayers of a porcine lung surfactant extract has been studied in order to try to shed light on the physicochemical bases underlying the potential adverse effects associated with pollutant inhalation. The surface pressure-area isotherms of lung surfactant (LS) films including increasing amounts of particles revealed that particle incorporation into LS monolayers modifies the organization of the molecules at the water/vapor interface, which alters the mechanical resistance of the interfacial films, hindering the ability of LS layers for reducing the surface tension, and reestablishing the interface upon compression. This influences the normal physiological function of LS as is inferred from the analysis of the response of the Langmuir films upon the incorporation of particles against harmonic changes of the interfacial area (successive compression-expansion cycles). These experiments evidenced that particles alter the relaxation mechanisms of LS films, which may be correlated to a modification of the transport of material within the interface and between the interface and the adjacent fluid during the respiratory cycle.
    MeSH term(s) Animals ; Lung ; Pressure ; Pulmonary Surfactants/chemistry ; Pulmonary Surfactants/metabolism ; Silicon Dioxide ; Surface Properties ; Surface Tension ; Surface-Active Agents/metabolism ; Swine
    Chemical Substances Pulmonary Surfactants ; Surface-Active Agents ; Silicon Dioxide (7631-86-9)
    Language English
    Publishing date 2022-01-25
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ISSN 1520-5851
    ISSN (online) 1520-5851
    DOI 10.1021/acs.est.1c06885
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  2. Article: Evaluating the Impact of Hydrophobic Silicon Dioxide in the Interfacial Properties of Lung Surfactant Films

    Guzmán, Eduardo / Santini, Eva / Ferrari, Michele / Liggieri, Libero / Ravera, Francesca

    Environmental science & technology. 2022 Jan. 26, v. 56, no. 11

    2022  

    Abstract: The interaction of hydrophobic silicon dioxide particles (fumed silicon dioxide), as model air pollutants, and Langmuir monolayers of a porcine lung surfactant extract has been studied in order to try to shed light on the physicochemical bases underlying ...

    Abstract The interaction of hydrophobic silicon dioxide particles (fumed silicon dioxide), as model air pollutants, and Langmuir monolayers of a porcine lung surfactant extract has been studied in order to try to shed light on the physicochemical bases underlying the potential adverse effects associated with pollutant inhalation. The surface pressure–area isotherms of lung surfactant (LS) films including increasing amounts of particles revealed that particle incorporation into LS monolayers modifies the organization of the molecules at the water/vapor interface, which alters the mechanical resistance of the interfacial films, hindering the ability of LS layers for reducing the surface tension, and reestablishing the interface upon compression. This influences the normal physiological function of LS as is inferred from the analysis of the response of the Langmuir films upon the incorporation of particles against harmonic changes of the interfacial area (successive compression–expansion cycles). These experiments evidenced that particles alter the relaxation mechanisms of LS films, which may be correlated to a modification of the transport of material within the interface and between the interface and the adjacent fluid during the respiratory cycle.
    Keywords air ; breathing ; hydrophobicity ; lungs ; mechanical properties ; silica ; surface tension ; surfactants ; swine ; technology ; vapors
    Language English
    Dates of publication 2022-0126
    Size p. 7308-7318.
    Publishing place American Chemical Society
    Document type Article
    ISSN 1520-5851
    DOI 10.1021/acs.est.1c06885
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

  3. Article: Evaluation of the impact of carbonaceous particles in the mechanical performance of lipid Langmuir monolayers

    Guzmán, Eduardo / Santini, Eva / Ferrari, Michele / Liggieri, Libero / Ravera, Francesca

    Colloids and surfaces. 2022 Feb. 05, v. 634

    2022  

    Abstract: Carbonaceous particles are accounted among the most common environmental pollutants. This makes necessary a careful examination of their potential impact on the physico-chemical properties of different biological films, e.g. tear film, skin, or lung ... ...

    Abstract Carbonaceous particles are accounted among the most common environmental pollutants. This makes necessary a careful examination of their potential impact on the physico-chemical properties of different biological films, e.g. tear film, skin, or lung surfactant. This work analyzes the interaction of three different types of carbonaceous particles with Langmuir monolayers of 1,2-Dipalmitoyl-sn-glycerol-3-phosphocholine (DPPC) spread at the water/vapor interface. This type of studies can be exploited as preliminary in vitro tests for evaluating the potential risks and hazards of this type of pollutants for human health, which requires to study the effect of the particles on the ability of lipid layers for reducing the surface tension under static and dynamics conditions. The obtained results have shown that the insertion of particles into lipid films leads to the emergence of excluded area-like effects which modify the interfacial cohesion and packing. This hinders partially the ability of the lipid films for reducing the surface tension, which may present important adverse effects for the normal physiological performance of lipid membranes, and in particular for the performance of lung surfactant layers. Furthermore, the analysis of the response of lipid layers including carbonaceous particles against mechanical stresses also evidenced that particle incorporation worsens the mechanical performance of lipid layers, which may alter both their functional and structural roles.
    Keywords cohesion ; human health ; lipids ; lungs ; surface tension ; surfactants ; vapors
    Language English
    Dates of publication 2022-0205
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 1500517-3
    ISSN 0927-7757
    ISSN 0927-7757
    DOI 10.1016/j.colsurfa.2021.127974
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

  4. Article ; Online: Vibrational Spectroscopy for In Vitro Monitoring Stem Cell Differentiation.

    Ravera, Francesca / Efeoglu, Esen / Byrne, Hugh J

    Molecules (Basel, Switzerland)

    2020  Volume 25, Issue 23

    Abstract: Stem cell technology has attracted considerable attention over recent decades due to its enormous potential in regenerative medicine and disease therapeutics. Studying the underlying mechanisms of stem cell differentiation and tissue generation is ... ...

    Abstract Stem cell technology has attracted considerable attention over recent decades due to its enormous potential in regenerative medicine and disease therapeutics. Studying the underlying mechanisms of stem cell differentiation and tissue generation is critical, and robust methodologies and different technologies are required. Towards establishing improved understanding and optimised triggering and control of differentiation processes, analytical techniques such as flow cytometry, immunohistochemistry, reverse transcription polymerase chain reaction, RNA in situ hybridisation analysis, and fluorescence-activated cell sorting have contributed much. However, progress in the field remains limited because such techniques provide only limited information, as they are only able to address specific, selected aspects of the process, and/or cannot visualise the process at the subcellular level. Additionally, many current analytical techniques involve the disruption of the investigation process (tissue sectioning, immunostaining) and cannot monitor the cellular differentiation process in situ, in real-time. Vibrational spectroscopy, as a label-free, non-invasive and non-destructive analytical technique, appears to be a promising candidate to potentially overcome many of these limitations as it can provide detailed biochemical fingerprint information for analysis of cells, tissues, and body fluids. The technique has been widely used in disease diagnosis and increasingly in stem cell technology. In this work, the efforts regarding the use of vibrational spectroscopy to identify mechanisms of stem cell differentiation at a single cell and tissue level are summarised. Both infrared absorption and Raman spectroscopic investigations are explored, and the relative merits, and future perspectives of the techniques are discussed.
    MeSH term(s) Animals ; Biomarkers ; Cell Differentiation ; Cell Tracking/methods ; Humans ; Immunohistochemistry ; In Vitro Techniques ; Machine Learning ; Nanotechnology ; Spectroscopy, Fourier Transform Infrared ; Spectrum Analysis/methods ; Spectrum Analysis, Raman ; Stem Cells/cytology ; Stem Cells/metabolism
    Chemical Substances Biomarkers
    Language English
    Publishing date 2020-11-26
    Publishing country Switzerland
    Document type Journal Article ; Review
    ZDB-ID 1413402-0
    ISSN 1420-3049 ; 1431-5165 ; 1420-3049
    ISSN (online) 1420-3049
    ISSN 1431-5165 ; 1420-3049
    DOI 10.3390/molecules25235554
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  5. Article ; Online: Monitoring stem cell differentiation using Raman microspectroscopy: chondrogenic differentiation, towards cartilage formation.

    Ravera, Francesca / Efeoglu, Esen / Byrne, Hugh J

    The Analyst

    2020  Volume 146, Issue 1, Page(s) 322–337

    Abstract: Mesenchymal Stem Cells (MSCs) have the ability to differentiate into chondrocytes, the only cellular components of cartilage and are therefore ideal candidates for cartilage and tissue repair technologies. Chondrocytes are surrounded by cartilage-like ... ...

    Abstract Mesenchymal Stem Cells (MSCs) have the ability to differentiate into chondrocytes, the only cellular components of cartilage and are therefore ideal candidates for cartilage and tissue repair technologies. Chondrocytes are surrounded by cartilage-like extracellular matrix (ECM), a complex network rich in glycosaminoglycans, proteoglycans, and collagen, which, together with a multitude of intracellular signalling molecules, trigger the chondrogenesis and allow the chondroprogenitor to acquire the spherical morphology of the chondrocytes. However, although the mechanisms of the differentiation of MSCs have been extensively explored, it has been difficult to provide a holistic picture of the process, in situ. Raman Micro Spectroscopy (RMS) has been demonstrated to be a powerful analytical tool, which provides detailed label free biochemical fingerprint information in a non-invasive way, for analysis of cells, tissues and body fluids. In this work, RMS is explored to monitor the process of Mesenchymal Stem Cell (MSC) differentiation into chondrocytes in vitro, providing a holistic molecular picture of cellular events governing the differentiation. Spectral signatures of the subcellular compartments, nucleolus, nucleus and cytoplasm were initially probed and characteristic molecular changes between differentiated and undifferentiated were identified. Moreover, high density cell micromasses were cultured over a period of three weeks, and a systematic monitoring of cellular molecular components and the progress of the ECM formation, associated with the chondrogenic differentiation, was performed. This study shows the potential applicability of RMS as a powerful tool to monitor and better understand the differentiation pathways and process.
    MeSH term(s) Cartilage ; Cell Differentiation ; Cells, Cultured ; Chondrocytes ; Chondrogenesis ; Mesenchymal Stem Cells
    Language English
    Publishing date 2020-11-06
    Publishing country England
    Document type Journal Article
    ZDB-ID 210747-8
    ISSN 1364-5528 ; 0003-2654
    ISSN (online) 1364-5528
    ISSN 0003-2654
    DOI 10.1039/d0an01983f
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  6. Article ; Online: Emulsification and emulsion stability: The role of the interfacial properties.

    Ravera, Francesca / Dziza, Katarzyna / Santini, Eva / Cristofolini, Luigi / Liggieri, Libero

    Advances in colloid and interface science

    2020  Volume 288, Page(s) 102344

    Abstract: In this review, we highlight and discuss the effects of interfacial properties on the major mechanisms governing the aging of emulsions: flocculation, coalescence and Ostwald ripening. The process of emulsification is also addressed, as it is well ... ...

    Abstract In this review, we highlight and discuss the effects of interfacial properties on the major mechanisms governing the aging of emulsions: flocculation, coalescence and Ostwald ripening. The process of emulsification is also addressed, as it is well recognized that the adsorption properties of emulsifiers play an important role on it. The consolidated background on these phenomena is briefly summarised based on selected literature, reporting relevant findings and results, and discussing some criticalities. The typical experimental approaches adopted to investigate the above effects are also summarised, underlining in particular the role of adsorption at the droplet interface. Attention is paid to different types of surface-active species involved with emulsion production, including solid particles. The latter being of increasing interest in a wide variety of emulsions-related products and technologies in various fields. The possibility to stop the long term aging caused by Ostwald ripening in emulsions is also discussed, quantifying under which conditions it may occur in practice.
    Language English
    Publishing date 2020-12-14
    Publishing country Netherlands
    Document type Journal Article ; Review
    ZDB-ID 210507-x
    ISSN 1873-3727 ; 0001-8686
    ISSN (online) 1873-3727
    ISSN 0001-8686
    DOI 10.1016/j.cis.2020.102344
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  7. Article ; Online: Hydrophobisation of Silica Nanoparticles Using Lauroyl Ethyl Arginate and Chitosan Mixtures to Induce the Foaming Process.

    Krzan, Marcel / Jarek, Ewelina / Petkova, Hristina / Santini, Eva / Szyk-Warszynska, Lilianna / Ravera, Francesca / Liggieri, Libero / Mileva, Elena / Warszynski, Piotr

    Polymers

    2022  Volume 14, Issue 19

    Abstract: We studied silica suspensions with chitosan and biodegradable synthetic surfactant lauroyl ethyl arginate (LAE). Hydrophilic and negatively charged silica nanoparticles were neutralised due to the coating with chitosan. That presence of LAE led to the ... ...

    Abstract We studied silica suspensions with chitosan and biodegradable synthetic surfactant lauroyl ethyl arginate (LAE). Hydrophilic and negatively charged silica nanoparticles were neutralised due to the coating with chitosan. That presence of LAE led to the partial hydrophobisation of their surface, which favoured their attachment to the surface of a thin foam film. It was found that the presence of small and medium-sized (6-9 nm) hydrophobic particles in the interfacial layer of lamella foam film inhibited the coalescence and coarsening processes, which prolonged the life of the foam. Furthermore, hydrophobising of 30 nm particles allowed the formation of large aggregates precipitating from the mixture under steady-state conditions. These aggregates, however, under the conditions of the dynamic froth flotation process in the foam column, were floated into the foam layer. As a result, they were trapped in the foam film and Plateau borders, effectively preventing liquid leakage out of the foam. These results demonstrate the efficiency of using chitosan-LAE mixtures to remove silica nanoparticles from aqueous phase by foaming and flotation.
    Language English
    Publishing date 2022-09-28
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2527146-5
    ISSN 2073-4360 ; 2073-4360
    ISSN (online) 2073-4360
    ISSN 2073-4360
    DOI 10.3390/polym14194076
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  8. Article ; Online: Surface Properties of Saponin-Chitosan Mixtures.

    Krzan, Marcel / Rey, Natalia García / Jarek, Ewelina / Czakaj, Agnieszka / Santini, Eva / Ravera, Francesca / Liggieri, Libero / Warszynski, Piotr / Braunschweig, Björn

    Molecules (Basel, Switzerland)

    2022  Volume 27, Issue 21

    Abstract: The surface properties of saponin and saponin-chitosan mixtures were analysed as a function of their bulk mixing ratio using vibrational sum-frequency generation (SFG), surface tensiometry and dilational rheology measurements. Our experiments show that ... ...

    Abstract The surface properties of saponin and saponin-chitosan mixtures were analysed as a function of their bulk mixing ratio using vibrational sum-frequency generation (SFG), surface tensiometry and dilational rheology measurements. Our experiments show that saponin-chitosan mixtures present some remarkable properties, such as a strong amphiphilicity of the saponin and high dilational viscoelasticity. We believe this points to the presence of chitosan in the adsorption layer, despite its complete lack of surface activity. We explain this phenomenon by electrostatic interactions between the saponin as an anionic surfactant and chitosan as a polycation, leading to surface-active saponin-chitosan complexes and aggregates. Analysing the SFG intensity of the O-H stretching bands from interfacial water molecules, we found that in the case of pH 3.4 for a mixture consisting of 0.1 g/L saponin and 0.001 g/L chitosan, the adsorption layer was electrically neutral. This conclusion from SFG spectra is corroborated by results from surface tensiometry showing a significant reduction in surface tension and effects on the dilational surface elasticity strictly at saponin/chitosan ratios, where SFG spectra indicate zero net charge at the air-water interface.
    MeSH term(s) Chitosan ; Saponins/chemistry ; Surface Tension ; Surface Properties ; Surface-Active Agents/chemistry ; Adsorption ; Water/chemistry
    Chemical Substances Chitosan (9012-76-4) ; Saponins ; Surface-Active Agents ; Water (059QF0KO0R)
    Language English
    Publishing date 2022-11-03
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 1413402-0
    ISSN 1420-3049 ; 1431-5165 ; 1420-3049
    ISSN (online) 1420-3049
    ISSN 1431-5165 ; 1420-3049
    DOI 10.3390/molecules27217505
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  9. Article: A Multistate Adsorption Model for the Characterization of C₁₃DMPO Adsorption Layers at the Aqueous Solution/Air Interface

    Fainerman, Valentin B. / Kovalchuk, Volodymyr I. / Aksenenko, Eugene V. / Ravera, Francesca / Liggieri, Libero / Loglio, Giuseppe / Makievski, Alexander V. / Mishchuk, Natalia O. / Schneck, Emanuel / Miller, Reinhard

    Langmuir. 2022 Apr. 13, v. 38, no. 16

    2022  

    Abstract: Experimental data for tridecyl dimethyl phosphine oxide (C₁₃DMPO) adsorption layers at the water/air interface, including equilibrium surface tension and surface dilational viscoelasticity, are measured by bubble and drop profile analysis tensiometry at ... ...

    Abstract Experimental data for tridecyl dimethyl phosphine oxide (C₁₃DMPO) adsorption layers at the water/air interface, including equilibrium surface tension and surface dilational viscoelasticity, are measured by bubble and drop profile analysis tensiometry at different solution concentrations and surface area oscillation frequencies. The results are used to assess the applicability of a multistate model with more than two possible adsorption states. For the experiments with single drops, the depletion of surfactant molecules due to adsorption at the drop surface is taken into account. For the assessment, the same set of model parameters is used for the description of all obtained experimental dependencies. The agreement between the proposed model and the experimental data shows that for the nonionic surfactant C₁₃DMPO, the description of the adsorption layer behavior by three adsorption states is superior to that with only two adsorption states.
    Keywords adsorption ; air ; aqueous solutions ; models ; nonionic surfactants ; phosphine ; surface area ; surface tension ; viscoelasticity
    Language English
    Dates of publication 2022-0413
    Size p. 4913-4920.
    Publishing place American Chemical Society
    Document type Article
    ZDB-ID 2005937-1
    ISSN 1520-5827 ; 0743-7463
    ISSN (online) 1520-5827
    ISSN 0743-7463
    DOI 10.1021/acs.langmuir.2c00289
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

  10. Article: Surface properties of binary TiO2 - SiO2 nanoparticle dispersions relevant for foams stabilization

    Llamas, Sara / Liggieri, Libero / Ponce Torres, Alberto / Ravera, Francesca / Santini, Eva

    Colloids and surfaces. 2019 Aug. 20, v. 575

    2019  

    Abstract: This work focuses on the surface properties of binary dispersions of nanoparticles, namely Titania (TiO2) and amorphous silica (SiO2), associated to a short chain ionic surfactant (CTAB) which has the role of modifying their amphiphilicity, inducing the ... ...

    Abstract This work focuses on the surface properties of binary dispersions of nanoparticles, namely Titania (TiO2) and amorphous silica (SiO2), associated to a short chain ionic surfactant (CTAB) which has the role of modifying their amphiphilicity, inducing the segregation of particle-surfactant complexes at the liquid interface. The foams produced by these dispersions are also investigated. The adsorption of these complexes at water-air interfaces has been investigated by surface tension and dilational rheology measurements. The results obtained, discussed on the basis of the main characteristics of the two types of particles, allow us to understand the role of the dispersion composition and, especially, of the cationic surfactant in the determination of the surface activity of the different complexes and of the properties of the mixed NP layers at the water- air interfaces. In particular, important synergetic effects on the interfacial properties have been observed, when both types of particles are adsorbed. These effects reflect in an enhanced stability of the corresponding foams. In addition, the study evidences the possibility to formulate binary dispersions in order to drive selectively the adsorption of one type of particles at the liquid interface, which can be particularly significant for the formulation of particle-stabilized foams with tailored lamella and cell surface composition/structure.
    Keywords adsorption ; air ; cationic surfactants ; cetyltrimethylammonium bromide ; dispersions ; foams ; liquid-air interface ; liquids ; nanoparticles ; rheology ; silica ; surface tension ; titanium dioxide
    Language English
    Dates of publication 2019-0820
    Size p. 299-309.
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 1500517-3
    ISSN 0927-7757
    ISSN 0927-7757
    DOI 10.1016/j.colsurfa.2019.05.023
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

To top