1
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Róg T, Girych M, Bunker A. Mechanistic Understanding from Molecular Dynamics in Pharmaceutical Research 2: Lipid Membrane in Drug Design. Pharmaceuticals (Basel) 2021; 14:1062. [PMID: 34681286 PMCID: PMC8537670 DOI: 10.3390/ph14101062] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 10/14/2021] [Accepted: 10/15/2021] [Indexed: 11/17/2022] Open
Abstract
We review the use of molecular dynamics (MD) simulation as a drug design tool in the context of the role that the lipid membrane can play in drug action, i.e., the interaction between candidate drug molecules and lipid membranes. In the standard "lock and key" paradigm, only the interaction between the drug and a specific active site of a specific protein is considered; the environment in which the drug acts is, from a biophysical perspective, far more complex than this. The possible mechanisms though which a drug can be designed to tinker with physiological processes are significantly broader than merely fitting to a single active site of a single protein. In this paper, we focus on the role of the lipid membrane, arguably the most important element outside the proteins themselves, as a case study. We discuss work that has been carried out, using MD simulation, concerning the transfection of drugs through membranes that act as biological barriers in the path of the drugs, the behavior of drug molecules within membranes, how their collective behavior can affect the structure and properties of the membrane and, finally, the role lipid membranes, to which the vast majority of drug target proteins are associated, can play in mediating the interaction between drug and target protein. This review paper is the second in a two-part series covering MD simulation as a tool in pharmaceutical research; both are designed as pedagogical review papers aimed at both pharmaceutical scientists interested in exploring how the tool of MD simulation can be applied to their research and computational scientists interested in exploring the possibility of a pharmaceutical context for their research.
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Affiliation(s)
- Tomasz Róg
- Department of Physics, University of Helsinki, 00014 Helsinki, Finland;
| | - Mykhailo Girych
- Department of Physics, University of Helsinki, 00014 Helsinki, Finland;
| | - Alex Bunker
- Drug Research Program, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, 00014 Helsinki, Finland;
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2
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Lolicato F, Juhola H, Zak A, Postila PA, Saukko A, Rissanen S, Enkavi G, Vattulainen I, Kepczynski M, Róg T. Membrane-Dependent Binding and Entry Mechanism of Dopamine into Its Receptor. ACS Chem Neurosci 2020; 11:1914-1924. [PMID: 32538079 PMCID: PMC7735663 DOI: 10.1021/acschemneuro.9b00656] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Synaptic neurotransmission has recently been proposed to function via either a membrane-independent or a membrane-dependent mechanism, depending on the neurotransmitter type. In the membrane-dependent mechanism, amphipathic neurotransmitters first partition to the lipid headgroup region and then diffuse along the membrane plane to their membrane-buried receptors. However, to date, this mechanism has not been demonstrated for any neurotransmitter-receptor complex. Here, we combined isothermal calorimetry measurements with a diverse set of molecular dynamics simulation methods to investigate the partitioning of an amphipathic neurotransmitter (dopamine) and the mechanism of its entry into the ligand-binding site. Our results show that the binding of dopamine to its receptor is consistent with the membrane-dependent binding and entry mechanism. Both experimental and simulation results showed that dopamine favors binding to lipid membranes especially in the headgroup region. Moreover, our simulations revealed a ligand-entry pathway from the membrane to the binding site. This pathway passes through a lateral gate between transmembrane alpha-helices 5 and 6 on the membrane-facing side of the protein. All in all, our results demonstrate that dopamine binds to its receptor by a membrane-dependent mechanism, and this is complemented by the more traditional binding mechanism directly through the aqueous phase. The results suggest that the membrane-dependent mechanism is common in other synaptic receptors, too.
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Affiliation(s)
- Fabio Lolicato
- Department of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
- Biochemistry Center, Heidelberg University, D-69120 Heidelberg, Germany
| | - Hanna Juhola
- Computational Physics Laboratory, Tampere University, FI-33100 Tampere, Finland
| | - Agata Zak
- Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Kraków, Poland
| | - Pekka A. Postila
- Institute of Biomedicine, Faculty of Medicine, University of Turku, FI-20014 Turku, Finland
| | - Annina Saukko
- Department of Applied Physics, University of Eastern Finland, P.O.B. 1627, FI-70211 Kuopio, Finland
- Department of Medical Physics, Turku University Hospital, FI-20520 Turku, Finland
| | - Sami Rissanen
- Computational Physics Laboratory, Tampere University, FI-33100 Tampere, Finland
| | - Giray Enkavi
- Department of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - Ilpo Vattulainen
- Department of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
- Computational Physics Laboratory, Tampere University, FI-33100 Tampere, Finland
- MEMPHYS − Center for Biomembrane Physics
| | - Mariusz Kepczynski
- Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Kraków, Poland
| | - Tomasz Róg
- Department of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
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3
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Poojari C, Zak A, Dzieciuch-Rojek M, Bunker A, Kepczynski M, Róg T. Cholesterol Reduces Partitioning of Antifungal Drug Itraconazole into Lipid Bilayers. J Phys Chem B 2020; 124:2139-2148. [PMID: 32101005 PMCID: PMC7735721 DOI: 10.1021/acs.jpcb.9b11005] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
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Cholesterol
plays a crucial role in modulating the physicochemical
properties of biomembranes, both increasing mechanical strength and
decreasing permeability. Cholesterol is also a common component of
vesicle-based delivery systems, including liposome-based drug delivery
systems (LDSs). However, its effect on the partitioning of drug molecules
to lipid membranes is very poorly recognized. Herein, we performed
a combined experimental/computational study of the potential for the
use of the LDS formulation for the delivery of the antifungal drug
itraconazole (ITZ). We consider the addition of cholesterol to the
lipid membrane. Since ITZ is only weakly soluble in water, its bioavailability
is limited. Use of an LDS has thus been proposed. We studied lipid
membranes composed of cholesterol, 1-palmitoyl-2-oleoyl-sn-glycerol-3-phosphocholine (POPC), and ITZ using a combination of
computational molecular dynamics (MD) simulations of lipid bilayers
and Brewster angle microscopy (BAM) experiments of monolayers. Both
experimental and computational results show separation of cholesterol
and ITZ. Cholesterol has a strong preference to orient parallel to
the bilayer normal. However, ITZ, a long and relatively rigid molecule
with weakly hydrophilic groups along the backbone, predominantly locates
below the interface between the hydrocarbon chain region and the polar
region of the membrane, with its backbone oriented parallel to the
membrane surface; the orthogonal orientation in the membrane could
be the cause of the observed separation. In addition, fluorescence
measurements demonstrated that the affinity of ITZ for the lipid membrane
is decreased by the presence of cholesterol, which is thus probably
not a suitable formulation component of an LDS designed for ITZ delivery.
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Affiliation(s)
- Chetan Poojari
- Department of Physics, Faculty of Science, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland.,Theoretical Physics and Center for Biophysics, Saarland University, 66123 Saarbrücken, Germany
| | - Agata Zak
- Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Kraków, Poland
| | | | - Alex Bunker
- Division of Pharmaceutical Biosciences, Drug Research Program, Faculty of Pharmacy, University of Helsinki, Viikinkaari 5 E, 00014 Helsinki, Finland
| | - Mariusz Kepczynski
- Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Kraków, Poland
| | - Tomasz Róg
- Department of Physics, Faculty of Science, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
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4
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Poojari C, Wilkosz N, Lira RB, Dimova R, Jurkiewicz P, Petka R, Kepczynski M, Róg T. Behavior of the DPH fluorescence probe in membranes perturbed by drugs. Chem Phys Lipids 2019; 223:104784. [PMID: 31199906 DOI: 10.1016/j.chemphyslip.2019.104784] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Revised: 05/09/2019] [Accepted: 06/08/2019] [Indexed: 12/22/2022]
Abstract
1,6-Diphenyl-1,3,5-hexatriene (DPH) is one of the most commonly used fluorescent probes to study dynamical and structural properties of lipid bilayers and cellular membranes via measuring steady-state or time-resolved fluorescence anisotropy. In this study, we present a limitation in the use of DPH to predict the order of lipid acyl chains when the lipid bilayer is doped with itraconazole (ITZ), an antifungal drug. Our steady-state fluorescence anisotropy measurements showed a significant decrease in fluorescence anisotropy of DPH embedded in the ITZ-containing membrane, suggesting a substantial increase in membrane fluidity, which indirectly indicates a decrease in the order of the hydrocarbon chains. This result or its interpretation is in disagreement with the fluorescence recovery after photobleaching measurements and molecular dynamics (MD) simulation data. The results of these experiments and calculations indicate an increase in the hydrocarbon chain order. The MD simulations of the bilayer containing both ITZ and DPH provide explanations for these observations. Apparently, in the presence of the drug, the DPH molecules are pushed deeper into the hydrophobic membrane core below the lipid double bonds, and the probe predominately adopts the orientation of the ITZ molecules that is parallel to the membrane surface, instead of orienting parallel to the lipid acyl chains. For this reason, DPH anisotropy provides information related to the less ordered central region of the membrane rather than reporting the properties of the upper segments of the lipid acyl chains.
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Affiliation(s)
- Chetan Poojari
- Department of Physics, Tampere University of Technology, PO Box 692, FI-33101 Tampere, Finland
| | - Natalia Wilkosz
- Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387, Kraków, Poland
| | - Rafael B Lira
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14424, Potsdam, Germany
| | - Rumiana Dimova
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14424, Potsdam, Germany
| | - Piotr Jurkiewicz
- J. Heyrovský Institute of Physical Chemistry AS CR, v.v.i, Dolejškova 2155/3, 182 23 Prague 8, Czech Republic
| | - Rafał Petka
- Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387, Kraków, Poland
| | - Mariusz Kepczynski
- Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387, Kraków, Poland.
| | - Tomasz Róg
- Department of Physics, Tampere University of Technology, PO Box 692, FI-33101 Tampere, Finland; Department of Physics, University of Helsinki, PO Box 64, FI-00014, Helsinki, Finland.
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5
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Dzieciuch-Rojek M, Poojari C, Bednar J, Bunker A, Kozik B, Nowakowska M, Vattulainen I, Wydro P, Kepczynski M, Róg T. Effects of Membrane PEGylation on Entry and Location of Antifungal Drug Itraconazole and Their Pharmacological Implications. Mol Pharm 2017; 14:1057-1070. [PMID: 28234487 DOI: 10.1021/acs.molpharmaceut.6b00969] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Itraconazole (ITZ) is an antifungal agent used clinically to treat mycotic infections. However, its therapeutic effects are limited by low solubility in aqueous media. Liposome-based delivery systems (LDS) have been proposed as a delivery mechanism for ITZ to alleviate this problem. Furthermore, PEGylation, the inclusion in the formulation of a protective "stealth sheath" of poly(ethylene glycol) around carrier particles, is widely used to increase circulation time in the bloodstream and hence efficacy. Together, these themes highlight the importance of mechanistic and structural understanding of ITZ incorporation into liposomes both with and without PEGylation because it can provide a potential foundation for the rational design of LDS-based systems for delivery of ITZ, using alternate protective polymers or formulations. Here we have combined atomistic simulations, cryo-TEM, Langmuir film balance, and fluorescence quenching experiments to explore how ITZ interacts with both pristine and PEGylated liposomes. We found that the drug can be incorporated into conventional and PEGylated liposomes for drug concentrations up to 15 mol % without phase separation. We observed that, in addition to its protective properties, PEGylation significantly increases the stability of liposomes that host ITZ. In a 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) bilayer without PEGylation, ITZ was found to reside inside the lipid bilayer between the glycerol and the double-bond regions of POPC, adopting a largely parallel orientation along the membrane surface. In a PEGylated liposome, ITZ partitions mainly to the PEG layer. The results provide a solid basis for further development of liposome-based delivery systems.
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Affiliation(s)
| | - Chetan Poojari
- Department of Physics, Tampere University of Technology , P.O. Box 692, FI-33101 Tampere, Finland
| | - Jan Bednar
- Université de Grenoble Alpes/CNRS, Institut Albert Bonniot , UMR 5309, 38042 CEDEX 9 Grenoble, France.,First Faculty of Medicine, Laboratory of Biology and Pathology of the Eye, Institute of Inherited Metabolic Disorders, Charles University in Prague , KeKarlovu 2, 12800 Prague 2, Czech Republic
| | - Alex Bunker
- Centre for Drug Research, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki , FI-00014 Helsinki, Finland
| | - Bartłomiej Kozik
- Faculty of Chemistry, Jagiellonian University , Ingardena 3, 30-060 Kraków, Poland
| | - Maria Nowakowska
- Faculty of Chemistry, Jagiellonian University , Ingardena 3, 30-060 Kraków, Poland
| | - Ilpo Vattulainen
- Department of Physics, Tampere University of Technology , P.O. Box 692, FI-33101 Tampere, Finland.,Department of Physics, University of Helsinki , P.O. Box 64, FI-00014 Helsinki, Finland.,MEMPHYS-Center for Biomembrane Physics, University of Southern Denmark , Odense, Denmark
| | - Paweł Wydro
- Faculty of Chemistry, Jagiellonian University , Ingardena 3, 30-060 Kraków, Poland
| | - Mariusz Kepczynski
- Faculty of Chemistry, Jagiellonian University , Ingardena 3, 30-060 Kraków, Poland
| | - Tomasz Róg
- Department of Physics, Tampere University of Technology , P.O. Box 692, FI-33101 Tampere, Finland.,Department of Physics, University of Helsinki , P.O. Box 64, FI-00014 Helsinki, Finland
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6
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Kepczynski M, Róg T. Functionalized lipids and surfactants for specific applications. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:2362-2379. [PMID: 26946243 DOI: 10.1016/j.bbamem.2016.02.038] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 02/23/2016] [Accepted: 02/25/2016] [Indexed: 12/17/2022]
Abstract
Synthetic lipids and surfactants that do not exist in biological systems have been used for the last few decades in both basic and applied science. The most notable applications for synthetic lipids and surfactants are drug delivery, gene transfection, as reporting molecules, and as support for structural lipid biology. In this review, we describe the potential of the synergistic combination of computational and experimental methodologies to study the behavior of synthetic lipids and surfactants embedded in lipid membranes and liposomes. We focused on select cases in which molecular dynamics simulations were used to complement experimental studies aiming to understand the structure and properties of new compounds at the atomistic level. We also describe cases in which molecular dynamics simulations were used to design new synthetic lipids and surfactants, as well as emerging fields for the application of these compounds. This article is part of a Special Issue entitled: Biosimulations edited by Ilpo Vattulainen and Tomasz Róg.
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Affiliation(s)
- Mariusz Kepczynski
- Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland.
| | - Tomasz Róg
- Department of Physics, Tampere University of Technology, P.O. Box 692, FI-33101, Tampere, Finland; Department of Physics, Helsinki University, P.O. Box 64, FI 00014 Helsinki, Finland.
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7
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Dzieciuch M, Rissanen S, Szydłowska N, Bunker A, Kumorek M, Jamróz D, Vattulainen I, Nowakowska M, Róg T, Kepczynski M. PEGylated Liposomes as Carriers of Hydrophobic Porphyrins. J Phys Chem B 2015; 119:6646-57. [DOI: 10.1021/acs.jpcb.5b01351] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Monika Dzieciuch
- Faculty
of Chemistry, Jagiellonian University, Krakow 31-007, Poland
| | - Sami Rissanen
- Department
of Physics, Tampere University of Technology, Tampere 33720, Finland
| | | | - Alex Bunker
- Centre
for Drug Research, Faculty of Pharmacy, University of Helsinki, Helsinki 00100, Finland
| | - Marta Kumorek
- Faculty
of Chemistry, Jagiellonian University, Krakow 31-007, Poland
| | - Dorota Jamróz
- Faculty
of Chemistry, Jagiellonian University, Krakow 31-007, Poland
| | - Ilpo Vattulainen
- Department
of Physics, Tampere University of Technology, Tampere 33720, Finland
- MEMPHYS-Center
for Biomembrane Physics, University of Southern Denmark, Odense 5230, Denmark
| | - Maria Nowakowska
- Faculty
of Chemistry, Jagiellonian University, Krakow 31-007, Poland
| | - Tomasz Róg
- Department
of Physics, Tampere University of Technology, Tampere 33720, Finland
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8
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Stępniewski M, Kepczynski M, Jamróz D, Nowakowska M, Rissanen S, Vattulainen I, Róg T. Interaction of Hematoporphyrin with Lipid Membranes. J Phys Chem B 2012; 116:4889-97. [DOI: 10.1021/jp300899b] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Michał Stępniewski
- Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków,
Poland
| | - Mariusz Kepczynski
- Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków,
Poland
| | - Dorota Jamróz
- Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków,
Poland
| | - Maria Nowakowska
- Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków,
Poland
| | - Sami Rissanen
- Department of Physics, Tampere University of Technology, PO Box 692, FI-33101
Tampere, Finland
| | - Ilpo Vattulainen
- Department of Physics, Tampere University of Technology, PO Box 692, FI-33101
Tampere, Finland
- MEMPHYS-Center
for Biomembrane
Physics, University of Southern Denmark, Odense, Denmark
| | - Tomasz Róg
- Department of Physics, Tampere University of Technology, PO Box 692, FI-33101
Tampere, Finland
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9
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Kepczynski M, Jamróz D, Wytrwal M, Bednar J, Rzad E, Nowakowska M. Interactions of a hydrophobically modified polycation with zwitterionic lipid membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:676-688. [PMID: 22085465 DOI: 10.1021/la203748q] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The interactions between synthetic polycations and phospholipid bilayers play an important role in some biophysical applications such as gene delivery or antibacterial usage. Despite extensive investigation into the nature of these interactions, their physical and molecular bases remain poorly understood. In this Article, we present the results of our studies on the impact of a hydrophobically modified strong polycation on the properties of a zwitterionic bilayer used as a model of the mammalian cellular membrane. The study was carried out using a set of complementary experimental methods and molecular dynamic (MD) simulations. A new polycation, poly(allyl-N,N-dimethyl-N-hexylammonium chloride) (polymer 3), was synthesized, and its interactions with liposomes composed of 2-oleoyl-1-palmitoyl-sn-glycero-3-phosphocholine (POPC) were examined using dynamic light scattering (DLS), zeta potential measurements, and cryo-transmission electron microscopy (cryo-TEM). Our results have shown that polymer 3 can efficiently associate with and insert into the POPC membrane. However, it does not change its lamellar structure, as was demonstrated by cryo-TEM. The influence of polymer 3 on the membrane functionality was studied by leakage experiments applying a fluorescence dye (calcein) encapsulated in the phospholipid vesicles. The MD simulations of model systems reveal that polymer 3 promotes formation of hydrophilic pores in the membrane, thus increasing considerably its permeability.
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Affiliation(s)
- Mariusz Kepczynski
- Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland.
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10
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Cerezo J, Zúñiga J, Bastida A, Requena A, Cerón-Carrasco JP. Atomistic Molecular Dynamics Simulations of the Interactions of Oleic and 2-Hydroxyoleic Acids with Phosphatidylcholine Bilayers. J Phys Chem B 2011; 115:11727-38. [DOI: 10.1021/jp203498x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Javier Cerezo
- Departamento de Química Física, Universidad de Murcia, 30100 Murcia, Spain
| | - José Zúñiga
- Departamento de Química Física, Universidad de Murcia, 30100 Murcia, Spain
| | - Adolfo Bastida
- Departamento de Química Física, Universidad de Murcia, 30100 Murcia, Spain
| | - Alberto Requena
- Departamento de Química Física, Universidad de Murcia, 30100 Murcia, Spain
| | - José Pedro Cerón-Carrasco
- CEISAM, UMR CNRS 6230, BP 92208, Université de Nantes, 2, rue de la Houssiniére, 44322 Nantes Cedex 3, France
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11
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Karewicz A, Bielska D, Gzyl-Malcher B, Kepczynski M, Lach R, Nowakowska M. Interaction of curcumin with lipid monolayers and liposomal bilayers. Colloids Surf B Biointerfaces 2011; 88:231-9. [PMID: 21778041 DOI: 10.1016/j.colsurfb.2011.06.037] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Accepted: 06/24/2011] [Indexed: 10/17/2022]
Abstract
Curcumin shows huge potential as an anticancer and anti-inflammatory agent. However, to achieve a satisfactory bioavailability and stability of this compound, its liposomal form is preferable. Our detailed studies on the curcumin interaction with lipid membranes are aimed to obtain better understanding of the mechanism and eventually to improve the efficiency of curcumin delivery to cells. Egg yolk phosphatidylcholine (EYPC) one-component monolayers and bilayers, as well as mixed systems containing additionally dihexadecyl phosphate (DHP) and cholesterol, were studied. Curcumin binding constant to EYPC liposomes was determined based on two different methods: UV/Vis absorption and fluorescence measurements to be 4.26×10(4)M(-1) and 3.79×10(4)M(-1), respectively. The fluorescence quenching experiment revealed that curcumin locates in the hydrophobic region of EYPC liposomal bilayer. It was shown that curcumin impacts the size and stability of the liposomal carriers significantly. Loaded into the EYPC/DPH/cholesterol liposomal bilayer curcumin stabilizes the system proportionally to its content, while the EYPC/DPH system is destabilized upon drug loading. The three-component lipid composition of the liposome seems to be the most promising system for curcumin delivery. An interaction of free and liposomal curcumin with EYPC and mixed monolayers was also studied using Langmuir balance measurements. Monolayer systems were treated as a simple model of cell membrane. Condensing effect of curcumin on EYPC and EYPC/DHP monolayers and loosening influence on EYPC/DHP/chol ones were observed. It was also demonstrated that curcumin-loaded EYPC liposomes are more stable upon interaction with the model lipid membrane than the unloaded ones.
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Affiliation(s)
- Anna Karewicz
- Physical Chemistry Department, Faculty of Chemistry, Jagiellonian University, Kraków, Poland.
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