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Liu H, Fa K, Hu X, Li Z, Zhang L, Ma K, Fragneto G, Li P, Webster JRP, Petkov JT, Thomas RK, Ren Lu J. Structural features of interfacially adsorbed acyl-l-carnitines. J Colloid Interface Sci 2022; 623:368-377. [PMID: 35594595 DOI: 10.1016/j.jcis.2022.05.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 05/02/2022] [Accepted: 05/04/2022] [Indexed: 11/19/2022]
Abstract
HYPOTHESIS Acyl-l-carnitines (CnLCs) are potentially important as biosurfactants in drug delivery and tissue engineering due to their good biocompatibility. However, little is currently known about the basic interfacial behavior underlying their technological applications. Following our previous characterization of their solution aggregation and adsorption at the air/water interface, this work examines how they adsorb at the hydrophilic solid/liquid interface. EXPERIMENTS As the SiO2/water interface has served as the model substrate for many interfacial adsorption studies, so it has been used in this work as the solid substrate to facilitate dynamic adsorption by spectroscopic ellipsometry (SE) and structural determination of the adsorbed layers by neutron reflection (NR) under different conditions at the SiO2/water interface from a group of CnLC (n = 12, 14, and 16). FINDINGS CnLC surfactants are zwitterionic at neutral pH. They reached saturated adsorption above their critical micellar concentrations (CMCs) and formed a sandwich bilayer with a head-tail-head structure at the hydrophilic SiO2/water interface. The total thicknesses of the adsorbed layers at CMC were found to be 33 ± 2, 35 ± 2, and 37 ± 2 Å for C12LC, C14LC, and C16LC, respectively, with their inner and outer head layers remaining similar but the thickness of the interdigitated middle layer increasing with acyl chain length. As the solution becomes acidic, the carboxyl groups become protonated and the l-carnitine heads are net positively charged, resulting in increased repulsion between the head groups. In this situation, the CnLC surfactants are adsorbed as distinct aggregates to reduce repulsive interaction, resulting in reduced surfactant volume fraction and layer thickness. However, a high ionic strength can screen the repulsive interaction and enhance the adsorbed amount, effectively diminishing the impact of pH. This information provides a useful basis for exploring the technological applications of CnLCs involving a solid substrate.
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Affiliation(s)
- Huayang Liu
- Biological Physics Laboratory, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Ke Fa
- Biological Physics Laboratory, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Xuzhi Hu
- Biological Physics Laboratory, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Zongyi Li
- Biological Physics Laboratory, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Lin Zhang
- Biological Physics Laboratory, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Kun Ma
- ISIS Neutron Facility, Rutherford Appleton Laboratory, STFC, Chilton, Didcot, Oxon OX11 0QX, UK
| | - Giovanna Fragneto
- Institut Laue-Langevin, 71 Avenue des Martyrs, CS20156, 38042 Grenoble Cedex 9, France
| | - Peixun Li
- ISIS Neutron Facility, Rutherford Appleton Laboratory, STFC, Chilton, Didcot, Oxon OX11 0QX, UK
| | - John R P Webster
- ISIS Neutron Facility, Rutherford Appleton Laboratory, STFC, Chilton, Didcot, Oxon OX11 0QX, UK
| | - Jordan T Petkov
- Arxada, Hexagon Tower, Delaunays Road, Blackley, Manchester M9 8ZS, UK
| | - Robert K Thomas
- Physical and Theoretical Chemistry, University of Oxford, South Parks, Oxford OX1 3QZ, UK
| | - Jian Ren Lu
- Biological Physics Laboratory, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
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Khadka NK, Mortimer MF, Marosvari M, Timsina R, Mainali L. Membrane elasticity modulated by cholesterol in model of porcine eye lens-lipid membrane. Exp Eye Res 2022; 220:109131. [PMID: 35636489 PMCID: PMC10131281 DOI: 10.1016/j.exer.2022.109131] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 05/08/2022] [Accepted: 05/22/2022] [Indexed: 11/29/2022]
Abstract
Experimental evidence shows that the eye lens loses its elasticity dramatically with age. It has also been reported that the cholesterol (Chol) content in the eye lens fiber cell plasma membrane increases significantly with age. High Chol content leads to the formation of cholesterol bilayer domains (CBDs) in the lens membrane. The role of high Chol associated with lens elasticity is unclear. The purpose of this research is to investigate the membrane elasticity of the model of porcine lens-lipid (MPLL) membrane with increasing Chol content to elucidate the role of high Chol in lens membrane elasticity. In this study, we used atomic force microscopy (AFM) to study the mechanical properties (breakthrough force and area compressibility modulus (KA)) of the MPLL membrane with increasing Chol content where KA is the measure of membrane elasticity. We varied Chol concentration in Chol/MPLL membrane from 0 to ∼71 mol%. Supported Chol/MPLL membranes were prepared by fusion of small unilamellar vesicles (SUVs) on top of a flat mica surface. SUVs of the Chol/MPLL lipid mixture were prepared with the rapid solvent exchange method followed by probe-tip sonication. For the Chol/MPLL mixing ratio of 0, AFM image showed the formation of two distinct phases of the membrane, i.e., liquid-disordered phase (ld) and solid-ordered phase (so) membrane. However, with Chol/MPLL mixing ratio of 0.5 and above, only liquid-ordered phase (lo) membrane was formed. Also, two distinct breakthrough forces corresponding to ld and so were observed for Chol/MPLL mixing ratio of 0, whereas only one breakthrough force was observed for membranes with Chol/MPLL mixing ratio of 0.5 and above. No significant difference in the membrane surface roughness was measured with increasing Chol content for these membranes; however, breakthrough force and KA for lo membrane increased when Chol/MPLL mixing ratio was increased from 0.5 to 1. Interestingly above the Chol/MPLL mixing ratio of 1, both breakthrough force and KA decreased, indicating the formation of CBDs. Furthermore, these results showed that membrane elasticity increases at high Chol content, suggesting that high Chol content in lens membrane might be responsible for maintaining lens membrane elasticity.
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Affiliation(s)
- Nawal K Khadka
- Department of Physics, Boise State University, Boise, ID, USA
| | | | - Mason Marosvari
- Department of Physics, Boise State University, Boise, ID, USA
| | - Raju Timsina
- Department of Physics, Boise State University, Boise, ID, USA
| | - Laxman Mainali
- Department of Physics, Boise State University, Boise, ID, USA; Biomolecular Sciences Graduate Program, Boise State University, Boise, ID, USA.
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3
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Sabin J, Alatorre-Meda M, Miñones J, Domínguez-Arca V, Prieto G. New insights on the mechanism of polyethylenimine transfection and their implications on gene therapy and DNA vaccines. Colloids Surf B Biointerfaces 2021; 210:112219. [PMID: 34836707 DOI: 10.1016/j.colsurfb.2021.112219] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 10/30/2021] [Accepted: 11/12/2021] [Indexed: 12/28/2022]
Abstract
Polyethylenimine (PEI) has been demonstrated as an efficient DNA delivery vehicle both in vitro and in vivo. There is a consensus that PEI-DNA complexes enter the cells by endocytosis and escape from endosomes by the so-called "proton sponge" effect. However, little is known on how and where the polyplexes are de-complexed for DNA transcription and replication to occur inside the cell nucleus. To better understand this issue, we (i) tracked the cell internalization of PEI upon transfection to human epithelial cells and (ii) studied the interaction of PEI with phospholipidic layers mimicking nuclear membranes. Both the biological and physicochemical experiments provided evidence of a strong binding affinity between PEI and the lipidic bilayer. Firstly, confocal microscopy revealed that PEI alone could not penetrate the cell nucleus; instead, it arranged throughout the cytoplasm and formed a sort of aureole surrounding the nuclei periphery. Secondly, surface tension measurements, fluorescence dye leakage assays, and differential scanning calorimetry demonstrated that a combination of hydrophobic and electrostatic interactions between PEI and the phospholipidic monolayers/bilayers led to the formation of stable defects along the model membranes, allowing the intercalation of PEI through the monolayer/bilayer structure. Results are also supported by molecular dynamics simulation of the pore formation in PEI-lipidic bilayers. As discussed throughout the text, these results might shed light on a the mechanism in which the interaction between PEI and the nucleus membrane might play an active role on the DNA release: on the one hand, the PEI-membrane interaction is anticipated to facilitate the DNA disassembly from the polyplex by establishing a competition with DNA for the PEI binding and on the other hand, the forming defects are expected to serve as channels for the entrance of de-complexed DNA into the cell nucleus. A better understanding of the mechanism of transfection of cationic polymers opens paths to development of more efficiency vectors to improve gene therapy treatment and the new generation of DNA vaccines.
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Affiliation(s)
- Juan Sabin
- Biophysics and Interfaces Group, Applied Physics Department, Universidade de Santiago de Compostela, Spain; AFFINImeter-Software 4 Science Developments S.L. Edificio Emprendia s/n Campus Vida, Santiago de Compostela, Spain.
| | - Manuel Alatorre-Meda
- Cátedras CONACyT-Tecnológico Nacional de México/I. T. Tijuana, Centro de Graduados e Investigación en Química-Grupo de Biomateriales y Nanomedicina, Blvd. Alberto Limón Padilla S/N, 22510 Tijuana, BC, Mexico
| | - Jose Miñones
- Department of Physical Chemistry, Faculty of Pharmacy Universidade de Santiago de Compostela, Spain
| | - Vicente Domínguez-Arca
- Biophysics and Interfaces Group, Applied Physics Department, Universidade de Santiago de Compostela, Spain.
| | - Gerardo Prieto
- Biophysics and Interfaces Group, Applied Physics Department, Universidade de Santiago de Compostela, Spain
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Gahan CG, Patel SJ, Chen LM, Manson DE, Ehmer ZJ, Blackwell HE, Van Lehn RC, Lynn DM. Bacterial Quorum Sensing Signals Promote Large-Scale Remodeling of Lipid Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:9120-9136. [PMID: 34283628 PMCID: PMC8450678 DOI: 10.1021/acs.langmuir.1c01204] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
We report that N-acyl-l-homoserine lactones (AHLs), a class of nonionic amphiphiles that common bacteria use as signals to coordinate group behaviors, can promote large-scale remodeling in model lipid membranes. Characterization of supported lipid bilayers (SLBs) of the phospholipid 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) by fluorescence microscopy and quartz crystal microbalance with dissipation (QCM-D) reveals the well-studied AHL signal 3-oxo-C12-AHL and its anionic head group hydrolysis product (3-oxo-C12-HS) to promote the formation of long microtubules that can retract into hemispherical caps on the surface of the bilayer. These transformations are dynamic, reversible, and dependent upon the head group structure. Additional experiments demonstrate that 3-oxo-C12-AHL can promote remodeling to form microtubules in lipid vesicles and promote molecular transport across bilayers. Molecular dynamics (MD) simulations predict differences in thermodynamic barriers to translocation of these amphiphiles across a bilayer that are reflected in both the type and extent of reformation and associated dynamics. Our experimental observations can thus be interpreted in terms of accumulation and relief of asymmetric stresses in the inner and outer leaflets of a bilayer upon intercalation and translocation of these amphiphiles. Finally, experiments on Pseudomonas aeruginosa, a pathogen that uses 3-oxo-C12-AHL for cell-to-cell signaling, demonstrate that 3-oxo-C12-AHL and 3-oxo-C12-HS can promote membrane remodeling at biologically relevant concentrations and in the absence of other biosurfactants, such as rhamnolipids, that are produced at high population densities. Overall, these results have implications for the roles that 3-oxo-C12-AHL and its hydrolysis product may play in not only mediating intraspecies bacterial communication but also processes such as interspecies signaling and bacterial control of host-cell response. Our findings also provide guidance that could prove useful for the design of synthetic self-assembled materials that respond to bacteria in ways that are useful in the context of sensing, drug delivery, and in other fundamental and applied areas.
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Affiliation(s)
- Curran G Gahan
- Dept. of Chemical and Biological Engineering, Univ. of Wisconsin-Madison, 1415 Engineering Dr., Madison, Wisconsin 53706, United States
| | - Samarthaben J Patel
- Dept. of Chemical and Biological Engineering, Univ. of Wisconsin-Madison, 1415 Engineering Dr., Madison, Wisconsin 53706, United States
| | - Lawrence M Chen
- Dept. of Chemical and Biological Engineering, Univ. of Wisconsin-Madison, 1415 Engineering Dr., Madison, Wisconsin 53706, United States
| | - Daniel E Manson
- Dept. of Chemistry, Univ. of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, United States
| | - Zachary J Ehmer
- Dept. of Chemical and Biological Engineering, Univ. of Wisconsin-Madison, 1415 Engineering Dr., Madison, Wisconsin 53706, United States
| | - Helen E Blackwell
- Dept. of Chemistry, Univ. of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, United States
| | - Reid C Van Lehn
- Dept. of Chemical and Biological Engineering, Univ. of Wisconsin-Madison, 1415 Engineering Dr., Madison, Wisconsin 53706, United States
| | - David M Lynn
- Dept. of Chemical and Biological Engineering, Univ. of Wisconsin-Madison, 1415 Engineering Dr., Madison, Wisconsin 53706, United States
- Dept. of Chemistry, Univ. of Wisconsin-Madison, 1101 University Ave., Madison, Wisconsin 53706, United States
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Salem HF, Kharshoum RM, Awad SM, Ahmed Mostafa M, Abou-Taleb HA. Tailoring of Retinyl Palmitate-Based Ethosomal Hydrogel as a Novel Nanoplatform for Acne Vulgaris Management: Fabrication, Optimization, and Clinical Evaluation Employing a Split-Face Comparative Study. Int J Nanomedicine 2021; 16:4251-4276. [PMID: 34211271 PMCID: PMC8239256 DOI: 10.2147/ijn.s301597] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 05/18/2021] [Indexed: 12/19/2022] Open
Abstract
AIM Retinyl palmitate (RP), the most stable vitamin A derivative, is used to treat photoaging and other skin disorders. The need to minimize the adverse effects of topical drug administration has led to an enhanced interest in loading RP on ethosomes for topical drug delivery. The aim of the current study was to prepare and compare the performance of RP decorated ethosomal hydrogel with tretinoin cream in the treatment of acne vulgaris as an approach to improve drug efficacy and decrease its side effects. METHODS RP-loaded ethosomes were prepared using the injection sonication technique. A Box-Behnken design using Design Expert® software was used for the optimization of formulation variables. Particle size, zeta potential (ZP), entrapment efficiency percent (EE%), % drug release, and permeation over 24 h of different formulations were determined. The optimal formulation was incorporated into a hydrogel. Finally, the efficacy and tolerability of the optimized RP ethosomal hydrogel were clinically evaluated for acne treatment using a split-face comparative clinical study. RESULTS The optimized ethosomal RP showed particle size of 195.8±5.45 nm, ZP of -62.1±2.85 mV, EE% of 92.63±4.33%, drug release % of 96.63±6.81%, and drug permeation % of 85.98 ±4.79%. Both the optimized RP ethosomal hydrogel and tretinoin effectively reduced all types of acne lesions (inflammatory, non-inflammatory, and total lesions). However, RP resulted in significantly lower non-inflammatory and total acne lesion count than the marketed tretinoin formulation. Besides, RP-loaded ethosomes showed significantly improved tolerability compared to marketed tretinoin with no or minimal skin irritation symptoms. CONCLUSION RP ethosomal hydrogel is considerably effective in controlling acne vulgaris with excellent skin tolerability. Therefore, it represents an interesting alternative to conventional marketed tretinoin formulation for topical acne treatment.
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Affiliation(s)
- Heba F Salem
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, Egypt
| | - Rasha M Kharshoum
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, Egypt
| | - Sara M Awad
- Department of Dermatology, Venereology and Andrology, Assiut University Hospital, Assiut, Egypt
| | - Mai Ahmed Mostafa
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Nahda University (NUB), Beni-Suef, Egypt
| | - Heba A Abou-Taleb
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Nahda University (NUB), Beni-Suef, Egypt
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6
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Khadka NK, Timsina R, Rowe E, O'Dell M, Mainali L. Mechanical properties of the high cholesterol-containing membrane: An AFM study. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1863:183625. [PMID: 33891910 DOI: 10.1016/j.bbamem.2021.183625] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 04/02/2021] [Accepted: 04/12/2021] [Indexed: 12/11/2022]
Abstract
Cholesterol (Chol) content in most cellular membranes does not exceed 50 mol%, only in the eye lens's fiber cell plasma membrane, its content surpasses 50 mol%. At this high concentration, Chol induces the formation of pure cholesterol bilayer domains (CBDs), which coexist with the surrounding phospholipid-cholesterol domain (PCD). Here, we applied atomic force microscopy to study the mechanical properties of Chol/phosphatidylcholine membranes where the Chol content was increased from 0 to 75 mol%, relevant to eye lens membranes. The surface roughness of the membrane decreases with an increase of Chol content until it reaches 60 mol%, and roughness increases with a further increment in Chol content. We propose that the increased roughness at higher Chol content results from the formation of CBDs. Force spectroscopy on the membrane with Chol content of 50 mol% or lesser exhibited single breakthrough events, whereas two distinct puncture events were observed for membranes with the Chol content greater than 50 mol%. We propose that the first puncture force corresponds to the membranes containing coexisting PCD and CBDs. In contrast, the second puncture force corresponds to the "CBD water pocket" formed due to coexisting CBDs and PCD. Membrane area compressibility modulus (KA) increases with an increase in Chol content until it reaches 60 mol%, and with further increment in Chol content, CBDs are formed, and KA starts to decrease. Our results report the increase in membrane roughness and decrease KA at very high Chol content (>60 mol%) relevant to the eye lens membrane.
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Affiliation(s)
- Nawal K Khadka
- Department of Physics, Boise State University, Boise, ID, USA
| | - Raju Timsina
- Department of Physics, Boise State University, Boise, ID, USA
| | - Erica Rowe
- Department of Biology, Boise State University, Boise, ID, USA
| | - Matthew O'Dell
- Biomolecular Sciences Graduate Program, Boise State University, Boise, ID, USA
| | - Laxman Mainali
- Department of Physics, Boise State University, Boise, ID, USA; Biomolecular Sciences Graduate Program, Boise State University, Boise, ID, USA.
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7
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Verbeek SF, Awasthi N, Teiwes NK, Mey I, Hub JS, Janshoff A. How arginine derivatives alter the stability of lipid membranes: dissecting the roles of side chains, backbone and termini. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2021; 50:127-142. [PMID: 33661339 PMCID: PMC8071801 DOI: 10.1007/s00249-021-01503-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 01/08/2021] [Accepted: 01/19/2021] [Indexed: 12/22/2022]
Abstract
Arginine (R)-rich peptides constitute the most relevant class of cell-penetrating peptides and other membrane-active peptides that can translocate across the cell membrane or generate defects in lipid bilayers such as water-filled pores. The mode of action of R-rich peptides remains a topic of controversy, mainly because a quantitative and energetic understanding of arginine effects on membrane stability is lacking. Here, we explore the ability of several oligo-arginines R[Formula: see text] and of an arginine side chain mimic R[Formula: see text] to induce pore formation in lipid bilayers employing MD simulations, free-energy calculations, breakthrough force spectroscopy and leakage assays. Our experiments reveal that R[Formula: see text] but not R[Formula: see text] reduces the line tension of a membrane with anionic lipids. While R[Formula: see text] peptides form a layer on top of a partly negatively charged lipid bilayer, R[Formula: see text] leads to its disintegration. Complementary, our simulations show R[Formula: see text] causes membrane thinning and area per lipid increase beside lowering the pore nucleation free energy. Model polyarginine R[Formula: see text] similarly promoted pore formation in simulations, but without overall bilayer destabilization. We conclude that while the guanidine moiety is intrinsically membrane-disruptive, poly-arginines favor pore formation in negatively charged membranes via a different mechanism. Pore formation by R-rich peptides seems to be counteracted by lipids with PC headgroups. We found that long R[Formula: see text] and R[Formula: see text] but not short R[Formula: see text] reduce the free energy of nucleating a pore. In short R[Formula: see text], the substantial effect of the charged termini prevent their membrane activity, rationalizing why only longer [Formula: see text] are membrane-active.
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Affiliation(s)
- Sarah F. Verbeek
- Department of Chemistry, Institute of Physical Chemistry, Georg-August-Universität Göttingen, 37077 Göttingen, Germany
| | - Neha Awasthi
- Institute of Microbiology and Genetics, Georg-August-Universität Göttingen, 37077 Göttingen, Germany
| | - Nikolas K. Teiwes
- Department of Chemistry, Institute of Physical Chemistry, Georg-August-Universität Göttingen, 37077 Göttingen, Germany
| | - Ingo Mey
- Department of Chemistry, Institute of Physical Chemistry, Georg-August-Universität Göttingen, 37077 Göttingen, Germany
| | - Jochen S. Hub
- Institute of Microbiology and Genetics, Georg-August-Universität Göttingen, 37077 Göttingen, Germany
- Theoretical Physics and Center for Biophyics, Saarland University, 66123 Saarbrücken, Germany
| | - Andreas Janshoff
- Department of Chemistry, Institute of Physical Chemistry, Georg-August-Universität Göttingen, 37077 Göttingen, Germany
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Majewska M, Mrdenovic D, Pieta I, Nowakowski R, Pieta P. Nanomechanical characterization of single phospholipid bilayer in ripple phase with PF-QNM AFM. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183347. [DOI: 10.1016/j.bbamem.2020.183347] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 04/16/2020] [Accepted: 05/07/2020] [Indexed: 12/31/2022]
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Deplazes E, Tafalla BD, Cranfield CG, Garcia A. Role of Ion-Phospholipid Interactions in Zwitterionic Phospholipid Bilayer Ion Permeation. J Phys Chem Lett 2020; 11:6353-6358. [PMID: 32687371 DOI: 10.1021/acs.jpclett.0c01479] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Despite the central role of Na+ and K+ in physiological processes, it is still unclear whether they interact or alter the physical properties of simple zwitterionic phospholipid bilayers at physiologically relevant concentrations. Here we report a difference in membrane permeability between Na+ and K+, as measured with electrical impedance spectroscopy and tethered bilayer lipid membranes. We reveal that the differences in membrane permeability originate from distinct ion coordination by carbonyl oxygens at the phospholipid-water interface, altering the propensity for bilayer pore formation. Molecular dynamics simulations showed differences in the coordination of Na+ and K+ at the phospholipid-water interface of zwitterionic phospholipid bilayers. The ability of Na+ to conscript more phospholipids with a greater number of coordinating interactions causes a higher localized energy barrier for pore formation. These results provide evidence that ion-specific interactions at the phospholipid-water interface can modulate the physical properties of zwitterionic phospholipid bilayers.
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Affiliation(s)
- Evelyne Deplazes
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | | | - Charles G Cranfield
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Alvaro Garcia
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW 2007, Australia
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Ammar HO, Tadros MI, Salama NM, Ghoneim AM. Ethosome-Derived Invasomes as a Potential Transdermal Delivery System for Vardenafil Hydrochloride: Development, Optimization and Application of Physiologically Based Pharmacokinetic Modeling in Adults and Geriatrics. Int J Nanomedicine 2020; 15:5671-5685. [PMID: 32821096 PMCID: PMC7418156 DOI: 10.2147/ijn.s261764] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 07/08/2020] [Indexed: 01/15/2023] Open
Abstract
Aim The aim of the current work was to develop vardenafil hydrochloride (VRD)-loaded ethosome-derived invasomes as a possible transdermal system which could be used for patients suffering from pulmonary arterial hypertension. Methods VRD-loaded ethosomes were developed at three concentrations of phosphatidylcholine (5, 10 and 15 mg/mL) and three percentages of ethanol (20%, 30% and 40%, v/v). The best achieved VRD-loaded ethosomes (ETH9) were optimized to invasomes via incorporation of terpenes (limonene, cineole and a 1:1 mixture) at three concentrations (0.5%, 1% and 2%, v/v). All systems were evaluated for vesicle size, zeta potential, drug entrapment efficiency (EE%), cumulative drug permeated percentages after 0.5hrs (Q0.5h) and 12hrs (Q12h) and steady-state flux (Jss). The optimized system (ETH9-INV8) was further characterized for morphology, histopathology and confocal laser scanning microscopy (CLSM). Physiologically based pharmacokinetic (PBPK) modeling was employed to estimate VRD pharmacokinetic parameters from the optimized transdermal system and an oral aqueous drug dispersion, in adults and geriatrics. Results The optimized invasomal system (ETH9-INV8) was characterized with spherical vesicles (159.9 nm) possessing negative zeta potential (-20.3 mV), promising EE% (81.3%), low Q0.5h (25.4%), high Q12h (85.3%) and the largest steady-state flux (6.4 µg.cm-2h-1). Following a leave-on period of 12hrs in rats, it showed minor histopathologic changes. CLSM studies proved its ability to deeply permeate rat skin. Lower Cmax values, delayed Tmax estimates and greater AUC0-24h folds in adults and geriatrics (≈ 2.18 and 1.69, respectively) were estimated following the transdermal application of ETH9-INV8 system. Conclusion ETH9-INV8 is a promising transdermal system for VRD.
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Affiliation(s)
- Hussein O Ammar
- Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmaceutical Sciences and Pharmaceutical Industries, Future University in Egypt (FUE), New Cairo, Egypt
| | - Mina Ibrahim Tadros
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Nahla M Salama
- Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmaceutical Sciences and Pharmaceutical Industries, Future University in Egypt (FUE), New Cairo, Egypt
| | - Amira Mohsen Ghoneim
- Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmaceutical Sciences and Pharmaceutical Industries, Future University in Egypt (FUE), New Cairo, Egypt
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11
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Salem HF, Nafady MM, Kharshoum RM, Abd El-Ghafar OA, Farouk HO. Mitigation of Rheumatic Arthritis in a Rat Model via Transdermal Delivery of Dapoxetine HCl Amalgamated as a Nanoplatform: In vitro and in vivo Assessment. Int J Nanomedicine 2020; 15:1517-1535. [PMID: 32189966 PMCID: PMC7065716 DOI: 10.2147/ijn.s238709] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 02/01/2020] [Indexed: 12/17/2022] Open
Abstract
Purpose Dapoxetine HCl (DH), a selective serotonin reuptake inhibitor, may be useful for the treatment of rheumatic arthritis (RA). The purpose of this study was to investigate the therapeutic efficacy of transdermal delivery of DH in transethosome nanovesicles (TENVs). This novel delivery of DH may overcome the drawbacks associated with orally administered DH and improve patient compliance. Methods DH-TENV formulations were prepared using an injection- sonication method and optimized using a 33 Box-Behnken-design with Design Expert® software. The TENV formulations were assessed for entrapment efficiency (EE-%), vesicle size, zeta potential, in vitro DH release, and skin permeation. The tolerability of the optimized DH-TENV gel was investigated using a rat skin irritation test. A pharmacokinetic analysis of the optimized DH-TENV gel was also conducted in rats. Moreover, the anti-RA activity of the optimized DH-TENV gel was assessed based on the RA-specific marker anti-cyclic cirtullinated peptide antibody (anti-CCP), the cartilage destruction marker cartilage oligomeric matrix protein (COMP) and the inflammatory marker interleukin-6 (IL-6). Level of tissue receptor activator of nuclear factor kappa-Β ligand (RANKL) were also assessed. Results The optimized DH-TENV formulation involved spherical nanovesicles that had an appropriate EE- % and skin permeation characteristic. The DH-TENV gel was well tolerated by rats. The pharmacokinetics analysis showed that the optimized DH-TENV gel boosted the bioavailability of the DH by 2.42- and 4.16-fold compared to the oral DH solution and the control DH gel, respectively. Moreover, it significantly reduced the serum anti-CCP, COMP and IL-6 levels and decreased the RANKL levels. Furthermore, the DH-TENV gel attenuated histopathological changes by almost normalizing the articular surface and synovial fluid. Conclusion The results indicate that DH-TENVs can improve transdermal delivery of DH and thereby alleviate RA.
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Affiliation(s)
- Heba Farouk Salem
- Pharmaceutics and Industrial Pharmacy Department, Faculty of Pharmacy, Beni- Suef University, Beni Suef, Egypt
| | - Mohamed Mahmoud Nafady
- Pharmaceutics and Clinical Pharmacy Department, Faculty of Pharmacy, Nahda University, Beni Suef, Egypt
| | - Rasha Mostafa Kharshoum
- Pharmaceutics and Industrial Pharmacy Department, Faculty of Pharmacy, Beni- Suef University, Beni Suef, Egypt
| | | | - Hanan Osman Farouk
- Pharmaceutics and Clinical Pharmacy Department, Faculty of Pharmacy, Nahda University, Beni Suef, Egypt
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12
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Khairalla B, Juhaniewicz-Debinska J, Sek S, Brand I. The shape of lipid molecules affects potential-driven molecular-scale rearrangements in model cell membranes on electrodes. Bioelectrochemistry 2019; 132:107443. [PMID: 31869700 DOI: 10.1016/j.bioelechem.2019.107443] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 12/04/2019] [Accepted: 12/05/2019] [Indexed: 12/24/2022]
Abstract
Planar asymmetric lipid bilayers composed of phosphatidylethanolamine and phosphatidylglycerol lipids are transferred onto a gold electrode surface. Lipids containing two saturated, one monounsaturated and two monounsaturated hydrocarbon chains compose the model membranes. Results of electrochemically controlled polarization modulation infrared reflection absorption spectroscopy and quartz crystal microbalance with energy dissipation studies reveal two different types of electric potential-dependent structural rearrangements in the bilayers. They are correlated with the geometry of the lipid molecule. Packing parameter correlates the cross-section area of the hydrophobic and hydrophilic parts of amphiphilic molecules. In bilayers composed of lipids with the packing parameter <1, the hydrocarbon chains are tilted with respect to the bilayer plane and the polar head groups are well hydrated. At a threshold potential an abrupt flow of water through the bilayer is connected with membrane dehydration and upward orientation of the chains. In bilayers composed of lipids with packing parameter ≥1, electric potentials have negligible effect on the membrane structure. A simple rule correlating the packing parameter with molecular scale changes occurring at electrified membranes has a large diagnostic implication for biomimetic studies and our understanding of molecular processes occurring in biological cell membranes.
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Affiliation(s)
- Bishoy Khairalla
- Department of Chemistry, Carl von Ossietzky University of Oldenburg, 26111 Oldenburg, Germany
| | - Joanna Juhaniewicz-Debinska
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Zwirki i Wigury 101, 02089 Warsaw, Poland
| | - Slawomir Sek
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Zwirki i Wigury 101, 02089 Warsaw, Poland
| | - Izabella Brand
- Department of Chemistry, Carl von Ossietzky University of Oldenburg, 26111 Oldenburg, Germany.
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13
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Sah BK, Kundu S. Behaviour of protein (BSA)-lipid (DMPA) mixed monolayer on the spreading order of the individual component. Chem Phys Lipids 2019; 225:104810. [PMID: 31415733 DOI: 10.1016/j.chemphyslip.2019.104810] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 07/24/2019] [Accepted: 08/10/2019] [Indexed: 11/19/2022]
Abstract
Surface pressure (π) - mean molecular area (A) isotherms of protein (BSA) - lipid (DMPA) mixed films are examined by varying their ratio and altering the spreading order of BSA and DMPA on the water surface to study the protein-lipid interactions and the corresponding structures and patterns at different interfacial conditions. π-A isotherms and compression-decompression isotherm cycles of protein-lipid mixed monolayers below and above of the isoelectric point of BSA (pI ≈ 4.8) are also examined. Below the isoelectric point of BSA (pH ≈ 4.0), i.e., when BSA is weakly hydrophobic and has net positive charge shows low hysteresis irrespective of the spreading order of the molecules. However, at pH ≈ 7.0, i.e., when the overall charge of BSA is negative and is strongly hydrophobic the protein-lipid mixed films display higher hysteresis value. Besides the properties of the isotherms, the surface morphology and secondary conformations of protein inside the mixed films are obtained from X-ray reflectivity, atomic force microscopy (AFM) and Fourier transform infrared (FTIR) spectroscopy respectively after depositing the mixed films on solid substrates. Nearly similar information is obtained after altering the spreading order of BSA and DMPA, which indicates that the spreading of molecules on the water surface is one of the better ways of forming the lipid-protein mixed film at the air-water interface.
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Affiliation(s)
- Bijay K Sah
- Soft Nano Laboratory, Physical Sciences Division, Institute of Advanced Study in Science and Technology, Vigyan Path, Paschim Boragaon, Garchuk, Guwahati, Assam 781035, India
| | - Sarathi Kundu
- Soft Nano Laboratory, Physical Sciences Division, Institute of Advanced Study in Science and Technology, Vigyan Path, Paschim Boragaon, Garchuk, Guwahati, Assam 781035, India.
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14
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Deplazes E, White J, Murphy C, Cranfield CG, Garcia A. Competing for the same space: protons and alkali ions at the interface of phospholipid bilayers. Biophys Rev 2019; 11:483-490. [PMID: 31115866 DOI: 10.1007/s12551-019-00541-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 04/29/2019] [Indexed: 10/26/2022] Open
Abstract
Maintaining gradients of solvated protons and alkali metal ions such as Na+ and K+ across membranes is critical for cellular function. Over the last few decades, both the interactions of protons and alkali metal ions with phospholipid membranes have been studied extensively and the reported interactions of these ions with phospholipid headgroups are very similar, yet few studies have investigated the potential interdependence between proton and alkali metal ion binding at the water-lipid interface. In this short review, we discuss the similarities between the proton-membrane and alkali ion-membrane interactions. Such interactions include cation attraction to the phosphate and carbonyl oxygens of the phospholipid headgroups that form strong lipid-ion and lipid-ion-water complexes. We also propose potential mechanisms that may modulate the affinities of these cationic species to the water-phospholipid interfacial oxygen moieties. This review aims to highlight the potential interdependence between protons and alkali metal ions at the membrane surface and encourage a more nuanced understanding of the complex nature of these biologically relevant processes.
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Affiliation(s)
- Evelyne Deplazes
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW, 2007, Australia. .,School of Pharmacy and Biomedical Sciences, Curtin University, Perth, WA, 6845, Australia.
| | - Jacqueline White
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW, 2007, Australia
| | - Christopher Murphy
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW, 2007, Australia
| | - Charles G Cranfield
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW, 2007, Australia
| | - Alvaro Garcia
- School of Life Sciences, University of Technology Sydney, Ultimo, NSW, 2007, Australia.
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15
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Gumí-Audenis B, Illa-Tuset S, Grimaldi N, Pasquina-Lemonche L, Ferrer-Tasies L, Sanz F, Veciana J, Ratera I, Faraudo J, Ventosa N, Giannotti MI. Insights into the structure and nanomechanics of a quatsome membrane by force spectroscopy measurements and molecular simulations. NANOSCALE 2018; 10:23001-23011. [PMID: 30500043 DOI: 10.1039/c8nr07110a] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Quatsomes (QS) are unilamellar nanovesicles constituted by quaternary ammonium surfactants and sterols in defined molar ratios. Unlike conventional liposomes, QS are stable upon long storage such as for several years, they show outstanding vesicle-to-vesicle homogeneity regarding size and lamellarity, and they have the structural and physicochemical requirements to be a potential platform for site-specific delivery of hydrophilic and lipophilic molecules. Knowing in detail the structure and mechanical properties of the QS membrane is of great importance for the design of deformable and flexible nanovesicle alternatives, highly pursued in nanomedicine applications such as the transdermal administration route. In this work, we report the first study on the detailed structure of the cholesterol : CTAB QS membrane at the nanoscale, using atomic force microscopy (AFM) and spectroscopy (AFM-FS) in a controlled liquid environment (ionic medium and temperature) to assess the topography of supported QS membranes (SQMs) and to evaluate the local membrane mechanics. We further perform molecular dynamics (MD) simulations to provide an atomistic interpretation of the obtained results. Our results are direct evidence of the bilayer nature of the QS membrane, with characteristics of a fluid-like membrane, compact and homogeneous in composition, and with structural and mechanical properties that depend on the surrounding environment. We show how ions alter the lateral packing, modifying the membrane mechanics. We observe that according to the ionic environment and temperature, different domains may coexist in the QS membranes, ascribed to variations in molecular tilt angles. Our results indicate that QS membrane properties may be easily tuned by altering the lateral interactions with either different environmental ions or counterions.
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Affiliation(s)
- Berta Gumí-Audenis
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain.
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16
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Casein interaction with lipid membranes: Are the phase state or charge density of the phospholipids affecting protein adsorption? BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:2588-2598. [DOI: 10.1016/j.bbamem.2018.09.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 09/11/2018] [Accepted: 09/26/2018] [Indexed: 01/03/2023]
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17
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Dols-Perez A, Fumagalli L, Gomila G. Interdigitation in spin-coated lipid layers in air. Colloids Surf B Biointerfaces 2018; 172:400-406. [PMID: 30195157 DOI: 10.1016/j.colsurfb.2018.08.041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 08/14/2018] [Accepted: 08/19/2018] [Indexed: 10/28/2022]
Abstract
In this study, we show that dry saturated phospholipid layers prepared by the spin-coating technique could present thinner regions associated to interdigitated phases under some conditions. The morphological characteristics of lipid layers of saturated phosphocholines, such as dilauroylphosphatidylcholine (DLPC), dimyristoylphosphatidylcholine (DMPC), dipalmitoylphosphatidylcholine (DPPC) and distearoylphosphatidylcholine (DSPC), have been measured by Atomic Force Microscopy and revealed that the presence of interdigitated regions is not induced by the same parameters that induce them in hydrated samples. To achieve these results the effect of the lipid hidrocabonated chain length, the presence of alcohol in the coating solution, the spinning velocity and the presence of cholesterol were tested. We showed that DPPC and DSPC bilayers, on the one side, can show structures with similar height than interdigitated regions observed in hydrated samples, while, on the other side, DLPC and DMPC tend to show no evidence of interdigitation. Results indicate that the presence of interdigitated areas is due to the presence of lateral tensions and, hence, that they can be eliminated by releasing these tensions by, for instance, the addition of cholesterol. These results demonstrate that interdigitation in lipid layers is a rather general phenomena and can be observed in lipid bilayers in dry conditions.
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Affiliation(s)
- Aurora Dols-Perez
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ, Delft, Netherlands.
| | - Laura Fumagalli
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom
| | - Gabriel Gomila
- Institut de Bioenginyeria de Catalunya (IBEC), C/ Baldiri i Reixac 15-21, 08028, Barcelona, Spain; Departament d'Enginyeria Electrònica i Biomèdica, Universitat de Barcelona, C/ Martí i Franquès 1, 08028, Barcelona, Spain
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18
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Effects of mono- and di-valent metal cations on the morphology of lipid vesicles. Chem Phys Lipids 2018; 217:19-28. [PMID: 30253127 DOI: 10.1016/j.chemphyslip.2018.09.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 08/09/2018] [Accepted: 09/18/2018] [Indexed: 12/22/2022]
Abstract
Lipid vesicles are an attractive model membrane experimental platform that is widely used in a biological context. The stability of vesicles can affect their performance and depends on various experimental conditions. How bio-related ions affect vesicle morphology is poorly understood in some cases. Herein, we investigated changes in vesicle morphology influenced by cation in the static and flowing environments. The effects of different mono- and di-valent metal cations on the morphology of lipid vesicles were systematically studied using the various techniques. The results showed that divalent cations caused significant aggregation or fusion of lipid vesicles, but monovalent cations had little effect on the vesicle morphology. Cation binding increased the net surface potential of vesicles, leading to changes in the zeta potential. The same qualitative kinetics were observed for cations that had the same valence at the same ionic strength. However, different types of cations gave different quantitative effects. The order of the ability to destroy the vesicle morphology was Cu2+ > Mg2+ > Ca2+ > Na+ > K+. These results are of practical value in the use of lipid vesicles as a bionic model, and help to shed light on the role of ions at membrane surfaces and interfaces.
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19
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Gumí-Audenis B, Costa L, Ferrer-Tasies L, Ratera I, Ventosa N, Sanz F, Giannotti MI. Pulling lipid tubes from supported bilayers unveils the underlying substrate contribution to the membrane mechanics. NANOSCALE 2018; 10:14763-14770. [PMID: 30043793 DOI: 10.1039/c8nr03249a] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Cell processes like endocytosis, membrane resealing, signaling and transcription involve conformational changes which depend on the chemical composition and the physicochemical properties of the lipid membrane. The better understanding of the mechanical role of lipids in cell membrane force-triggered and sensing mechanisms has recently become the focus of attention. Different membrane models and experimental methodologies are commonly explored. While general approaches involve controlled vesicle deformation using micropipettes or optical tweezers, due to the local and dynamic nature of the membrane, high spatial resolution atomic force microscopy (AFM) has been widely used to study the mechanical compression and indentation of supported lipid bilayers (SLBs). However, the substrate contribution remains unkown. Here, we demonstrate how pulling lipid tubes with an AFM out of model SLBs can be used to assess the nanomechanics of SLBs through the evaluation of the tube growing force (Ftube), allowing for very local evaluation with high spatial and force resolution of the lipid membrane tension. We first validate this approach to determine the contribution of different phospholipids, by varying the membrane composition, in both one-component and phase-segregated membranes. Finally, we successfully assess the contribution of the underlying substrate to the membrane mechanics, demonstrating that SLB models may represent an intermediate scenario between a free membrane (blebs) and a cytoskeleton supported membrane.
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Affiliation(s)
- Berta Gumí-Audenis
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology (BIST), Baldiri Reixac 10-12, 08028 Barcelona, Spain.
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20
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Motegi T, Yamazaki K, Ogino T, Tero R. Substrate-Induced Structure and Molecular Dynamics in a Lipid Bilayer Membrane. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:14748-14755. [PMID: 29236511 DOI: 10.1021/acs.langmuir.7b03212] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The solid-substrate-dependent structure and dynamics of molecules in a supported lipid bilayer (SLB) were directly investigated via atomic force microscopy (AFM) and single particle tracking (SPT) measurements. The appearance of either vertical or horizontal heterogeneities in the SLB was found to be strongly dependent on the underlying substrates. SLB has been widely used as a biointerface with incorporated proteins and other biological materials. Both silica and mica are popular substrates for SLB. Using single-molecule dynamics, the fluidity of the upper and lower membrane leaflets was found to depend on the substrate, undergoing coupling and decoupling on the SiO2/Si and mica substrates, respectively. The anisotropic diffusion caused by the locally destabilized structure of the SLB at atomic steps appeared on the Al2O3(0001) substrate because of the strong van der Waals interaction between the SLB and the substrate. Our finding that the well-defined surfaces of mica and sapphire result in asymmetry and anisotropy in the plasma membrane is useful for the design of new plasma-membrane-mimetic systems. The application of well-defined supporting substrates for SLBs should have similar effects as cell membrane scaffolds, which regulate the dynamic structure of the membrane.
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Affiliation(s)
| | - Kenji Yamazaki
- Division of Applied Physics, Graduate School of Engineering, Hokkaido University , Sapporo 060-8628, Japan
| | - Toshio Ogino
- Department of Engineering, Yokohama National University , Yokohama 240-8501, Japan
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21
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Piantanida L, Bolt HL, Rozatian N, Cobb SL, Voïtchovsky K. Ions Modulate Stress-Induced Nanotexture in Supported Fluid Lipid Bilayers. Biophys J 2017; 113:426-439. [PMID: 28746853 PMCID: PMC5529180 DOI: 10.1016/j.bpj.2017.05.049] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 05/22/2017] [Accepted: 05/30/2017] [Indexed: 12/13/2022] Open
Abstract
Most plasma membranes comprise a large number of different molecules including lipids and proteins. In the standard fluid mosaic model, the membrane function is effected by proteins whereas lipids are largely passive and serve solely in the membrane cohesion. Here we show, using supported 1,2-dioleoyl-sn-glycero-3-phosphocholine lipid bilayers in different saline solutions, that ions can locally induce ordering of the lipid molecules within the otherwise fluid bilayer when the latter is supported. This nanoordering exhibits a characteristic length scale of ∼20 nm, and manifests itself clearly when mechanical stress is applied to the membrane. Atomic force microscopy (AFM) measurements in aqueous solutions containing NaCl, KCl, CaCl2, and Tris buffer show that the magnitude of the effect is strongly ion-specific, with Ca2+ and Tris, respectively, promoting and reducing stress-induced nanotexturing of the membrane. The AFM results are complemented by fluorescence recovery after photobleaching experiments, which reveal an inverse correlation between the tendency for molecular nanoordering and the diffusion coefficient within the bilayer. Control AFM experiments on other lipids and at different temperatures support the hypothesis that the nanotexturing is induced by reversible, localized gel-like solidification of the membrane. These results suggest that supported fluid phospholipid bilayers are not homogenous at the nanoscale, but specific ions are able to locally alter molecular organization and mobility, and spatially modulate the membrane’s properties on a length scale of ∼20 nm. To illustrate this point, AFM was used to follow the adsorption of the membrane-penetrating antimicrobial peptide Temporin L in different solutions. The results confirm that the peptides do not absorb randomly, but follow the ion-induced spatial modulation of the membrane. Our results suggest that ionic effects have a significant impact for passively modulating the local properties of biological membranes, when in contact with a support such as the cytoskeleton.
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Affiliation(s)
- Luca Piantanida
- Department of Physics, Durham University, Durham, United Kingdom
| | - Hannah L Bolt
- Department of Chemistry, Durham University, Durham, United Kingdom
| | - Neshat Rozatian
- Department of Chemistry, Durham University, Durham, United Kingdom
| | - Steven L Cobb
- Department of Chemistry, Durham University, Durham, United Kingdom
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22
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Ruiz-Rincón S, González-Orive A, de la Fuente JM, Cea P. Reversible Monolayer-Bilayer Transition in Supported Phospholipid LB Films under the Presence of Water: Morphological and Nanomechanical Behavior. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:7538-7547. [PMID: 28691823 DOI: 10.1021/acs.langmuir.7b01268] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Mixed monolayer Langmuir-Blodgett (LB) films of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and cholesterol (Chol) in the 1:1 ratio have been prepared onto solid mica substrates. Upon immersion in water or in an aqueous HEPES solution (pH 7.4) the monolayer LB films were spontaneously converted into well-organized bilayers leaving free mica areas. The process has been demonstrated to be reversible upon removal of the aqueous solution, resulting in remarkably free of defects monolayers that are homogeneously distributed onto the mica. In addition, the nanomechanical properties exhibited by the as-formed bilayers have been determined by means of AFM breakthrough force studies. The bilayers formed by immersion of the monolayer in an aqueous media exhibit nanomechanical properties and stability under compression analogous to those of DPPC:Chol supported bilayers obtained by other methods previously described in the literature. Consequently, the hydration of a monolayer LB film has been revealed as an easy method to produce well-ordered bilayers that mimic the cell membrane and that could be used as model cell membranes.
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Affiliation(s)
| | | | - Jesús M de la Fuente
- Instituto de Ciencia de Materiales de Aragón (ICMA), Universidad de Zaragoza-CSIC , 50009 Zaragoza, Spain
- Networking Biomedical Research Center of Bioengineering, Biomaterials, and Nanomedicine (CIBER-BBN), Zaragoza, Spain
| | - Pilar Cea
- Departamento de Química Física, Facultad de Ciencias, Universidad de Zaragoza , 50009, Zaragoza, Spain
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23
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Cheng C, Peng S, Li Z, Zou L, Liu W, Liu C. Improved bioavailability of curcumin in liposomes prepared using a pH-driven, organic solvent-free, easily scalable process. RSC Adv 2017. [DOI: 10.1039/c7ra02861j] [Citation(s) in RCA: 118] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
pH-driven method, an organic solvent-free and easily scale-upable method, was firstly utilized to prepared curcumin-loaded liposomes.
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Affiliation(s)
- Ce Cheng
- State Key Laboratory of Food Science and Technology
- Nanchang University
- Nanchang 330047
- PR China
| | - Shengfeng Peng
- State Key Laboratory of Food Science and Technology
- Nanchang University
- Nanchang 330047
- PR China
| | - Ziling Li
- State Key Laboratory of Food Science and Technology
- Nanchang University
- Nanchang 330047
- PR China
- School of Life Science
| | - Liqiang Zou
- State Key Laboratory of Food Science and Technology
- Nanchang University
- Nanchang 330047
- PR China
| | - Wei Liu
- State Key Laboratory of Food Science and Technology
- Nanchang University
- Nanchang 330047
- PR China
| | - Chengmei Liu
- State Key Laboratory of Food Science and Technology
- Nanchang University
- Nanchang 330047
- PR China
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24
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Kong X, Lu D, Wu J, Liu Z. A theoretical study on the morphological phase diagram of supported lipid bilayers. Phys Chem Chem Phys 2017. [DOI: 10.1039/c7cp03383d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A morphological phase diagram is constructed using classical density function theory (CDFT).
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Affiliation(s)
- Xian Kong
- Key Laboratory of Industrial Biocatalysis
- Chinese Ministry of Education and Department of Chemical Engineering
- Tsinghua University
- Beijing 100084
- China
| | - Diannan Lu
- Key Laboratory of Industrial Biocatalysis
- Chinese Ministry of Education and Department of Chemical Engineering
- Tsinghua University
- Beijing 100084
- China
| | - Jianzhong Wu
- Department of Chemical and Environmental Engineering
- University of California
- Riverside, California 92521
- USA
| | - Zheng Liu
- Key Laboratory of Industrial Biocatalysis
- Chinese Ministry of Education and Department of Chemical Engineering
- Tsinghua University
- Beijing 100084
- China
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25
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Gumí-Audenis B, Costa L, Carlá F, Comin F, Sanz F, Giannotti MI. Structure and Nanomechanics of Model Membranes by Atomic Force Microscopy and Spectroscopy: Insights into the Role of Cholesterol and Sphingolipids. MEMBRANES 2016; 6:E58. [PMID: 27999368 PMCID: PMC5192414 DOI: 10.3390/membranes6040058] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 12/12/2016] [Accepted: 12/14/2016] [Indexed: 11/17/2022]
Abstract
Biological membranes mediate several biological processes that are directly associated with their physical properties but sometimes difficult to evaluate. Supported lipid bilayers (SLBs) are model systems widely used to characterize the structure of biological membranes. Cholesterol (Chol) plays an essential role in the modulation of membrane physical properties. It directly influences the order and mechanical stability of the lipid bilayers, and it is known to laterally segregate in rafts in the outer leaflet of the membrane together with sphingolipids (SLs). Atomic force microscope (AFM) is a powerful tool as it is capable to sense and apply forces with high accuracy, with distance and force resolution at the nanoscale, and in a controlled environment. AFM-based force spectroscopy (AFM-FS) has become a crucial technique to study the nanomechanical stability of SLBs by controlling the liquid media and the temperature variations. In this contribution, we review recent AFM and AFM-FS studies on the effect of Chol on the morphology and mechanical properties of model SLBs, including complex bilayers containing SLs. We also introduce a promising combination of AFM and X-ray (XR) techniques that allows for in situ characterization of dynamic processes, providing structural, morphological, and nanomechanical information.
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Affiliation(s)
- Berta Gumí-Audenis
- Nanoprobes and Nanoswitches group, Institute for Bioengineering of Catalunya (IBEC), Barcelona 08028, Spain.
- Physical Chemistry Department, Universitat de Barcelona, Barcelona 08028, Spain.
- European Synchrotron Radiation Facility (ESRF), Grenoble 38043, France.
- Networking Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid 28028, Spain.
| | - Luca Costa
- Structure and Dynamics of Nucleoproteic and Membrane Assemblies, Centre de Biochimie Structurale (CBS), Montpellier 34090, France.
| | - Francesco Carlá
- European Synchrotron Radiation Facility (ESRF), Grenoble 38043, France.
| | - Fabio Comin
- European Synchrotron Radiation Facility (ESRF), Grenoble 38043, France.
| | - Fausto Sanz
- Nanoprobes and Nanoswitches group, Institute for Bioengineering of Catalunya (IBEC), Barcelona 08028, Spain.
- Physical Chemistry Department, Universitat de Barcelona, Barcelona 08028, Spain.
- Networking Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid 28028, Spain.
| | - Marina I Giannotti
- Nanoprobes and Nanoswitches group, Institute for Bioengineering of Catalunya (IBEC), Barcelona 08028, Spain.
- Physical Chemistry Department, Universitat de Barcelona, Barcelona 08028, Spain.
- Networking Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid 28028, Spain.
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Formation of planar unilamellar phospholipid membranes on oxidized gold substrate. Biointerphases 2016; 11:031017. [DOI: 10.1116/1.4963188] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Kong X, Lu D, Wu J, Liu Z. Spreading of a Unilamellar Liposome on Charged Substrates: A Coarse-Grained Molecular Simulation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:3785-3793. [PMID: 27019394 DOI: 10.1021/acs.langmuir.6b00043] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Supported lipid bilayers (SLBs) are able to accommodate membrane proteins useful for diverse biomimetic applications. Although liposome spreading represents a common procedure for preparation of SLBs, the underlying mechanism is not yet fully understood, particularly from a molecular perspective. The present study examines the effects of the substrate charge on unilamellar liposome spreading on the basis of molecular dynamics simulations for a coarse-grained model of the solvent and lipid molecules. Liposome transformation into a lipid bilayer of different microscopic structures suggests three types of kinetic pathways depending on the substrate charge density, that is, top-receding, parachute, and parachute with wormholes. Each pathway leads to a unique distribution of the lipid molecules and thereby distinctive properties of SLBs. An increase of the substrate charge density results in a magnified asymmetry of the SLBs in terms of the ratio of charged lipids, parallel surface movements, and the distribution of lipid molecules. While the lipid mobility in the proximal layer is strongly correlated with the substrate potential, the dynamics of lipid molecules in the distal monolayer is similar to that of a freestanding lipid bilayer. For liposome spreading on a highly charged surface, wormhole formation promotes lipid exchange between the SLB monolayers thus reduces the asymmetry on the number density of lipid molecules, the lipid order parameter, and the monolayer thickness. The simulation results reveal the important regulatory role of electrostatic interactions on liposome spreading and the properties of SLBs.
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Affiliation(s)
- Xian Kong
- Key Laboratory of Industrial Biocatalysis, Chinese Ministry of Education and Department of Chemical Engineering, Tsinghua University , Beijing 100084, China
| | - Diannan Lu
- Key Laboratory of Industrial Biocatalysis, Chinese Ministry of Education and Department of Chemical Engineering, Tsinghua University , Beijing 100084, China
| | - Jianzhong Wu
- Department of Chemical and Environmental Engineering, University of California , Riverside California 92521, United States
| | - Zheng Liu
- Key Laboratory of Industrial Biocatalysis, Chinese Ministry of Education and Department of Chemical Engineering, Tsinghua University , Beijing 100084, China
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Wayment-Steele HK, Jing Y, Swann MJ, Johnson LE, Agnarsson B, Svedhem S, Johal MS, Kunze A. Effects of Al(3+) on Phosphocholine and Phosphoglycerol Containing Solid Supported Lipid Bilayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:1771-1781. [PMID: 26783873 DOI: 10.1021/acs.langmuir.5b03999] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Aluminum has attracted great attention recently as it has been suggested by several studies to be associated with increased risks for Alzheimer's and Parkinson's disease. The toxicity of the trivalent ion is assumed to derive from structural changes induced in lipid bilayers upon binding, though the mechanism of this process is still not well understood. In the present study we elucidate the effect of Al(3+) on supported lipid bilayers (SLBs) using fluorescence microscopy, the quartz crystal microbalance with dissipation (QCM-D) technique, dual-polarization interferometry (DPI), and molecular dynamics (MD) simulations. Results from these techniques show that binding of Al(3+) to SLBs containing negatively charged and neutral phospholipids induces irreversible changes such as domain formation. The measured variations in SLB thickness, birefringence, and density indicate a phase transition from a disordered to a densely packed ordered phase.
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Affiliation(s)
- Hannah K Wayment-Steele
- Department of Chemistry, Pomona College , 645 North College Ave., Claremont, California 91711, United States
| | - Yujia Jing
- Department of Applied Physics, Chalmers University of Technology , 412 96 Göteborg, Sweden
| | - Marcus J Swann
- Swann Scientific Consulting Ltd., 110 Sandy Lane, Lymm, Cheshire, U.K
| | - Lewis E Johnson
- Department of Chemistry, Pomona College , 645 North College Ave., Claremont, California 91711, United States
- Department of Chemistry, University of Washington , 109 Bagley Hall, Seattle, Washington 98195, United States
| | - Björn Agnarsson
- Department of Applied Physics, Chalmers University of Technology , 412 96 Göteborg, Sweden
| | - Sofia Svedhem
- Department of Applied Physics, Chalmers University of Technology , 412 96 Göteborg, Sweden
| | - Malkiat S Johal
- Department of Chemistry, Pomona College , 645 North College Ave., Claremont, California 91711, United States
| | - Angelika Kunze
- Department of Applied Physics, Chalmers University of Technology , 412 96 Göteborg, Sweden
- Institute of Physical Chemistry, University of Göttingen , 37077 Göttingen, Germany
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29
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Catte A, Girych M, Javanainen M, Loison C, Melcr J, Miettinen MS, Monticelli L, Määttä J, Oganesyan VS, Ollila OHS, Tynkkynen J, Vilov S. Molecular electrometer and binding of cations to phospholipid bilayers. Phys Chem Chem Phys 2016; 18:32560-32569. [DOI: 10.1039/c6cp04883h] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The molecular electrometer – reorientation of lipid head due to bound charge – allows direct quantitative vetting of simulations against noninvasive NMR experiments; most simulation models overestimated lipid–cation affinities.
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Gumí-Audenis B, Sanz F, Giannotti MI. Impact of galactosylceramides on the nanomechanical properties of lipid bilayer models: an AFM-force spectroscopy study. SOFT MATTER 2015; 11:5447-5454. [PMID: 26058499 DOI: 10.1039/c5sm01252j] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Galactosylceramides (GalCer) are glycosphingolipids bound to a monosaccharide group, responsible for inducing extensive hydrogen bonds that yield their alignment and accumulation in the outer leaflet of the biological membrane together with cholesterol (Chol) in rafts. In this work, the influence of GalCer on the nanomechanical properties of supported lipid bilayers (SLBs) based on DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine) and DLPC (1,2-didodecanoyl-sn-glycero-3-phosphocoline) as model systems was assessed. Phosphatidylcholine (PC):GalCer SLBs were characterized by means of differential scanning calorimetry (DSC) and atomic force microscopy (AFM), in both imaging and force spectroscopy (AFM-FS) modes. Comparing both PC systems, we determined that the behaviour of SLB mixtures is governed by the PC phase-like state at the working temperature. While a phase segregated system is observed for DLPC:GalCer SLBs, GalCer are found to be dissolved in DPPC SLBs for GalCer contents up to 20 mol%. In both systems, the incorporation of GalCer intensifies the nanomechanical properties of SLBs. Interestingly, segregated domains of exceptionally high mechanical stability are formed in DLPC:GalCer SLBs. Finally, the role of 20 mol% Chol in GalCer organization and function in the membranes was assessed. Both PC model systems displayed phase segregation and remarkable nanomechanical stability when GalCer and Chol coexist in SLBs.
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Affiliation(s)
- Berta Gumí-Audenis
- Institute for Bioengineering of Catalonia (IBEC), Baldiri Reixac 10-12, Barcelona, 08028, Spain.
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31
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Šegota S, Vojta D, Kendziora D, Ahmed I, Fruk L, Baranović G. Ligand-Dependent Nanoparticle Clustering within Lipid Membranes Induced by Surrounding Medium. J Phys Chem B 2015; 119:5208-19. [DOI: 10.1021/acs.jpcb.5b00898] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | - Dania Kendziora
- DFG—Center
for Functional Nanostructures, Karlsruhe Institute for Technology (KIT), Karlsruhe, 76131 Germany
| | - Ishtiaq Ahmed
- DFG—Center
for Functional Nanostructures, Karlsruhe Institute for Technology (KIT), Karlsruhe, 76131 Germany
| | - Ljiljana Fruk
- DFG—Center
for Functional Nanostructures, Karlsruhe Institute for Technology (KIT), Karlsruhe, 76131 Germany
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32
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Drazenovic J, Ahmed S, Tuzinkiewicz NM, Wunder SL. Lipid exchange and transfer on nanoparticle supported lipid bilayers: effect of defects, ionic strength, and size. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:721-31. [PMID: 25425021 DOI: 10.1021/la503967m] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Lipid exchange/transfer has been compared for zwitterionic 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dimyristoyl-d54-sn-glycero-3-phosphocholine (DMPC) small unilamellar vesicles (SUVs) and for the same lipids on silica (SiO2) nanoparticle supported lipid bilayers (NP-SLBs) as a function of ionic strength, temperature, temperature cycling, and NP size, above the main gel-to-liquid crystal phase transition temperature, Tm, using d- and h-DMPC and DPPC. Increasing ionic strength decreases the exchange kinetics for the SUVs, but more so for the NP-SLBs, due to better packing of the lipids and increased attraction between the lipid and support. When the NP-SLBs (or SUVs) are cycled above and below Tm, the exchange rate increases compared with exchange at the same temperature without cycling, for similar total times, suggesting that defects provide sites for more facile removal and thus exchange of lipids. Defects can occur: (i) at the phase boundaries between coexisting gel and fluid phases at Tm; (ii) in bare regions of exposed SiO2 that form during NP-SLB formation due to mismatched surface areas of lipid and NPs; and (iii) during cycling as the result of changes in area of the lipids at Tm and mismatched thermal expansion coefficient between the lipids and SiO2 support. Exchange rates are faster for NP-SLBs prepared with the nominal amount of lipid required to form a NP-SLB compared with NP-SLBs that have been prepared with excess lipids to minimize SiO2 patches. Nanosystems prepared with equimolar mixtures of NP-SLBs composed of d-DMPC (d(DMPC)-NP-SLB) and SUVs composed of h-DMPC (h(DMPC)-SUV) show that the calorimetric transition of the "donor" h(DMPC)-SUV decreases in intensity without an initial shift in Tm, indicating that the "acceptor" d(DMPC)-NP-SLB can accommodate more lipids, through either further fusion or insertion of lipids into the distal monolayer. Exchange for d/h(DMPC)-NP-SLB is in the order 100 nm SiO2 > 45 nm SiO2 > 5 nm SiO2.
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Affiliation(s)
- Jelena Drazenovic
- Department of Chemistry, Temple University , Philadephia, Pennsylvania 19122, United States
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Ionic strength and composition govern the elasticity of biological membranes. A study of model DMPC bilayers by force- and transmission IR spectroscopy. Chem Phys Lipids 2014; 186:17-29. [PMID: 25447291 DOI: 10.1016/j.chemphyslip.2014.11.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 11/05/2014] [Accepted: 11/11/2014] [Indexed: 12/15/2022]
Abstract
Infrared (IR) spectroscopy was used to quantify the ion mixture effect of seawater (SW), particularly the contribution of Mg(2+) and Ca(2+) as dominant divalent cations, on the thermotropic phase behaviour of 1,2-dimyristoyl-sn-glycero-3-posphocholine (DMPC) bilayers. The changed character of the main transition at 24 °C from sharp to gradual in films and the 1 °C shift of the main transition temperature in dispersions reflect the interactions of lipid headgroups with the ions in SW. Force spectroscopy was used to quantify the nanomechanical hardness of a DMPC supported lipid bilayer (SLB). Considering the electrostatic and ion binding equilibrium contributions while systematically probing the SLB in various salt solutions, we showed that ionic strength had a decisive influence on its nanomechanics. The mechanical hardness of DMPC SLBs in the liquid crystalline phase linearly increases with the increasing fraction of all ion-bound lipids in a series of monovalent salt solutions. It also linearly increases in the gel phase but almost three times faster (the corresponding slopes are 4.9 nN/100 mM and 13.32 nN/100 mM, respectively). We also showed that in the presence of divalent ions (Ca(2+) and Mg(2+)) the bilayer mechanical hardness was unproportionally increased, and that was accompanied with the decrease of Na(+) ion and increase of Cl(-) ion bound lipids. The underlying process is a cooperative and competitive ion binding in both the gel and the liquid crystalline phase. Bilayer hardness thus turned out to be very sensitive to ionic strength as well as to ionic composition of the surrounding medium. In particular, the indicated correlation helped us to emphasize the colligative properties of SW as a naturally occurring complex ion mixture.
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Le QC, Ropers MH, Terrisse H, Humbert B. Interactions between phospholipids and titanium dioxide particles. Colloids Surf B Biointerfaces 2014; 123:150-7. [DOI: 10.1016/j.colsurfb.2014.09.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Revised: 08/29/2014] [Accepted: 09/03/2014] [Indexed: 01/01/2023]
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Morphological and physical analysis of natural phospholipids-based biomembranes. PLoS One 2014; 9:e107435. [PMID: 25238543 PMCID: PMC4169657 DOI: 10.1371/journal.pone.0107435] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2014] [Accepted: 08/11/2014] [Indexed: 01/15/2023] Open
Abstract
Background Liposomes are currently an important part of biological, pharmaceutical, medical and nutritional research, as they are considered to be among the most effective carriers for the introduction of various types of bioactive agents into target cells. Scope of Review In this work, we study the lipid organization and mechanical properties of biomembranes made of marine and plant phospholipids. Membranes based on phospholipids extracted from rapeseed and salmon are studied in the form of liposome and as supported lipid bilayer. Dioleylphosphatidylcholine (DOPC) and dipalmitoylphosphatidylcholine (DPPC) are used as references to determine the lipid organization of marine and plant phospholipid based membranes. Atomic force microscopy (AFM) imaging and force spectroscopy measurements are performed to investigate the membranes' topography at the micrometer scale and to determine their mechanical properties. Major Conclusions The mechanical properties of the membranes are correlated to the fatty acid composition, the morphology, the electrophoretic mobility and the membrane fluidity. Thus, soft and homogeneous mechanical properties are evidenced for salmon phospholipids membrane containing various polyunsaturated fatty acids. Besides, phase segregation in rapeseed membrane and more important mechanical properties were emphasized for this type of membranes by contrast to the marine phospholipids based membranes. General Significance This paper provides new information on the nanomechanical and morphological properties of membrane in form of liposome by AFM. The originality of this work is to characterize the physico-chemical properties of the nanoliposome from the natural sources containing various fatty acids and polar head.
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Lee J, Gillman AL, Jang H, Ramachandran S, Kagan BL, Nussinov R, Teran Arce F. Role of the fast kinetics of pyroglutamate-modified amyloid-β oligomers in membrane binding and membrane permeability. Biochemistry 2014; 53:4704-14. [PMID: 24950761 PMCID: PMC4215883 DOI: 10.1021/bi500587p] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
![]()
Membrane
permeability to ions and small molecules is believed to
be a critical step in the pathology of Alzheimer’s disease
(AD). Interactions of oligomers formed by amyloid-β (Aβ)
peptides with the plasma cell membrane are believed to play a fundamental
role in the processes leading to membrane permeability. Among the
family of Aβs, pyroglutamate (pE)-modified Aβ peptides
constitute the most abundant oligomeric species in the brains of AD
patients. Although membrane permeability mechanisms have been studied
for full-length Aβ1–40/42 peptides, these
have not been sufficiently characterized for the more abundant AβpE3–42 fragment. Here we have compared the adsorbed
and membrane-inserted oligomeric species of AβpE3–42 and Aβ1–42 peptides. We find lower concentrations
and larger dimensions for both species of membrane-associated AβpE3–42 oligomers. The larger dimensions are attributed
to the faster self-assembly kinetics of AβpE3–42, and the lower concentrations are attributed to weaker interactions
with zwitterionic lipid headgroups. While adsorbed oligomers produced
little or no significant membrane structural damage, increased membrane
permeabilization to ionic species is understood in terms of enlarged
membrane-inserted oligomers. Membrane-inserted AβpE3–42 oligomers were also found to modify the mechanical properties of
the membrane. Taken together, our results suggest that membrane-inserted
oligomers are the primary species responsible for membrane permeability.
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Affiliation(s)
- Joon Lee
- Department of Bioengineering, University of California at San Diego , La Jolla, California 92093, United States
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37
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Imura T, Tsukui Y, Taira T, Aburai K, Sakai K, Sakai H, Abe M, Kitamoto D. Surfactant-like properties of an amphiphilic α-helical peptide leading to lipid nanodisc formation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:4752-4759. [PMID: 24738727 DOI: 10.1021/la500267b] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Nanodiscs are self-assembled discoidal nanoparticles composed of amphiphilic α-helical scaffold proteins or peptides that wrap themselves around the circumference of a lipid bilayer in a beltlike manner. In this study, an amphiphilic helical peptide that mimics helix 10 of human apoA-I was newly synthesized by solid phase peptide synthesis using Fmoc chemistry, and its physicochemical properties, including surface tension, self-association, and solubilization abilities, were evaluated and related directly to nanodisc formation. The synthesized peptide having hydrophobic and hydrophilic faces behaves like a general surfactant, affording a critical association concentration (CAC) of 2.7 × 10(-5) M and a γCAC of 51.2 mN m(-1) in aqueous solution. Interestingly, only a peptide solution above its CAC was able to microsolubilize L-α-dimyristoylphosphatidylcholine (DMPC) vesicles, and lipid nanodiscs with an average diameter of 9.5 ± 2.7 nm were observed by dynamic light scattering and negative stain transmission electron microscopy. Moreover, the ζ potentials of the lipid nanodiscs were measured for the first time as a function of pH, and the values changed from positive (20 mV) to negative (-30 mV). In particular, nanodisc solutions at acidic pH 4 (20 mV) or basic pH 9 (-20 mV) were found to be stable for more than 6 months as a result of the electrostatic repulsion between the particles.
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Affiliation(s)
- Tomohiro Imura
- Research Institute for Innovation in Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST) , Tsukuba Central 5-2, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
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Mukhametshina AR, Mustafina AR, Davydov NA, Nizameev IR, Kadirov MK, Gorbatchuk VV, Konovalov AI. The energy transfer based fluorescent approach to detect the formation of silica supported phosphatidylcholine and phosphatidylserine containing bilayers. Colloids Surf B Biointerfaces 2014; 115:93-9. [DOI: 10.1016/j.colsurfb.2013.11.035] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 11/12/2013] [Accepted: 11/15/2013] [Indexed: 11/25/2022]
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Redondo-Morata L, Giannotti MI, Sanz F. Structural impact of cations on lipid bilayer models: Nanomechanical properties by AFM-force spectroscopy. Mol Membr Biol 2013; 31:17-28. [DOI: 10.3109/09687688.2013.868940] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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41
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Jarerattanachat V, Karttunen M, Wong-ekkabut J. Molecular Dynamics Study of Oxidized Lipid Bilayers in NaCl Solution. J Phys Chem B 2013; 117:8490-501. [DOI: 10.1021/jp4040612] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Viwan Jarerattanachat
- Department of Physics, Faculty
of Science, Kasetsart University, 50 Phahon
Yothin Rd, Chatuchak, Bangkok, Thailand
| | - Mikko Karttunen
- Department of Chemistry and
Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario,
Canada
| | - Jirasak Wong-ekkabut
- Department of Physics, Faculty
of Science, Kasetsart University, 50 Phahon
Yothin Rd, Chatuchak, Bangkok, Thailand
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42
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Zhu T, Jiang Z, Nurlybaeva EMR, Sheng J, Ma Y. Effect of osmotic stress on membrane fusion on solid substrate. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:6377-6385. [PMID: 23631459 DOI: 10.1021/la401054g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
There is currently a lack of comprehensive understanding of osmotic effect on lipid vesicle fusion on solid oxide surface. The question has both biological and biomedical implications. We studied the effect by quartz crystal microbalance with dissipation monitoring using NaCl, sucrose as osmolytes, and two different osmotic stress imposition methods, which allowed us to separate the osmotic effects from the solute impacts. Osmotic stress was found to have limited influence on the fusion kinetics, independently of the direction of the gradient. Further atomic force microscopy experiments and energy consideration implied that osmotic stress spends the majority of chemical potential energy associated in directed transport of water across membrane. Its contribution to vesicle deformation and fusion on substrate is therefore small compared to that of adhesion.
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Affiliation(s)
- Tao Zhu
- National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, China
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Harb FF, Tinland B. Effect of ionic strength on dynamics of supported phosphatidylcholine lipid bilayer revealed by FRAPP and Langmuir-Blodgett transfer ratios. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:5540-5546. [PMID: 23581462 DOI: 10.1021/la304962n] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
To determine how lipid bilayer/support interactions are affected by ionic strength, we carried out lipid diffusion coefficient measurements by fluorescence recovery after patterned photobleaching (FRAPP) and transfer ratio measurements using a Langmuir balance on supported bilayers of phosphatidylcholine lipids. The main effect of increasing ionic strength is shown to be enhanced diffusion of the lipids due to a decrease in the electrostatic interaction between the bilayer and the support. We experimentally confirm that the two main parameters governing bilayer behavior are electrostatic interaction and bilayer/support distance. Both these parameters can therefore be used to vary the potential that acts on the bilayer. Additionally, our findings show that FRAPP is an extremely sensitive tool to study interaction effects: here, variations in diffusion coefficient as well as the presence or absence of leaflet decoupling.
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Kagawa R, Hirano Y, Taiji M, Yasuoka K, Yasui M. Dynamic interactions of cations, water and lipids and influence on membrane fluidity. J Memb Sci 2013. [DOI: 10.1016/j.memsci.2013.02.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Kaufman Y, Grinberg S, Linder C, Heldman E, Gilron J, Freger V. Fusion of bolaamphiphile micelles: a method to prepare stable supported biomimetic membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:1152-61. [PMID: 23281661 DOI: 10.1021/la304484p] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Supported biomimetic membranes (SBMs) on solid substrates have been commonly prepared from vesicle-forming double-tail lipids, such as zwitterionic phospholipids, using the method of vesicle fusion. Here we report on the preparation of SBMs on silica surfaces via a similar process of "micelle fusion" from a cationic single-tail bolaamphiphile GLH-20 that forms spherical and elongated thread-like micelles in solution. We demonstrate that, in contrast to zwitterionic phospholipids, GLH-20 self-assembles into a stable contiguous SBM at both low and high ionic strengths. The cationic charge of GLH-20 promotes the formation of a stable SBM through enhanced double-layer interactions with the negatively charged silica surface. It is also shown that spinach aquaporin PM-28 was successfully incorporated within bolaamphiphile SBM in a manner similar to SBMs prepared by vesicle/proteoliposome fusion; thereby the inherent curvature of the micelle surface does not inhibit protein reconstitution. The results suggest that SBMs based on charged bolaamphiphiles might be an attractive platform for applications such as water purification and biosensors, where the stability and low defect rate of SBMs in diverse conditions are crucial for achieving desired performance.
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Affiliation(s)
- Y Kaufman
- Albert Katz International School for Desert Studies and Unit of Environmental Engineering, Ben-Gurion University of the Negev, Sde-Boqer, Israel
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46
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Kunze A, Bally M, Höök F, Larson G. Equilibrium-fluctuation-analysis of single liposome binding events reveals how cholesterol and Ca2+ modulate glycosphingolipid trans-interactions. Sci Rep 2013; 3:1452. [PMID: 23486243 PMCID: PMC3596795 DOI: 10.1038/srep01452] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Accepted: 03/01/2013] [Indexed: 12/18/2022] Open
Abstract
Carbohydrate-carbohydrate interactions (CCIs) are of central importance for several biological processes. However, the ultra-weak nature of CCIs generates difficulties in studying this interaction, thus only little is known about CCIs. Here we present a highly sensitive equilibrium-fluctuation-analysis of single liposome binding events to supported lipid bilayers (SLBs) based on total internal reflection fluorescence (TIRF) microscopy that allows us to determine apparent kinetic rate constants of CCIs. The liposomes and SLBs both contained natural Le(x) glycosphingolipids (Galβ4(Fucα3)GlcNAcβ3Galβ4Glcβ1Cer), which were employed to mimic cell-cell contacts. The kinetic parameters of the self-interaction between Le(x)-containing liposomes and SLBs were measured and found to be modulated by bivalent cations. Even more interestingly, upon addition of cholesterol, the strength of the CCIs increases, suggesting that this interaction is strongly influenced by a cholesterol-dependent presentation and/or spatial organization of glycosphingolipids in cell membranes.
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Affiliation(s)
- Angelika Kunze
- Department of Clinical Chemistry and Transfusion Medicine, Sahlgrenska Academy, University of Gothenburg, SE-413 45 Göteborg, Sweden
| | - Marta Bally
- Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg, Sweden
| | - Fredrik Höök
- Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg, Sweden
| | - Göran Larson
- Department of Clinical Chemistry and Transfusion Medicine, Sahlgrenska Academy, University of Gothenburg, SE-413 45 Göteborg, Sweden
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Morandat S, Azouzi S, Beauvais E, Mastouri A, El Kirat K. Atomic force microscopy of model lipid membranes. Anal Bioanal Chem 2012; 405:1445-61. [DOI: 10.1007/s00216-012-6383-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2012] [Revised: 08/02/2012] [Accepted: 08/24/2012] [Indexed: 10/27/2022]
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Ye S, Li H, Wei F, Jasensky J, Boughton AP, Yang P, Chen Z. Observing a model ion channel gating action in model cell membranes in real time in situ: membrane potential change induced alamethicin orientation change. J Am Chem Soc 2012; 134:6237-43. [PMID: 22420296 PMCID: PMC3328217 DOI: 10.1021/ja2110784] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Ion channels play crucial roles in transport and regulatory functions of living cells. Understanding the gating mechanisms of these channels is important to understanding and treating diseases that have been linked to ion channels. One potential model peptide for studying the mechanism of ion channel gating is alamethicin, which adopts a split α/3(10)-helix structure and responds to changes in electric potential. In this study, sum frequency generation vibrational spectroscopy (SFG-VS), supplemented by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), has been applied to characterize interactions between alamethicin (a model for larger channel proteins) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) lipid bilayers in the presence of an electric potential across the membrane. The membrane potential difference was controlled by changing the pH of the solution in contact with the bilayer and was measured using fluorescence spectroscopy. The orientation angle of alamethicin in POPC lipid bilayers was then determined at different pH values using polarized SFG amide I spectra. Assuming that all molecules adopt the same orientation (a δ distribution), at pH = 6.7 the α-helix at the N-terminus and the 3(10)-helix at the C-terminus tilt at about 72° (θ(1)) and 50° (θ(2)) versus the surface normal, respectively. When pH increases to 11.9, θ(1) and θ(2) decrease to 56.5° and 45°, respectively. The δ distribution assumption was verified using a combination of SFG and ATR-FTIR measurements, which showed a quite narrow distribution in the angle of θ(1) for both pH conditions. This indicates that all alamethicin molecules at the surface adopt a nearly identical orientation in POPC lipid bilayers. The localized pH change in proximity to the bilayer modulates the membrane potential and thus induces a decrease in both the tilt and the bend angles of the two helices in alamethicin. This is the first reported application of SFG to the study of model ion channel gating mechanisms in model cell membranes.
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Affiliation(s)
- Shuji Ye
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui, P.R.China 230026
| | - Hongchun Li
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui, P.R.China 230026
| | - Feng Wei
- Hefei National Laboratory for Physical Sciences at Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui, P.R.China 230026
| | - Joshua Jasensky
- Department of Biophysics, University of Michigan, AnnArbor, MI 48109, USA
| | - Andrew P. Boughton
- Department of Chemistry, University of Michigan, AnnArbor, MI 48109, USA
| | - Pei Yang
- Department of Chemistry, University of Michigan, AnnArbor, MI 48109, USA
| | - Zhan Chen
- Department of Biophysics, University of Michigan, AnnArbor, MI 48109, USA
- Department of Chemistry, University of Michigan, AnnArbor, MI 48109, USA
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Redondo-Morata L, Oncins G, Sanz F. Force spectroscopy reveals the effect of different ions in the nanomechanical behavior of phospholipid model membranes: the case of potassium cation. Biophys J 2012; 102:66-74. [PMID: 22225799 DOI: 10.1016/j.bpj.2011.10.051] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Revised: 10/06/2011] [Accepted: 10/24/2011] [Indexed: 10/14/2022] Open
Abstract
How do metal cations affect the stability and structure of phospholipid bilayers? What role does ion binding play in the insertion of proteins and the overall mechanical stability of biological membranes? Investigators have used different theoretical and microscopic approaches to study the mechanical properties of lipid bilayers. Although they are crucial for such studies, molecular-dynamics simulations cannot yet span the complexity of biological membranes. In addition, there are still some experimental difficulties when it comes to testing the ion binding to lipid bilayers in an accurate way. Hence, there is a need to establish a new approach from the perspective of the nanometric scale, where most of the specific molecular phenomena take place. Atomic force microscopy has become an essential tool for examining the structure and behavior of lipid bilayers. In this work, we used force spectroscopy to quantitatively characterize nanomechanical resistance as a function of the electrolyte composition by means of a reliable molecular fingerprint that reveals itself as a repetitive jump in the approaching force curve. By systematically probing a set of bilayers of different composition immersed in electrolytes composed of a variety of monovalent and divalent metal cations, we were able to obtain a wealth of information showing that each ion makes an independent and important contribution to the gross mechanical resistance and its plastic properties. This work addresses the need to assess the effects of different ions on the structure of phospholipid membranes, and opens new avenues for characterizing the (nano)mechanical stability of membranes.
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Affiliation(s)
- Lorena Redondo-Morata
- Institute for Bioengineering of Catalonia, University of Barcelona, Barcelona, Spain
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