1
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Caselli L, Conti L, De Santis I, Berti D. Small-angle X-ray and neutron scattering applied to lipid-based nanoparticles: Recent advancements across different length scales. Adv Colloid Interface Sci 2024; 327:103156. [PMID: 38643519 DOI: 10.1016/j.cis.2024.103156] [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: 10/19/2023] [Revised: 02/28/2024] [Accepted: 04/08/2024] [Indexed: 04/23/2024]
Abstract
Lipid-based nanoparticles (LNPs), ranging from nanovesicles to non-lamellar assemblies, have gained significant attention in recent years, as versatile carriers for delivering drugs, vaccines, and nutrients. Small-angle scattering methods, employing X-rays (SAXS) or neutrons (SANS), represent unique tools to unveil structure, dynamics, and interactions of such particles on different length scales, spanning from the nano to the molecular scale. This review explores the state-of-the-art on scattering methods applied to unveil the structure of lipid-based nanoparticles and their interactions with drugs and bioactive molecules, to inform their rational design and formulation for medical applications. We will focus on complementary information accessible with X-rays or neutrons, ranging from insights on the structure and colloidal processes at a nanoscale level (SAXS) to details on the lipid organization and molecular interactions of LNPs (SANS). In addition, we will review new opportunities offered by Time-resolved (TR)-SAXS and -SANS for the investigation of dynamic processes involving LNPs. These span from real-time monitoring of LNPs structural evolution in response to endogenous or external stimuli (TR-SANS), to the investigation of the kinetics of lipid diffusion and exchange upon interaction with biomolecules (TR-SANS). Finally, we will spotlight novel combinations of SAXS and SANS with complementary on-line techniques, recently enabled at Large Scale Facilities for X-rays and neutrons. This emerging technology enables synchronized multi-method investigation, offering exciting opportunities for the simultaneous characterization of the structure and chemical or mechanical properties of LNPs.
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Affiliation(s)
- Lucrezia Caselli
- Physical Chemistry 1, University of Lund, S-221 00 Lund, Sweden.
| | - Laura Conti
- Consorzio Sistemi a Grande Interfase, Department of Chemistry, University of Florence, Sesto Fiorentino, Italy
| | - Ilaria De Santis
- Department of Chemistry, University of Florence, Via della Lastruccia 3, Sesto Fiorentino, Florence 50019, Italy
| | - Debora Berti
- Department of Chemistry, University of Florence, Via della Lastruccia 3, Sesto Fiorentino, Florence 50019, Italy; Consorzio Sistemi a Grande Interfase, Department of Chemistry, University of Florence, Sesto Fiorentino, Italy.
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2
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Awad MN, Brown SJ, Abraham AN, Sezer D, Han Q, Wang X, Le TC, Elbourne A, Bryant G, Greaves TL, Bryant SJ. Biophysical Characterization and Cryopreservation of Mammalian Cells Using Ionic Liquids. J Phys Chem B 2024; 128:2504-2515. [PMID: 38416751 DOI: 10.1021/acs.jpcb.3c06797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2024]
Abstract
Ionic liquids (ILs) are a diverse class of solvents which can be selected for task-specific properties, making them attractive alternatives to traditional solvents. To tailor ILs for specific biological applications, it is necessary to understand the structure-property relationships of ILs and their interactions with cells. Here, a selection of carboxylate anion-based ILs were investigated as cryoprotectants, which are compounds added to cells before freezing to mitigate lethal freezing damage. The cytotoxicity, cell permeability, thermal behavior, and cryoprotective efficacy of the ILs were assessed with two model mammalian cell lines. We found that the biophysical interactions, including permeability of the ILs, were influenced by considering the IL pair together, rather than as single species acting independently. All of the ILs tested had high cytotoxicity, but ethylammonium acetate demonstrated good cryoprotective efficacy for both cell types tested. These results demonstrate that despite toxicity, ILs may be suitable for certain biological applications. It also demonstrates that more research is required to understand the contribution of ion pairs to structure-property relationships and that knowing the behavior of a single ionic species will not necessarily predict its behavior as part of an IL.
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Affiliation(s)
- Miyah N Awad
- School of Science, College of STEM, RMIT University, Melbourne, Victoria 3000, Australia
| | - Stuart J Brown
- School of Science, College of STEM, RMIT University, Melbourne, Victoria 3000, Australia
| | - Amanda N Abraham
- School of Science, College of STEM, RMIT University, Melbourne, Victoria 3000, Australia
- ARC Centre of Excellence for Nanoscale BioPhotonics, RMIT University, Melbourne, Victoria 3001, Australia
| | - Dilek Sezer
- School of Science, College of STEM, RMIT University, Melbourne, Victoria 3000, Australia
| | - Qi Han
- School of Science, College of STEM, RMIT University, Melbourne, Victoria 3000, Australia
| | - Xiaoying Wang
- School of Engineering, College of STEM, RMIT University, Melbourne, Victoria 3000, Australia
- Digital Services, Deakin University, Melbourne, Victoria 3008, Australia
| | - Tu C Le
- School of Engineering, College of STEM, RMIT University, Melbourne, Victoria 3000, Australia
| | - Aaron Elbourne
- School of Science, College of STEM, RMIT University, Melbourne, Victoria 3000, Australia
| | - Gary Bryant
- School of Science, College of STEM, RMIT University, Melbourne, Victoria 3000, Australia
| | - Tamar L Greaves
- School of Science, College of STEM, RMIT University, Melbourne, Victoria 3000, Australia
| | - Saffron J Bryant
- School of Science, College of STEM, RMIT University, Melbourne, Victoria 3000, Australia
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3
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Salvati Manni L, Fong WK, Wood K, Kirby N, Seibt S, Atkin R, Warr GG. H-bond network, interfacial tension and chain melting temperature govern phospholipid self-assembly in ionic liquids. J Colloid Interface Sci 2024; 657:320-326. [PMID: 38043233 DOI: 10.1016/j.jcis.2023.11.158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 11/19/2023] [Accepted: 11/24/2023] [Indexed: 12/05/2023]
Abstract
HYPOTHESIS The self-assembly structures and phase behaviour of phospholipids in protic ionic liquids (ILs) depend on intermolecular forces that can be controlled through changes in the size, polarity, and H-bond capacity of the solvent. EXPERIMENTS The structure and temperature stability of the self-assembled phases formed by four phospholipids in three ILs was determined by a combination of small- and wide-angle X-ray scattering (SAXS and WAXS) and small-angle neutron scattering (SANS). The phospholipids have identical phosphocholine head groups but different alkyl tail lengths and saturations (DOPC, POPC, DPPC and DSPC), while the ILs' amphiphilicity, H-bond network density and polarity are varied between propylammonium nitrate (PAN) to ethylammonium nitrate (EAN) to ethanolammonium nitrate (EtAN). FINDINGS The observed structures and phase behaviour of the lipids becomes more surfactant-like with decreasing average solvent polarity, H-bond network density and surface tension. In PAN, all the investigated phospholipids behave like surfactants in water. In EAN they exhibit anomalous phase sequences and unexpected transitions as a function of temperature, while EtAN supports structures that share characteristics with water and EAN. Structures formed are also sensitive to proximity to the lipid chain melting temperature.
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Affiliation(s)
- Livia Salvati Manni
- School of Chemistry and University of Sydney Nano Institute, The University of Sydney, Sydney, NSW 2006, Australia; School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia; School of Chemistry, Monash University, Wellington Road, Clayton, VIC 3800, Australia
| | - Wye-Khay Fong
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia; School of Chemistry, Monash University, Wellington Road, Clayton, VIC 3800, Australia
| | - Kathleen Wood
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organization, New Illawarra Road, Lucas Heights, NSW 2234, Australia
| | - Nigel Kirby
- Australian Synchrotron, ANSTO, 800 Blackburn Rd, Clayton, VIC 3168, Australia
| | - Susanne Seibt
- Australian Synchrotron, ANSTO, 800 Blackburn Rd, Clayton, VIC 3168, Australia
| | - Rob Atkin
- School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia
| | - Gregory G Warr
- School of Chemistry and University of Sydney Nano Institute, The University of Sydney, Sydney, NSW 2006, Australia.
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4
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Paporakis S, Brown SJ, Darmanin C, Seibt S, Adams P, Hassett M, Martin AV, Greaves TL. Lyotropic liquid crystal phases of monoolein in protic ionic liquids. J Chem Phys 2024; 160:024901. [PMID: 38189602 DOI: 10.1063/5.0180420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 11/26/2023] [Indexed: 01/09/2024] Open
Abstract
Monoolein-based liquid crystal phases are established media that are researched for various biological applications, including drug delivery. While water is the most common solvent for self-assembly, some ionic liquids (ILs) can support lipidic self-assembly. However, currently, there is limited knowledge of IL-lipid phase behavior in ILs. In this study, the lyotropic liquid crystal phase behavior of monoolein was investigated in six protic ILs known to support amphiphile self-assembly, namely ethylammonium nitrate, ethanolammonium nitrate, ethylammonium formate, ethanolammonium formate, ethylammonium acetate, and ethanolammonium acetate. These ILs were selected to identify specific ion effects on monoolein self-assembly, specifically increasing the alkyl chain length of the cation or anion, the presence of a hydroxyl group in the cation, and varying the anion. The lyotropic liquid crystal phases with 20-80 wt. % of monoolein were characterized over a temperature range from 25 to 65 °C using synchrotron small angle x-ray scattering and cross-polarized optical microscopy. These results were used to construct partial phase diagrams of monoolein in each of the six protic ILs, with inverse hexagonal, bicontinuous cubic, and lamellar phases observed. Protic ILs containing the ethylammonium cation led to monoolein forming lamellar and bicontinuous cubic phases, while those containing the ethanolammonium cation formed inverse hexagonal and bicontinuous cubic phases. Protic ILs containing formate and acetate anions favored bicontinuous cubic phases across a broader range of protic IL concentrations than those containing the nitrate anion.
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Affiliation(s)
- Stefan Paporakis
- School of Science, College of STEM, RMIT University, 124 La Trobe Street, Melbourne VIC 3000, Australia
| | - Stuart J Brown
- School of Science, College of STEM, RMIT University, 124 La Trobe Street, Melbourne VIC 3000, Australia
| | - Connie Darmanin
- La Trobe Institute for Molecular Science, Department of Mathematical and Physical Sciences, School of Computing Engineering and Mathematical Science, La Trobe University, Bundoora VIC 3086, Australia
| | - Susanne Seibt
- SAXS/WAXS Beamline, Australian Synchrotron, ANSTO, 800 Blackburn Road, VIC-3168 Clayton, Australia
| | - Patrick Adams
- School of Science, College of STEM, RMIT University, 124 La Trobe Street, Melbourne VIC 3000, Australia
| | - Michael Hassett
- School of Science, College of STEM, RMIT University, 124 La Trobe Street, Melbourne VIC 3000, Australia
| | - Andrew V Martin
- School of Science, College of STEM, RMIT University, 124 La Trobe Street, Melbourne VIC 3000, Australia
| | - Tamar L Greaves
- School of Science, College of STEM, RMIT University, 124 La Trobe Street, Melbourne VIC 3000, Australia
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5
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Salvati Manni L, Davies C, Wood K, Assenza S, Atkin R, Warr GG. Unusual phosphatidylcholine lipid phase behavior in the ionic liquid ethylammonium nitrate. J Colloid Interface Sci 2023; 643:276-281. [PMID: 37068361 DOI: 10.1016/j.jcis.2023.03.161] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 03/22/2023] [Accepted: 03/25/2023] [Indexed: 05/12/2023]
Abstract
HYPOTHESIS The forces that govern lipid self-assembly ionic liquids are similar to water, but their different balance can result in unexpected behaviour. EXPERIMENTS The self-assembly behaviour and phase equilibria of two phospholipids, 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), in the most common protic ionic liquid, ethylammonium nitrate (EAN) have been investigated as function of composition and temperature by small- and wide-angle X-ray scattering (SAXS/WAXS) and small-angle neutron scattering (SANS). FINDINGS Both lipids form unusual self-assembly structures and show complex and unexpected phase behaviour unlike that seen in water; DSPC undergoes a gel Lβ to crystalline Lc phase transition on warming, while POPC forms worm-like micelles L1 upon dilution. This surprising phase behaviour is attributed to the large size of the EAN ions that solvate the lipid headgroup compared to water changing amphiphile packing. Weaker H-bonding between EAN and lipid headgroups also contributes. These results provide new insight for the design of lipid based nanostructured materials in ionic liquids with atypical properties.
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Affiliation(s)
- Livia Salvati Manni
- School of Chemistry and University of Sydney Nano Institute, The University of Sydney, Sydney, NSW 2006, Australia; School of Environmental and Life Sciences, University of Newcastle, Callaghan 2308, NSW, Australia
| | - Caitlin Davies
- School of Chemistry and University of Sydney Nano Institute, The University of Sydney, Sydney, NSW 2006, Australia
| | - Kathleen Wood
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organization, New Illawarra Road, Lucas Heights, NSW 2234, Australia
| | - Salvatore Assenza
- Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, Madrid, Spain; Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Madrid, Spain; Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, Madrid, Spain
| | - Rob Atkin
- School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia
| | - Gregory G Warr
- School of Chemistry and University of Sydney Nano Institute, The University of Sydney, Sydney, NSW 2006, Australia.
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6
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Pan Y, Tong K, Lin M, Zhuang W, Zhu W, Chen X, Li Q. Aggregation behaviours of sulfobetaine zwitterionic surfactants in EAN. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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7
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Biological activity, solvation properties and microstructuring of protic imidazolium ionic liquids. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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8
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Miao S, Hoffmann I, Gradzielski M, Warr GG. Lipid Membrane Flexibility in Protic Ionic Liquids. J Phys Chem Lett 2022; 13:5240-5245. [PMID: 35670673 DOI: 10.1021/acs.jpclett.2c00980] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Here, we determine by neutron spin echo spectrometry (NSE) how the flexibility of egg lecithin vesicles depends on solvent composition in two protic ionic liquids (PILs) and their aqueous mixtures. In combination with small-angle neutron scattering (SANS), dynamic light scattering (DLS), and fluorescent probe microscopy, we show that the bending modulus is up to an order of magnitude lower than in water but with no change in bilayer thickness or nonpolar chain composition. This effect is attributed to the dynamic association and exchange of the IL cation between the membrane and bulk liquid, which has the same origin as the underlying amphiphilic nanostructure of the IL solvent itself. This provides a new mechanism by which to tune and control lipid membrane behavior.
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Affiliation(s)
- Shurui Miao
- School of Chemistry and University of Sydney Nano Institute, The University of Sydney, Sydney, NSW 2006, Australia
| | - Ingo Hoffmann
- Institut Max von Laue-Paul Langevin (ILL), 71 avenue des Martyrs, CS 20156, Cedex 9, F-38042 Grenoble, France
| | - Michael Gradzielski
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 124, Sekr. TC7, D-10623 Berlin, Germany
| | - Gregory G Warr
- School of Chemistry and University of Sydney Nano Institute, The University of Sydney, Sydney, NSW 2006, Australia
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9
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Bulk and interfacial nanostructure and properties in deep eutectic solvents: Current perspectives and future directions. J Colloid Interface Sci 2021; 608:2430-2454. [PMID: 34785053 DOI: 10.1016/j.jcis.2021.10.163] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/25/2021] [Accepted: 10/26/2021] [Indexed: 12/25/2022]
Abstract
Deep eutectic solvents (DESs) are a tailorable class of solvents that are rapidly gaining scientific and industrial interest. This is because they are distinct from conventional molecular solvents, inherently tuneable via careful selection of constituents, and possess many attractive properties for applications, including catalysis, chemical extraction, reaction media, novel lubricants, materials chemistry, and electrochemistry. DESs are a class of solvents composed solely of hydrogen bond donors and acceptors with a melting point lower than the individual components and are often fluidic at room temperature. A unique feature of DESs is that they possess distinct bulk liquid and interfacial nanostructure, which results from intra- and inter-molecular interactions, including coulomb forces, hydrogen bonding, van der Waals interactions, electrostatics, dispersion forces, and apolar-polar segregation. This nanostructure manifests as preferential spatial arrangements of the different species, and exists over several length scales, from molecular- to nano- and meso-scales. The physicochemical properties of DESs are dictated by structure-property relationships; however, there is a significant gap in our understanding of the underlying factors which govern their solvent properties. This is a major limitation of DES-based technologies, as nanostructure can significantly influence physical properties and thus potential applications. This perspective provides an overview of the current state of knowledge of DES nanostructure, both in the bulk liquid and at solid interfaces. We provide definitions which clearly distinguish DESs as a unique solvent class, rather than a subset of ILs. An appraisal of recent work provides hints towards trends in structure-property relationships, while also highlighting inconsistencies within the literature suggesting new research directions for the field. It is hoped that this review will provide insight into DES nanostructure, their potential applications, and development of a robust framework for systematic investigation moving forward.
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10
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Bryant SJ, Brown SJ, Martin AV, Arunkumar R, Raju R, Elbourne A, Bryant G, Drummond CJ, Greaves TL. Cryopreservation of mammalian cells using protic ionic liquid solutions. J Colloid Interface Sci 2021; 603:491-500. [PMID: 34214724 DOI: 10.1016/j.jcis.2021.06.096] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 06/02/2021] [Accepted: 06/15/2021] [Indexed: 02/08/2023]
Abstract
Cryopreservation has facilitated considerable advances in both medical technology and scientific research. However, further developments have been limited by the relatively low number of effective cryoprotective agents. Even after fifty years of research, most protocols rely on the same two toxic agents, i.e. dimethylsulfoxide or glycerol. Ionic liquids are a class of promising solvents which are known glass formers and may offer a less-toxic alternative. The research presented here investigates ten protic ionic liquids as potential cryoprotective agents. The liquids are screened for key properties including cellular toxicity, permeability and thermal behaviour. The most promising, ethylammonium acetate, was then tested as a cryoprotective agent on a model cell line and was found to be as effective as the common cryoprotectant, dimethylsulfoxide. This work reports the first use of a protic ionic liquid as an effective cryoprotective agent for a mammalian cell line. This will inform the development of a suite of potential new ionic liquid-based cryoprotectants that could potentially allow the cryopreservation of new cell types.
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Affiliation(s)
- Saffron J Bryant
- School of Science, College of Science, Engineering and Health, RMIT University, Melbourne, Australia
| | - Stuart J Brown
- School of Science, College of Science, Engineering and Health, RMIT University, Melbourne, Australia
| | - Andrew V Martin
- School of Science, College of Science, Engineering and Health, RMIT University, Melbourne, Australia
| | - Radhika Arunkumar
- School of Science, College of Science, Engineering and Health, RMIT University, Melbourne, Australia
| | - Rekha Raju
- School of Science, College of Science, Engineering and Health, RMIT University, Melbourne, Australia
| | - Aaron Elbourne
- School of Science, College of Science, Engineering and Health, RMIT University, Melbourne, Australia
| | - Gary Bryant
- School of Science, College of Science, Engineering and Health, RMIT University, Melbourne, Australia
| | - Calum J Drummond
- School of Science, College of Science, Engineering and Health, RMIT University, Melbourne, Australia
| | - Tamar L Greaves
- School of Science, College of Science, Engineering and Health, RMIT University, Melbourne, Australia.
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11
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Witika BA, Mweetwa LL, Tshiamo KO, Edler K, Matafawali SK, Ntemi PV, Chikukwa MTR, Makoni PA. Vesicular drug delivery for the treatment of topical disorders: current and future perspectives. J Pharm Pharmacol 2021; 73:1427-1441. [PMID: 34132342 DOI: 10.1093/jpp/rgab082] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 05/12/2021] [Indexed: 11/13/2022]
Abstract
OBJECTIVES Vesicular drug delivery has become a useful approach for therapeutic administration of pharmaceutical compounds. Lipid vesicles have found application in membrane biology, immunology, genetic engineering and theragnostics. This review summarizes topical delivery, specifically dermal/transdermal, ocular and transungual, via these vesicles, including future formulation perspectives. KEY FINDINGS Liposomes and their subsequent derivatives, viz. niosomes, transferosomes, pharmacososmes and ethosomes, form a significant part of vesicular systems that have been successfully utilized in treating an array of topical disorders. These vesicles are thought to be a safe and effective mode of improving the delivery of lipophilic and hydrophilic drugs. SUMMARY Several drug molecules are available for topical disorders. However, physicochemical properties and undesirable toxicity have limited their efficacy. Vesicular delivery systems have the potential to overcome these shortcomings due to properties such as high biocompatibility, simplicity of surface modification and suitability as controlled delivery vehicles. However, incorporating these systems into environmentally responsive dispersants such as hydrogels, ionic liquids and deep eutectic solvents may further enhance therapeutic prowess of these delivery systems. Consequently, improved vesicular drug delivery can be achieved by considering combining some of these formulation approaches.
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Affiliation(s)
- Bwalya A Witika
- Division of Pharmaceutics, Department of Pharmacy, DDT College of Medicine, Gaborone, Botswana
| | - Larry L Mweetwa
- Division of Pharmaceutics, Department of Pharmacy, DDT College of Medicine, Gaborone, Botswana
| | - Kabo O Tshiamo
- Division of Pharmaceutics, Department of Pharmacy, DDT College of Medicine, Gaborone, Botswana
| | - Karen Edler
- Department of Chemistry, University of Bath, Bath, UK
| | - Scott K Matafawali
- Department of Basic Sciences, School of Medicine, Copperbelt University, Ndola, Zambia
| | - Pascal V Ntemi
- Department of Pharmaceutics, School of Pharmacy, Muhimbili University of Health Allied Sciences, Dar es Salaam, Tanzania
| | - Melissa T R Chikukwa
- Division of Pharmaceutics, Faculty of Pharmacy, Rhodes University, Makhanda, South Africa
| | - Pedzisai A Makoni
- Division of Pharmacology, Faculty of Pharmacy, Rhodes University, Makhanda, South Africa
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12
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Bryant SJ, Garcia A, Clarke RJ, Warr GG. Selective ion transport across a lipid bilayer in a protic ionic liquid. SOFT MATTER 2021; 17:2688-2694. [PMID: 33533359 DOI: 10.1039/d0sm02225j] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Ionic liquids (ILs) have exhibited enormous potential as electrolytes, designer solvents and reaction media, as well as being surprisingly effective platforms for amphiphile self-assembly and for preserving structure of complex biomolecules. This has led to their exploration as media for long-term biopreservation and in biosensors, for which their viability depends on their ability to sustain both structure and function within complex, multicomponent nanoscale compartments and assemblies. Here we show that a tethered lipid bilayer can be assembled directly in a purely IL environment that retains its structure upon exchange between IL and aqueous buffer, and that the membrane transporter valinomycin can be incorporated so as to retain its functionality and cation selectivity. This paves the way for the development of long-lived, non-aqueous microreactors and sensor assemblies, and demonstrates the potential for complex proteins to retain functionality in non-aqueous, ionic liquid solvents.
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Affiliation(s)
- Saffron J Bryant
- School of Chemistry, The University of Sydney, NSW 2006, Australia and School of Science, RMIT University, Melbourne, Victoria 3001, Australia.
| | - Alvaro Garcia
- School of Chemistry, The University of Sydney, NSW 2006, Australia and School of Life Sciences, University of Technology Sydney, NSW 2007, Australia
| | - Ronald J Clarke
- School of Chemistry, The University of Sydney, NSW 2006, Australia
| | - Gregory G Warr
- School of Chemistry, The University of Sydney, NSW 2006, Australia and University of Sydney Nano Institute, The University of Sydney, NSW 2006, Australia
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13
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Elbourne A, Meftahi N, Greaves TL, McConville CF, Bryant G, Bryant SJ, Christofferson AJ. Nanostructure of a deep eutectic solvent at solid interfaces. J Colloid Interface Sci 2021; 591:38-51. [PMID: 33592524 DOI: 10.1016/j.jcis.2021.01.089] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 01/26/2021] [Accepted: 01/27/2021] [Indexed: 12/24/2022]
Abstract
HYPOTHESIS Deep eutectic solvents (DESs) are an attractive class of tunable solvents. However, their uptake for relevant applications has been limited due to a lack of detailed information on their structure-property relationships, both in the bulk and at interfaces. The lateral nanostructure of the DES-solid interfaces is likely to be more complex than previously reported and requires detailed, high-resolution investigation. EXPERIMENTS We employ a combination of high-resolution amplitude-modulated atomic force microscopy and molecular dynamics simulations to elucidate the lateral nanostructure of a DES at the solid-liquid interface. Specifically, the lateral and near-surface nanostructure of the DES choline chloride:glycerol is probed at the mica and highly-ordered pyrolytic graphite interfaces. FINDINGS The lateral nanostructure of the DES-solid interface is heterogeneous and well-ordered in both systems. At the mica interface, the DES is strongly ordered via polar interactions. The adsorbed layer has a distinct rhomboidal symmetry with a repeat spacing of ~0.9 nm comprising all DES species. At the highly ordered pyrolytic graphite interface, the adsorbed layer appears distinctly different, forming an apolor-driven row-like structure with a repeat spacing of ~0.6 nm, which largely excludes the chloride ion. The interfacial nanostructure results from a delicate balance of substrate templating, liquid-liquid interactions, species surface affinity, and packing constraints of cations, anions, and molecular components within the DES. For both systems, distinct near-surface nanostructural layering is observed, which becomes more pronounced close to the substrate. The surface nanostructures elucidated here significantly expand our understanding of DES interfacial behavior and will enhance the optimization of DES systems for surface-based applications.
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Affiliation(s)
- Aaron Elbourne
- School of Science, RMIT University, Melbourne, VIC 3000, Australia.
| | - Nastaran Meftahi
- ARC Centre of Excellence in Exciton Science, School of Science, RMIT University, Melbourne, VIC 3001, Australia
| | - Tamar L Greaves
- School of Science, RMIT University, Melbourne, VIC 3000, Australia
| | - Christopher F McConville
- School of Science, RMIT University, Melbourne, VIC 3000, Australia; Institute for Frontier Materials, Deakin University, Geelong, Victoria 3216, Australia
| | - Gary Bryant
- School of Science, RMIT University, Melbourne, VIC 3000, Australia
| | - Saffron J Bryant
- School of Science, RMIT University, Melbourne, VIC 3000, Australia.
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14
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Bryant SJ, Atkin R, Gradzielski M, Warr GG. Catanionic Surfactant Self-Assembly in Protic Ionic Liquids. J Phys Chem Lett 2020; 11:5926-5931. [PMID: 32628489 DOI: 10.1021/acs.jpclett.0c01608] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Mixing of cationic and anionic surfactants in water can result in pseudo-double-tailed catanionic surfactant ion pairs that form lamellar phases or vesicles that are unstable toward electrolyte addition. Here we show that despite the very high ionic strengths, catanionic surfactants counterintuitively form a wider variety of self-assembled aggregates in pure ionic liquids (ILs, pure salts in a liquid phase) than in water, including micelles, vesicles, and lyotropic phases. Self-assembled structures only form when the IL is sufficiently polar to drive self-assembly through electrostatic interactions and/or H-bond networks, but the catanionic effect is manifested only when the IL does not itself exhibit pronounced amphiphilic nanostructure. This enables the type of catanionic aggregate formed to be designed by changing the hydrogen bonds between the ions through variation of the structures of the cation and anion. These results reveal an entirely new way of controlling catanionic surfactant self-assembly under nonaqueous and high-salt conditions.
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Affiliation(s)
- Saffron J Bryant
- School of Chemistry and Sydney Nano Institute, The University of Sydney, Sydney, NSW 2006, Australia
| | - Rob Atkin
- School of Molecular Sciences, University of Western Australia, Crawley, WA 6009, Australia
| | - Michael Gradzielski
- Institute for Chemistry, Technische Universität Berlin, Strasse des 17 Juni 124, D-10623 Berlin, Germany
| | - Gregory G Warr
- School of Chemistry and Sydney Nano Institute, The University of Sydney, Sydney, NSW 2006, Australia
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Warr GG, Atkin R. Solvophobicity and amphiphilic self-assembly in neoteric and nanostructured solvents. Curr Opin Colloid Interface Sci 2020. [DOI: 10.1016/j.cocis.2019.12.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Susceptibility of biomembrane structure towards amphiphiles, ionic liquids, and deep eutectic solvents. ADVANCES IN BIOMEMBRANES AND LIPID SELF-ASSEMBLY 2020. [DOI: 10.1016/bs.abl.2020.02.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Catanionic and chain-packing effects on surfactant self-assembly in the ionic liquid ethylammonium nitrate. J Colloid Interface Sci 2019; 540:515-523. [DOI: 10.1016/j.jcis.2019.01.048] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 01/11/2019] [Accepted: 01/11/2019] [Indexed: 11/19/2022]
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Mitra S, Ray D, Bhattacharya G, Gupta R, Sen D, Aswal VK, Ghosh SK. Probing the effect of a room temperature ionic liquid on phospholipid membranes in multilamellar vesicles. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2018; 48:119-129. [DOI: 10.1007/s00249-018-1339-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 10/16/2018] [Accepted: 11/19/2018] [Indexed: 01/12/2023]
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Benedetto A, Ballone P. Room-Temperature Ionic Liquids and Biomembranes: Setting the Stage for Applications in Pharmacology, Biomedicine, and Bionanotechnology. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:9579-9597. [PMID: 29510045 DOI: 10.1021/acs.langmuir.7b04361] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Empirical evidence and conceptual elaboration reveal and rationalize the remarkable affinity of organic ionic liquids for biomembranes. Cations of the so-called room-temperature ionic liquids (RTILs), in particular, are readily absorbed into the lipid fraction of biomembranes, causing a variety of observable biological effects, including generic cytotoxicity, broad antibacterial potential, and anticancer activity. Chemical physics analysis of model systems made of phospholipid bilayers, RTIL ions, and water confirm and partially explain this evidence, quantifying the mild destabilizing effect of RTILs on the structural, dynamic, and thermodynamic properties of lipids in biomembranes. Our Feature Article presents a brief introduction to these systems and to their roles in biophysics and biotechnology, summarizing recent experimental and computational results on their properties. More importantly, it highlights the many developments in pharmacology, biomedicine, and bionanotechnology expected from the current research effort on this topic. To anticipate future developments, we speculate on (i) potential applications of (magnetic) RTILs to affect and control the rheology of cells and biological tissues, of great relevance for diagnostics and (ii) the use of RTILs to improve the durability, reliability, and output of biomimetic photovoltaic devices.
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Affiliation(s)
- Antonio Benedetto
- Laboratory for Neutron Scattering , Paul Scherrer Institute , Villigen 5232 , Switzerland
- Conway Institute of Biomolecular and Biomedical Research , University College Dublin , Dublin 4 , Ireland
| | - Pietro Ballone
- Italian Institute of Technology , Via Morego 30 , 16163 Genova , Italy
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