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Venettacci S, Ponticelli GS, Tagliaferri F, Guarino S. Environmental and Economic Impact of an Innovative Biocide-Free Antifouling Coating for Naval Applications. MATERIALS (BASEL, SWITZERLAND) 2023; 16:748. [PMID: 36676483 PMCID: PMC9860572 DOI: 10.3390/ma16020748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 01/08/2023] [Accepted: 01/09/2023] [Indexed: 06/17/2023]
Abstract
The work provides an economic sustainability and environmental impact analysis for the validation of a biocide-free antifouling coating for marine applications able to reduce fuel consumption during navigation, CO2 emissions, and the overall environmental impacts associated with shipping, thanks to the reduction of incrustation and the avoidance of biocides release into the water. The results, related to the life cycle of the coating of a motor yacht, with an average sailing life of 25 years, show around 8.8% reduction in overall costs compared to a conventional paint, thanks to a more efficient antifouling action, which reduces the annual fuel consumption by ~13,700 kg/y, or ~9.6%. This leads to a reduction in CO2 emissions, associated with fuel consumption, of ~43.3 ton/y, as well as a lowering of the overall environmental impacts associated with the life cycle of the paint, by almost 10% for the most impactful damage classes, ensuring a greater environmental sustainability of the innovative coating, for the overall service life of the yacht on which it is applied.
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Affiliation(s)
- Simone Venettacci
- Department of Engineering, University of Rome Niccolò Cusano, Via don Carlo Gnocchi 3, 00166 Rome, Italy
| | | | - Flaviana Tagliaferri
- Faculty of Engineering Sciences, Hochschule Mittweida University of Applied Sciences, Technikumplatz 17, 09644 Mittweida, Germany
| | - Stefano Guarino
- Department of Engineering, University of Rome Niccolò Cusano, Via don Carlo Gnocchi 3, 00166 Rome, Italy
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2
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Nigam P. Equilibrium penetration of pluronic F-68 in lipid monolayers. Chem Phys Lipids 2020; 228:104888. [DOI: 10.1016/j.chemphyslip.2020.104888] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 01/06/2020] [Accepted: 02/01/2020] [Indexed: 10/25/2022]
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3
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Langeveld SAG, Schwieger C, Beekers I, Blaffert J, van Rooij T, Blume A, Kooiman K. Ligand Distribution and Lipid Phase Behavior in Phospholipid-Coated Microbubbles and Monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:3221-3233. [PMID: 32109064 PMCID: PMC7279639 DOI: 10.1021/acs.langmuir.9b03912] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Phospholipid-coated targeted microbubbles are ultrasound contrast agents that can be used for molecular imaging and enhanced drug delivery. However, a better understanding is needed of their targeting capabilities and how they relate to microstructures in the microbubble coating. Here, we investigated the ligand distribution, lipid phase behavior, and their correlation in targeted microbubbles of clinically relevant sizes, coated with a ternary mixture of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) or 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC), with PEG40-stearate and DSPE-PEG2000. To investigate the effect of lipid handling prior to microbubble production in DSPC-based microbubbles, the components were either dispersed in aqueous medium (direct method) or first dissolved and mixed in an organic solvent (indirect method). To determine the lipid-phase behavior of all components, experiments were conducted on monolayers at the air/water interface. In comparison to pure DSPC and DPPC, the ternary mixtures had an additional transition plateau around 10-12 mN/m. As confirmed by infrared reflection absorption spectroscopy (IRRAS), this plateau was due to a transition in the conformation of the PEGylated components (mushroom to brush). While the condensed phase domains had a different morphology in the ternary DPPC and DSPC monolayers on the Langmuir trough, the domain morphology was similar in the coating of both ternary DPPC and DSPC microbubbles (1.5-8 μm diameter). The ternary DPPC microbubbles had a homogenous ligand distribution and significantly less liquid condensed (LC) phase area in their coating than the DSPC-based microbubbles. For ternary DSPC microbubbles, the ligand distribution and LC phase area in the coating depended on the lipid handling. The direct method resulted in a heterogeneous ligand distribution, less LC phase area than the indirect method, and the ligand colocalizing with the liquid expanded (LE) phase area. The indirect method resulted in a homogenous ligand distribution with the largest LC phase area. In conclusion, lipid handling prior to microbubble production is of importance for a ternary mixture of DSPC, PEG40-stearate, and DSPE-PEG2000.
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Affiliation(s)
- Simone A. G. Langeveld
- Department
of Biomedical Engineering, Thoraxcenter,
Erasmus MC, 3000 CA Rotterdam, The Netherlands
- E-mail: . Phone: +31107044041
| | - Christian Schwieger
- Physical
Chemistry, Institute of Chemistry, Martin
Luther University Halle-Wittenberg, 06099 Halle (Saale), Germany
- Institute
for Biochemistry and Biotechnology, Interdisciplinary Research Center
HALOmem, Martin Luther University Halle-Wittenberg, Charles Tanford Protein Center, 06120 Halle (Saale), Germany
| | - Inés Beekers
- Department
of Biomedical Engineering, Thoraxcenter,
Erasmus MC, 3000 CA Rotterdam, The Netherlands
| | - Jacob Blaffert
- Physical
Chemistry, Institute of Chemistry, Martin
Luther University Halle-Wittenberg, 06099 Halle (Saale), Germany
| | - Tom van Rooij
- Department
of Biomedical Engineering, Thoraxcenter,
Erasmus MC, 3000 CA Rotterdam, The Netherlands
| | - Alfred Blume
- Physical
Chemistry, Institute of Chemistry, Martin
Luther University Halle-Wittenberg, 06099 Halle (Saale), Germany
| | - Klazina Kooiman
- Department
of Biomedical Engineering, Thoraxcenter,
Erasmus MC, 3000 CA Rotterdam, The Netherlands
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Williams I, Zasadzinski JA, Squires TM. Interfacial rheology and direct imaging reveal domain-templated network formation in phospholipid monolayers penetrated by fibrinogen. SOFT MATTER 2019; 15:9076-9084. [PMID: 31651923 PMCID: PMC6937482 DOI: 10.1039/c9sm01519a] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Phospholipids are found throughout the natural world, including the lung surfactant (LS) layer that reduces pulmonary surface tension and enables breathing. Fibrinogen, a protein involved in the blood clotting process, is implicated in LS inactivation and the progression of disorders such as acute respiratory distress syndrome. However, the interaction between fibrinogen and LS at the air-water interface is poorly understood. Through a combined microrheological, confocal and epifluorescence microscopy approach we quantify the interfacial shear response and directly image the morphological evolution when a model LS monolayer is penetrated by fibrinogen. When injected into the subphase beneath a monolayer of the phospholipid dipalmitoylphosphatidylcholine (DPPC, the majority component of LS), fibrinogen preferentially penetrates disordered liquid expanded (LE) regions and accumulates on the boundaries between LE DPPC and liquid condensed (LC) DPPC domains. Thus, fibrinogen is line active. Aggregates grow from the LC domain boundaries, ultimately forming a percolating network. This network stiffens the interface compared to pure DPPC and imparts the penetrated monolayer with a viscoelastic character reminiscent of a weak gel. When the DPPC monolayer is initially compressed beyond LE-LC coexistence, stiffening is significantly more modest and the penetrated monolayer retains a viscous-dominated, DPPC-like character.
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Affiliation(s)
- Ian Williams
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA.
| | - Joseph A Zasadzinski
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, MN 55455, USA
| | - Todd M Squires
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA.
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5
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Langmuir film formation of amphiphilic hybrid block copolymers based on poly(ethylene glycol) and poly(methacrylo polyhedral oligomeric silsesquioxane). Colloid Polym Sci 2019. [DOI: 10.1007/s00396-019-04517-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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6
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Hasan N, Schwieger C, Tee HT, Wurm FR, Busse K, Kressler J. Crystallization of a polyphosphoester at the air-water interface. Eur Polym J 2018. [DOI: 10.1016/j.eurpolymj.2018.03.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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7
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Jbeily M, Schwieger C, Kressler J. Mixed Langmuir monolayers of perfluorostearic acid and stearic acid studied by epifluorescence microscopy using fluorinated rhodamines and infrared reflection absorption spectroscopy (IRRAS). Colloids Surf A Physicochem Eng Asp 2017. [DOI: 10.1016/j.colsurfa.2017.06.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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8
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Tang X, Wang T, Guo W, Pei M. Solvent- and Coating Mode-induced Surface Patterns of a Ternary Hydrophilic–Lipophilic–Fluorophilic Block Copolymer. CHEM LETT 2016. [DOI: 10.1246/cl.151129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Xinde Tang
- School of Material Science and Engineering, Shandong Jiaotong University
| | - Tieshi Wang
- School of Chemistry and Chemical Engineering, University of Jinan
| | - Wenjuan Guo
- School of Chemistry and Chemical Engineering, University of Jinan
| | - Meishan Pei
- School of Chemistry and Chemical Engineering, University of Jinan
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Naolou T, Hussain H, Baleed S, Busse K, Lechner BD, Kressler J. The behavior of fatty acid modified poly(glycerol adipate) at the air/water interface. Colloids Surf A Physicochem Eng Asp 2015. [DOI: 10.1016/j.colsurfa.2014.12.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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10
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Molecular arrangement of symmetric and non-symmetric triblock copolymers of poly(ethylene oxide) and poly(isobutylene) at the air/water interface. J Colloid Interface Sci 2015; 437:80-89. [PMID: 25313470 DOI: 10.1016/j.jcis.2014.09.050] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2014] [Revised: 09/12/2014] [Accepted: 09/15/2014] [Indexed: 12/16/2022]
Abstract
The behavior of a series of amphiphilic triblock copolymers of poly(ethylene oxide) (PEO) and poly(isobutylene) (PIB); including both symmetric (same degree of polymerization (DP) of the terminal PEO blocks) PEOm-b-PIBn-b-PEOm and non-symmetric (different DP of the terminal PEO blocks) PEOm-b-PIBn-b-PEOz, is investigated at the air/water interface by measuring surface pressure vs mean molecular area isotherms (π vs mmA), Langmuir-Blodgett (LB) technique, and infrared reflection-absorption spectroscopy (IRRAS). The block copolymer (PEO32-b-PIB160-b-PEO32) with longer PEO segments forms a stable monolayer and the isotherm reveals a pseudo-plateau starting at π∼5.7 mN/m, also observed in the IRRAS, which is assigned to the pancake-to-brush transition related to the PEO dissolution into the subphase and subsequent PEO brush dehydration. Another plateau is observed at π∼40 mN/m, which is attributed to the film collapse due to multilayer formation. The pancake-to-brush transition could not be observed for samples with smaller PEO chains. The isotherms for block copolymers, with short PEO chains, both symmetric (PEO3-b-PIBn-b-PEO3) and non-symmetric (PEO12-b-PIBn-b-PEO3), reveal another transition at π∼20-25 mN/m. This is interpreted to be due to the conformational transition from a folded state where the middle PIB block is anchored to the water surface at both ends by the terminal hydrophilic segments to an unfolded state with PIB anchored to the water surface at one end. It is assumed that this transition involves the removal of PEO3 chains from the water surface in case of non-symmetric PEO12-b-PIB85-b-PEO3 and in case of symmetric, probably one PEO3 of each PEO3-b-PIB85-b-PEO3 chain. Because of the weaker interaction of the short PEO3 chains with the water surface as compared with the relatively longer PEO12 chains, the film of PEO3-b-PIB85-b-PEO3 collapses at much lower surface pressure after the transition as compared with the PEO12-b-PIB85-b-PEO3. The AFM images reveal the formation of microdomains of almost uniform height (6-7 nm) in LB films of PEO3-b-PIB85-b-PEO3 and PEO12-b-PIB85-b-PEO3 after transferring onto silicon surfaces. These domains are assumed to be the mesomorphic domains of ordered and folded PIB chains.
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11
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Fuchs C, Hussain H, Amado E, Busse K, Kressler J. Self-Organization of Poly(ethylene oxide) on the Surface of Aqueous Salt Solutions. Macromol Rapid Commun 2014; 36:211-8. [DOI: 10.1002/marc.201400451] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 09/02/2014] [Indexed: 11/10/2022]
Affiliation(s)
- Christian Fuchs
- Martin Luther University Halle-Wittenberg; Department of Chemistry; D-06099 Halle (Saale) Germany
| | - Hazrat Hussain
- Martin Luther University Halle-Wittenberg; Department of Chemistry; D-06099 Halle (Saale) Germany
- Department of Chemistry; Quaid-i-Azam University Islamabad; PK-45320 Islamabad Pakistan
| | - Elkin Amado
- Martin Luther University Halle-Wittenberg; Department of Chemistry; D-06099 Halle (Saale) Germany
| | - Karsten Busse
- Martin Luther University Halle-Wittenberg; Department of Chemistry; D-06099 Halle (Saale) Germany
| | - Joerg Kressler
- Martin Luther University Halle-Wittenberg; Department of Chemistry; D-06099 Halle (Saale) Germany
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12
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Haraguchi K, Kubota K, Takada T, Mahara S. Highly Protein-Resistant Coatings and Suspension Cell Culture Thereon from Amphiphilic Block Copolymers Prepared by RAFT Polymerization. Biomacromolecules 2014; 15:1992-2003. [DOI: 10.1021/bm401914c] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Kazutoshi Haraguchi
- Material Chemistry
Laboratory, Kawamura Institute of Chemical Research, 631 Sakado, Sakura, Chiba, 285-0078, Japan
- Department
of Applied Molecular Chemistry, College of Industrial Technology, Nihon University, Izumi-cho, Narashino, Chiba, 275-8575, Japan
| | - Kazuomi Kubota
- Material Chemistry
Laboratory, Kawamura Institute of Chemical Research, 631 Sakado, Sakura, Chiba, 285-0078, Japan
| | - Tetsuo Takada
- Material Chemistry
Laboratory, Kawamura Institute of Chemical Research, 631 Sakado, Sakura, Chiba, 285-0078, Japan
| | - Saori Mahara
- Material Chemistry
Laboratory, Kawamura Institute of Chemical Research, 631 Sakado, Sakura, Chiba, 285-0078, Japan
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13
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Blume A, Kerth A. Peptide and protein binding to lipid monolayers studied by FT-IRRA spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:2294-305. [PMID: 23816442 DOI: 10.1016/j.bbamem.2013.04.014] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Accepted: 04/12/2013] [Indexed: 12/30/2022]
Abstract
Lipid monolayers at the air-water interface represent half of a lipid bilayer and are therefore suitable model systems for studying the binding of peripheral proteins and polypeptides as well as proteins containing hydrophobic membrane anchors to membrane interfaces. Infrared reflection-absorption spectroscopy (IRRAS) of these monolayer films at the air-water interface provides information on the state of the lipid monolayers as well as on the conformational and orientational order of the film constituents. We will review shortly the experimental set-up and the possibilities for obtaining structural information before several applications of the method to lipid-protein monolayers will be described. We will focus on examples where the analysis of the protein and peptide bands for pure monolayers of these compounds are combined with experiments where the same compounds are bound to lipid monolayers. Combination of these experiments leads to detailed information about the conformational properties and the orientation of the molecules at the air-water interface in contrast to being bound to the lipid-water interface. This article is part of a Special Issue entitled: FTIR in membrane proteins and peptide studies.
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Affiliation(s)
- Alfred Blume
- Institute of Chemistry, Martin-Luther-University Halle-Wittenberg, von-Danckelmann-Platz 4, D-06120, Halle Saale, Germany.
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14
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Hädicke A, Blume A. Interactions of Pluronic block copolymers with lipid monolayers studied by epi-fluorescence microscopy and by adsorption experiments. J Colloid Interface Sci 2013; 407:327-38. [PMID: 23859816 DOI: 10.1016/j.jcis.2013.06.041] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 06/12/2013] [Accepted: 06/13/2013] [Indexed: 10/26/2022]
Abstract
The interactions of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers, i.e. Pluronics F87, F88 and F127, with monolayers composed of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) were investigated with different monolayer techniques. Surface pressure-area isotherms were recorded of co-spread Pluronic/lipid mixtures with different Pluronic content to determine the influence of the polymers on the monolayer phase transitions. The squeeze-out pressure of the polymers upon film compression was dependent on the PPO block length. The monolayer compression experiments were coupled with fluorescence microscopy to visualize the phase separation into polymer-rich and lipid-rich domains and to monitor morphological changes of the lipid domains in the monolayer. Extensive phase separation was observed in the coexistence region between liquid-expanded (LE) and liquid-condensed (LC) lipid phases, where pure polymer domains coexisting with round LE-domains containing polymer, and polymer-free LC-domains were seen. We also investigated the adsorption of Pluronics to a lipid monolayer after injecting a polymer solution underneath a pre-formed lipid monolayer by following the change in pressure at constant area. The results show that polymer adsorption is a superposition of two individual processes with different kinetics. Pluronics with a higher hydrophobicity and with a smaller molecular weight adsorb faster and the type and phase state of the lipid determines the surface pressure where no further Pluronic molecules adsorb to the interface. This critical surface pressure depends on the PPO block length, whereas the strength of the interaction with the lipids is determined by the relative PEO content. This indicates that also interactions between the PEO blocks and the lipid headgroup region are occurring. The interactions with the unsaturated lipid POPC in the liquid-expanded phase turn out to be stronger than for lipids in the liquid-condensed phase, where the polymers are excluded.
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Affiliation(s)
- André Hädicke
- Institute of Chemistry, Martin-Luther-University Halle-Wittenberg, von-Danckelmann-Platz 4, 06120 Halle/Saale, Germany
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Hezaveh S, Samanta S, De Nicola A, Milano G, Roccatano D. Understanding the interaction of block copolymers with DMPC lipid bilayer using coarse-grained molecular dynamics simulations. J Phys Chem B 2012; 116:14333-45. [PMID: 23137298 DOI: 10.1021/jp306565e] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
In this paper, we present a computational model of the adsorption and percolation mechanism of poloxamers (poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) triblock copolymers) across a 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) lipid bilayer. A coarse-grained model was used to cope with the long time scale of the percolation process. The simulations have provided details of the interaction mechanism of Pluronics with lipid bilayer. In particular, the results have shown that polymer chains containing a PPO block with a length comparable to the DMPC bilayer thickness, such as P85, tends to percolate across the lipid bilayer. On the contrary, Pluronics with a shorter PPO chain, such as L64 and F38, insert partially into the membrane with the PPO block part while the PEO blocks remain in water on one side of the lipid bilayer. The percolation of the polymers into the lipid tail groups reduces the membrane thickness and increases the area per lipid. These effects are more evident for P85 than L64 or F38. Our findings are qualitatively in good agreement with published small-angle X-ray scattering experiments that have evidenced a thinning effect of Pluronics on the lipid bilayer as well as the role of the length of the PPO block on the permeation process of the polymer through the lipid bilayer. Our theoretical results complement the experimental data with a detailed structural and dynamic model of poloxamers at the interface and inside the lipid bilayer.
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Affiliation(s)
- Samira Hezaveh
- Jacobs University Bremen, Campus Ring 1, D-28759 Bremen, Germany
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Scholtysek P, Li Z, Kressler J, Blume A. Interactions of DPPC with semitelechelic poly(glycerol methacrylate)s with perfluoroalkyl end groups. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:15651-62. [PMID: 23046205 DOI: 10.1021/la3028226] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Semitelechelic poly(glycerol methacrylate)s having a perfluoroalkyl end group (PGMA(n)-F(9)) were synthesized by ATRP. The interactions of these polymers with different degrees of polymerization with chiral or racemic dipalmitoylphosphatidylcholine (l-DPPC, d-DPPC, or rac-DPPC) monolayers at the air/water interface were studied. Langmuir trough measurements coupled with epifluorescence microscopy allowed for the observation of domain formation within the coexistence region of liquid-expanded (LE) and liquid-condensed (LC) states of DPPC in mixed DPPC-polymer films prepared by spreading a solution of both compounds in the same organic solvent (cospread films). Because of the incorporation of PGMA(n)-F(9) polymers into the LE phase and their line-active behavior, a formation of novel types of domains could be observed. During compression, a thinning out of the tips of two- to six-lobed flowerlike domain structures and consecutive spiral formation appeared for l- and d-DPPC within the two-phase coexistence region (LE/LC) of the monolayer. When rac-DPPC was used, symmetrical stripe formation was induced at the vertices of the domains and fingerprint-like structures were created by convection-inducing movements of the domains at the air/water interface. Additional investigations of the interaction of PGMA(n)-F(9) with DPPC vesicles using differential scanning calorimetry (DSC) supported the finding on the monolayer system that the incorporation of the polymers into the lipid monolayers is not solely driven by the perfluoroalkyl chain but significantly by the hydrophilic polymer part. Apparently, interactions of the PGMA chain with the lipid headgroups are important as the interactions increase with the elongation of the polymer chain, indicating that the polymer also has hydrophobic character.
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Affiliation(s)
- Peggy Scholtysek
- Institute of Chemistry, Martin-Luther University Halle-Wittenberg, Saale, Germany
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Schwieger C, Chen B, Tschierske C, Kressler J, Blume A. Organization of T-shaped facial amphiphiles at the air/water interface studied by infrared reflection absorption spectroscopy. J Phys Chem B 2012; 116:12245-56. [PMID: 22931365 DOI: 10.1021/jp306612k] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We studied the behavior of monolayers at the air/water interface of T-shaped facial amphiphiles which show liquid-crystalline mesophases in the bulk. The compounds are composed of a rigid p-terphenyl core (TP) with two terminal hydrophobic ether linked alkyl chains of equal length and one facial hydrophilic tri(ethylene oxide) chain with a carboxylic acid end group. Due to their amphiphilic nature they form stable Langmuir films at the air/water interface. Depending on the alkyl chain length they show markedly different compression isotherms. We used infrared reflection absorption spectroscopy (IRRAS) to study the changes in molecular organization of the TP films upon compression. We could retrieve information on layer thickness, alkyl chain crystallization, and the orientation of the TP cores within the films. Films of TPs with long (16 carbon atoms: TP 16/3) and short (10 carbon atoms: TP 10/3) alkyl chains were compared. Compression of TP 16/3 leads to crystallization of the terminal alkyl chains, whereas the alkyl chains of TP 10/3 stay fluid over the complete compression range. TP 10/3 shows an extended plateau in the compression isotherm which is due to a layering transition. The mechanism of this layering transition is discussed. Special attention was paid to the question of whether a so-called roll-over collapse occurs during compression. From the beginning to the end of the plateau, the layer thickness is increased from 15 to 38 Å and the orientation of the TP cores changes from parallel to the water surface to isotropic. We conclude that the plateau in the compression isotherm reflects the transition of a TP monolayer to a TP multilayer. The monolayer consists of a sublayer of well-organized TP cores underneath a sublayer of fluid alkyl chains whereas the multilayer consists of a well oriented bottom layer and a disordered top layer. Our findings do not support the model of a roll-over collapse. This study demonstrates how the IRRA band intensity of OH or OD stretching vibrations can be used to retrieve information about layer thickness and refractive indices of the film and how multicomponent IRRA bands can be fitted to retrieve information about the orientation of molecules within the monolayer.
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Affiliation(s)
- Christian Schwieger
- Institute of Chemistry, Martin-Luther-University Halle-Wittenberg, von-Dankelmann-Platz 4, D-06120 Halle (Saale), Germany.
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Li S, Micic M, Orbulescu J, Whyte JD, Leblanc RM. Human islet amyloid polypeptide at the air-aqueous interface: a Langmuir monolayer approach. J R Soc Interface 2012; 9:3118-28. [PMID: 22787008 DOI: 10.1098/rsif.2012.0368] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Human islet amyloid polypeptide (hIAPP) is the source of the major component of the amyloid deposits found in the islets of Langerhans of around 95 per cent type 2 diabetic patients. The formation of aggregates and mature fibrils is thought to be responsible for the dysfunction and death of the insulin-producing pancreatic β-cells. Investigation on the conformation, orientation and self-assembly of the hIAPP at time zero could be beneficial for our understanding of its stability and aggregation process. To obtain these insights, the hIAPP at time zero was studied at the air-aqueous interface using the Langmuir monolayer technique. The properties of the hIAPP Langmuir monolayer at the air-aqueous interface on a NaCl subphase with pH 2.0, 5.6 and 9.0 were examined by surface pressure- and potential-area isotherms, UV-Vis absorption, fluorescence spectroscopy and Brewster angle microscopy. The conformational and orientational changes of the hIAPP Langmuir monolayer under different surface pressures were characterized by p-polarized infrared-reflection absorption spectroscopy, and the results did not show any prominent changes of conformation or orientation. The predominant secondary structure of the hIAPP at the air-aqueous interface was α-helix conformation, with a parallel orientation to the interface during compression. These results showed that the hIAPP Langmuir monolayer at the air-aqueous interface was stable, and no aggregate or domain of the hIAPP at the air-aqueous interface was observed during the time of experiments.
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Affiliation(s)
- Shanghao Li
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Cox Science Center, Coral Gables, FL 33146, USA
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Reuter S, Amado E, Busse K, Kraska M, Stühn B, Tschierske C, Kressler J. Formation of 2D spherulites in Langmuir films of amphiphilic T-shaped liquid crystals. J Colloid Interface Sci 2012; 372:192-201. [DOI: 10.1016/j.jcis.2012.01.036] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Revised: 01/19/2012] [Accepted: 01/20/2012] [Indexed: 10/14/2022]
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20
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Peng X, Hofmann AM, Reuter S, Frey H, Kressler J. Mixed layers of DPPC and a linear poly(ethylene glycol)-b-hyperbranched poly(glycerol) block copolymer having a cholesteryl end group. Colloid Polym Sci 2012. [DOI: 10.1007/s00396-012-2613-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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21
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Brehmer T, Kerth A, Graubner W, Malesevic M, Hou B, Brüser T, Blume A. Negatively charged phospholipids trigger the interaction of a bacterial Tat substrate precursor protein with lipid monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:3534-3541. [PMID: 22263701 DOI: 10.1021/la204473t] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Folded proteins can be translocated across biological membranes via the Tat machinery. It has been shown in vitro that these Tat substrates can interact with membranes prior to translocation. Here we report a monolayer and infrared reflection-absorption spectroscopic (IRRAS) study of the initial states of this membrane interaction, the binding to a lipid monolayer at the air/water interface serving as a model for half of a biological membrane. Using the model Tat substrate HiPIP (high potential iron-sulfur protein) from Allochromatium vinosum, we found that the precursor preferentially interacts with monolayers of negatively charged phospholipids. The signal peptide is essential for the interaction of the precursor protein with the monolayer because the mature HiPIP protein showed no interaction with the lipid monolayer. However, the individual signal peptide interacted differently with the monolayer compared to the complete precursor protein. IRRA spectroscopy indicated that the individual signal peptide forms mainly aggregated β-sheet structures. This β-sheet formation did not occur for the signal peptide when being part of the full length precursor. In this case it adopted an α-helical structure upon membrane insertion. The importance of the signal peptide and the mature domain for the membrane interaction is discussed in terms of current ideas of Tat substrate-membrane interactions.
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Affiliation(s)
- Tina Brehmer
- Institute of Chemistry-Physical Chemistry, Martin-Luther-University Halle-Wittenberg, Von-Danckelmann-Platz 4, 06120 Halle, Germany
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22
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Martinelli E, Sarvothaman MK, Galli G, Pettitt ME, Callow ME, Callow JA, Conlan SL, Clare AS, Sugiharto AB, Davies C, Williams D. Poly(dimethyl siloxane) (PDMS) network blends of amphiphilic acrylic copolymers with poly(ethylene glycol)-fluoroalkyl side chains for fouling-release coatings. II. Laboratory assays and field immersion trials. BIOFOULING 2012; 28:571-582. [PMID: 22702904 DOI: 10.1080/08927014.2012.697897] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Amphiphilic copolymers containing different amounts of poly(ethylene glycol)-fluoroalkyl acrylate and polysiloxane methacrylate units were blended with a poly(dimethyl siloxane) (PDMS) matrix in different proportions to investigate the effect of both copolymer composition and loading on the biological performance of the coatings. Laboratory bioassays revealed optimal compositions for the release of sporelings of Ulva linza, and the settlement of cypris larvae of Balanus amphitrite. The best-performing coatings were subjected to field immersion tests. Experimental coatings containing copolymer showed significantly reduced levels of hard fouling compared to the control coatings (PDMS without copolymer), their performance being equivalent to a coating based on Intersleek 700™. XPS analysis showed that only small amounts of fluorine at the coating surface were sufficient for good antifouling/fouling-release properties. AFM analyses of coatings under immersion showed that the presence of a regular surface structure with nanosized domains correlated with biological performance.
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Affiliation(s)
- Elisa Martinelli
- Dipartimento di Chimica e Chimica Industriale and UdR Pisa INSTM, Università di Pisa, 56126, Pisa, Italy
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Kerth A, Brehmer T, Meister A, Hanner P, Jakob M, Klösgen RB, Blume A. Interaction of a Tat Substrate and a Tat Signal Peptide with Thylakoid Lipids at the Air-Water Interface. Chembiochem 2011; 13:231-9. [DOI: 10.1002/cbic.201100458] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Indexed: 11/09/2022]
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24
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Arouri A, Kerth A, Dathe M, Blume A. The binding of an amphipathic peptide to lipid monolayers at the air/water interface is modulated by the lipid headgroup structure. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:2811-2818. [PMID: 21319763 DOI: 10.1021/la104887s] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We used monolayer techniques combined with infrared reflection absorption spectroscopy (IRRAS) to study the behavior of the 18-mer cationic peptide KLA1 (KLAL KLAL KAW KAAL KLA-NH2) at the air/water interface as well as its interaction with lipid films of different composition. The adsorption of the peptide from the subphase to the air/water interface was observed measuring the increase in surface pressure (π) at constant surface area. The binding of the peptide to lipid monolayers was followed by recording the change in lipid area at a constant surface pressure (π = 30 mN m(-1)). At the air/water interface, the peptide initially adopted an α-helix at large surface area per molecule, that is, low surface pressure, but further accumulation of the peptide at the interface induced a conformational change from α-helix to intermolecular β-sheet, driven by intermolecular aggregation. When the peptide was injected into the subphase underneath lipid monolayers, it adsorbed pronouncedly to anionic monolayers containing phosphatidylglycerol forming an α-helix, but not to zwitterionic lipid monolayers. The large change in area observed upon peptide binding suggests that the peptide helix was incorporated into the apolar chain region of the lipids. An apparent partition coefficient of (0.3-1) × 10(6) M(-1) could be calculated for binding to pure POPG monolayers. Significant differences in binding affinity were observed comparing PG/PC with PG/PE monolayers, with the latter showing a higher binding constant. This shows that not only electrostatic and hydrophobic effects but also specific interactions between the headgroups of the lipids and the peptide side chains modulate the binding affinity.
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Affiliation(s)
- Ahmad Arouri
- Institute of Chemistry, Martin-Luther-University Halle-Wittenberg , von-Danckelmann-Platz 4, D-06120 Halle (Saale), Germany
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Guo W, Tang X, Xu J, Wang X, Chen Y, Yu F, Pei M. Synthesis, characterization, and property of amphiphilic fluorinated abc-type triblock copolymers. ACTA ACUST UNITED AC 2011. [DOI: 10.1002/pola.24573] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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26
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Hussain H, Amado E, Kressler J. Functional Polyether-based Amphiphilic Block Copolymers Synthesized by Atom-transfer Radical Polymerization. Aust J Chem 2011. [DOI: 10.1071/ch11147] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This review deals with the synthesis, physical properties, and applications of amphiphilic block copolymers based on hydrophilic poly(ethylene oxide) (PEO) or hydrophobic poly(propylene oxide) (PPO). Oligomeric PEO and PPO are frequently functionalized by converting their OH end groups into macroinitiators for atom-transfer radical polymerization. They are then used to generate additional blocks as part of complex copolymer architectures. Adding hydrophobic and hydrophilic blocks, respectively, leads to polymers with amphiphilic character in water. They are surface active and form micelles above a critical micellization concentration. Together with recent developments in post-polymerization techniques through quantitative coupling reactions (‘click’ chemistry) a broad variety of tailored functionalities can be introduced to the amphiphilic block copolymers. Examples are outlined including stimuli responsiveness, membrane penetrating ability, formation of multi-compartmentalized micelles, etc.
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Guntupalli R, Sorokulova I, Long R, Olsen E, Neely W, Vodyanoy V. Phage Langmuir monolayers and Langmuir–Blodgett films. Colloids Surf B Biointerfaces 2011; 82:182-9. [DOI: 10.1016/j.colsurfb.2010.08.032] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2010] [Revised: 08/22/2010] [Accepted: 08/23/2010] [Indexed: 11/25/2022]
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28
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Rother M, Barqawi H, Pfefferkorn D, Kressler J, Binder WH. Synthesis and Organization of Three-Arm-Star PIB-PEO Block Copolymers at the Air/Water Interface: Langmuir- and Langmuir-Blodgett Film Investigations. MACROMOL CHEM PHYS 2009. [DOI: 10.1002/macp.200900435] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Zheng H, Du X. Protein-Directed Spatial Rearrangement of Glycolipids at the Air−Water Interface for Bivalent Protein Binding: In Situ Infrared Reflection Absorption Spectroscopy. J Phys Chem B 2009; 114:577-84. [DOI: 10.1021/jp908559n] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Haifu Zheng
- Key Laboratory of Mesoscopic Chemistry (Ministry of Education), State Key Laboratory of Coordination Chemistry, and School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, People’s Republic of China
| | - Xuezhong Du
- Key Laboratory of Mesoscopic Chemistry (Ministry of Education), State Key Laboratory of Coordination Chemistry, and School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, People’s Republic of China
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30
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Mackenzie CD, Smith BO, Meister A, Blume A, Zhao X, Lu JR, Kennedy MW, Cooper A. Ranaspumin-2: structure and function of a surfactant protein from the foam nests of a tropical frog. Biophys J 2009; 96:4984-92. [PMID: 19527658 PMCID: PMC2712023 DOI: 10.1016/j.bpj.2009.03.044] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2009] [Revised: 03/19/2009] [Accepted: 03/23/2009] [Indexed: 10/20/2022] Open
Abstract
Ranaspumin-2 (Rsn-2) is a monomeric, 11 kDa surfactant protein identified as one of the major foam nest components of the túngara frog (Engystomops pustulosus), with an amino acid sequence unlike any other protein described so far. We report here on its structure in solution as determined by high-resolution NMR analysis, together with investigations of its conformation and packing at the air-water interface using a combination of infrared and neutron reflectivity techniques. Despite the lack of any significant sequence similarity, Rsn-2 in solution adopts a compact globular fold characteristic of the cystatin family, comprising a single helix over a four-stranded sheet, in a motif not previously associated with surfactant activity. The NMR structure of Rsn-2 shows no obvious amphiphilicity that might be anticipated for a surfactant protein. This suggests that it must undergo a significant conformational change when incorporated into the air-water interface that may involve a hinge-bending, clamshell opening of the separate helix and sheet segments to expose hydrophobic faces to air while maintaining the highly polar surfaces in contact with the underlying water layer. This model is supported by direct observation of the relative orientations of secondary structure elements at the interface by infrared reflection absorption spectroscopy, and by protein packing densities determined from neutron reflectivity profiles.
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Affiliation(s)
- Cameron D Mackenzie
- WestChem Department of Chemistry, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom
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31
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Li Z, Schön V, Huber P, Kressler J, Busse K. Comparison of the Monolayer Formation of Fluorinated and Nonfluorinated Amphiphilic Block Copolymers at the Air−Water Interface. J Phys Chem B 2009; 113:11841-7. [DOI: 10.1021/jp905016s] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Zheng Li
- Institute of Physical Chemistry, Department of Chemistry, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany, and Faculty of Physics and Mechatronics Engineering, Department of Engineering Physics, Saarland University, D-66123 Saarbrücken, Germany
| | - Volker Schön
- Institute of Physical Chemistry, Department of Chemistry, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany, and Faculty of Physics and Mechatronics Engineering, Department of Engineering Physics, Saarland University, D-66123 Saarbrücken, Germany
| | - Patrick Huber
- Institute of Physical Chemistry, Department of Chemistry, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany, and Faculty of Physics and Mechatronics Engineering, Department of Engineering Physics, Saarland University, D-66123 Saarbrücken, Germany
| | - Jörg Kressler
- Institute of Physical Chemistry, Department of Chemistry, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany, and Faculty of Physics and Mechatronics Engineering, Department of Engineering Physics, Saarland University, D-66123 Saarbrücken, Germany
| | - Karsten Busse
- Institute of Physical Chemistry, Department of Chemistry, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany, and Faculty of Physics and Mechatronics Engineering, Department of Engineering Physics, Saarland University, D-66123 Saarbrücken, Germany
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Li H, Sachsenhofer R, Binder WH, Henze T, Thurn-Albrecht T, Busse K, Kressler J. Hierarchical organization of poly(ethylene oxide)-block-poly(isobutylene) and hydrophobically modified Fe(2)O(3) nanoparticles at the air/water interface and on solid supports. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:8320-8329. [PMID: 19441824 DOI: 10.1021/la900549h] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Langmuir monolayers and Langmuir-Blodgett (LB) film morphologies of block copolymers and hydrophobically modified iron oxide nanoparticles were studied by surface pressure-mean molecular area (pi-mmA) measurements and by tapping mode atomic force microscopy (AFM). The amphiphilic diblock copolymers consisted of a hydrophilic poly(ethylene oxide) (PEO) block and a hydrophobic poly(isobutylene) (PIB) block. The pi-mmA isotherm of PEO(97)-b-PIB(37) (the subscripts refer to the respective degrees of polymerization) at the air/water interface had an extended plateau reflecting the extension of PEO chains into the water subphase at a surface pressure of 10 mN.m(-1), which is absent for the more hydrophobic PEO(19)-b-PIB(130). Iron oxide (Fe(2)O(3)) nanoparticles capped with oleic acid ligands as the shell were dispersed in the amphiphilic block copolymers at the air/water interface to prevent macroscopic aggregation of the particles. When the nanoparticles were mixed with PEO(97)-b-PIB(37), using a particle to polymer chain ratio of 1:100, macroscopic aggregation of the nanoparticles was not observed, and the pi-mmA isotherm was dominated by PEO(97)-b-PIB(37). Monolayers of block copolymers were transferred at different surface pressures from the air/water interface to hydrophilic silicon substrates using the Langmuir-Blodgett technique. The AFM images of PEO(97)-b-PIB(37) LB films depicted not only the typical finger-like morphology of the crystallized PEO blocks but also PIB blocks arranged in vertical columns growing perpendicular to the substrate surface. The columns are characteristic for PEO(19)-b-PIB(130) LB films after transfer at high surface pressures and can be assigned to a mesomorphic PIB phase with ordered chains. Finally, it was observed that small clusters of a few Fe(2)O(3) nanoparticles occupy the top of PIB phases after compression and transfer of the block copolymer nanoparticle mixtures to solid supports.
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Affiliation(s)
- Hangsheng Li
- Martin Luther University Halle-Wittenberg, D-06099 Halle, Germany
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33
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Amado E, Blume A, Kressler J. Novel non-ionic block copolymers tailored for interactions with phospholipids. REACT FUNCT POLYM 2009. [DOI: 10.1016/j.reactfunctpolym.2008.12.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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34
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Heinrich F, Ng T, Vanderah DJ, Shekhar P, Mihailescu M, Nanda H, Lösche M. A new lipid anchor for sparsely tethered bilayer lipid membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:4219-29. [PMID: 19714901 DOI: 10.1021/la8033275] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Mixed self-assembled monolayers (SAMs) of beta-mercaptoethanol and the new synthetic lipid 1,2-dipalmityl-3-[w-mercaptonona(ethylene oxide)] glycerol (FC 16) were investigated for their ability to form sparsely tethered bilayer lipid membranes (stBLMs) completed with various phospholipids. We investigated the structural and functional properties of FC16-based stBLMs and compared these to stBLMs prepared using a previously characterized synthetic lipid, 1,2-dimyristyl-3-[omega-mercaptohexa(ethylene oxide)] glycerol (WC14). FC16-based stBLMs show increased resistivity to ion transfer and an increase in the submembrane space of approximately 0.5 nm. Importantly, FC16-based stBLMs formed well-defined, complete bilayers with charged phospholipids such as 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol (POPG). In these, POPG incorporates into the outer monolayer leaflet in the same ratio as in the immersion solution but is excluded from the inner leaflet. In all cases that we have investigated thus far, the area densities of the lipids within the bilayers were on average close to those in free bilayer membranes. For charged phospholipids, FC16 appears to provide a distinct advantage over WC14 for the formation of well-defined stBLMs.
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Affiliation(s)
- Frank Heinrich
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6102, USA
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Liu H, Zheng H, Miao W, Du X. In situ studies of metal coordinations and molecular orientations in monolayers of amino-acid-derived Schiff bases at the air-water interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:2941-2948. [PMID: 19437705 DOI: 10.1021/la803976c] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The surface behaviors of monolayers of amino-acid-derived Schiff bases, namely, 4-(4-(hexadecyloxy)benzylideneamino)benzoic acid (HBA), at the air-water interface on pure water and ion-containing subphases (Cu2+, Ca2+, and Ba2+) have been clarified by a combination of surface pressure-area isotherms and surface plasmon resonance (SPR) technique, and the metal coordinations and molecular orientations in the monolayers have been investigated using in situ infrared reflection absorption spectroscopy (IRRAS). The presence of metal ions gives rise to condensation of the monolayers (Cu2+, pH 6.1; Ca2+, pH 11; Ba2+, pH 10), even leading to the formation of three-dimensional structures of the compressed monolayer in the case of Ba2+ (pH 12). The metal coordinations with the carboxyl groups at the interface depend on the type of metal ions and pH of the aqueous subphase. The orientations of the aromatic Schiff base segments with surface pressure are elaborately described. The spectral behaviors of the Schiff base segments with incidence angle in the case of Ba2+ (pH 12) have so far presented an excellent example for the selection rule of IRRAS at the air-water interface for p-polarization with vibrational transition moments perpendicular to the water surface. The chain orientations in the monolayers are quantitatively determined on the assumption that the thicknesses of the HBA monolayers at the air-water interface are composed of the sublayers of alkyl chains and Schiff base segments.
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Affiliation(s)
- Huijin Liu
- MOE Key Laboratory of Mesoscopic Chemistry, State Key Laboratory of Coordination Chemistry, and School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, People's Republic of China
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36
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37
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Amado E, Kerth A, Blume A, Kressler J. Infrared reflection absorption spectroscopy coupled with Brewster angle microscopy for studying interactions of amphiphilic triblock copolymers with phospholipid monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:10041-10053. [PMID: 18698867 DOI: 10.1021/la801768m] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Novel water-soluble amphiphilic triblock copolymers poly(glycerol monomethacrylate)-b-poly(propylene oxide)-b-poly(glycerol monomethacrylate) (PGMA-b-PPO-b-PGMA) were synthesized because of their expected enhanced ability to interact with biological membranes compared to the well-known poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (PEO-b-PPO-b-PEO) block copolymers. Their bulkier hydrophilic PGMA blocks might induce a disturbance in the packing of liquid-crystalline lipid bilayers in addition to the effect caused by the hydrophobic PPO block alone. To gain a better insight into the polymer-membrane interactions at the molecular level, the adsorption kinetics and concomitant interactions of (PGMA14)(2-)PPO(34) with model membranes of dipalmitoylphosphatidylcholine (DPPC) and dimyristoylphosphatidylcholine (DMPC) were monitored using infrared reflection absorption spectroscopy (IRRAS) coupled with Brewster angle microscopy (BAM) and surface pressure (pi) measurements. The maximum penetration surface pressure of ca. 39 mN/m suggests that (PGMA14)(2-)PPO(34) is able to insert into lipid monolayers even above the so-called monolayer-bilayer equivalent pressure of 30-35 mN/m. Copolymer adsorption to a liquid-expanded DPPC-d62 monolayer proceeds in a two-step mechanism: (i) initially only the more hydrophobic PPO middle block penetrates the lipid monolayer; (ii) following the liquid-expanded-liquid-condensed (LE-LC) phase transition, the bulky PGMA hydrophilic blocks are dragged into the headgroup region as the PPO block inserts further into the fatty acid region. The adsorption kinetics is considerably faster for DMPC-d54 monolayers due to their higher fluidity. Copolymer adsorption to an LC-DPPC-d62 monolayer leads to a change in the monolayer packing by forcing the lipid alkyl chains into a more vertical orientation, their tilt angle with respect to the surface normal being reduced from initially 30 degrees +/- 3 degrees to 18 degrees +/- 3 degrees. BAM images rule out macroscopic phase separation and show that coalescence of DPPC-d62 LC domains takes place at relatively low surface pressures of pi > or = 23 mN/m, suggesting that (PGMA14)(2-)PPO (34) partitions into both LE as well as LC domains.
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Affiliation(s)
- Elkin Amado
- Department of Chemistry, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
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38
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Sommer K, Kaiser S, Krylova OO, Kressler J, Pohl P, Busse K. Influence of amphiphilic block copolymer induced changes in membrane ion conductance on the reversal of multidrug resistance. J Med Chem 2008; 51:4253-9. [PMID: 18588278 DOI: 10.1021/jm800177c] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Block copolymers are able to reverse multidrug resistance (MDR) of tumor cells by a yet unknown mechanism. The drug efflux system's direct and indirect inhibition mediated by polymer P-glycoprotein (Pgp) interactions or adenosine triphosphate (ATP) depletion, respectively, may be involved in MDR reversal as well as damage to the membrane barrier caused by polymer insertion into the membrane. To test the latter hypothesis, cellular drug accumulation was monitored in the presence of both overexpressed fluorescently labeled Pgp and different block copolymers. Therefore, a new triblock copolymer (poly(ethylene oxide)- block-poly(hexafluoropropylene oxide)- block-poly(ethylene oxide)) was designed and synthesized by combined polymerization and polymer analogous reaction. Its administration induced drug uptake, whereas control cells with high Pgp expression levels showed no drug accumulation. Drug uptake was even more pronounced in the presence of another triblock copolymer: (poly(perfluorohexylethyl methacrylate)- block-poly(ethylene oxide)- block-poly(perfluorohexylethyl methacrylate). The latter polymer's lack of ionophoric activity suggests that ion transport facilitation by polymers is not a determinative factor for MDR reversal.
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Affiliation(s)
- Klaus Sommer
- Johannes Kepler Universitat, Fachbereich Physik, Institut fur Biophysik, Altenbergerstrasse 69, 4040 Linz, Austria
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39
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40
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41
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Ropers MH, Meister A, Blume A, Ralet MC. Pectin−Lipid Assembly at the Air–Water Interface: Effect of the Pectin Charge Distribution. Biomacromolecules 2008; 9:1306-12. [DOI: 10.1021/bm7013685] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Marie-Hélène Ropers
- UR1268 Biopolymères Interactions Assemblages, INRA, F-44300 Nantes, France, and Institute of Chemistry, MLU Halle-Wittenberg, Mühlpforte 1, D-06108 Halle, Germany
| | - Annette Meister
- UR1268 Biopolymères Interactions Assemblages, INRA, F-44300 Nantes, France, and Institute of Chemistry, MLU Halle-Wittenberg, Mühlpforte 1, D-06108 Halle, Germany
| | - Alfred Blume
- UR1268 Biopolymères Interactions Assemblages, INRA, F-44300 Nantes, France, and Institute of Chemistry, MLU Halle-Wittenberg, Mühlpforte 1, D-06108 Halle, Germany
| | - Marie-Christine Ralet
- UR1268 Biopolymères Interactions Assemblages, INRA, F-44300 Nantes, France, and Institute of Chemistry, MLU Halle-Wittenberg, Mühlpforte 1, D-06108 Halle, Germany
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Dyck M, Kerth A, Blume A, Lösche M. Interaction of the neurotransmitter, neuropeptide Y, with phospholipid membranes: infrared spectroscopic characterization at the air/water interface. J Phys Chem B 2007; 110:22152-9. [PMID: 17078651 PMCID: PMC2626140 DOI: 10.1021/jp062537q] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The association of neuropeptide Y (NPY) at the air/water interface and with phospholipid monolayers on water as subphase has been investigated using external infrared reflection absorption spectroscopy (IRRAS). Studies of the conformation and orientation of NPY suggest that it adopts an alpha-helical structure and is oriented parallel to the air/water interface in neat peptide monolayers. Both secondary structure and orientation are preserved in mixed lipid/NPY monolayers. Comparison of NPY associated with zwitterionic DPPC and with anionic DMPS suggests that electrostatic attraction plays a major role for peptide binding to the membrane surface.
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Du X, Wang Y, Ding Y, Guo R. Protein-directed assembly of binary monolayers at the interface and surface patterns of protein on the monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:8142-9. [PMID: 17583923 DOI: 10.1021/la700955f] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Ferritin-directed assembly of binary monolayers of zwitterionic dipalmitoylphosphatidylcholine and cationic dioctadecyldimethylammonium bromide (DOMA) at the interface and surface patterns of ferritin on the monolayers have been investigated using a combination of infrared reflection absorption spectroscopy, surface plasmon resonance, and atomic force microscopy. Ferritin binding to the binary monolayers at the air-water interface at the surface pressure 30 mN/m, primarily driven by the electrostatic interaction, gives rise to a change in tilt angle of hydrocarbon chains from 15 degrees +/- 1 degrees to 10 degrees +/- 1 degrees with respect to the normal of the monolayer at the mole fraction of DOMA (XDOMA) of 0.1. The chains at XDOMA = 0.3 are oriented vertical to the water surface before and after protein binding. A new mechanism for protein binding to the binary monolayers is proposed. The secondary structures of the adsorbed ferritin are prevented from changing to some extent due to the existence of the monolayers. The amounts of the bound protein on the monolayers at the air-water interface are increased in comparison with those on the pre-immobilized monolayers at low XDOMA. The increased amounts and different patterns of the adsorbed protein at the monolayers are mostly attributed to the formation of multiple binding sites available for ferritin, which is due to the lateral reorganization of the lipid components in the monolayers induced by the protein in the subphase. The created multiple binding sites on the monolayer surfaces through the protein-directed assembly can be preserved for subsequent protein binding.
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Affiliation(s)
- Xuezhong Du
- Key Laboratory of Mesoscopic Chemistry (Ministry of Education), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China.
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Busse K, Peetla C, Kressler J. Water surface covering of fluorinated amphiphilic triblock copolymers: surface pressure-area and X-ray reflectivity investigations. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:6975-82. [PMID: 17503856 DOI: 10.1021/la0637059] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Monolayers of ABA amphiphilic triblock block copolymers are studied using surface pressure-area and X-ray reflectivity (XR) measurements. The triblock copolymers are composed of long poly(ethylene oxide) (PEO) middle blocks with poly((perfluorohexyl)ethyl methacrylate) (PFMA) end blocks. The surface pressure-area isotherms of water-insoluble species show two pseudoplateaus. The plateau at low surface pressure is consistent with the pseudoplateau observed for PEO copolymers in the literature. The plateau in the brush region can be assigned to the horizontal to vertical rearrangement of whole PFMA chains at the air-water interface, which was followed by XR measurements. For water-soluble species with a very low amount of PFMA no (significant) second pseudoplateau and no enrichment of PFMA at the air-water interface were observed.
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Affiliation(s)
- Karsten Busse
- Institute of Physical Chemistry, Department of Chemistry, Martin Luther University Halle-Wittenberg, D-06099 Halle (Saale), Germany.
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Meister A, Weygand MJ, Brezesinski G, Kerth A, Drescher S, Dobner B, Blume A. Evidence for a reverse U-shaped conformation of single-chain bolaamphiphiles at the air-water interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:6063-9. [PMID: 17447798 DOI: 10.1021/la070029h] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Infrared reflection absorption spectroscopy and X-ray reflectivity have been used to elucidate the molecular orientation and hydrocarbon chain conformation and packing of the symmetric long-chain bolaamphiphiles dotriacontane-1,1'-diyl-bis-[2-(trimethylammonio)ethylphosphate] (PC-C32-PC) and dotriacontane-1,1'-diyl-bis-[2-(dimethylammonio)ethylphosphate] (Me2PE-C32-Me2PE) at the air-water interface. At low surface pressures, these bipolar amphiphiles are found to lie flat on the water surface with a disordered chain. With increasing surface pressure, the alkyl chain becomes more ordered. Concomitantly, the chain is bent pointing into the air, whereas both polar headgroups keep contact with the water subphase. At an area of 0.9-1.1 nm2 per molecule, a surface pressure plateau is reached for both bolaamphiphiles, where the molecules adopt a reverse U-shaped conformation with a strongly tilted alkyl chain. Further compression leads to the formation of 3-D aggregates.
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Affiliation(s)
- Annette Meister
- Institute of Chemistry, Martin-Luther-University Halle-Wittenberg, Mühlpforte 1, 06108 Halle, Germany
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Du X, Wang Y. Directed Assembly of Binary Monolayers with a High Protein Affinity: Infrared Reflection Absorption Spectroscopy (IRRAS) and Surface Plasmon Resonance (SPR). J Phys Chem B 2007; 111:2347-56. [PMID: 17286427 DOI: 10.1021/jp0653196] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Infrared reflection absorption spectroscopy (IRRAS) and surface plasmon resonance (SPR) techniques have been employed to investigate human serum albumin (HSA) binding to binary monolayers of zwitterionic dipalmitoylphosphatidylcholine (DPPC) and cationic dioctadecyldimethylammonium bromide (DOMA). At the air-water interface, the favorable electrostatic interaction between DPPC and DOMA leads to a dense chain packing. The tilt angle of the hydrocarbon chains decreases with increasing mole fraction of DOMA (X(DOMA)) in the monolayers at the surface pressure 30 mN/m: DPPC ( approximately 30 degrees ), X(DOMA) = 0.1 ( approximately 15 degrees ), and X(DOMA) = 0.3 ( approximately 0 degrees ). Negligible protein binding to the DPPC monolayer is observed in contrast to a significant binding to the binary monolayers. After HSA binding, the hydrocarbon chains at X(DOMA) = 0.1 undergo an increase in tilt angle from 15 degrees to 25 approximately 30 degrees , and the chains at X(DOMA) = 0.3 remain almost unchanged. The two components in the monolayers deliver through lateral reorganization, induced by the protein in the subphase, to form multiple interaction sites favorable for protein binding. The surfaces with a high protein affinity are created through the directed assembly of binary monolayers for use in biosensing.
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Affiliation(s)
- Xuezhong Du
- Key Laboratory of Mesoscopic Chemistry (Ministry of Education), State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093, People's Republic of China.
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Joncheray TJ, Denoncourt KM, Mathieu C, Meier MAR, Schubert US, Duran RS. Langmuir and Langmuir-Blodgett films of poly(ethylene oxide)-b-poly(epsilon-caprolactone) star-shaped block copolymers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:9264-71. [PMID: 17042541 DOI: 10.1021/la061290l] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Self-assembly of poly(ethylene oxide)-block-poly(epsilon-caprolactone) five-arm stars (PEO-b-PCL) was studied at the air/water (A/W) interface. The block copolymers consist of a hydrophilic PEO core with hydrophobic PCL chains at the star periphery. All the polymers have the same number of ethylene oxide repeat units (9 per arm), and the number of epsilon-caprolactone repeat units ranges from 0 to 18 per arm. The Langmuir monolayers were analyzed by surface pressure/mean molecular area isotherms, compression-expansion hysteresis experiments, and isobaric relaxation measurements, and the Langmuir-Blodgett (LB) films' morphologies were investigated by atomic force microscopy (AFM). PCL homopolymers crystallize directly at the A/W interface in a narrow surface pressure range (11-15 mN/m). In the same pressure region, the star-shaped block copolymers undergo a phase transition corresponding to the collapse and the crystallization of the PCL chains as shown by the presence of a pseudoplateau in the isotherms. The LB films were prepared by transferring the Langmuir monolayers onto mica substrates at various surface pressures. AFM imaging confirmed the formation of PCL crystals in the LB monolayers of the PCL homopolymers and of the copolymers, but also showed that the PCL segments can undergo additional crystallization after monolayer transfer during water evaporation. The PCL crystal morphologies were also strongly influenced by the surface pressure and by the PEO segments.
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Affiliation(s)
- Thomas J Joncheray
- The George and Josephine Butler Polymer Research Laboratory, Department of Chemistry, University of Florida, Post Office Box 117200, Gainesville, Florida 32611-7200, USA
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Peetla C, Graf K, Kressler J. Langmuir monolayer and Langmuir–Blodgett films of amphiphilic triblock copolymers with water-soluble middle block. Colloid Polym Sci 2006. [DOI: 10.1007/s00396-006-1527-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Krishnan S, Ayothi R, Hexemer A, Finlay JA, Sohn KE, Perry R, Ober CK, Kramer EJ, Callow ME, Callow JA, Fischer DA. Anti-biofouling properties of comblike block copolymers with amphiphilic side chains. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:5075-86. [PMID: 16700597 DOI: 10.1021/la052978l] [Citation(s) in RCA: 223] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Surfaces of novel block copolymers with amphiphilic side chains were studied for their ability to influence the adhesion of marine organisms. The surface-active polymer, obtained by grafting fluorinated molecules with hydrophobic and hydrophilic blocks to a block copolymer precursor, showed interesting bioadhesion properties. Two different algal species, one of which adhered strongly to hydrophobic surfaces, and the other, to hydrophilic surfaces, showed notably weak adhesion to the amphiphilic surfaces. Both organisms are known to secrete adhesive macromolecules, with apparently different wetting characteristics, to attach to underwater surfaces. The ability of the amphiphilic surface to undergo an environment-dependent transformation in surface chemistry when in contact with the extracellular polymeric substances is a possible reason for its antifouling nature. Near-edge X-ray absorption fine structure spectroscopy (NEXAFS) was used, in a new approach based on angle-resolved X-ray photoelectron spectroscopy (XPS), to determine the variation in chemical composition within the top few nanometers of the surface and also to study the surface segregation of the amphiphilic block. A mathematical model to extract depth-profile information from the normalized NEXAFS partial electron yield is developed.
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Affiliation(s)
- Sitaraman Krishnan
- Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, USA
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Maltseva E, Kerth A, Blume A, Möhwald H, Brezesinski G. Adsorption of Amyloid β (1-40) Peptide at Phospholipid Monolayers. Chembiochem 2005; 6:1817-24. [PMID: 16175542 DOI: 10.1002/cbic.200500116] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The folding of amyloid beta (1-40) peptide into beta-sheet-containing fibrils is thought to play a causative role in Alzheimer's disease. Because of its amphiphilic character, the peptide can interact with phospholipid membranes. Langmuir monolayers of negatively charged DPPS, DPPG, and DMPG, and also of zwitterionic DPPC and DMPC, have been used to study the influence of the peptide on the lipid packing and, vice versa, the influence of phospholipid monolayers on the peptide secondary structure by infrared reflection absorption spectroscopy and grazing incidence X-ray diffraction. The peptide adsorbs at the air/water (buffer) interface, and also inserts into uncompressed phospholipid monolayers. When adsorbed at the interface, the peptide adopts a beta-sheet conformation, with the long axis of these beta-sheets oriented almost parallel to the surface. If the lipid exhibits a condensed monolayer phase, then compression of the complex monolayer with the inserted peptide leads to the squeezing out of the peptide at higher surface pressures (above 30 mN m(-1)). The peptide desorbs completely from zwitterionic monolayers and negatively charged DPPG and DPPS monolayers on buffer, but remains adsorbed in the beta-sheet conformation at negatively charged monolayers on water. This can be explained in terms of electrostatic interactions with the lipid head groups. It also remains adsorbed at, or penetrating into, disordered anionic monolayers on buffer. Additionally, the peptide does not influence the condensed monolayer structure at physiological pH and modest ionic strength.
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Affiliation(s)
- Elena Maltseva
- Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476 Golm/Potsdam, Germany
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