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Mitra S, Sharma VK, Mitra JB, Chowdhury S, Mukhopadhyay MK, Mukhopadhyay R, Ghosh SK. Thermodynamics and structure of model bio-membrane of liver lipids in presence of imidazolium-based ionic liquids. Biochim Biophys Acta Biomembr 2021; 1863:183589. [PMID: 33652006 DOI: 10.1016/j.bbamem.2021.183589] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Revised: 01/29/2021] [Accepted: 02/17/2021] [Indexed: 12/20/2022]
Abstract
Ionic liquids (ILs) are the attractions of researchers today due to their vast area of potential applications. For biomedical uses, it becomes essential to understand their interactions with cellular membrane. Here, the membrane is mimicked with lipid bilayer and monolayer composed of liver lipids extract. Three archetypal imidazolium based ILs, 1-decyl-3-methylimidazolium tetrafluoroborate ([DMIM][BF4] or [C10MIM][BF4]), 1-octyl-3-methylimidazolium tetrafluoroborate, ([OMIM][BF4] or [C8MIM][BF4]) and 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF4] or [C2MIM][BF4]) having different alkyl chain lengths are used in the present study. The isothermal titration calorimetry (ITC) measurements showed that [DMIM][BF4] interacts strongest with the liver lipid membrane compared to other two ILs which have relatively shorter alkyl chain length. The low values of stoichiometry ratio of ILs indicates that ILs penetrate within the core of the lipid bilayer. The interaction of ILs with the liver lipid membrane is found to be mainly driven by entropy which could be due to the change in the structure of the lipid membrane at local or global scales. Dynamic light scattering (DLS) measurements indicate that there are no changes in the size of vesicles due to addition of [DMIM][BF4] indicating stability of the vesicles. On the other hand, x-ray reflectivity (XRR) measurements showed a concentration dependent change in the monolayer structure. At low concentration of the IL, the monolayer thickness decreases, exhibiting an increase in the electron density of the layer. However, at higher concentrations, the monolayer thickness increases proving a concentration dependent effects of the IL on the arrangement of the molecules.
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Affiliation(s)
- Saheli Mitra
- Department of Physics, School of Natural Sciences, Shiv Nadar University, NH 92, Tehsil Dadri, G. B. Nagar, Uttar Pradesh 201314, India
| | | | - Jyotsna Bhatt Mitra
- Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - Subhadip Chowdhury
- Surface Physics and Material Science Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064, India
| | - Mrinmay Kumar Mukhopadhyay
- Surface Physics and Material Science Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064, India
| | | | - Sajal Kumar Ghosh
- Department of Physics, School of Natural Sciences, Shiv Nadar University, NH 92, Tehsil Dadri, G. B. Nagar, Uttar Pradesh 201314, India.
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Mitra S, Das R, Singh A, Mukhopadhyay MK, Roy G, Ghosh SK. Surface Activities of a Lipid Analogue Room-Temperature Ionic Liquid and Its Effects on Phospholipid Membrane. Langmuir 2020; 36:328-339. [PMID: 31826620 DOI: 10.1021/acs.langmuir.9b02716] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
There are great efforts of synthesizing imidazolium-based ionic liquids (ILs) for developing new antibiotics as these molecules have shown strong antibacterial activities. Compared to a single-hydrocarbon-chained IL, the lipid analogues (LAs) with two chains are more effective. In the present study, the LA molecule MeIm(COOH)Me(Oleylamine)Iodide has been synthesized and its surface activities along with the effectiveness in restructuring of a model cellular membrane have been quantified. The molecule is found to be highly surface active as estimated from the area-pressure isotherm of a monolayer of the molecules formed at the air-water interface. The X-ray reflectivity (XRR) studies of a monolayer dip-coated on a hydrophilic substrate have shown the structural properties of the layer which resembles to those of unsaturated phospholipids. The LA molecules are observed to fluidize a phospholipid bilayer formed by the saturated lipid 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC). At a lower surface pressure, the lipid monolayer of DPPC has exhibited a thickening effect at a low concentration of added LA and a thinning effect at higher concentration. However, at a high surface pressure of the monolayer, the thickness is found to decrease monotonically. The in-plane pressure-dependent interaction of LA molecules with model cellular membrane and the corresponding perturbation in the structure and physical properties of the membrane may be linked to the strong lysing effect of these types of molecules.
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Affiliation(s)
| | | | - A Singh
- Surface Physics and Material Science Division , Saha Institute of Nuclear Physics , AF Block, Bidhannagar , Kolkata 700064 , India
| | - M K Mukhopadhyay
- Surface Physics and Material Science Division , Saha Institute of Nuclear Physics , AF Block, Bidhannagar , Kolkata 700064 , India
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Bhattacharya G, Giri RP, Dubey A, Mitra S, Priyadarshini R, Gupta A, Mukhopadhyay MK, Ghosh SK. Structural changes in cellular membranes induced by ionic liquids: From model to bacterial membranes. Chem Phys Lipids 2018; 215:1-10. [PMID: 29944866 DOI: 10.1016/j.chemphyslip.2018.06.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 06/16/2018] [Accepted: 06/18/2018] [Indexed: 12/19/2022]
Abstract
Ionic liquids (ILs) have generated considerable attention recently because of their cytotoxicity and application as antibiotics. However, the mechanism of how they damage cell membranes is not currently well understood. In this paper, the antibacterial activities of two imidazolium-based ILs, namely 1-butyl- 3-methylimidazolium tetrafluroborate ([BMIM][BF4]) and 1-ethyl- 3-methylimidazolium tetrafluroborate ([EMIM][BF4]) have been investigated. The activity of [BMIM][BF4] on gram negative bacteria E. coli is observed to be stronger compared with the short chained [EMIM][BF4]. To explain this observation, the effects of these ILs on the self-assembled structures of model cellular membranes have been investigated. The in-plane elasticity of a monolayer formed at air-water interface by 1,2-dipalmitoyl- sn-glycero- 3-phosphocholine (DPPC) lipids was reduced in the presence of the ILs. The x-ray reflectivity studies on polymer supported lipid bilayer have shown the bilayer to shrink and correspondingly exhibit an increase in electron density. The presence of a certain mol% of negatively charged lipid, 1,2-dipalmitoyl-rac-glycero-3-phospho-L-serine (DPPS), in DPPC mono- and bi-layers enhances the effect considerably.
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Affiliation(s)
- G Bhattacharya
- Department of Physics, School of Natural Sciences, Shiv Nadar University, NH-91, Tehsil Dadri, G. B. Nagar, Uttar Pradesh, 201314, India
| | - R P Giri
- Surface Physics and Material Science Division, Saha Institute of Nuclear Physics, Bidhannagar, Kolkata, 700064, India
| | - A Dubey
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, NH-91, Tehsil Dadri, G. B. Nagar, Uttar Pradesh, 201314, India
| | - S Mitra
- Department of Physics, School of Natural Sciences, Shiv Nadar University, NH-91, Tehsil Dadri, G. B. Nagar, Uttar Pradesh, 201314, India
| | - R Priyadarshini
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, NH-91, Tehsil Dadri, G. B. Nagar, Uttar Pradesh, 201314, India
| | - A Gupta
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, NH-91, Tehsil Dadri, G. B. Nagar, Uttar Pradesh, 201314, India
| | - M K Mukhopadhyay
- Surface Physics and Material Science Division, Saha Institute of Nuclear Physics, Bidhannagar, Kolkata, 700064, India
| | - S K Ghosh
- Department of Physics, School of Natural Sciences, Shiv Nadar University, NH-91, Tehsil Dadri, G. B. Nagar, Uttar Pradesh, 201314, India.
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Bhattacharya G, Giri RP, Saxena H, Agrawal VV, Gupta A, Mukhopadhyay MK, Ghosh SK. X-ray Reflectivity Study of the Interaction of an Imidazolium-Based Ionic Liquid with a Soft Supported Lipid Membrane. Langmuir 2017; 33:1295-1304. [PMID: 28092704 DOI: 10.1021/acs.langmuir.6b03192] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Ionic liquids (ILs) are important for their antimicrobial activity and are found to be toxic to some microorganisms. To shed light on the mechanism of their activities, the interaction of an imidazolium-based IL 1-butyl-3-methylimidazolium tetrfluoroborate ([BMIM][BF4]) with E. coli bacteria and cell-membrane-mimicking lipid mono- and bilayers has been studied. The survival of the bacteria and corresponding growth inhibition are observed to be functions of the concentration of the IL. The IL alters the pressure-area isotherm of the monolayer formed at an air-water interface by the 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) lipid. The in-plane elasticity of the lipid layer is reduced as a consequence of the insertion of this IL. The X-ray reflectivity study from a polymer-supported lipid bilayer shows strong perturbation in the self-assembled structure of the bilayer due to the interaction. As a consequence, there is a considerable decrease in bilayer thickness and a corresponding increase in electron density. These results, however, depend on the chain configurations of the lipid molecules.
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Affiliation(s)
| | - R P Giri
- Saha Institute of Nuclear Physics, Bidhannagar, Kolkata 700064, India
| | | | - V V Agrawal
- National Physical Laboratory, Dr. K S Krishnan Marg, New Delhi 110012, India
| | | | - M K Mukhopadhyay
- Saha Institute of Nuclear Physics, Bidhannagar, Kolkata 700064, India
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Mukhopadhyay MK, Lurio LB, Jiang Z, Jiao X, Sprung M, DeCaro C, Sinha SK. Measurement of the interior structure of thin polymer films using grazing incidence diffuse x-ray scattering. Phys Rev E Stat Nonlin Soft Matter Phys 2010; 82:011804. [PMID: 20866641 DOI: 10.1103/physreve.82.011804] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Indexed: 05/29/2023]
Abstract
A method is developed for calculating the small-angle x-ray scattering originating from within the interior of a thin film under grazing incidence illumination. This offers the possibility of using x-ray scattering to probe how the structure of polymers is modified by confinement. When the diffuse scattering from a thin film is measured over a range of incident angles, it is possible to separate the contributions to scattering from the interfaces and the contribution from the film interior. Using the distorted-wave Born approximation the structure factor, S(q), of the film interior can then be obtained. We apply this method to analyze density fluctuations from within the interior of a silicon supported molten polystyrene (PS) film. Measurements were made as a function of film thickness ranging from one to ten times the polymer radius of gyration (Rg). The compressibility, calculated by extrapolating the measured S(q) to q=0, agrees well with that of bulk PS for thick films, but thinner films exhibit a peak in S(q) near q=0. This peak, which grows with decreasing thickness, is attributed to a decreased interpenetration of chains and a consequent enhanced compressibility.
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Affiliation(s)
- M K Mukhopadhyay
- Department of Physics, University of California-San Diego, La Jolla, California 92093, USA
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Srivastava S, Kandar AK, Basu JK, Mukhopadhyay MK, Lurio LB, Narayanan S, Sinha SK. Complex dynamics in polymer nanocomposites. Phys Rev E Stat Nonlin Soft Matter Phys 2009; 79:021408. [PMID: 19391748 DOI: 10.1103/physreve.79.021408] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2008] [Indexed: 05/27/2023]
Abstract
Polymer nanocomposites offer the potential to create a new type of hybrid material with unique thermal, optical, or electrical properties. Understanding their structure, phase behavior, and dynamics is crucial for realizing such potentials. In this work we provide an experimental insight into the dynamics of such composites in terms of the temperature, wave vector, and volume fraction of nanoparticles, using multispeckle synchrotron x-ray photon correlation spectroscopy measurements on gold nanoparticles embedded in polymethylmethacrylate. Detailed analysis of the intermediate scattering functions reveals possible existence of an intrinsic length scale for dynamic heterogeneity in polymer nanocomposites similar to that seen in other soft materials like colloidal gels and glasses.
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Affiliation(s)
- S Srivastava
- Department of Physics, Indian Institute of Science, Bangalore 560 012, India
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Mukhopadhyay MK, Jiao X, Lurio LB, Jiang Z, Stark J, Sprung M, Narayanan S, Sandy AR, Sinha SK. Thickness induced structural changes in polystyrene films. Phys Rev Lett 2008; 101:115501. [PMID: 18851293 DOI: 10.1103/physrevlett.101.115501] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2007] [Revised: 07/17/2008] [Indexed: 05/26/2023]
Abstract
Changes to the structure of polystyrene melt films as measured through the spectrum of density fluctuations have been observed as a function of film thickness down to the polymer radius of gyration (Rg). Films thicker than 4Rg show bulklike density fluctuations. Thinner films exhibit a peak in S(q) near q=0 which grows with decreasing thickness. This peak is attributed to a decreased interpenetration of chains resulting in an enhanced compressibility. Measurements were made using small angle x-ray scattering in a standing wave geometry designed to enhance scattering from the interior of the film compared to interface scattering.
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Affiliation(s)
- M K Mukhopadhyay
- Department of Physics, University of California San Diego, La Jolla, California 92093, USA
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Mondal D, Barat S, Mukhopadhyay MK. Toxicity of neem pesticides on a fresh water loach, Lepidocephalichthys guntea (Hamilton Buchanan) of Darjeeling district in West Bengal. J Environ Biol 2007; 28:119-22. [PMID: 17717997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Static renewal bioassay tests were conducted to evaluate the acute toxicity of two neem based biopesticides, applied widely on tea plantation namely, Nimbecidine and Neem Gold either separately as well as, in combination to the fingerlings (mean body length- 4.46 +/- 0.15 cm; mean body weight- 0.49 +/- 0.15g) of a fresh water loach, Lepidocephalichthys guntea (Hamilton Buchanan) acclimatized to laboratory conditions prior to experiment. The 96 hours LC50 values for Nimbecidine and Neem Gold and the combination of the two were 0.0135 mgl(-1), 0.0525mgl(-1) and 0.0396 mgl(-1), respectively. The regular water quality analysis showed, that with increasing doses of biopesticides, dissolved oxygen level was lower and other parameters like pH, free carbon dioxide, total alkalinity total hardness, chloride ions of water increased. The fish under toxicity stress suffered several abnormalities such as erratic and rapid movement, body imbalance and surface floating responding proportionately to the increase in concentrations of the toxicant biopesticides. The 96 hours LC50 values proved Nimbecidine more toxic than Neem Gold and the combination of the two biopesticides.
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Affiliation(s)
- Debashri Mondal
- Aquaculture and Limnology Laboratory, Department of Zoology University of North Bengal, Darjeeling-734 013, India
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