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Abstract
Fatty acids, cholesterol, and phospholipids are amphiphilic compounds of biological interest, which form ordered monolayers mimicking biomembranes, and can be studied with the Langmuir technique using surface pressure-area isotherms and compressibility plots. Proteins are also components of biomembranes or are present in body fluids. In this study, the influence of lysozyme on different films of a fatty acid (stearic acid or oleic acid), cholesterol, a phospholipid (dipalmitoylphosphatidylcholine, DPPC, or palmitoyloleoylphosphatidylcholine, POPC), and mixtures of them is presented using a 0.9% saline solution as subphase. Results show that the presence of lysozyme alters the lipid monolayer formation in an important way at the beginning (low surface pressures) and the middle (intermediate surface pressures) parts of the isotherm. At high surface pressures, the phospholipids DPPC and POPC and the saturated fatty acid, stearic acid, expel lysozyme from the surface, while oleic acid and cholesterol permit the presence of lysozyme on it. The mixtures of oleic acid-DPPC also expel lysozyme from the surface at high surface pressures, while mixtures of oleic acid-POPC and cholesterol-POPC permit the presence of lysozyme on it. The compressibility of the monolayer is affected in all cases, with an important reduction in the elastic modulus values and an increase in the fluidity, especially at low and intermediate surface pressures.
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Rehman J, Sowah-Kuma D, Stevens AL, Bu W, Paige MF. Immiscible Anionic Gemini Surfactant-Perfluorinated Fatty Acid Langmuir Monolayer Films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:10551-10560. [PMID: 31309841 DOI: 10.1021/acs.langmuir.9b01554] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
A new member of the N,N,N',N'-dialkyl-N,N'-diacetate ethylenediamine family of anionic gemini surfactants has been synthesized, and its miscibility with the model perfluorocarbon, perfluorotetradecanoic acid (PF), has been investigated in monolayer films at the air-water interface. Thermodynamics of mixing and the accompanying changes in the mixed film structure have been probed using a combination of compression isotherm measurements supported by Brewster angle microscope imaging and X-ray scattering measurements, and results have been compared with those collected for a previously studied, shorter tail chain variant of the surfactant. Thermodynamic measurements showed that the gemini surfactant and perfluorotetradecanoic acid were immiscible, with weak repulsive interactions, manifesting as small positive deviations from ideal mixing, observed between the two film components. Films were highly textured, with micrometer-scale, phase-separated domains readily detectable. Grazing incidence X-ray diffraction measurements showed that the gemini surfactant was disordered in the monolayers, whereas the perfluorocarbon formed discrete crystallites in the disordered matrix. Despite the small deviations from ideal mixing detected in the thermodynamic measurements, the X-ray measurements indicated that the presence of the gemini perturbs the PF crystal lattice from that of pure PF. Finally, X-ray reflectivity measurements showed that the addition of equimolar PF to the gemini monolayer induces a significant increase in the nominal head group thickness of the film, suggesting that interactions between the two surfactants can lead to structural rearrangements of gemini's head group near to the water surface.
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Affiliation(s)
- Jeveria Rehman
- Department of Chemistry, 110 Science Place , University of Saskatchewan , Saskatoon , Saskatchewan S7N 5C9 , Canada
| | - David Sowah-Kuma
- Department of Chemistry, 110 Science Place , University of Saskatchewan , Saskatoon , Saskatchewan S7N 5C9 , Canada
| | - Amy L Stevens
- Department of Chemistry, 110 Science Place , University of Saskatchewan , Saskatoon , Saskatchewan S7N 5C9 , Canada
| | - Wei Bu
- NSF's ChemMatCARS , The University of Chicago , Chicago , Illinois 60637 , United States
| | - Matthew F Paige
- Department of Chemistry, 110 Science Place , University of Saskatchewan , Saskatoon , Saskatchewan S7N 5C9 , Canada
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Wang D, de Jong DH, Rühling A, Lesch V, Shimizu K, Wulff S, Heuer A, Glorius F, Galla HJ. Imidazolium-Based Lipid Analogues and Their Interaction with Phosphatidylcholine Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:12579-12592. [PMID: 27934518 DOI: 10.1021/acs.langmuir.6b02496] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
4,5-Dialkylated imidazolium lipid salts are a new class of lipid analogues showing distinct biological activities. The potential effects of the imidazolium lipids on artificial lipid membranes and the corresponding membrane interactions was analyzed. Therefore, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) was employed to create an established lipid monolayer model and a bilayer membrane. Mixed monolayers of DPPC and 4,5-dialkylimidazolium lipids differing by their alkyl chain length (C7, C11, and C15) were characterized by surface pressure-area (π-A) isotherms using a Wilhelmy film balance in combination with epifluorescence microscopy. Monolayer hysteresis for binary mixtures was examined by recording triplicate consecutive compression-expansion cycles. The lipid miscibility and membrane stability of DPPC/imidazolium lipids were subsequently evaluated by the excess mean molecular area (ΔAex) and the excess Gibbs free energy (ΔGex) of mixing. Furthermore, the thermotropic behavior of mixed liposomes of DPPC/imidazolium lipids was investigated by differential scanning calorimetry (DSC). The C15-imidazolium lipid (C15-IMe·HI) forms a thermodynamically favored and kinetically reversible Langmuir monolayer with DPPC and exhibits a rigidification effect on both DPPC monolayer and bilayer structures at low molar fractions (X ≤ 0.3). However, the incorporation of the C11-imidazolium lipid (C11-IMe·HI) causes the formation of an unstable and irreversible Langmuir-Gibbs monolayer with DPPC and disordered DPPC liposomes. The C7-imidazolium lipid (C7-IMe·HI) displays negligible membrane activity. To better understand these results on a molecular level, all-atom molecular dynamics (MD) simulations were performed. The simulations yield two opposing molecular mechanisms governing the different behavior of the three imidazolium lipids: a lateral ordering effect and a free volume/stretching effect. Overall, our study provides the first evidence that the membrane interaction of the C15 and C11 derivatives modulates the structural organization of lipid membranes. On the contrary, for the C7 derivative its membrane activity is too low to contribute to its earlier reported potent cytotoxicity.
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Affiliation(s)
- Da Wang
- Institut für Biochemie, ‡Institut für Physikalische Chemie, and §Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster , Wilhelm-Klemm-Straße 2, D-48149 Münster, Germany
| | - Djurre H de Jong
- Institut für Biochemie, ‡Institut für Physikalische Chemie, and §Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster , Wilhelm-Klemm-Straße 2, D-48149 Münster, Germany
| | - Andreas Rühling
- Institut für Biochemie, ‡Institut für Physikalische Chemie, and §Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster , Wilhelm-Klemm-Straße 2, D-48149 Münster, Germany
| | - Volker Lesch
- Institut für Biochemie, ‡Institut für Physikalische Chemie, and §Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster , Wilhelm-Klemm-Straße 2, D-48149 Münster, Germany
| | - Karina Shimizu
- Institut für Biochemie, ‡Institut für Physikalische Chemie, and §Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster , Wilhelm-Klemm-Straße 2, D-48149 Münster, Germany
| | - Stephanie Wulff
- Institut für Biochemie, ‡Institut für Physikalische Chemie, and §Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster , Wilhelm-Klemm-Straße 2, D-48149 Münster, Germany
| | - Andreas Heuer
- Institut für Biochemie, ‡Institut für Physikalische Chemie, and §Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster , Wilhelm-Klemm-Straße 2, D-48149 Münster, Germany
| | - Frank Glorius
- Institut für Biochemie, ‡Institut für Physikalische Chemie, and §Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster , Wilhelm-Klemm-Straße 2, D-48149 Münster, Germany
| | - Hans-Joachim Galla
- Institut für Biochemie, ‡Institut für Physikalische Chemie, and §Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster , Wilhelm-Klemm-Straße 2, D-48149 Münster, Germany
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4
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Rühling A, Wang D, Ernst JB, Wulff S, Honeker R, Richter C, Ferry A, Galla HJ, Glorius F. Influence of the Headgroup of Azolium-Based Lipids on Their Biophysical Properties and Cytotoxicity. Chemistry 2016; 23:5920-5924. [PMID: 27726228 DOI: 10.1002/chem.201604182] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Indexed: 02/01/2023]
Abstract
A series of (un-)charged NHC derivatives bearing two pentadecyl chains in the backbone was studied in detail to find cooperative effects between the membrane and the NHC derivative. The tendency to show lipid-like behavior is dependent on the properties of the NHC derivative headgroup, which can be modified on demand. The surface activity was investigated by film balance measurements, epifluorescence microscopy, and differential scanning calorimetry. Additionally the cytotoxicity was evaluated against different cell lines such as eukaryotic tumor cell lines. These novel lipid-like NHC derivatives offer a broad spectrum for biological applications.
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Affiliation(s)
- Andreas Rühling
- Westfälische Wilhelms-Universität Münster, Organisch-Chemisches Institut, Corrensstrasse 40, 48149, Münster, Germany
| | - Da Wang
- Westfälische Wilhelms-Universität Münster, Institut für Biochemie, Wilhelm-Klemm-Straße 2, 48149, Münster, Germany
| | - Johannes B Ernst
- Westfälische Wilhelms-Universität Münster, Organisch-Chemisches Institut, Corrensstrasse 40, 48149, Münster, Germany
| | - Stephanie Wulff
- Westfälische Wilhelms-Universität Münster, Institut für Biochemie, Wilhelm-Klemm-Straße 2, 48149, Münster, Germany
| | - Roman Honeker
- Westfälische Wilhelms-Universität Münster, Organisch-Chemisches Institut, Corrensstrasse 40, 48149, Münster, Germany
| | - Christian Richter
- Westfälische Wilhelms-Universität Münster, Organisch-Chemisches Institut, Corrensstrasse 40, 48149, Münster, Germany
| | - Angélique Ferry
- Westfälische Wilhelms-Universität Münster, Organisch-Chemisches Institut, Corrensstrasse 40, 48149, Münster, Germany
| | - Hans-Joachim Galla
- Westfälische Wilhelms-Universität Münster, Institut für Biochemie, Wilhelm-Klemm-Straße 2, 48149, Münster, Germany
| | - Frank Glorius
- Westfälische Wilhelms-Universität Münster, Organisch-Chemisches Institut, Corrensstrasse 40, 48149, Münster, Germany
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The effect of perfluorooctadecanoic acid on a model phosphatidylcholine–peptide pulmonary lung surfactant mixture. J Fluor Chem 2015. [DOI: 10.1016/j.jfluchem.2015.05.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Thermodynamic analysis and AFM study of the interaction of palmitic acid with DPPE in Langmuir monolayers. Colloids Surf A Physicochem Eng Asp 2014. [DOI: 10.1016/j.colsurfa.2013.08.073] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Farnoud AM, Fiegel J. Interaction of Dipalmitoyl Phosphatidylcholine Monolayers with a Particle-Laden Subphase. J Phys Chem B 2013; 117:12124-34. [DOI: 10.1021/jp405924y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Amir M. Farnoud
- Department
of Chemical and Biochemical Engineering, The University of Iowa, 4133 Seamans Center, Iowa City, Iowa 52242, United States
| | - Jennifer Fiegel
- Department
of Chemical and Biochemical Engineering, The University of Iowa, 4133 Seamans Center, Iowa City, Iowa 52242, United States
- Department
of Pharmaceutical Sciences and Experimental Therapeutics, The University of Iowa, 115 South Grand Avenue, S215 Pharmacy
Building, Iowa City, Iowa 52242, United States
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Bernardini C, Stoyanov SD, Arnaudov LN, Cohen Stuart MA. Colloids in Flatland: a perspective on 2D phase-separated systems, characterisation methods, and lineactant design. Chem Soc Rev 2013; 42:2100-29. [DOI: 10.1039/c2cs35269a] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Eftaiha AF, Brunet SMK, Paige MF. Influence of film composition on the morphology, mechanical properties, and surfactant recovery of phase-separated phospholipid-perfluorinated fatty acid mixed monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:15150-15159. [PMID: 23043367 DOI: 10.1021/la3026655] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Monolayer surfactant films composed of a mixture of phospholipids and perfluorinated (or partially fluorinated) surfactants are of potential utility for applications in pulmonary lung surfactant-based therapies. As a simple, minimal model of such a lung surfactant system, binary mixed monolayer films composed of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and perfluorooctadecanoic acid (C18F) prepared on a simplified lung fluid mimic subphase (pH 7.4, 150 mM NaCl) have been characterized in terms of mixing thermodynamics and compressibility (measured through π–A compression isotherms), film morphology (via atomic force, fluorescence, and Brewster angle microscopy), as well as spreading rate and hysteresis response to repeated expansion–contraction cycles for a variety of compositions of mixed films. Under all mixing conditions, films and their components were found to be completely immiscible and phase-separated, though there were significant changes in the aforementioned film properties as a function of composition. Of particular note was the existence of a maximum in the extent of immiscibility (characterized by ΔG(ex)(π) values) and enhanced surfactant recovery during hysteresis experiments at χ(C18F) ≥ 0.30. The latter was attributed to the relatively rapid respreading rate of the perfluorinated amphiphile in comparison with DPPC alone at the air–water interface, which enhances the performance of this mixture as a potential pulmonary lung surfactant. Further, monolayer film structure could be tracked dynamically as a function of compression at the air–water interface via Brewster angle microscopy, with the C18F component being preferentially squeezed out of the film with compression, but returning rapidly upon re-expansion. In general, addition of C18F to DPPC monolayers resulted in improvements to mechanical, structural, and respreading properties of the film, indicating the potential value of these compounds as additives to pulmonary lung surfactant formulations.
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Affiliation(s)
- Ala'a F Eftaiha
- Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, Saskatchewan, Canada S7N 5C9
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Nakahara H, Shibata O. Langmuir Monolayer Miscibility of Perfluorocarboxylic Acids with Biomembrane Constituents at the Air-Water Interface. J Oleo Sci 2012; 61:197-210. [DOI: 10.5650/jos.61.197] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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11
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Head group effects on molecular packing in lamellar liquid crystals. J Colloid Interface Sci 2011; 361:148-53. [DOI: 10.1016/j.jcis.2011.04.084] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Revised: 04/21/2011] [Accepted: 04/21/2011] [Indexed: 11/20/2022]
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12
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Eftaiha AF, Paige MF. The influence of salinity on surfactant miscibility in mixed dipalmitoylphosphatidylcholine – perfluorooctadecanoic acid monolayer films. J Colloid Interface Sci 2011; 353:210-9. [DOI: 10.1016/j.jcis.2010.09.045] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Revised: 09/16/2010] [Accepted: 09/17/2010] [Indexed: 12/20/2022]
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13
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Kita-Tokarczyk K, Itel F, Grzelakowski M, Egli S, Rossbach P, Meier W. Monolayer interactions between lipids and amphiphilic block copolymers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:9847-9856. [PMID: 19705885 DOI: 10.1021/la900948a] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Interactions in binary mixed monolayers from lipids 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and amphiphilic poly(2-methyloxazoline)-block-poly(dimethylsiloxane)-block-poly(2-methyloxazoline) block copolymers were studied by using the Langmuir balance technique and Brewster angle microscopy. It is shown that monolayers from the saturated lipid (DPPC) are more sensitive to the presence of polymers in the film, resulting in phase separation and the formation of pure lipid domains at high surface pressure. The morphology and composition of such phase-separated lipid-polymer films were studied by fluorescence microscopy and ToF-SIMS. In contrast, in DOPC-containing monolayers, the polymers tend to phase-separate at low surface pressures only and homogeneous films are obtained upon further compression, due to higher lipid fluidity. The analysis of excess energy of mixing shows that while the separation effect in densely packed DPPC-containing films is strongly dependent on the polymer size (with the larger polymer having a much stronger influence), in the case of monolayers with DOPC much smaller effects are observed. The results are discussed in terms of the monolayer composition, lipid fluidity, and polymer size.
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Li WT, Yang YM, Chang CH. Stability enhancement effect of normal long-chain alcohols on ion pair amphiphile monolayers at the air/water interface. J Colloid Interface Sci 2008; 327:426-32. [DOI: 10.1016/j.jcis.2008.08.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2008] [Revised: 07/31/2008] [Accepted: 08/01/2008] [Indexed: 10/21/2022]
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15
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Duncan SL, Larson RG. Comparing experimental and simulated pressure-area isotherms for DPPC. Biophys J 2008; 94:2965-86. [PMID: 18199666 PMCID: PMC2275714 DOI: 10.1529/biophysj.107.114215] [Citation(s) in RCA: 163] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2007] [Accepted: 12/03/2007] [Indexed: 11/18/2022] Open
Abstract
Although pressure-area isotherms are commonly measured for lipid monolayers, it is not always appreciated how much they can vary depending on experimental factors. Here, we compare experimental and simulated pressure-area isotherms for dipalmitoylphosphatidylcholine (DPPC) at temperatures ranging between 293.15 K and 323.15 K, and explore possible factors influencing the shape and position of the isotherms. Molecular dynamics simulations of DPPC monolayers using both coarse-grained (CG) and atomistic models yield results that are in rough agreement with some of the experimental isotherms, but with a steeper slope in the liquid-condensed region than seen experimentally and shifted to larger areas. The CG lipid model gives predictions that are very close to those of atomistic simulations, while greatly improving computational efficiency. There is much more variation among experimental isotherms than between isotherms obtained from CG simulations and from the most refined simulation available. Both atomistic and CG simulations yield liquid-condensed and liquid-expanded phase area compressibility moduli that are significantly larger than those typically measured experimentally, but compare well with some experimental values obtained under rapid compression.
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Affiliation(s)
- Susan L Duncan
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan, USA
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Nakamura S, Nakahara H, Krafft MP, Shibata O. Two-component Langmuir monolayers of single-chain partially fluorinated amphiphiles with dipalmitoylphosphatidylcholine (DPPC). LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:12634-12644. [PMID: 17988164 DOI: 10.1021/la702420v] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The surface pressure (pi)-area (A) and surface potential (DeltaV)-A isotherms were measured for two-component monolayers made of dipalmitoylphosphatidylcholine (DPPC)/single-chain (perfluorooctyl)pentanol (F8C5OH) and DPPC/single-chain (perfluorooctyl)pentylphosphocholine (F8C5PC) on a substrate solution of 0.15 M NaCl at 293.2 K as a function of the composition of the two components. The Langmuir method and the ionizing electrode method were used. The data for these systems were analyzed using an additivity rule. Assuming a regular surface mixture, the Joos equation, which allows description of the collapse pressure of a monolayer made of two miscible components, was used to establish the miscibility within the monolayer. An interaction parameter and an interaction energy were calculated. The two-component DPPC/F8C5OH and DPPC/F8C5PC monolayers were miscible. Furthermore, the mean molecular area, surface potential, and phase diagrams enabled us to determine the molecular orientation of DPPC/F8C5OH and DPPC/F8C5PC in the monolayer. Two types of phase diagrams were obtained and classified into the positive azeotropic and negative azeotropic types. Fluorescence microscopy (FM) and Brewster angle microscopy (BAM) for the DPPC/F8C5OH and DPPC/F8C5PC systems show that both systems can dissolve the ordered micrometer-size solid DPPC domains. However, morphological analyses using atomic force microscopy (AFM) suggest partial miscibility or phase separation for DPPC and the partially fluorinated compounds on the nanometer scale. In particular, triskelion-shaped domains were evidenced for F8C5OH. These results indicate that the partially fluorinated amphiphiles investigated here fluidize the DPPC monolayer upon lateral compression and that these chemicals may be useful to develop their innovative applications in the biomedical field.
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Affiliation(s)
- Shohei Nakamura
- Division of Biointerfacial Science, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
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Chen P, Ma X, Zhang Y, Hu K, Liu M. Nanofibers and nanospirals fabricated through the interfacial organization of a partially fluorinated compound. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:11100-6. [PMID: 17894510 DOI: 10.1021/la701383y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Nanostructures composed of fluorinated compounds are of great interest both for fundamental investigations and practical applications. In this paper, we have investigated the supramolecular assembly of two carbamate derivatives, 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,12-henicosa fluorododecyl 1-naphthylcarbamate (F10C2Np) and 3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,12,12,12-henicosa fluorododecyl phenylcarbamate (F10C2Ph), which bear partially fluorinated alkyl tails on their molecular skeletons, through the air/water interfacial organization. It has been found that F10C2Np could form nanofiber or nanospiral structure with a dimension of several micrometers, while F10C2Ph formed straight ribbon-like structures. More interestingly, when the multilayer films of both of the compounds were subjected to the circular dichroism (CD) measurements, distinct CD signals could be detected, although the compounds themselves are optically inactive. Based on a series of characterizations on the films and the structural features of the molecules, a size mismatching effect was suggested to explain the interesting phenomenon.
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Affiliation(s)
- Penglei Chen
- Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Colloid, Interface and Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences
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