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Kocman V, Di Mauro GM, Veglia G, Ramamoorthy A. Use of paramagnetic systems to speed-up NMR data acquisition and for structural and dynamic studies. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2019; 102:36-46. [PMID: 31325686 PMCID: PMC6698407 DOI: 10.1016/j.ssnmr.2019.07.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 07/10/2019] [Accepted: 07/11/2019] [Indexed: 05/05/2023]
Abstract
NMR spectroscopy is a powerful experimental technique to study biological systems at the atomic resolution. However, its intrinsic low sensitivity results in long acquisition times that in extreme cases lasts for days (or even weeks) often exceeding the lifetime of the sample under investigation. Different paramagnetic agents have been used in an effort to decrease the spin-lattice (T1) relaxation times of the studied nuclei, which are the main cause for long acquisition times necessary for signal averaging to enhance the signal-to-noise ratio of NMR spectra. Consequently, most of the experimental time is "wasted" in waiting for the magnetization to recover between successive scans. In this review, we discuss how to set up an optimal paramagnetic relaxation enhancement (PRE) system to effectively reduce the T1 relaxation times avoiding significant broadening of NMR signals. Additionally, we describe how PRE-agents can be used to provide structural and dynamic information and can even be used to follow the intermediates of chemical reactions and to speed-up data acquisition. We also describe the unique challenges and benefits associated with the application of PRE to solid-state NMR spectroscopy, explaining how the use of PREs is more complex for membrane mimetic systems as PREs can also be exploited to change the alignment of oriented membrane systems. Functionalization of membrane mimetics, such as bicelles, can provide a controlled region of paramagnetic effect that has the potential, together with the desired alignment, to provide crucial biologically relevant structural information. And finally, we discuss how paramagnetic metals can be utilized to further increase the dynamic nuclear polarization (DNP) effects and how to preserve the enhancements when dissolution DNP is implemented.
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Affiliation(s)
- Vojč Kocman
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA; Biophysics, Biomedical Engineering, Macromolecular Science and Engineering, University of Michigan, Ann Arbor, MI, USA
| | | | - Gianluigi Veglia
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Ayyalusamy Ramamoorthy
- Department of Chemistry, University of Michigan, Ann Arbor, MI, USA; Biophysics, Biomedical Engineering, Macromolecular Science and Engineering, University of Michigan, Ann Arbor, MI, USA.
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2
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Đorđević L, Marangoni T, Liu M, De Zorzi R, Geremia S, Minoia A, Lazzaroni R, Ishida Y, Bonifazi D. Templating Porphyrin Anisotropy via Magnetically Aligned Carbon Nanotubes. Chempluschem 2019; 84:1270-1278. [DOI: 10.1002/cplu.201800623] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Indexed: 12/13/2022]
Affiliation(s)
- Luka Đorđević
- Department of Chemical and Pharmaceutical SciencesUniversity of Trieste Via L. Giorgieri 1 34127 Trieste Italy
| | - Tomas Marangoni
- Department of Chemical and Pharmaceutical SciencesUniversity of Trieste Via L. Giorgieri 1 34127 Trieste Italy
| | - Mingjie Liu
- RIKEN Center for Emergent Matter Science 2-1 Hirosawa, Wako Saitama 351-0198 Japan
| | - Rita De Zorzi
- Department of Chemical and Pharmaceutical SciencesUniversity of Trieste Via L. Giorgieri 1 34127 Trieste Italy
| | - Silvano Geremia
- Department of Chemical and Pharmaceutical SciencesUniversity of Trieste Via L. Giorgieri 1 34127 Trieste Italy
| | - Andrea Minoia
- Laboratory for Chemistry of Novel Materials, CIRMAPUniversité de Mons-UMONS Place du Parc 20 B-7000 Mons Belgium
| | - Roberto Lazzaroni
- Laboratory for Chemistry of Novel Materials, CIRMAPUniversité de Mons-UMONS Place du Parc 20 B-7000 Mons Belgium
| | - Yasuhiro Ishida
- RIKEN Center for Emergent Matter Science 2-1 Hirosawa, Wako Saitama 351-0198 Japan
| | - Davide Bonifazi
- School of ChemistryCardiff University Park Place Main Building CF10 3AT United Kingdom
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3
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Isabettini S, Stucki S, Massabni S, Baumgartner ME, Reckey PQ, Kohlbrecher J, Ishikawa T, Windhab EJ, Fischer P, Kuster S. Development of Smart Optical Gels with Highly Magnetically Responsive Bicelles. ACS APPLIED MATERIALS & INTERFACES 2018; 10:8926-8936. [PMID: 29460620 DOI: 10.1021/acsami.7b17134] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Hydrogels delivering on-demand tailorable optical properties are formidable smart materials with promising perspectives in numerous fields, including the development of modern sensors and switches, the essential quality criterion being a defined and readily measured response to environmental changes. Lanthanide ion (Ln3+)-chelating bicelles are interesting building blocks for such materials because of their magnetic responsive nature. Imbedding these phospholipid-based nanodiscs in a magnetically aligned state in gelatin permits an orientation-dependent retardation of polarized light. The resulting tailorable anisotropy gives the gel a well-defined optical signature observed as a birefringence signal. These phenomena were only reported for a single bicelle-gelatin pair and required high magnetic field strengths of 8 T. Herein, we demonstrate the versatility and enhance the viability of this technology with a new generation of aminocholesterol (Chol-NH2)-doped bicelles imbedded in two different types of gelatin. The highly magnetically responsive nature of the bicelles allowed to gel the anisotropy at commercially viable magnetic field strengths between 1 and 3 T. Thermoreversible gels with a unique optical signature were generated by exposing the system to various temperature conditions and external magnetic field strengths. The resulting optical properties were a signature of the gel's environmental history, effectively acting as a sensor. Solutions containing the bicelles simultaneously aligning parallel and perpendicular to the magnetic field directions were obtained by mixing samples chelating Tm3+ and Dy3+. These systems were successfully gelled, providing a material with two distinct temperature-dependent optical characteristics. The high degree of tunability in the magnetic response of the bicelles enables encryption of the gel's optical properties. The proposed gels are viable candidates for temperature tracking of sensitive goods and provide numerous perspectives for future development of tomorrow's smart materials and technologies.
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Affiliation(s)
- Stéphane Isabettini
- Laboratory of Food Process Engineering , ETH Zürich , Schmelzbergstrasse 7 , 8092 Zurich , Switzerland
| | - Sandro Stucki
- Laboratory of Food Process Engineering , ETH Zürich , Schmelzbergstrasse 7 , 8092 Zurich , Switzerland
| | - Sarah Massabni
- Laboratory of Food Process Engineering , ETH Zürich , Schmelzbergstrasse 7 , 8092 Zurich , Switzerland
| | - Mirjam E Baumgartner
- Laboratory of Food Process Engineering , ETH Zürich , Schmelzbergstrasse 7 , 8092 Zurich , Switzerland
| | - Pernille Q Reckey
- Laboratory of Food Process Engineering , ETH Zürich , Schmelzbergstrasse 7 , 8092 Zurich , Switzerland
| | | | | | - Erich J Windhab
- Laboratory of Food Process Engineering , ETH Zürich , Schmelzbergstrasse 7 , 8092 Zurich , Switzerland
| | - Peter Fischer
- Laboratory of Food Process Engineering , ETH Zürich , Schmelzbergstrasse 7 , 8092 Zurich , Switzerland
| | - Simon Kuster
- Laboratory of Food Process Engineering , ETH Zürich , Schmelzbergstrasse 7 , 8092 Zurich , Switzerland
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4
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Isabettini S, Massabni S, Hodzic A, Durovic D, Kohlbrecher J, Ishikawa T, Fischer P, Windhab EJ, Walde P, Kuster S. Molecular engineering of lanthanide ion chelating phospholipids generating assemblies with a switched magnetic susceptibility. Phys Chem Chem Phys 2018; 19:20991-21002. [PMID: 28745755 DOI: 10.1039/c7cp03994h] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Lanthanide ion (Ln3+) chelating amphiphiles are powerful molecules for tailoring the magnetic response of polymolecular assemblies. Mixtures of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and 1,2-dimyristoyl-sn-glycero-3-phospho-ethanolamine-diethylene triaminepentaacetate (DMPE-DTPA) complexed to Ln3+ deliver highly magnetically responsive bicelles. Their magnetic properties are readily tuned by changing the bicellar size or the magnetic susceptibility Δχ of the bilayer lipids. The former technique is intrinsically bound to the region of the phase diagram guarantying the formation of bicelles. Methods aiming towards manipulating the Δχ of the bilayer are comparatively more robust, flexible and lacking. Herein, we synthesized a new Ln3+ chelating phospholipid using glutamic acid as a backbone: DMPE-Glu-DTPA. The chelate polyhedron was specifically engineered to alter the Δχ, whilst remaining geometrically similar to DMPE-DTPA. Planar asymmetric assemblies hundreds of nanometers in size were achieved presenting unprecedented magnetic alignments. The DMPE-Glu-DTPA/Ln3+ complex switched the Δχ, achieving perpendicular alignment of assemblies containing Dy3+ and parallel alignment of those containing Tm3+. Moreover, samples with chelated Yb3+ were more alignable than the Tm3+ chelating counterparts. Such a possibility has never been demonstrated for planar Ln3+ chelating polymolecular assemblies. The physico-chemical properties of these novel assemblies were further studied by monitoring the alignment behavior at different temperatures and by including 16 mol% of cholesterol (Chol-OH) in the phospholipid bilayer. The DMPE-Glu-DTPA/Ln3+ complex and the resulting assemblies are promising candidates for applications in numerous fields including pharmaceutical technologies, structural characterization of membrane biomolecules by NMR spectroscopy, as contrasting agents for magnetic resonance imaging, and for the development of smart optical gels.
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Affiliation(s)
- Stéphane Isabettini
- Laboratory of Food Process Engineering, ETH Zürich, Schmelzbergstrasse 7, 8092 Zürich, Switzerland.
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5
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Isabettini S, Liebi M, Kohlbrecher J, Ishikawa T, Fischer P, Windhab EJ, Walde P, Kuster S. Mastering the magnetic susceptibility of magnetically responsive bicelles with 3β-amino-5-cholestene and complexed lanthanide ions. Phys Chem Chem Phys 2018; 19:10820-10824. [PMID: 28401210 DOI: 10.1039/c7cp01025g] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The magnetic susceptibility of lanthanide-chelating bicelles was selectively enhanced by introducing 3β-amino-5-cholestene (aminocholesterol, Chol-NH2) in the bilayer. Unprecedented magnetic alignment of the bicelles was achieved without altering their size. An aminocholesterol conjugate (Chol-C2OC2-NH2), in combination with different lanthanide ions, offers the possibility of fine-tuning the bicelle's magnetic susceptibility.
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Affiliation(s)
- Stéphane Isabettini
- Laboratory of Food Process Engineering, ETH Zürich, Schmelzbergstrasse 7, 8092 Zürich, Switzerland.
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6
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Isabettini S, Baumgartner ME, Fischer P, Windhab EJ, Liebi M, Kuster S. Fabrication Procedures and Birefringence Measurements for Designing Magnetically Responsive Lanthanide Ion Chelating Phospholipid Assemblies. J Vis Exp 2018. [PMID: 29364235 DOI: 10.3791/56812] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Bicelles are tunable disk-like polymolecular assemblies formed from a large variety of lipid mixtures. Applications range from membrane protein structural studies by nuclear magnetic resonance (NMR) to nanotechnological developments including the formation of optically active and magnetically switchable gels. Such technologies require high control of the assembly size, magnetic response and thermal resistance. Mixtures of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and its lanthanide ion (Ln3+) chelating phospholipid conjugate, 1,2-dimyristoyl-sn-glycero-3-phospho-ethanolamine-diethylene triaminepentaacetate (DMPE-DTPA), assemble into highly magnetically responsive assemblies such as DMPC/DMPE-DTPA/Ln3+ (molar ratio 4:1:1) bicelles. Introduction of cholesterol (Chol-OH) and steroid derivatives in the bilayer results in another set of assemblies offering unique physico-chemical properties. For a given lipid composition, the magnetic alignability is proportional to the bicelle size. The complexation of Ln3+ results in unprecedented magnetic responses in terms of both magnitude and alignment direction. The thermo-reversible collapse of the disk-like structures into vesicles upon heating allows tailoring of the assemblies' dimensions by extrusion through membrane filters with defined pore sizes. The magnetically alignable bicelles are regenerated by cooling to 5 °C, resulting in assembly dimensions defined by the vesicle precursors. Herein, this fabrication procedure is explained and the magnetic alignability of the assemblies is quantified by birefringence measurements under a 5.5 T magnetic field. The birefringence signal, originating from the phospholipid bilayer, further enables monitoring of polymolecular changes occurring in the bilayer. This simple technique is complementary to NMR experiments that are commonly employed to characterize bicelles.
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Affiliation(s)
| | | | | | | | | | - Simon Kuster
- Laboratory of Food Process Engineering, ETH Zurich
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7
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Isabettini S, Massabni S, Kohlbrecher J, Schuler LD, Walde P, Sturm M, Windhab EJ, Fischer P, Kuster S. Understanding the Enhanced Magnetic Response of Aminocholesterol Doped Lanthanide-Ion-Chelating Phospholipid Bicelles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:8533-8544. [PMID: 28759249 DOI: 10.1021/acs.langmuir.7b01370] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Cholesterol (Chol-OH) and its conjugates are powerful molecules for engineering the physicochemical and magnetic properties of phospholipid bilayers in bicelles. Introduction of aminocholesterol (3β-amino-5-cholestene, Chol-NH2) in bicelles composed of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and the thulium-ion-chelating phospholipid 1,2-dimyristoyl-sn-glycero-3-phospho-ethanolamine-diethylene triaminepentaacetate (DMPE-DTPA/Tm3+) results in unprecedented high magnetic alignments by selectively tuning the magnetic susceptibility Δχ of the bilayer. However, little is known on the underlying mechanisms behind the magnetic response and, more generally, on the physicochemical forces governing a Chol-NH2 doped DMPC bilayer. We tackled this shortcoming with a multiscale bottom-up comparative investigation of Chol-OH and Chol-NH2 mixed with DMPC. First, simplified monolayer models on a Langmuir trough were employed to compare the two steroid molecules at various contents in DMPC. In a second step, a molecular dynamics (MD) simulation allowed for a more representative model of the bicelle bilayer while monitoring the amphiphiles and their interactions on the molecular level. In a final step, we moved away from the models and investigated the effect of temperature on the structure and magnetic alignment of Chol-NH2 doped bicelles by SANS. The DMPC/steroid monolayer studies showed that Chol-OH induces a larger condensation effect than Chol-NH2 at steroid contents of 16 and 20 mol %. However, this tendency was inversed at steroid contents of 10, 30, and 40 mol %. Although the MD simulation with 16 mol % steroid revealed that both compounds induce a liquid-ordered state in DMPC, the bilayer containing Chol-NH2 was much less ordered than the analogous system containing Chol-OH. Chol-NH2 underwent significantly more hydrogen bonding interactions with neighboring DMPC lipids than Chol-OH. It seems that, by altering the dynamics of the hydrophilic environment of the bicelle, Chol-NH2 changes the crystal field and angle of the phospholipid-lanthanide DMPE-DTPA/Tm3+ complex. These parameters largely determine the magnetic susceptibility Δχ of the complex, explaining the SANS results, which show significant differences in magnetic alignment of the steroid doped bicelles. Highly magnetically alignable DMPC/Chol-NH2/DMPE-DTPA/Tm3+ (molar ratio 16:4:5:5) bicelles were achieved up to temperatures of 35 °C before a thermoreversible rearrangement into nonalignable vesicles occurred. The results confirm the potential of Chol-NH2 doped bicelles to act as building blocks for the development of the magnetically responsive soft materials of tomorrow.
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Affiliation(s)
- Stéphane Isabettini
- Laboratory of Food Process Engineering, ETH Zürich , Schmelzbergstrasse 9, 8092 Zürich, Switzerland
| | - Sarah Massabni
- Laboratory of Food Process Engineering, ETH Zürich , Schmelzbergstrasse 9, 8092 Zürich, Switzerland
| | - Joachim Kohlbrecher
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute , 5232 Villigen PSI, Switzerland
| | | | - Peter Walde
- Department of Materials, ETH Zürich , Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland
| | - Marina Sturm
- Max Planck Institute of Colloids and Interfaces , Am Mühlenberg 1, 14476 Potsdam, Germany
| | - Erich J Windhab
- Laboratory of Food Process Engineering, ETH Zürich , Schmelzbergstrasse 9, 8092 Zürich, Switzerland
| | - Peter Fischer
- Laboratory of Food Process Engineering, ETH Zürich , Schmelzbergstrasse 9, 8092 Zürich, Switzerland
| | - Simon Kuster
- Laboratory of Food Process Engineering, ETH Zürich , Schmelzbergstrasse 9, 8092 Zürich, Switzerland
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8
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Isabettini S, Baumgartner ME, Reckey PQ, Kohlbrecher J, Ishikawa T, Fischer P, Windhab EJ, Kuster S. Methods for Generating Highly Magnetically Responsive Lanthanide-Chelating Phospholipid Polymolecular Assemblies. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:6363-6371. [PMID: 28594186 DOI: 10.1021/acs.langmuir.7b00725] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Mixtures of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and its lanthanide ion (Ln3+) chelating phospholipid conjugate, 1,2-dimyristoyl-sn-glycero-3-phospho-ethanolamine-diethylene triaminepentaacetate (DMPE-DTPA), assemble into highly magnetically responsive polymolecular assemblies such as DMPC/DMPE-DTPA/Ln3+ (molar ratio 4:1:1) bicelles. Their geometry and magnetic alignability is enhanced by introducing cholesterol into the bilayer in DMPC/Cholesterol/DMPE-DTPA/Ln3+ (molar ratio 16:4:5:5). However, the reported fabrication procedures remain tedious and limit the generation of highly magnetically alignable species. Herein, a simplified procedure where freeze thawing cycles and extrusion are replaced by gentle heating and cooling cycles for the hydration of the dry lipid film was developed. Heating above the phase transition temperature Tm of the lipids composing the bilayer before cooling back below the Tm was essential to guarantee successful formation of the polymolecular assemblies composed of DMPC/DMPE-DTPA/Ln3+ (molar ratio 4:1:1). Planar polymolecular assemblies in the size range of hundreds of nanometers are achieved and deliver unprecedented gains in magnetic response. The proposed heating and cooling procedure further allowed to regenerate the highly magnetically alignable DMPC/Cholesterol/DMPE-DTPA/Ln3+ (molar ratio 16:4:5:5) species after storage for one month frozen at -18 °C. The simplicity and viability of the proposed fabrication procedure offers a new set of highly magnetically responsive lanthanide ion chelating phospholipid polymolecular assemblies as building blocks for the smart soft materials of tomorrow.
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Affiliation(s)
- Stéphane Isabettini
- Laboratory of Food Process Engineering, ETH Zurich , Schmelzbergstrasse 9, 8092 Zurich, Switzerland
| | - Mirjam E Baumgartner
- Laboratory of Food Process Engineering, ETH Zurich , Schmelzbergstrasse 9, 8092 Zurich, Switzerland
| | - Pernille Q Reckey
- Laboratory of Food Process Engineering, ETH Zurich , Schmelzbergstrasse 9, 8092 Zurich, Switzerland
| | | | | | - Peter Fischer
- Laboratory of Food Process Engineering, ETH Zurich , Schmelzbergstrasse 9, 8092 Zurich, Switzerland
| | - Erich J Windhab
- Laboratory of Food Process Engineering, ETH Zurich , Schmelzbergstrasse 9, 8092 Zurich, Switzerland
| | - Simon Kuster
- Laboratory of Food Process Engineering, ETH Zurich , Schmelzbergstrasse 9, 8092 Zurich, Switzerland
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9
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Isabettini S, Liebi M, Kohlbrecher J, Ishikawa T, Windhab EJ, Fischer P, Walde P, Kuster S. Tailoring Bicelle Morphology and Thermal Stability with Lanthanide-Chelating Cholesterol Conjugates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:9005-9014. [PMID: 27529644 DOI: 10.1021/acs.langmuir.6b01968] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Bicelles composed of DMPC and phospholipids capable of chelating lanthanide ions, such as 1,2-dimyristoyl-sn-glycero-3-phospho-ethanolamine-diethylene triaminepentaacetate (DMPE-DTPA), are highly tunable magnetically responsive soft materials. Further doping of these systems with cholesterol-DTPA conjugates complexed to a lanthanide ion considerably enhances the bicelle's size and magnetic alignability. The high value of these cholesterol conjugates for bicelle design remains largely unexplored. Herein, we examine how molecular structural alterations within the cholesterol-DTPA conjugates lead to contrasting self-assembled polymolecular aggregate structures when incorporated into DMPC/DMPE-DTPA/Tm(3+) bilayers. The nature of the linker connecting the DTPA-chelating moiety to the sterol backbone is examined by synthesizing conjugates of various linker lengths and polarities. The incorporation of these compounds within the bilayer results in polymolecular aggregate geometries of higher curvature. The increasing degrees of freedom for conformational changes conveyed to the chelator headgroup with increasing linker atomic length reduce the cholesterol-DTPA conjugate's critical packing parameter. Consequently, an inverse correlation between the number of carbon atoms in the linker and the bicelle radius is established. The introduction of polarity into the carbon chain of the linker did not cause major changes in the polymolecular aggregate architecture. Under specific conditions, the additives permit the formation of remarkably temperature-resistant bicelles. The versatility of design offered by these amphiphiles gives rise to new and viable tools for the growing field of magnetically responsive soft materials.
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Affiliation(s)
- Stéphane Isabettini
- Laboratory of Food Process Engineering, ETH Zurich , Schmelzbergstrasse 9, 8092 Zurich, Switzerland
| | | | | | | | - Erich J Windhab
- Laboratory of Food Process Engineering, ETH Zurich , Schmelzbergstrasse 9, 8092 Zurich, Switzerland
| | - Peter Fischer
- Laboratory of Food Process Engineering, ETH Zurich , Schmelzbergstrasse 9, 8092 Zurich, Switzerland
| | - Peter Walde
- Department of Materials, ETH Zurich , Vladimir-Prelog-Weg 5, 8093 Zurich, Switzerland
| | - Simon Kuster
- Laboratory of Food Process Engineering, ETH Zurich , Schmelzbergstrasse 9, 8092 Zurich, Switzerland
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10
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Wallace M, Cardoso AZ, Frith WJ, Iggo JA, Adams DJ. Magnetically aligned supramolecular hydrogels. Chemistry 2014; 20:16484-7. [PMID: 25345918 PMCID: PMC4497324 DOI: 10.1002/chem.201405500] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Indexed: 01/30/2023]
Abstract
The magnetic-field-induced alignment of the fibrillar structures present in an aqueous solution of a dipeptide gelator, and the subsequent retention of this alignment upon transformation to a hydrogel upon the addition of CaCl2 or upon a reduction in solution pH is reported. Utilising the switchable nature of the magnetic field coupled with the slow diffusion of CaCl2 , it is possible to precisely control the extent of anisotropy across a hydrogel, something that is generally very difficult to do using alternative methods. The approach is readily extended to other compounds that form viscous solutions at high pH. It is expected that this work will greatly expand the utility of such low-molecular-weight gelators (LMWG) in areas where alignment is key.
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Affiliation(s)
- Matthew Wallace
- Department of Chemistry, University of LiverpoolCrown Street, Liverpool, L69 7ZD (UK)
| | - Andre Zamith Cardoso
- Department of Chemistry, University of LiverpoolCrown Street, Liverpool, L69 7ZD (UK)
| | - William J Frith
- Unilever R&D Colworth, Colworth Science ParkSharnbrook, Bedfordshire, MK44 1 LQ (UK)
| | - Jonathan A Iggo
- Department of Chemistry, University of LiverpoolCrown Street, Liverpool, L69 7ZD (UK)
| | - Dave J Adams
- Department of Chemistry, University of LiverpoolCrown Street, Liverpool, L69 7ZD (UK)
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11
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Pietra F, Rabouw FT, van Rhee PG, van Rijssel J, Petukhov AV, Erné BH, Christianen PCM, de Mello Donegá C, Vanmaekelbergh D. Self-assembled CdSe/CdS nanorod sheets studied in the bulk suspension by magnetic alignment. ACS NANO 2014; 8:10486-10495. [PMID: 25197767 DOI: 10.1021/nn503857t] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We studied spontaneously self-assembled aggregates in a suspension of CdSe/CdS core/shell nanorods (NRs). The influence of the length and concentration of the NRs and the suspension temperature on the size of the aggregates was investigated using in situ small-angle X-ray scattering (SAXS) and linear dichroism (LD) measurements under high magnetic fields (up to 30 T). The SAXS patterns reveal the existence of crystalline 2-dimensional sheets of ordered NRs with an unusually large distance between the rods. The LD measurements show that the size of the sheets depends on the free-energy driving force for NR self-assembly. More precisely, the sheets are larger if the attraction between NRs is stronger, if the temperature is lower, or if the NR concentration is higher. We show that the formation of large NR sheets is a slow process that can take days. Our in situ results of the structures that spontaneously form in the bulk suspension could further our understanding of NR self-assembly into mono- or multilayer superlattices that occurs at the suspension/air interface upon evaporation of the solvent.
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Affiliation(s)
- Francesca Pietra
- Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science , Princetonplein 1, 3584 CC Utrecht, The Netherlands
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12
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van Rhee P, Rikken R, Abdelmohsen L, Maan J, Nolte R, van Hest J, Christianen P, Wilson D. Polymersome magneto-valves for reversible capture and release of nanoparticles. Nat Commun 2014; 5:5010. [PMID: 25248402 PMCID: PMC4176683 DOI: 10.1038/ncomms6010] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 08/19/2014] [Indexed: 01/25/2023] Open
Abstract
Stomatocytes are polymersomes with an infolded bowl-shaped architecture. This internal cavity is connected to the outside environment via a small 'mouth' region. Stomatocytes are assembled from diamagnetic amphiphilic block-copolymers with a highly anisotropic magnetic susceptibility, which permits to magnetically align and deform the polymeric self-assemblies. Here we show the reversible opening and closing of the mouth region of stomatocytes in homogeneous magnetic fields. The control over the size of the opening yields magneto-responsive supramolecular valves that are able to reversibly capture and release cargo. Furthermore, the increase in the size of the opening is gradual and starts at fields below 10 T, which opens the possibility of using these structures for delivery and nanoreactor applications.
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Affiliation(s)
- P.G. van Rhee
- High Field Magnet Laboratory, Institute for Molecules and Materials, Radboud University Nijmegen, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | - R.S.M. Rikken
- High Field Magnet Laboratory, Institute for Molecules and Materials, Radboud University Nijmegen, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
- Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - L.K.E.A. Abdelmohsen
- Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - J.C. Maan
- High Field Magnet Laboratory, Institute for Molecules and Materials, Radboud University Nijmegen, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | - R.J.M. Nolte
- Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - J.C.M. van Hest
- Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - P.C.M. Christianen
- High Field Magnet Laboratory, Institute for Molecules and Materials, Radboud University Nijmegen, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands
| | - D.A. Wilson
- Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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Rikken RSM, Nolte RJM, Maan JC, van Hest JCM, Wilson DA, Christianen PCM. Manipulation of micro- and nanostructure motion with magnetic fields. SOFT MATTER 2014; 10:1295-308. [PMID: 24652392 DOI: 10.1039/c3sm52294f] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
In this review we will focus on how magnetic fields can be used to manipulate the motion of various micro- and nanostructures in solution. We will distinguish between ferromagnetic, paramagnetic and diamagnetic materials. Furthermore, the use of various kinds of magnetic fields, such as homogeneous, inhomogeneous and rotating magnetic fields, is discussed. To date most research has focused on the use of ferro- and paramagnetic materials, but here we also describe the possibilities of magnetic manipulation of diamagnetic materials. Since the vast majority of soft matter is diamagnetic, this paves the way for many new applications to manipulate the motion of micro- and nanostructures.
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Affiliation(s)
- Roger S M Rikken
- High Field Magnet Laboratory (HFML), Radboud University Nijmegen, Toernooiveld 7, 6525 ED Nijmegen, The Netherlands.
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Liebi M, Kuster S, Kohlbrecher J, Ishikawa T, Fischer P, Walde P, Windhab EJ. Magnetically enhanced bicelles delivering switchable anisotropy in optical gels. ACS APPLIED MATERIALS & INTERFACES 2014; 6:1100-1105. [PMID: 24369041 DOI: 10.1021/am4046469] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Mesostructures responding to external triggers such as temperature, pH, or magnetic field have the potential to be used as self-acting sensors, detectors, or switches. Key features are a strong and well-defined response to the external trigger. Here, we present magnetic alignable bicelles embedded into a gelatin matrix generating magnetically switchable structures, which can reversibly be locked and unlocked by adjusting the temperature. We show that the disk-like aggregates can be orientated in magnetic fields, and such orientation can be preserved after embedding into gelatin. The resulting gel cubes show an anisotropic transfer for electromagnetic waves, i.e., a different spatial birefringence. Cycling through the melting point of gelatin sets the structure back to its isotropic state providing a read-out of the thermal history. Stacking of the bicelles induced by the gelatin promotes magnetic aligning, as an increased aggregation number in the stacks increases the magnetic orientation energy.
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Affiliation(s)
- Marianne Liebi
- Laboratory of Food Process Engineering, ETH Zurich , Schmelzbergstrasse 9, 8092 Zurich, Switzerland
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Liebi M, Kuster S, Kohlbrecher J, Ishikawa T, Fischer P, Walde P, Windhab EJ. Cholesterol-diethylenetriaminepentaacetate complexed with thulium ions integrated into bicelles to increase their magnetic alignability. J Phys Chem B 2013; 117:14743-8. [PMID: 24205912 DOI: 10.1021/jp406599c] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Lanthanides have been used for several decades to increase the magnetic alignability of bicelles. DMPE-DTPA (1,2-dimyristoyl-sn-glycero-3-phospho-ethanolamine-diethylenetriaminepentaacetate) is commonly applied to anchor the lanthanides into the bicelles. However, because DMPE-DTPA has the tendency to accumulate at the highly curved edge region of the bicelles and if located there does not contribute to the magnetic orientation energy, we have tested cholesterol-DTPA complexed with thulium ions (Tm(3+)) as an alternative chelator to increase the magnetic alignability. Differential scanning calorimetric (DSC) measurements indicate the successful integration of cholesterol-DTPA into a DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine) bilayer. Cryo transmission electron microscopy and small-angle neutron scattering (SANS) measurements show that the disklike structure, that is, bicelles, is maintained if cholesterol-DTPA·Tm(3+) is integrated into a mixture of DMPC, cholesterol, and DMPE-DTPA·Tm(3+). The size of the bicelles is increased compared to the size of the bicelles obtained from mixtures without cholesterol-DTPA·Tm(3+). Magnetic-field-induced birefringence and SANS measurements in a magnetic field show that with addition of cholesterol-DTPA·Tm(3+) the magnetic alignability of these bicelles is significantly increased compared to bicelles composed of DMPC, cholesterol, and DMPE-DTPA·Tm(3+) only.
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Affiliation(s)
- Marianne Liebi
- Laboratory of Food Process Engineering, ETH Zurich , Schmelzbergstrasse 9, 8092 Zurich, Switzerland
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Kogan M, Nordén B, Beke-Somfai T. High anisotropy of flow-aligned bicellar membrane systems. Chem Phys Lipids 2013; 175-176:105-15. [PMID: 23999012 DOI: 10.1016/j.chemphyslip.2013.08.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 08/17/2013] [Accepted: 08/19/2013] [Indexed: 10/26/2022]
Abstract
In recent years, multi-lipid bicellar systems have emerged as promising membrane models. The fast orientational diffusion and magnetic alignability made these systems very attractive for NMR investigations. However, their alignment was so far achieved with a strong magnetic field, which limited their use with other methods that require macroscopic orientation. Recently, it was shown that bicelles could be aligned also by shear flow in a Couette flow cell, making it applicable to structural and biophysical studies by polarized light spectroscopy. Considering the sensitivity of this lipid system to small variations in composition and physicochemical parameters, efficient use of such a flow-cell method with coupled techniques will critically depend on the detailed understanding of how the lipid systems behave under flow conditions. In the present study we have characterized the flow alignment behavior of the commonly used dimyristoyl phosphatidylcholine/dicaproyl phosphatidylcholine (DMPC/DHPC) bicelle system, for various temperatures, lipid compositions, and lipid concentrations. We conclude that at optimal flow conditions the selected bicellar systems can produce the most efficient flow alignment out of any lipid systems used so far. The highest degree of orientation of DMPC/DHPC samples is noticed in a narrow temperature interval, at a practical temperature around 25 °C, most likely in the phase transition region characterized by maximum sample viscosity. The change of macroscopic orientation factor as function of the above conditions is now described in detail. The increase in macroscopic alignment observed for bicelles will most likely allow recording of higher resolution spectra on membrane systems, which provide deeper structural insight and analysis into properties of biomolecules interacting with solution phase lipid membranes.
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Affiliation(s)
- Maxim Kogan
- Department of Chemical and Biological Engineering, Physical Chemistry, Chalmers University of Technology, SE-412 96 Göteborg, Sweden
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