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Optimization of Aquaporin Loading for Performance Enhancement of Aquaporin-Based Biomimetic Thin-Film Composite Membranes. MEMBRANES 2021; 12:membranes12010032. [PMID: 35054558 PMCID: PMC8777877 DOI: 10.3390/membranes12010032] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 12/22/2021] [Accepted: 12/24/2021] [Indexed: 11/17/2022]
Abstract
The aquaporin-based biomimetic thin-film composite membrane (ABM-TFC) has demonstrated superior separation performance and achieved successful commercialization. The larger-scale production of the ABM membrane requires an appropriate balance between the performance and manufacturing cost. This study has systematically investigated the effects of proteoliposome concentration, protein-to-lipid ratio, as well as the additive on the separation performance of ABM for the purpose of finding the optimal preparation conditions for the ABM from the perspective of industrial production. Although increasing the proteoliposome concentration or protein-to-lipid ratio within a certain range could significantly enhance the water permeability of ABMs by increasing the loading of aquaporins in the selective layer, the enhancement effect was marginal or even compromised beyond an optimal point. Alternatively, adding cholesterol in the proteoliposome could further enhance the water flux of the ABM membrane, with minor effects on the salt rejection. The optimized ABM not only achieved a nearly doubled water flux with unchanged salt rejection compared to the control, but also demonstrated satisfactory filtration stability within a wide range of operation temperatures. This study provides a practical strategy for the optimization of ABM-TFC membranes to fit within the scheme of industrial-scale production.
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Kim T, Viard M, Afonin KA, Gupta K, Popov M, Salotti J, Johnson PF, Linder C, Heldman E, Shapiro BA. Characterization of Cationic Bolaamphiphile Vesicles for siRNA Delivery into Tumors and Brain. MOLECULAR THERAPY. NUCLEIC ACIDS 2020; 20:359-372. [PMID: 32200271 PMCID: PMC7090283 DOI: 10.1016/j.omtn.2020.02.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 12/19/2019] [Accepted: 02/23/2020] [Indexed: 12/27/2022]
Abstract
Small interfering RNAs (siRNAs) are potential therapeutic substances due to their gene silencing capability as exemplified by the recent approval by the US Food and Drug Administration (FDA) of the first siRNA therapeutic agent (patisiran). However, the delivery of naked siRNAs is challenging because of their short plasma half-lives and poor cell penetrability. In this study, we used vesicles made from bolaamphiphiles (bolas), GLH-19 and GLH-20, to investigate their ability to protect siRNA from degradation by nucleases while delivering it to target cells, including cells in the brain. Based on computational and experimental studies, we found that GLH-19 vesicles have better delivery characteristics than do GLH-20 vesicles in terms of stability, binding affinity, protection against nucleases, and transfection efficiency, while GLH-20 vesicles contribute to efficient release of the delivered siRNAs, which become available for silencing. Our studies with vesicles made from a mixture of the two bolas (GLH-19 and GLH-20) show that they were able to deliver siRNAs into cultured cancer cells, into a flank tumor and into the brain. The vesicles penetrate cell membranes and the blood-brain barrier (BBB) by endocytosis and transcytosis, respectively, mainly through the caveolae-dependent pathway. These results suggest that GLH-19 strengthens vesicle stability, provides protection against nucleases, and enhances transfection efficiency, while GLH-20 makes the siRNA available for gene silencing.
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Affiliation(s)
- Taejin Kim
- RNA Biology Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - Mathias Viard
- Basic Science Program, Frederick National Laboratory for Cancer Research, Frederick, MD, USA
| | - Kirill A Afonin
- Nanoscale Science Program, Department of Chemistry, University of North Carolina at Charlotte, Charlotte, NC 28223, USA; The Center for Biomedical Engineering and Science, University of North Carolina at Charlotte, Charlotte, NC 28223, USA
| | - Kshitij Gupta
- RNA Biology Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - Mary Popov
- Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Jacqueline Salotti
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Peter F Johnson
- Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | | | | | - Bruce A Shapiro
- RNA Biology Laboratory, National Cancer Institute, Frederick, MD 21702, USA.
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Seimei A, Saeki D, Matsuyama H. Effect of polyelectrolyte structure on formation of supported lipid bilayers on polyelectrolyte multilayers prepared using the layer-by-layer method. J Colloid Interface Sci 2020; 569:211-218. [DOI: 10.1016/j.jcis.2020.02.079] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 01/20/2020] [Accepted: 02/19/2020] [Indexed: 11/17/2022]
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Dey S, Saha J. Minimal Coarse-Grained Modeling toward Implicit Solvent Simulation of Generic Bolaamphiphiles. J Phys Chem B 2020; 124:2938-2949. [DOI: 10.1021/acs.jpcb.0c00734] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Somajit Dey
- Department of Physics, University of Calcutta, 92, A.P.C Road, Kolkata 700009, India
| | - Jayashree Saha
- Department of Physics, University of Calcutta, 92, A.P.C Road, Kolkata 700009, India
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Increasing Salt Rejection of Polybenzimidazole Nanofiltration Membranes via the Addition of Immobilized and Aligned Aquaporins. Processes (Basel) 2019; 7. [PMID: 31179235 PMCID: PMC6550480 DOI: 10.3390/pr7020076] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Aquaporins are water channel proteins in cell membrane, highly specific for water molecules while restricting the passage of contaminants and small molecules, such as urea and boric acid. Cysteine functional groups were installed on aquaporin Z for covalent attachment to the polymer membrane matrix so that the proteins could be immobilized to the membranes and aligned in the direction of the flow. Depth profiling using x-ray photoelectron spectrometer (XPS) analysis showed the presence of functional groups corresponding to aquaporin Z modified with cysteine (Aqp-SH). Aqp-SH modified membranes showed a higher salt rejection as compared to unmodified membranes. For 2 M NaCl and CaCl2 solutions, the rejection obtained from Aqp-SH membranes was 49.3 ± 7.5% and 59.1 ± 5.1%. On the other hand, the rejections obtained for 2 M NaCl and CaCl2 solutions from unmodified membranes were 0.8 ± 0.4% and 1.3 ± 0.2% respectively. Furthermore, Aqp-SH membranes did not show a significant decrease in salt rejection with increasing feed concentrations, as was observed with other membranes. Through simulation studies, it was determined that there was approximately 24% capping of membrane pores by dispersed aquaporins.
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Abdelrasoul A, Doan H, Lohi A, Cheng CH. Aquaporin-Based Biomimetic and Bioinspired Membranes for New Frontiers in Sustainable Water Treatment Technology: Approaches and Challenges. POLYMER SCIENCE SERIES A 2018. [DOI: 10.1134/s0965545x18040016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Ronen R, Kaufman Y, Freger V. Formation of pore-spanning lipid membrane and cross-membrane water and ion transport. J Memb Sci 2017. [DOI: 10.1016/j.memsci.2016.09.059] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Martínez-Ballesta MDC, Carvajal M. Mutual Interactions between Aquaporins and Membrane Components. FRONTIERS IN PLANT SCIENCE 2016; 7:1322. [PMID: 27625676 PMCID: PMC5003842 DOI: 10.3389/fpls.2016.01322] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 08/18/2016] [Indexed: 05/08/2023]
Abstract
In recent years, a number of studies have been focused on the structural evaluation of protein complexes in order to get mechanistic insights into how proteins communicate at the molecular level within the cell. Specific sites of protein-aquaporin interaction have been evaluated and new forms of regulation of aquaporins described, based on these associations. Heterotetramerizations of aquaporin isoforms are considered as novel regulatory mechanisms for plasma membrane (PIPs) and tonoplast (TIPs) proteins, influencing their intrinsic permeability and trafficking dynamics in the adaptive response to changing environmental conditions. However, protein-protein interaction is an extensive theme that is difficult to tackle and new methodologies are being used to study the physical interactions involved. Bimolecular fluorescence complementation and the identification of cross-linked peptides based on tandem mass spectra, that are complementary to other methodologies such as heterologous expression, co-precipitation assays or confocal fluorescence microscopy, are discussed in this review. The chemical composition and the physical characteristics of the lipid bilayer also influence many aspects of membrane aquaporins, including their functionality. The molecular driving forces stabilizing the positions of the lipids around aquaporins could define their activity, thereby altering the conformational properties. Therefore, an integrative approach to the relevance of the membrane-aquaporin interaction to different processes related to plant cell physiology is provided. Finally, it is described how the interactions between aquaporins and copolymer matrixes or biological compounds offer an opportunity for the functional incorporation of aquaporins into new biotechnological advances.
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Affiliation(s)
| | - Micaela Carvajal
- Plant Nutrition Department, Aquaporins Group, Centro de Edafología y Biología Aplicada del Segura-Consejo Superior de Investigaciones Científicas (CEBAS-CSIC)Murcia, Spain
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Brown PS, Bhushan B. Bioinspired materials for water supply and management: water collection, water purification and separation of water from oil. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2016; 374:rsta.2016.0135. [PMID: 27354732 DOI: 10.1098/rsta.2016.0135] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/21/2016] [Indexed: 05/25/2023]
Abstract
Access to a safe supply of water is a human right. However, with growing populations, global warming and contamination due to human activity, it is one that is increasingly under threat. It is hoped that nature can inspire the creation of materials to aid in the supply and management of water, from water collection and purification to water source clean-up and rehabilitation from oil contamination. Many species thrive in even the driest places, with some surviving on water harvested from fog. By studying these species, new materials can be developed to provide a source of fresh water from fog for communities across the globe. The vast majority of water on the Earth is in the oceans. However, current desalination processes are energy-intensive. Systems in our own bodies have evolved to transport water efficiently while blocking other molecules and ions. Inspiration can be taken from such to improve the efficiency of desalination and help purify water containing other contaminants. Finally, oil contamination of water from spills or the fracking technique can be a devastating environmental disaster. By studying how natural surfaces interact with liquids, new techniques can be developed to clean up oil spills and further protect our most precious resource.This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'.
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Affiliation(s)
- Philip S Brown
- Nanoprobe Laboratory for Bio- and Nanotechnology and Biomimetics (NLBB), The Ohio State University, 201 W. 19th Avenue, Columbus, OH 43210-1142, USA
| | - Bharat Bhushan
- Nanoprobe Laboratory for Bio- and Nanotechnology and Biomimetics (NLBB), The Ohio State University, 201 W. 19th Avenue, Columbus, OH 43210-1142, USA
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Nikoleli GP, Nikolelis DP, Evtugyn G, Hianik T. Advances in lipid film based biosensors. Trends Analyt Chem 2016. [DOI: 10.1016/j.trac.2016.01.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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van Weerd J, Karperien M, Jonkheijm P. Supported Lipid Bilayers for the Generation of Dynamic Cell-Material Interfaces. Adv Healthc Mater 2015; 4:2743-79. [PMID: 26573989 DOI: 10.1002/adhm.201500398] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 08/03/2015] [Indexed: 12/13/2022]
Abstract
Supported lipid bilayers (SLB) offer unique possibilities for studying cellular membranes and have been used as a synthetic architecture to interact with cells. Here, the state-of-the-art in SLB-based technology is presented. The fabrication, analysis, characteristics and modification of SLBs are described in great detail. Numerous strategies to form SLBs on different substrates, and the means to patteren them, are described. The use of SLBs as model membranes for the study of membrane organization and membrane processes in vitro is highlighted. In addition, the use of SLBs as a substratum for cell analysis is presented, with discrimination between cell-cell and cell-extracellular matrix (ECM) mimicry. The study is concluded with a discussion of the potential for in vivo applications of SLBs.
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Affiliation(s)
- Jasper van Weerd
- Bioinspired Molecular Engineering; University of Twente; PO Box 217 7500 AE Enschede The Netherlands
- Dept. of Developmental BioEngineering; MIRA Institute for Biomedical Technology and Technical Medicine; University of Twente; PO Box 217 7500 AE Enschede The Netherlands
- Molecular Nanofabrication Group, MESA+; University of Twente; Enschede 7500 AE The Netherlands
| | - Marcel Karperien
- Dept. of Developmental BioEngineering; MIRA Institute for Biomedical Technology and Technical Medicine; University of Twente; PO Box 217 7500 AE Enschede The Netherlands
| | - Pascal Jonkheijm
- Bioinspired Molecular Engineering; University of Twente; PO Box 217 7500 AE Enschede The Netherlands
- Molecular Nanofabrication Group, MESA+; University of Twente; Enschede 7500 AE The Netherlands
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Sengur-Tasdemir R, Aydin S, Turken T, Genceli EA, Koyuncu I. Biomimetic Approaches for Membrane Technologies. SEPARATION AND PURIFICATION REVIEWS 2015. [DOI: 10.1080/15422119.2015.1035443] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Habel J, Hansen M, Kynde S, Larsen N, Midtgaard SR, Jensen GV, Bomholt J, Ogbonna A, Almdal K, Schulz A, Hélix-Nielsen C. Aquaporin-Based Biomimetic Polymeric Membranes: Approaches and Challenges. MEMBRANES 2015; 5:307-51. [PMID: 26264033 PMCID: PMC4584284 DOI: 10.3390/membranes5030307] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 07/22/2015] [Indexed: 12/12/2022]
Abstract
In recent years, aquaporin biomimetic membranes (ABMs) for water separation have gained considerable interest. Although the first ABMs are commercially available, there are still many challenges associated with further ABM development. Here, we discuss the interplay of the main components of ABMs: aquaporin proteins (AQPs), block copolymers for AQP reconstitution, and polymer-based supporting structures. First, we briefly cover challenges and review recent developments in understanding the interplay between AQP and block copolymers. Second, we review some experimental characterization methods for investigating AQP incorporation including freeze-fracture transmission electron microscopy, fluorescence correlation spectroscopy, stopped-flow light scattering, and small-angle X-ray scattering. Third, we focus on recent efforts in embedding reconstituted AQPs in membrane designs that are based on conventional thin film interfacial polymerization techniques. Finally, we describe some new developments in interfacial polymerization using polyhedral oligomeric silsesquioxane cages for increasing the physical and chemical durability of thin film composite membranes.
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Affiliation(s)
- Joachim Habel
- Technical University of Denmark, Department of Environmental Engineering, Miljøvej, Building 113, 2800 Kgs. Lyngby, Denmark.
- Aquaporin A/S, Ole Maaløes Vej 3, 2200 Copenhagen, Denmark.
| | - Michael Hansen
- University of Copenhagen, Department of Plant and Environmental Sciences, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark.
| | - Søren Kynde
- University of Copenhagen, Copenhagen Biocenter, Ole Maaløes Vej 5, 2200 Copenhagen, Denmark.
| | - Nanna Larsen
- University of Copenhagen, Niels Bohr Institute, Hans Christian Ørsted building D, Universitetsparken, 5, 2100 Copenhagen, Denmark.
| | - Søren Roi Midtgaard
- University of Copenhagen, Copenhagen Biocenter, Ole Maaløes Vej 5, 2200 Copenhagen, Denmark.
| | | | - Julie Bomholt
- Aquaporin A/S, Ole Maaløes Vej 3, 2200 Copenhagen, Denmark.
| | - Anayo Ogbonna
- Aquaporin A/S, Ole Maaløes Vej 3, 2200 Copenhagen, Denmark.
| | - Kristoffer Almdal
- Technical University of Denmark, Department of Micro- and Nanotechnology, Produktionstorvet, Building 423, 2800 Kgs. Lyngby.
| | - Alexander Schulz
- University of Copenhagen, Department of Plant and Environmental Sciences, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark.
| | - Claus Hélix-Nielsen
- Technical University of Denmark, Department of Environmental Engineering, Miljøvej, Building 113, 2800 Kgs. Lyngby, Denmark.
- Aquaporin A/S, Ole Maaløes Vej 3, 2200 Copenhagen, Denmark.
- University of Maribor, Laboratory for Water Biophysics and Membrane Processes, Faculty of Chemistry and Chemical Engineering, Smetanova ulica 17, 2000 Maribor, Slovenia.
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Wang M, Wang Z, Wang X, Wang S, Ding W, Gao C. Layer-by-layer assembly of aquaporin Z-incorporated biomimetic membranes for water purification. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:3761-3768. [PMID: 25730158 DOI: 10.1021/es5056337] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We fabricated a biomimetic nanofiltration (NF) membrane by immobilizing an Aquaporin Z (AqpZ)-incorporated supported lipid bilayer (SLB) on a layer-by-layer (LbL) complex polyelectrolyte membrane to achieve excellent permeability and salt rejection with a high stability. The polyelectrolyte membranes were prepared by LbL assembly of poly(ethylenimine) (PEI) with positive charges and poly(sodium 4-styrenesulfonate) (PSS) with negative charges alternately on a porous hydrolyzed polyacrylonitrile (H-PAN) substrate. AqpZ-incorporated 1,2-dioleloyl-sn-glycero-3-phosphocholine (DOPC)/1,2-dioleoyl-3-trimethylammo-nium-propane (chloride salt) (DOTAP) vesicles with positive charges were deposited on the H-PAN/PEI/PSS polyelectrolytes membrane surface. The resulting biomimetic membrane exhibited a high flux of 22 L·m(-2)·h(-1) (LMH), excellent MgCl2 rejection of ∼97% and NaCl rejection of ∼75% under an operation pressure of 0.4 MPa. Due to the attractive electrostatic interaction between SLB and the polyelectrolyte membrane, the biomimetic membrane showed satisfactory stability and durability as well as stable NF flux and rejection for at least 36 h. In addition, the AqpZ-containing biomimetic membrane was immersed in a 0.24 mM (critical micellar concentration, CMC) Triton X-100 solution for 5 min. The flux and rejection were slightly influenced by the Triton X-100 treatment. The current investigation demonstrated that the AqpZ-incorporated biomimetic membranes fabricated by the LbL method led to excellent separation performances and robust structures that withstand a high operation pressure for a relatively long time.
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Affiliation(s)
- Miaoqi Wang
- †Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, Shandong 266100, China
| | - Zhining Wang
- †Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, Shandong 266100, China
| | - Xida Wang
- ‡Tianjin Branch of Baotou Research Institute of Rare Earth, Tianjin 300300, China
| | - Shuzheng Wang
- †Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, Shandong 266100, China
| | - Wande Ding
- †Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, Shandong 266100, China
| | - Congjie Gao
- †Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, Shandong 266100, China
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Terme N, Jacquemet A, Benvegnu T, Vié V, Lemiègre L. Modification of bipolar lipid conformation at the air/water interface by a single stereochemical variation. Chem Phys Lipids 2014; 183:9-17. [DOI: 10.1016/j.chemphyslip.2014.04.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 04/25/2014] [Accepted: 04/28/2014] [Indexed: 01/10/2023]
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Francisco V, Garcia-Rio L. Interaction of bolaform surfactants with p-sulfonatocalix[4]arene: the role of two positive charges in the binding. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:6748-6755. [PMID: 24845955 DOI: 10.1021/la501337c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The inclusion binding manners of bolaform surfactants of type C(n)R6(2+) 2Br(-) with different spacer lengths (n = 6, 12) and terminal headgroup volumes (R = methyl, ethyl) by p-sulfonatocalix[4]arene were studied. The combination of ITC parameters (binding constants and complexation enthalpy and entropy) and NMR chemical shifts and NOE cross-peaks obtained upon complexation allows us to propose different binding modes. The results point out that the spacer length has an influence on the binding stoichiometry. The bolaforms with larger spacer lengths between polar head groups enable the formation of 2:1 complexes in addition to 1:1, while with the shorter spacer they form only 1:1 complexes. On the other hand, the formation of 1:1 complexes is not affected by the headgroup volume or the spacer length of the bolaform. Unexpectedly, a complex binding mode was observed where both positive charged terminal groups of the bolaform are accommodated in the cavity of the calixarene. The inclusion of both terminal groups of the guests can be related to its own structure but also evidence the high flexibility of the calixarene.
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Affiliation(s)
- Vitor Francisco
- Departamento de Química Física, Centro de Investigación en Química Biológica y Materiales Moleculares (CIQUS), Universidad de Santiago de Compostela , 15782 Santiago de Compostela, Spain
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