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Valtierrez-Gaytan C, Barakat JM, Kohler M, Kieu K, Stottrup BL, Zasadzinski JA. Spontaneous evolution of equilibrium morphology in phospholipid-cholesterol monolayers. SCIENCE ADVANCES 2022; 8:eabl9152. [PMID: 35385307 PMCID: PMC8986108 DOI: 10.1126/sciadv.abl9152] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 02/16/2022] [Indexed: 06/14/2023]
Abstract
Competition between intradomain electrostatic repulsions and interdomain line tension leads to domain shape transitions in phase-separating lipid monolayers. The question remains if these morphologies are energy minima or are kinetically trapped metastable states. We show the reversible evolution of uniform width stripe domains from polydisperse semicircular domains in monolayers of dipalmitoylphosphatidylcholine (DPPC), hexadecanol (HD) or palmitic acid (PA), and dihydrocholesterol (DChol). The initial semicircular domains grow at a fixed 2:1 DPPC:HD (or PA) stoichiometry, depleting the liquid phase of HD, leaving behind a liquid enriched in DPPC and DChol. At higher surface pressures, the remaining DPPC precipitates onto existing domains, decreasing the ratio of line tension to the square of the dipole density difference, λ/μ2. Theory predicts that, as λ/μ2 decreases, circular domains reversibly transform to uniform width stripes as the minimum energy structure. Measuring the stripe width provides the first estimates of λ/μ2 at liquid condensed-liquid expanded phase coexistence.
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Affiliation(s)
- Cain Valtierrez-Gaytan
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA
| | - Joseph M. Barakat
- Department of Chemical Engineering, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Mitchell Kohler
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA
| | - Khanh Kieu
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA
| | | | - Joseph A. Zasadzinski
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA
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Zhang P, Villanueva V, Kalkowski J, Liu C, Donovan AJ, Bu W, Schlossman ML, Lin B, Liu Y. Molecular interactions of phospholipid monolayers with a model phospholipase. SOFT MATTER 2019; 15:4068-4077. [PMID: 30958491 DOI: 10.1039/c8sm01154k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The intrinsic overexpression of secretory phospholipase A2 (sPLA2) in various pro-inflammatory diseases and cancers has the potential to be exploited as a therapeutic strategy for diagnostics and treatment. To explore this potential and advance our knowledge of the role of sPLA2 in related diseases, it is necessary to systematically investigate the molecular interaction of the enzyme with lipids. By employing a Langmuir trough integrated with X-ray reflectivity and grazing incidence X-ray diffraction techniques, this study examined the molecular packing structure of 1,2-palmitoyl-sn-glycero-3-phosphocholine (DPPC) films before and after enzyme adsorption and enzyme-catalyzed degradation. Molecular interaction of sPLA2 (from bee venom) with the DPPC monolayer exhibited Ca2+ dependence. DPPC molecules at the interface without Ca2+ retained a monolayer organization; upon adsorption of sPLA2 to the monolayer the packing became tighter. In contrast, sPLA2-catalyzed degradation of DPPC occurred in the presence of Ca2+, leading to disruption of the ordered monolayer structure of DPPC. The interfacial film became a mixture of highly ordered multilayer domains of palmitic acid (PA) and loosely packed monolayer phase of 1-palmitoyl-2-hydroxy-sn-glycero-3-phosphocholine (lysoPC) that potentially contained the remaining un-degraded DPPC. The redistribution of lipid degradation products into the third dimension, which produced multilayer PA domains, damaged the structural integrity of the original lipid layer and may explain the bursting of liposomes observed in other studies after a latency period of mixing liposomes with sPLA2. A quantitative understanding of the lipid packing and lipid-enzyme interaction provides an intuitive means of designing and optimizing lipid-related drug delivery systems.
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Affiliation(s)
- Pin Zhang
- Department of Chemical Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA.
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Sachan AK, Choi SQ, Kim KH, Tang Q, Hwang L, Lee KYC, Squires TM, Zasadzinski JA. Interfacial rheology of coexisting solid and fluid monolayers. SOFT MATTER 2017; 13:1481-1492. [PMID: 28125114 PMCID: PMC5720834 DOI: 10.1039/c6sm02797k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Biologically relevant monolayer and bilayer films often consist of micron-scale high viscosity domains in a continuous low viscosity matrix. Here we show that this morphology can cause the overall monolayer fluidity to vary by orders of magnitude over a limited range of monolayer compositions. Modeling the system as a two-dimensional suspension in analogy with classic three-dimensional suspensions of hard spheres in a liquid solvent explains the rheological data with no adjustable parameters. In monolayers with ordered, highly viscous domains dispersed in a continuous low viscosity matrix, the surface viscosity increases as a power law with the area fraction of viscous domains. Changing the phase of the continuous matrix from a disordered fluid phase to a more ordered, condensed phase dramatically changes the overall monolayer viscosity. Small changes in the domain density and/or continuous matrix composition can alter the monolayer viscosity by orders of magnitude.
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Affiliation(s)
- A K Sachan
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, USA.
| | - S Q Choi
- Departments of Chemical and Biomolecular Engineering and KINC, KAIST, Daejeon, 305-701, Korea
| | - K H Kim
- Departments of Chemical and Biomolecular Engineering and KINC, KAIST, Daejeon, 305-701, Korea
| | - Q Tang
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, USA.
| | - L Hwang
- Department of Chemistry, Institute for Biophysical Dynamics, and James Franck Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - K Y C Lee
- Department of Chemistry, Institute for Biophysical Dynamics, and James Franck Institute, University of Chicago, Chicago, Illinois 60637, USA
| | - T M Squires
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, USA
| | - J A Zasadzinski
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, USA.
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Miller M, Chu M, Lin B, Meron M, Dutta P. Observation of Ordered Structures in Counterion Layers near Wet Charged Surfaces: A Potential Mechanism for Charge Inversion. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:73-77. [PMID: 26691202 DOI: 10.1021/acs.langmuir.5b04058] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Charged (e.g., colloidal) particles in aqueous solutions will sometimes behave as though their effective charge has reversed, rather than reduced, by the attracted counterions. This is counterintuitive because it increases the electrostatic energy, but it has been proposed that lateral ordering of the ions could lower the free energy and favor overcharging (charge inversion). Using X-ray diffraction, we have observed sharp diffraction peaks from incommensurate Er(3+) counterion monolayers near charged surfaces formed by floating molecular monolayers. When the counterion lattice does not match the molecular surface lattice, this means that there is no specific attachment of ions, and thus the ionic lattice is formed due to interactions between charges in the counterlayer. Therefore, the existence of incommensurate ion lattices indicates that counterion ordering is a realistic mechanism. However, in this system our data rule out a well-known proposed "physical" mechanism-the Wigner liquid phase driven by Coulomb interactions.
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Affiliation(s)
- Mitchell Miller
- Department of Physics & Astronomy, Northwestern University , Evanston, Illinois 60208, United States
| | - Miaoqi Chu
- Department of Physics & Astronomy, Northwestern University , Evanston, Illinois 60208, United States
| | - Binhua Lin
- Center for Advanced Radiation Sources, University of Chicago , Chicago, Illinois 60637, United States
| | - Mati Meron
- Center for Advanced Radiation Sources, University of Chicago , Chicago, Illinois 60637, United States
| | - Pulak Dutta
- Department of Physics & Astronomy, Northwestern University , Evanston, Illinois 60208, United States
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Mattu JS, Leach GW. Large Scale Crystallinity in Kinetically Stable Polythiophene-Based Langmuir−Blodgett Films. J Am Chem Soc 2010; 132:3204-10. [DOI: 10.1021/ja910390g] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jusroop S. Mattu
- Department of Chemistry, 4D LABS, and Laboratory for Advanced Spectroscopy and Imaging Research, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6 Canada
| | - Gary W. Leach
- Department of Chemistry, 4D LABS, and Laboratory for Advanced Spectroscopy and Imaging Research, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6 Canada
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Blanco E, Piñeiro A, Miller R, Ruso JM, Prieto G, Sarmiento F. Langmuir monolayers of a hydrogenated/fluorinated catanionic surfactant: from the macroscopic to the nanoscopic size scale. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:8075-8082. [PMID: 19449890 DOI: 10.1021/la900593c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Langmuir monolayers of the hydrogenated/fluorinated catanionic surfactant cetyltrimethylammonium perfluorooctanoate at the air/water interface are studied at room temperature. Excess Gibbs energies of mixing, DeltaG(E), as well as transition areas and pressures, were obtained from the surface pressure-area isotherm. The DeltaG(E) curve indicates that tail-tail interactions are more important than head-head interactions at low pressures and vice versa. Atomic force microscopy and molecular dynamics simulations allowed a fine characterization of the monolayer structure as a function of the area per molecule at mesoscopic and nanoscopic size scales, respectively. A combined analysis of the techniques allow us to conclude that electrostatic interactions between the ionic head groups are dominant in the monolayer while hydrophobic parts are of secondary importance. Overall, results obtained from the different techniques complement to each other, giving a comprehensive characterization of the monolayer.
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Affiliation(s)
- Elena Blanco
- Department of Applied Physics, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain
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Kmetko J, Datta A, Evmenenko G, Dutta P. The Effects of Divalent Ions on Langmuir Monolayer and Subphase Structure: A Grazing-Incidence Diffraction and Bragg Rod Study. J Phys Chem B 2001. [DOI: 10.1021/jp0122169] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Datta A, Sanyal MK, Dhanabalan A, Major SS. Formation of Highly Condensed Ferric Stearate Monolayers at the Air−Water Interface. J Phys Chem B 1997. [DOI: 10.1021/jp971703e] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Fenter P, Eberhardt A, Liang KS, Eisenberger P. Epitaxy and chainlength dependent strain in self-assembled monolayers. J Chem Phys 1997. [DOI: 10.1063/1.473281] [Citation(s) in RCA: 122] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Wang Z, Gong C. Molecular orientational vibrations in monolayer systems. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:17067-17077. [PMID: 9985840 DOI: 10.1103/physrevb.54.17067] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Wang Z, Gong C. Molecular orientational vibrations and thermodynamics in monolayers of chain molecules. J Chem Phys 1996. [DOI: 10.1063/1.472513] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Kurnaz ML, Schwartz DK. Morphology of Microphase Separation in Arachidic Acid/Cadmium Arachidate Langmuir-Blodgett Multilayers. ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp960665g] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- M. L. Kurnaz
- Department of Chemistry, Tulane University, New Orleans, Louisiana 70118
| | - D. K. Schwartz
- Department of Chemistry, Tulane University, New Orleans, Louisiana 70118
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Woodward JT, Zasadzinski JA. Amplitude, wave form, and temperature dependence of bilayer ripples in the P beta ' phase. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1996; 53:R3044-R3047. [PMID: 9964762 DOI: 10.1103/physreve.53.r3044] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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