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Anosov AA, Smirnova EY, Korepanova EA, Kazamanov VA, Derunets AS. Different effects of two Poloxamers (L61 and F68) on the conductance of bilayer lipid membranes. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2023; 46:14. [PMID: 36920579 DOI: 10.1140/epje/s10189-023-00270-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Accepted: 02/15/2023] [Indexed: 06/18/2023]
Abstract
The integral conductance of planar lipid bilayer membranes in the presence of two Poloxamers (Pluronics) L61 and F68 with the same lengths of hydrophobic poly(propylene oxide) blocks and the different lengths of hydrophilic poly(ethylene oxide) blocks increases with an increase in the concentration of both Pluronics; however, the shape of the conductance-concentration curves is super linear for L61 and sublinear for F68. In the presence of both Pluronics, rare discrete current jumps are observed against the background of continuous current. At high concentrations, the I-V curves of membranes with both L61 and F68 became nonlinear at sufficiently low voltages but differed significantly. At voltages greater than 50 mV, the conductance of membranes with L61 increased sharply and quantized jumps were observed toward higher conductance, which could be interpreted as the appearance of additional pores. On the contrary, the conductance of membranes with F68 decreased and quantized jumps to lower conductance were observed, which could be interpreted as blocking of already existing pores. We attributed the differences in the conductance-concentration and I-V curves of these two Pluronics to their different effects on the dynamics of membrane hydration and, accordingly, on the probability of formation of conducting pores.
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Affiliation(s)
- A A Anosov
- Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
- Kotelnikov Institute of Radioengineering and Electronics of RAS, Moscow, Russia
| | - E Yu Smirnova
- Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - E A Korepanova
- Pirogov Russian National Research Medical University, Moscow, Russia
| | - V A Kazamanov
- MIREA-Russian Technological University, Moscow, Russia
| | - A S Derunets
- National Research Center Kurchatov Institute, Moscow, Russia.
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2
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Kumar SS, Ward ML, Mountjoy KG. Quantitative high-throughput assay to measure MC4R-induced intracellular calcium. J Mol Endocrinol 2021; 66:285-297. [PMID: 33739935 PMCID: PMC8111326 DOI: 10.1530/jme-20-0285] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 03/19/2021] [Indexed: 12/17/2022]
Abstract
The melanocortin-4 receptor (MC4R), a critical G-protein-coupled receptor (GPCR) regulating energy homeostasis, activates multiple signalling pathways, including mobilisation of intracellular calcium ([Ca2+]i). However, very little is known about the physiological significance of MC4R-induced [Ca2+]i since few studies measure MC4R-induced [Ca2+]i. High-throughput, read-out assays for [Ca2+]i have proven unreliable for overexpressed GPCRs like MC4R, which exhibit low sensitivity mobilising [Ca2+]i. Therefore, we developed, optimised, and validated a robust quantitative high-throughput assay using Fura-2 ratio-metric calcium dye and HEK293 cells stably transfected with MC4R. The quantitation enables direct comparisons between assays and even between different research laboratories. Assay conditions were optimised step-by-step to eliminate interference from stretch-activated receptor increases in [Ca2+]i and to maximise ligand-activated MC4R-induced [Ca2+]i. Calcium imaging was performed using a PheraStar FS multi-well plate reader. Probenecid, included in the buffers to prevent extrusion of Fura-2 dye from cells, was found to interfere with the EGTA-chelation of calcium, required to determine Rmin for quantitation of [Ca2+]i. Therefore, we developed a method to determine Rmin in specific wells without probenecid, which was run in parallel with each assay. The validation of the assay was shown by reproducible α-melanocyte-stimulating hormone (α-MSH) concentration-dependent activation of the stably expressed human MC4R (hMC4R) and mouse MC4R (mMC4R), inducing increases in [Ca2+]i, for three independent experiments. This robust, reproducible, high-throughput assay that quantitatively measures MC4R-induced mobilisation of [Ca2+]i in vitro has potential to advance the development of therapeutic drugs and understanding of MC4R signalling associated with human obesity.
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Affiliation(s)
- Shree Senthil Kumar
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Marie-Louise Ward
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Kathleen Grace Mountjoy
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Department of Molecular Medicine and Pathology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, Auckland, New Zealand
- Correspondence should be addressed to K G Mountjoy:
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Kozon D, Bednarczyk P, Szewczyk A, Jańczewski D. Regulation of Lipid Bilayer Ion Permeability by Antibacterial Polymethyloxazoline-Polyethyleneimine Copolymers. Chembiochem 2020; 22:1020-1029. [PMID: 33124737 DOI: 10.1002/cbic.202000656] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 10/28/2020] [Indexed: 01/08/2023]
Abstract
Amphiphilic antimicrobial polymers display activity against the outer bacterial cell membrane, triggering various physiological effects. We investigated the regulation of ion transport across the lipid bilayer to understand differences in biological activity for a series of amphiphilic polymethyloxazoline - polyethyleneimine copolymers. The results confirmed that the tested structures were able to increase the permeability of the lipid bilayer (LB) membrane or its rupture. Black lipid membrane (BLM) experiments show that the triggered conductance profile and its character is strongly correlated with the polymer structure and zeta potential. The polymer exhibiting the highest antimicrobial activity promotes ion transport by using a unique mechanism and step-like characteristics with well-defined discreet openings and closings. The molecule was incorporated into the membrane in a reproducible way, and the observed channel-like activity could be responsible for the antibacterial activity of this molecule.
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Affiliation(s)
- Dominika Kozon
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664, Warsaw, Poland
| | - Piotr Bednarczyk
- Department of Physics and Biophysics, Institute of Biology, Warsaw University of Life Sciences - SGGW, Nowoursynowska 159, 02-787, Warsaw, Poland
| | - Adam Szewczyk
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Pasteura 3, 02-093, Warsaw, Poland
| | - Dominik Jańczewski
- Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664, Warsaw, Poland
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Ruiz-Picazo A, Lozoya-Agullo I, González-Álvarez I, Bermejo M, González-Álvarez M. Effect of excipients on oral absorption process according to the different gastrointestinal segments. Expert Opin Drug Deliv 2020; 18:1005-1024. [PMID: 32842776 DOI: 10.1080/17425247.2020.1813108] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
INTRODUCTION Excipients are necessary to develop oral dosage forms of any Active Pharmaceutical Ingredient (API). Traditionally, excipients have been considered inactive and inert substances, but, over the years, numerous studies have contradicted this belief. This review focuses on the effect of excipients on the physiological variables affecting oral absorption along the different segments of the gastrointestinal tract. The effect of excipients on the segmental absorption variables are illustrated with examples to help understand the complexity of predicting their in vivo effects. AREAS COVERED The effects of excipients on disintegration, solubility and dissolution, transit time, and absorption are analyzed in the context of the different gastrointestinal segments and the physiological factors affecting release and membrane permeation. The experimental techniques used to study excipient effects and their human predictive ability are reviewed. EXPERT OPINION The observed effects of excipient in oral absorption process have been characterized in the past, mainly in vitro (i.e. in dissolution studies, in vitro cell culture methods or in situ animal studies). Unfortunately, a clear link with their effects in vivo, i.e. their impact on Cmax or AUC, which need a mechanistic approach is still missing. The information compiled in this review leads to the conclusion that the effect of excipients in API oral absorption and bioavailability is undeniable and shows the need of implementing standardized and reproducible preclinical tools coupled with mechanistic and predictive physiological-based models to improve the current empirical retrospective approach.
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Affiliation(s)
- Alejandro Ruiz-Picazo
- Engineering: Pharmacokinetics and Pharmaceutical Technology Area, Miguel Hernandez University, Elche, Spain
| | - Isabel Lozoya-Agullo
- Engineering: Pharmacokinetics and Pharmaceutical Technology Area, Miguel Hernandez University, Elche, Spain
| | - Isabel González-Álvarez
- Engineering: Pharmacokinetics and Pharmaceutical Technology Area, Miguel Hernandez University, Elche, Spain
| | - Marival Bermejo
- Engineering: Pharmacokinetics and Pharmaceutical Technology Area, Miguel Hernandez University, Elche, Spain
| | - Marta González-Álvarez
- Engineering: Pharmacokinetics and Pharmaceutical Technology Area, Miguel Hernandez University, Elche, Spain
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Zhang W, Coughlin ML, Metzger JM, Hackel BJ, Bates FS, Lodge TP. Influence of Cholesterol and Bilayer Curvature on the Interaction of PPO-PEO Block Copolymers with Liposomes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:7231-7241. [PMID: 31117745 PMCID: PMC7050598 DOI: 10.1021/acs.langmuir.9b00572] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Interactions of nonionic poly(ethylene oxide)- b-poly(propylene oxide) (PEO-PPO) block copolymers, known as Pluronics or poloxamers, with cell membranes have been widely studied for a host of biomedical applications. Herein, we report how cholesterol within phosphatidylcholine (POPC) lipid bilayer liposomes and bilayer curvature affects the binding of several PPO-PEO-PPO triblocks with varying PPO content and a tPPO-PEO diblock, where t refers to a tert-butyl end group. Pulsed-field-gradient NMR was employed to quantify the extent of copolymer associated with liposomes prepared with cholesterol concentrations ranging from 0 to 30 mol % relative to the total content of POPC and cholesterol and vesicle extrusion radii of 25, 50, or 100 nm. The fraction of polymer bound to the liposomes was extracted from NMR data on the basis of the very different mobilities of the bound and free polymers in aqueous solution. Cholesterol concentration was manipulated by varying the molar percentage of this sterol in the POPC bilayer preparation. The membrane curvature was varied by adjusting the liposome size through a conventional pore extrusion technique. Although the PPO content significantly influences the overall amount of block copolymer adsorbed to the liposome, we found that polymer binding decreases with increasing cholesterol concentration in a universal fashion, with the fraction of bound polymer dropping 10-fold between 0 and 30 mol % cholesterol relative to the total content of POPC and cholesterol. Increasing the bilayer curvature (decreasing the radius of the liposome) in the absence of cholesterol increases polymer binding between 2- and 4-fold over the range of liposome sizes studied. These results demonstrate that cholesterol plays a dominant role, and bilayer curvature has a less significant impact as the curvature decreases, on polymer-membrane association.
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Affiliation(s)
- Wenjia Zhang
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - McKenzie L. Coughlin
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Joseph M. Metzger
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Benjamin J. Hackel
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Frank S. Bates
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Timothy P. Lodge
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
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Houang EM, Sham YY, Bates FS, Metzger JM. Muscle membrane integrity in Duchenne muscular dystrophy: recent advances in copolymer-based muscle membrane stabilizers. Skelet Muscle 2018; 8:31. [PMID: 30305165 PMCID: PMC6180502 DOI: 10.1186/s13395-018-0177-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 09/13/2018] [Indexed: 02/07/2023] Open
Abstract
The scientific premise, design, and structure-function analysis of chemical-based muscle membrane stabilizing block copolymers are reviewed here for applications in striated muscle membrane injury. Synthetic block copolymers have a rich history and wide array of applications from industry to biology. Potential for discovery is enabled by a large chemical space for block copolymers, including modifications in block copolymer mass, composition, and molecular architecture. Collectively, this presents an impressive chemical landscape to leverage distinct structure-function outcomes. Of particular relevance to biology and medicine, stabilization of damaged phospholipid membranes using amphiphilic block copolymers, classified as poloxamers or pluronics, has been the subject of increasing scientific inquiry. This review focuses on implementing block copolymers to protect fragile muscle membranes against mechanical stress. The review highlights interventions in Duchenne muscular dystrophy, a fatal disease of progressive muscle deterioration owing to marked instability of the striated muscle membrane. Biophysical and chemical engineering advances are presented that delineate and expand upon current understanding of copolymer-lipid membrane interactions and the mechanism of stabilization. The studies presented here serve to underscore the utility of copolymer discovery leading toward the therapeutic application of block copolymers in Duchenne muscular dystrophy and potentially other biomedical applications in which membrane integrity is compromised.
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Affiliation(s)
- Evelyne M. Houang
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, 6-125 Jackson Hall, 321 Church Street SE, Minneapolis, MN 55455 USA
| | - Yuk Y. Sham
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, 6-125 Jackson Hall, 321 Church Street SE, Minneapolis, MN 55455 USA
- University of Minnesota Informatics Institute, MN, USA
- Bioinformatics and Computational Biology Program, University of Minnesota, MN, USA
| | - Frank S. Bates
- Department of Chemical Engineering and Materials Science, University of Minnesota, MN, USA
| | - Joseph M. Metzger
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, 6-125 Jackson Hall, 321 Church Street SE, Minneapolis, MN 55455 USA
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Zhang W, Haman KJ, Metzger JM, Hackel BJ, Bates FS, Lodge TP. Quantifying Binding of Ethylene Oxide-Propylene Oxide Block Copolymers with Lipid Bilayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:12624-12634. [PMID: 29068209 PMCID: PMC6055234 DOI: 10.1021/acs.langmuir.7b02279] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Block copolymers composed of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) have been widely used in cell membrane stabilization and permeabilization. To explore the mechanism of interaction between PPO-PEO block copolymers and lipid membranes, we have investigated how polymer structure influences the polymer-lipid bilayer association by varying the overall molecular weight, the hydrophobic and hydrophilic block lengths, and the end-group structure systematically, using 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) unilamellar liposomes as model membranes. Pulsed-field-gradient NMR (PFG-NMR) was employed to probe polymer diffusion in the absence and presence of liposomes. The echo decay curves of free polymers in the absence of liposomes are single exponentials, indicative of simple translational diffusion, while in the presence of liposomes, the decays are biexponential, with the slower decay corresponding to polymers bound to liposomes. The binding percentage of polymer to the liposome was quantified by fitting the echo decay curves to a biexponential model. The NMR experiments show that increasing the total molecular weight and hydrophobicity of the polymer can significantly enhance the polymer-lipid bilayer association, as the binding percentage and liposome surface coverage both increase. We hypothesize that the hydrophobic PPO block inserts into the lipid bilayer due to the fact that little molecular exchange between bound and free polymers occurs on the time scale of the diffusion experiments. Additionally, as polymer concentration increases, the liposome surface coverage increases and approaches a limit. These results demonstrate that PFG-NMR is a simple yet powerful method to quantify interactions between polymers and lipid bilayers.
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Affiliation(s)
- Wenjia Zhang
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Karen J. Haman
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Joseph M. Metzger
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Benjamin J. Hackel
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Frank S. Bates
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Timothy P. Lodge
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
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8
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Effect of three pluronic polymers on the transport of an organic cation across a POPG bilayer studied by Second Harmonic spectroscopy. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2017.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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9
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Kim M, Haman KJ, Houang EM, Zhang W, Yannopoulos D, Metzger JM, Bates FS, Hackel BJ. PEO-PPO Diblock Copolymers Protect Myoblasts from Hypo-Osmotic Stress In Vitro Dependent on Copolymer Size, Composition, and Architecture. Biomacromolecules 2017; 18:2090-2101. [PMID: 28535058 DOI: 10.1021/acs.biomac.7b00419] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Poloxamer 188, a triblock copolymer of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO), protects cellular membranes from various stresses. Though numerous block copolymer variants exist, evaluation of alternative architecture, composition, and size has been minimal. Herein, cultured murine myoblasts are exposed to the stresses of hypotonic shock and isotonic recovery, and membrane integrity was evaluated by quantifying release of lactate dehydrogenase. Comparative evaluation of a systematic set of PEO-PPO diblock and PEO-PPO-PEO triblock copolymers demonstrates that the diblock architecture can be protective in vitro. Short PPO blocks hinder protection with >9 PPO units needed for protection at 150 μM and >16 units needed at 14 μM. Addition of a tert-butyl end group enhances protection at reduced concentration. When the end group and PPO length are fixed, increasing the PEO length improves protection. This systematic evaluation establishes a new in vitro screening tool for evaluating membrane-sealing amphiphiles and provides mechanistic insight to guide future copolymer design for membrane stabilization in vivo.
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Affiliation(s)
- Mihee Kim
- Department of Chemical Engineering and Materials Science, ‡Department of Integrative Biology and Physiology, and §Department of Medicine, Cardiovascular Division, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Karen J Haman
- Department of Chemical Engineering and Materials Science, ‡Department of Integrative Biology and Physiology, and §Department of Medicine, Cardiovascular Division, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Evelyne M Houang
- Department of Chemical Engineering and Materials Science, ‡Department of Integrative Biology and Physiology, and §Department of Medicine, Cardiovascular Division, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Wenjia Zhang
- Department of Chemical Engineering and Materials Science, ‡Department of Integrative Biology and Physiology, and §Department of Medicine, Cardiovascular Division, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Demetris Yannopoulos
- Department of Chemical Engineering and Materials Science, ‡Department of Integrative Biology and Physiology, and §Department of Medicine, Cardiovascular Division, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Joseph M Metzger
- Department of Chemical Engineering and Materials Science, ‡Department of Integrative Biology and Physiology, and §Department of Medicine, Cardiovascular Division, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Frank S Bates
- Department of Chemical Engineering and Materials Science, ‡Department of Integrative Biology and Physiology, and §Department of Medicine, Cardiovascular Division, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Benjamin J Hackel
- Department of Chemical Engineering and Materials Science, ‡Department of Integrative Biology and Physiology, and §Department of Medicine, Cardiovascular Division, University of Minnesota , Minneapolis, Minnesota 55455, United States
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Abstract
The increasing number of new chemical entities is bringing new challenges to the field of drug delivery. These drugs present bioavailability issues that are frequently associated with intestinal metabolism or efflux mechanisms. Some excipients, particularly surfactants, have demonstrated a capacity to interfere with these mechanisms, improving drug bioavailability. Consequently, these excipients can no longer be considered as inert and should be subject to special considerations from a regulatory perspective. In the present manuscript, the state-of-the-art research related to these abilities of excipients to interfere with intestinal metabolism and efflux mechanisms are presented and discussed. Here, a biopharmaceutical classification system of excipients is proposed for the first time as a tool in the development of new products and for regulatory purposes.
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11
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Ileri Ercan N, Stroeve P, Tringe JW, Faller R. Understanding the Interaction of Pluronics L61 and L64 with a DOPC Lipid Bilayer: An Atomistic Molecular Dynamics Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:10026-10033. [PMID: 27623289 DOI: 10.1021/acs.langmuir.6b02360] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We investigate the interactions of Pluronics L61 and L64 with a dioleylphosphatidylcholine (DOPC) lipid bilayer by atomistic molecular dynamics simulations using the all-atom OPLS force field. Our results show that the initial configuration of the polymer with respect to the bilayer determines its final conformation within the bilayer. When the polymer is initially placed at the lipid/water interface, we observe partial insertion of the polymer in a U-shaped conformation. On the other hand, when the polymer is centered at the bilayer, it stabilizes to a transmembrane state, which facilitates water transport across the bilayer. We show that membrane thickness decreases while its fluidity increases in the presence of Pluronics. When the polymer concentration inside the bilayer is high, pore formation is initiated with L64. Our results show good agreement with existing experimental data and reveal that the hydrophilic/lipophilic balance of the polymer plays a critical role in the interaction mechanisms as well as in the dynamics of Pluronics with and within the bilayer.
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Affiliation(s)
- Nazar Ileri Ercan
- Chemical Engineering Department, University of California, Davis , One Shields Avenue, Davis, California 95616, United States
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94551, United States
- Chemical Engineering Department, Bogazici University , Bebek, 34342 Istanbul, Turkey
| | - Pieter Stroeve
- Chemical Engineering Department, University of California, Davis , One Shields Avenue, Davis, California 95616, United States
| | - Joseph W Tringe
- Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94551, United States
| | - Roland Faller
- Chemical Engineering Department, University of California, Davis , One Shields Avenue, Davis, California 95616, United States
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12
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Elder DP, Kuentz M, Holm R. Pharmaceutical excipients — quality, regulatory and biopharmaceutical considerations. Eur J Pharm Sci 2016; 87:88-99. [DOI: 10.1016/j.ejps.2015.12.018] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 11/25/2015] [Accepted: 12/11/2015] [Indexed: 12/27/2022]
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13
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Yan L, Higbee E, Tsourkas A, Cheng Z. A simple method for the synthesis of porous polymeric vesicles and their application as MR contrast agents. J Mater Chem B 2015; 3:9277-9284. [PMID: 26693022 DOI: 10.1039/c5tb02067k] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Because of their low membrane permeability the use of polymeric vesicles in certain drug delivery and molecular imaging applications and as bioreactors is less than ideal. Here, we report a simple method to prepare porous polymeric vesicles that possess high membrane permeability. Specifically, porous vesicles were produced from the aqueous assembly of the diblock copolymer PEG-PBD, and the triblock copolymer PEG-PPO-PEG. It was found that PEG-PPO-PEG-doped polymersomes exhibited improved membrane permeability to molecules less than 5 kDa. Further, these porous vesicles retained molecules ≥10 kDa within their aqueous interiors with no significant leakage. To demonstrate its application, highly efficient magnetic resonance contrast agents were produced from porous polymersomes by encapsulating macromolecules labeled with gadolinium. Due to a fast water exchange rate with surrounding bulk water, these paramagnetic porous polymersomes exhibited higher r1 relaxivity compared with Gd-encapsulated vesicles with no pores. Due to their simplicity, the porous polymersomes prepared with this method are expected to have additional useful applications.
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Affiliation(s)
- Lesan Yan
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Elizabeth Higbee
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Andrew Tsourkas
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Zhiliang Cheng
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
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14
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Kwag DS, Park K, Youn YS, Lee ES. Facile synthesis of partially uncapped liposomes. Colloids Surf B Biointerfaces 2015; 135:143-149. [DOI: 10.1016/j.colsurfb.2015.07.050] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2015] [Revised: 07/16/2015] [Accepted: 07/20/2015] [Indexed: 11/29/2022]
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15
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Sosnik A, Menaker Raskin M. Polymeric micelles in mucosal drug delivery: Challenges towards clinical translation. Biotechnol Adv 2015; 33:1380-92. [PMID: 25597531 DOI: 10.1016/j.biotechadv.2015.01.003] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 01/06/2015] [Accepted: 01/10/2015] [Indexed: 12/19/2022]
Abstract
Polymeric micelles are nanostructures formed by the self-aggregation of copolymeric amphiphiles above the critical micellar concentration. Due to the flexibility to tailor different molecular features, they have been exploited to encapsulate motley poorly-water soluble therapeutic agents. Moreover, the possibility to combine different amphiphiles in one single aggregate and produce mixed micelles that capitalize on the features of the different components substantially expands the therapeutic potential of these nanocarriers. Despite their proven versatility, polymeric micelles remain elusive to the market and only a few products are currently undergoing advanced clinical trials or reached clinical application, all of them for the therapy of different types of cancer and administration by the intravenous route. At the same time, they emerge as a nanotechnology platform with great potential for non-parenteral mucosal administration. However, for this, the interaction of polymeric micelles with mucus needs to be strengthened. The present review describes the different attempts to develop mucoadhesive polymeric micelles and discusses the challenges faced in the near future for a successful bench-to-bedside translation.
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Affiliation(s)
- Alejandro Sosnik
- Laboratory of Pharmaceutical Nanomaterials Science, Department of Materials Science and Engineering, Technion-Israel Institute of Technology, Haifa, Israel.
| | - Maya Menaker Raskin
- Laboratory of Pharmaceutical Nanomaterials Science, Department of Materials Science and Engineering, Technion-Israel Institute of Technology, Haifa, Israel
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16
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Interactions between active pharmaceutical ingredients and excipients affecting bioavailability: Impact on bioequivalence. Eur J Pharm Sci 2014; 65:89-97. [DOI: 10.1016/j.ejps.2014.09.004] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 09/04/2014] [Accepted: 09/04/2014] [Indexed: 01/29/2023]
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17
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Tirotta I, Dichiarante V, Pigliacelli C, Cavallo G, Terraneo G, Bombelli FB, Metrangolo P, Resnati G. (19)F magnetic resonance imaging (MRI): from design of materials to clinical applications. Chem Rev 2014; 115:1106-29. [PMID: 25329814 DOI: 10.1021/cr500286d] [Citation(s) in RCA: 340] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Ilaria Tirotta
- Laboratory of Nanostructured Fluorinated Materials (NFMLab), Department of Chemistry, Materials, and Chemical Engineering "Giulio Natta" and ‡Fondazione Centro Europeo Nanomedicina, Politecnico di Milano , Milan 20131, Italy
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18
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Rahman M, Yu E, Forman E, Roberson-Mailloux C, Tung J, Tringe J, Stroeve P. Modified release from lipid bilayer coated mesoporous silica nanoparticles using PEO-PPO-PEO triblock copolymers. Colloids Surf B Biointerfaces 2014; 122:818-822. [PMID: 25200097 DOI: 10.1016/j.colsurfb.2014.08.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 08/05/2014] [Accepted: 08/12/2014] [Indexed: 10/24/2022]
Abstract
Triblock copolymers comprised of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO, or trade name Pluronic) interact with lipid bilayers to increase their permeability. Here we demonstrate a novel application of Pluronic L61 and L64 as modification agents in tailoring the release rate of a molecular indicator species from 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) bilayer-coated superparamagnetic Fe3O4/mesoporous silica core-shell nanoparticles. We show there is a direct relationship between the Pluronics' concentration and the indicator molecule release, suggesting Pluronics may be useful for the controlled release of drugs from lipid bilayer-coated carriers.
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Affiliation(s)
- Masoud Rahman
- Department of Chemical Engineering and Materials Science, University of California Davis, Davis, CA 95616, USA
| | - Erick Yu
- Department of Chemical Engineering and Materials Science, University of California Davis, Davis, CA 95616, USA
| | - Evan Forman
- Department of Chemical Engineering and Materials Science, University of California Davis, Davis, CA 95616, USA
| | - Cameron Roberson-Mailloux
- Department of Chemical Engineering and Materials Science, University of California Davis, Davis, CA 95616, USA
| | - Jonathan Tung
- Department of Chemical Engineering and Materials Science, University of California Davis, Davis, CA 95616, USA
| | - Joseph Tringe
- Lawrence Livermore National Laboratory, Livermore, CA 94550, USA
| | - Pieter Stroeve
- Department of Chemical Engineering and Materials Science, University of California Davis, Davis, CA 95616, USA.
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19
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Abstract
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Multidrug
resistance (MDR) remains one of the biggest obstacles
for effective cancer therapy. Currently there are only few methods
that are available clinically that are used to bypass MDR with very
limited success. In this review we describe how MDR can be overcome
by a simple yet effective approach of using amphiphilic block copolymers.
Triblock copolymers of poly(ethylene oxide) (PEO) and poly(propylene
oxide) (PPO), arranged in a triblock structure PEO-PPO-PEO, Pluronics
or “poloxamers”, raised a considerable interest in the
drug delivery field. Previous studies demonstrated that Pluronics
sensitize MDR cancer cells resulting in increased cytotoxic activity
of Dox, paclitaxel, and other drugs by 2–3 orders of magnitude.
Pluronics can also prevent the development of MDR in vitro and in vivo. Additionally, promising results of
clinical studies of Dox/Pluronic formulation reinforced the need to
ascertain a thorough understanding of Pluronic effects in tumors.
These effects are extremely comprehensive and appear on the level
of plasma membranes, mitochondria, and regulation of gene expression
selectively in MDR cancer cells. Moreover, it has been demonstrated
recently that Pluronics can effectively deplete tumorigenic intrinsically
drug-resistant cancer stem cells (CSC). Interestingly, sensitization
of MDR and inhibition of drug efflux transporters is not specific
or selective to Pluronics. Other amphiphilic polymers have shown similar
activities in various experimental models. This review summarizes
recent advances of understanding the Pluronic effects in sensitization
and prevention of MDR.
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Affiliation(s)
- Daria Y Alakhova
- Center for Nanotechnology in Drug Delivery and Division of Molecular Pharmaceutics, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599-7362, United States
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20
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Bondar OV, Badeev YV, Shtyrlin YG, Abdullin TI. Lipid-like trifunctional block copolymers of ethylene oxide and propylene oxide: effective and cytocompatible modulators of intracellular drug delivery. Int J Pharm 2013; 461:97-104. [PMID: 24239835 DOI: 10.1016/j.ijpharm.2013.11.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Accepted: 11/01/2013] [Indexed: 11/19/2022]
Abstract
A new glycerol-based trifunctional block copolymer (TBC) of propylene oxide and ethylene oxide and its conjugate with succinic acid (TBC-SA) were studied as a drug delivery system and compared with Pluronic L61. TBCs have multiple effects on the plasma membrane of human cells, e.g. increasing its fluidity and ion permeability, inhibiting ATPase activity of efflux transporter P-glycoprotein through reversible membrane destabilization. Such membrane-modulating properties attributed to the unimer form of copolymers increase in the order Pluronic L61≪TBC<TBC-SA and correlate with an ability of TBCs to promote the accumulation of P-glycoprotein substrates in lung cancer A549 cells. Furthermore, TBC, and especially TBC-SA, exhibit substantially lower hemolytic, cytotoxic and proapoptotic activities in comparison with Pluronic L61. Our results demonstrate that TBCs are promising analogs of bifunctional Pluronics in anticancer drug delivery.
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Affiliation(s)
- Oksana V Bondar
- Kazan (Volga Region) Federal University, 18 Kremlyovskaya Street, 420008 Kazan, Russia
| | - Yuriy V Badeev
- Kazan (Volga Region) Federal University, 18 Kremlyovskaya Street, 420008 Kazan, Russia
| | - Yurii G Shtyrlin
- Kazan (Volga Region) Federal University, 18 Kremlyovskaya Street, 420008 Kazan, Russia
| | - Timur I Abdullin
- Kazan (Volga Region) Federal University, 18 Kremlyovskaya Street, 420008 Kazan, Russia.
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21
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Sosnik A. Reversal of multidrug resistance by the inhibition of ATP-binding cassette pumps employing "Generally Recognized As Safe" (GRAS) nanopharmaceuticals: A review. Adv Drug Deliv Rev 2013; 65:1828-51. [PMID: 24055628 DOI: 10.1016/j.addr.2013.09.002] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 09/06/2013] [Accepted: 09/10/2013] [Indexed: 12/17/2022]
Abstract
Pumps of the ATP-binding cassette superfamily (ABCs) regulate the access of drugs to the intracellular space. In this context, the overexpression of ABCs is a well-known mechanism of multidrug resistance (MDR) in cancer and infectious diseases (e.g., viral hepatitis and the human immunodeficiency virus) and is associated with therapeutic failure. Since their discovery, ABCs have emerged as attractive therapeutic targets and the search of compounds that inhibit their genetic expression and/or their functional activity has gained growing interest. Different generations of pharmacological ABC inhibitors have been explored over the last four decades to address resistance in cancer, though clinical results have been somehow disappointing. "Generally Recognized As Safe" (GRAS) is a U.S. Food and Drug Administration designation for substances that are accepted as safe for addition in food. Far from being "inert", some amphiphilic excipients used in the production of pharmaceutical products have been shown to inhibit the activity of ABCs in MDR tumors, emerging as a clinically translatable approach to overcome resistance. The present article initially overviews the classification, structure and function of the different ABCs, with emphasis on those pumps related to drug resistance. Then, the different attempts to capitalize on the activity of GRAS nanopharmaceuticals as ABC inhibitors are discussed.
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Affiliation(s)
- Alejandro Sosnik
- The Group of Biomaterials and Nanotechnology for Improved Medicines (BIONIMED), Department of Pharmaceutical Technology, Faculty of Pharmacy and Biochemistry, University of Buenos Aires, Argentina; National Science Research Council (CONICET), Argentina; Department of Materials Science and Engineering, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel.
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22
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Hezaveh S, Samanta S, De Nicola A, Milano G, Roccatano D. Understanding the interaction of block copolymers with DMPC lipid bilayer using coarse-grained molecular dynamics simulations. J Phys Chem B 2012; 116:14333-45. [PMID: 23137298 DOI: 10.1021/jp306565e] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
In this paper, we present a computational model of the adsorption and percolation mechanism of poloxamers (poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) triblock copolymers) across a 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) lipid bilayer. A coarse-grained model was used to cope with the long time scale of the percolation process. The simulations have provided details of the interaction mechanism of Pluronics with lipid bilayer. In particular, the results have shown that polymer chains containing a PPO block with a length comparable to the DMPC bilayer thickness, such as P85, tends to percolate across the lipid bilayer. On the contrary, Pluronics with a shorter PPO chain, such as L64 and F38, insert partially into the membrane with the PPO block part while the PEO blocks remain in water on one side of the lipid bilayer. The percolation of the polymers into the lipid tail groups reduces the membrane thickness and increases the area per lipid. These effects are more evident for P85 than L64 or F38. Our findings are qualitatively in good agreement with published small-angle X-ray scattering experiments that have evidenced a thinning effect of Pluronics on the lipid bilayer as well as the role of the length of the PPO block on the permeation process of the polymer through the lipid bilayer. Our theoretical results complement the experimental data with a detailed structural and dynamic model of poloxamers at the interface and inside the lipid bilayer.
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Affiliation(s)
- Samira Hezaveh
- Jacobs University Bremen, Campus Ring 1, D-28759 Bremen, Germany
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23
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Polyethylenimine-modified pluronics (PCMs) improve morpholino oligomer delivery in cell culture and dystrophic mdx mice. Mol Ther 2012; 21:210-6. [PMID: 23164938 DOI: 10.1038/mt.2012.236] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
We investigated a series of small-sized polyethylenimine (PEI, 0.8/1.2 k)-conjugated pluronic copolymers (PCMs) for their potential to enhance delivery of an antisense phosphorodiamidate morpholino oligomer (PMO) in vitro and in dystrophic mdx mice. PCM polymers containing pluronics of molecular weight (Mw) ranging 2-6 k, with hydrophilic-lipophilic balance (HLB) 7-23, significantly enhanced PMO-induced exon-skipping in a green fluorescent protein (GFP) reporter-based myoblast culture system. Application of optimized formulations of PCMs with PMO targeted to dystrophin exon 23 demonstrated a significant increase in exon-skipping efficiency in dystrophic mdx mice. Consistent with our observations in vitro, optimization of molecular size and the HLB of pluronics are important factors for PCMs to achieve enhanced PMO delivery in vivo. Observed cytotoxicity of the PCMs was lower than Endo-porter and PEI 25 k. Tissue toxicity of PCMs in muscle was not clearly detected with the concentrations used, indicating the potential of the PCMs as effective and safe PMO carriers for treating diseases such as muscular dystrophy.
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24
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Wang JY, Marks J, Lee KYC. Nature of interactions between PEO-PPO-PEO triblock copolymers and lipid membranes: (I) effect of polymer hydrophobicity on its ability to protect liposomes from peroxidation. Biomacromolecules 2012; 13:2616-23. [PMID: 22808900 PMCID: PMC3689593 DOI: 10.1021/bm300847x] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PEO-PPO-PEO triblock copolymers have opposing effects on lipid membrane integrity: they can behave either as membrane sealants or as membrane permeabilizers. To gain insights into their biomembrane activities, the fundamental interactions between a series of PEO-based polymers and phospholipid vesicles were investigated. Specifically, the effect of copolymer hydrophobicity on its ability to prevent liposomes from peroxidation was evaluated, and partitioning free energy and coefficient involved in the interactions were derived. Our results show that the high degree of hydrophilicity is a key feature of the copolymers that can effectively protect liposomes from peroxidation and the protective effect of the copolymers stems from their adsorption at the membrane surface without penetrating into the bilayer core. The origin of this protective effect induced by polymer absorption is attributed to the retardation of membrane hydration dynamics, which is further illustrated in the accompanying study on dynamic nuclear polarization (DNP)-derived hydration dynamics (Cheng, C.-Y.; Wang, J.-Y.; Kausik, R.; Lee, K. Y. C.; Han S. Biomacromolecules, 2012, DOI: 10.1021/bm300848c).
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Affiliation(s)
- Jia-Yu Wang
- Department of Chemistry, Institute for Biophysical Dynamics & James Franck Institute, the University of Chicago, Illinois 60637
| | - Jeremy Marks
- Department of Pediatrics, the University of Chicago, Illinois 60637
| | - Ka Yee C. Lee
- Department of Chemistry, Institute for Biophysical Dynamics & James Franck Institute, the University of Chicago, Illinois 60637
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25
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Amado E, Kressler J. Interactions of amphiphilic block copolymers with lipid model membranes. Curr Opin Colloid Interface Sci 2011. [DOI: 10.1016/j.cocis.2011.07.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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26
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Alvarez-Lorenzo C, Rey-Rico A, Brea J, Loza MI, Concheiro A, Sosnik A. Inhibition of P-glycoprotein pumps by PEO–PPO amphiphiles: branched versus linear derivatives. Nanomedicine (Lond) 2010; 5:1371-83. [DOI: 10.2217/nnm.10.53] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Inhibition of the activity of efflux transporters may relevantly improve the chemotherapy of cancer and infectious diseases. Aim: To explore the ability of poloxamines (Tetronic®, X-shaped structure with a central ethylendiamine group and four branches of poly[ethylene oxide]–poly[propylene oxide] [PEO–PPO]) to inhibit the activity of P-glycoprotein (P-gp) on Caco-2 cell monolayers and to elucidate the incidence of the molecular architecture of PEO–PPO block copolymers on the intracellular accumulation of a relevant substrate, doxorubicin, by comparison with poloxamers (Pluronic®, linear triblock copolymers), well-known inhibitors of this efflux transporter. Methods: Both pristine and N-methylated poloxamines displaying a wide range of molecular weights and EO/PO ratios were tested regarding cytocompatibility and accumulation of doxorubicin in Caco-2 monolayers. Verapamil was used as a control. Results: The most active anti-P-gp poloxamines (which enhanced two- to three-fold doxorubicin accumulation compared with verapamil) resulted to be pristine medium-to-high hydrophobic T304, T904, T1301, T901 and T150R1. A notable dependence of the anti-P-gp activity on the copolymer concentration was found. A joint diagram of the inhibitory activity of poloxamers and poloxamines as a function of the effective length of the PPO block is proposed. Conclusion: The anti-P-gp activity is maxima for block copolymers possessing a low-to-medium hydrophilic–lipophilic balance and an ‘effective number’ of PO units ranging from 30 to 50.
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Affiliation(s)
- Carmen Alvarez-Lorenzo
- Departamento de Farmacia y Tecnología Farmacéutica, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain
- Instituto de Farmacia Industrial, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain
| | - Ana Rey-Rico
- Departamento de Farmacia y Tecnología Farmacéutica, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain
- Instituto de Farmacia Industrial, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain
| | - Jose Brea
- Instituto de Farmacia Industrial, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain
- Departamento de Farmacología, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain
| | - Maria Isabel Loza
- Instituto de Farmacia Industrial, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain
- Departamento de Farmacología, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain
| | - Angel Concheiro
- Departamento de Farmacia y Tecnología Farmacéutica, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain
- Instituto de Farmacia Industrial, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782-Santiago de Compostela, Spain
| | - Alejandro Sosnik
- The Group of Biomaterials & Nanotechnologies for Improved Medicines (BIONIMED), Department of Pharmaceutical Technology, Faculty of Pharmacy & Biochemistry, University of Buenos Aires, Argentina; Department of Pharmaceutical Technology, Faculty of Pharmacy & Biochemistry, University of Buenos Aires, 956 Junín St., 6th Floor, Buenos Aires CP1113, Argentina
- National Science Research Council (CONICET), 1113-Buenos Aires, Argentina
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27
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The effects of excipients on transporter mediated absorption. Int J Pharm 2010; 393:17-31. [DOI: 10.1016/j.ijpharm.2010.04.019] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Revised: 04/09/2010] [Accepted: 04/16/2010] [Indexed: 12/16/2022]
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28
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Srinivas M, Heerschap A, Ahrens ET, Figdor CG, de Vries IJM. (19)F MRI for quantitative in vivo cell tracking. Trends Biotechnol 2010; 28:363-70. [PMID: 20427096 DOI: 10.1016/j.tibtech.2010.04.002] [Citation(s) in RCA: 207] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2010] [Revised: 03/25/2010] [Accepted: 04/02/2010] [Indexed: 02/06/2023]
Abstract
Cellular therapy, including stem cell transplants and dendritic cell vaccines, is typically monitored for dosage optimization, accurate delivery, and localization using noninvasive imaging, of which magnetic resonance imaging (MRI) is a key modality. (19)F MRI retains the advantages of MRI as an imaging modality, and also allows direct detection of labeled cells for unambiguous identification and quantification, unlike typical metal-based contrast agents. Recent developments in (19)F MRI-based in vivo cell quantification, the existing clinical use of (19)F compounds and current explosive interest in cellular therapeutics have brought (19)F imaging technology closer to clinical application. We review the application of (19)F MRI to cell tracking, discussing intracellular (19)F labels, cell labeling and in vivo quantification, as well as the potential clinical uses of (19)F MRI.
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Affiliation(s)
- Mangala Srinivas
- Department of Tumor Immunology, Radboud University Nijmegen Medical Centre, 6500 HB Nijmegen, The Netherlands
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29
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Illy N, Bacri L, Wojno J, Destouches D, Brissault B, Courty J, Auvray L, Penelle J, Barbier V. Unexpected Interactions of an Alternating Poly(ether-ester) with Artificial and Biological Bilipidic Membranes. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/masy.201050109] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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30
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Alakhova DY, Rapoport NY, Batrakova EV, Timoshin AA, Li S, Nicholls D, Alakhov VY, Kabanov AV. Differential metabolic responses to pluronic in MDR and non-MDR cells: a novel pathway for chemosensitization of drug resistant cancers. J Control Release 2009; 142:89-100. [PMID: 19815037 DOI: 10.1016/j.jconrel.2009.09.026] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2009] [Revised: 09/06/2009] [Accepted: 09/29/2009] [Indexed: 12/13/2022]
Abstract
A synthetic amphiphilic block copolymer, Pluronic, is a potent chemosensitizer of multidrug resistant (MDR) cancers that has shown promise in clinical trials. It has unique activities in MDR cells, which include a decrease in ATP pools and inhibition of P-glycoprotein (Pgp) resulting in increased drug accumulation in cells. This work demonstrates that Pluronic rapidly (15min) translocates into MDR cells and co-localizes with the mitochondria. It inhibits complex I and complex IV of the mitochondria respiratory chain, decreases oxygen consumption and causes ATP depletion in MDR cells. These effects are selective and pronounced for MDR cells compared to non-MDR counterparts and demonstrated for both drug-selected and Pgp-transfected cell models. Furthermore, inhibition of Pgp functional activity also abolishes the effects of Pluronic on intracellular ATP levels in MDR cells suggesting that Pgp contributes to increased responsiveness of molecular "targets" of Pluronic in the mitochondria of MDR cells. The Pluronic-caused impairment of respiration in mitochondria of MDR cells is accompanied with a decrease in mitochondria membrane potential, production of ROS, and release of cytochrome c. Altogether these effects eventually enhance drug-induced apoptosis and contribute to potent chemosensitization of MDR tumors by Pluronic.
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Affiliation(s)
- Daria Yu Alakhova
- Center for Drug Delivery and Nanomedicine and Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, NE 68198-5830, United States
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31
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Amado E, Blume A, Kressler J. Novel non-ionic block copolymers tailored for interactions with phospholipids. REACT FUNCT POLYM 2009. [DOI: 10.1016/j.reactfunctpolym.2008.12.021] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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32
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Savić R, Eisenberg A, Maysinger D. Block copolymer micelles as delivery vehicles of hydrophobic drugs: Micelle–cell interactions. J Drug Target 2008; 14:343-55. [PMID: 17092835 DOI: 10.1080/10611860600874538] [Citation(s) in RCA: 154] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
One-third of drugs in development are water insoluble and one-half fail in trials because of poor pharmacokinetics. Block copolymer micelles are nanosized particles that can solubilize hydrophobic drugs and alter their kinetics in vitro and in vivo. However, block copolymer micelles are not solely passive drug containers that simply solubilize hydrophobic drugs; cells internalize micelles. To facilitate the development of advanced, controlled, micellar drug delivery vehicles, we have to understand the fate of micelles and micelle-incorporated drugs in cells and in vivo. With micelle-based drug formulations recently reaching clinical trials, the impetus for answers is ever so strong and detailed studies of interactions of micelles and cells are starting to emerge. Most notably, the question arises: Is the internalization of block copolymer micelles carrying small molecular weight drugs an undesired side effect or a useful means of improving the effectiveness of the incorporated drugs?
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Affiliation(s)
- Radoslav Savić
- Department of Pharmacology & Therapeutics, McGill University, Montreal, Quebec, Canada
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33
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Hartikka J, Geall A, Bozoukova V, Kurniadi D, Rusalov D, Enas J, Yi JH, Nanci A, Rolland A. Physical characterization and in vivo evaluation of poloxamer-based DNA vaccine formulations. J Gene Med 2008; 10:770-82. [PMID: 18425981 DOI: 10.1002/jgm.1199] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Plasmid DNA (pDNA) vaccines have generated significant interest for the prevention or treatment of infectious diseases. Broader applications may benefit from the identification of safe and potent vaccine adjuvants. This report describes the development of a novel polymer-based formulation to enhance the immunogenicity of pDNA-based vaccines. METHODS Plasmid DNA was formulated with a nonionic block copolymer, poloxamer CRL1005, and the cationic surfactant benzalkonium chloride (BAK) to produce a thermodynamically stable, self-assembling system. The influence of parameters such as polymer concentration and BAK composition on the immune responses was evaluated in mice vaccinated with pDNA encoding influenza nucleoprotein. RESULTS At concentrations of 7.5 mg/ml CRL1005, 0.3 mM BAK and 5 mg/ml pDNA, CRL1005/BAK/pDNA particles had a mean diameter of 261 +/- 0.2 nm and a surface charge of - 11.6 +/- 0.9 mV. The negative surface charge and atomic force microscopy images suggested that pDNA binds to BAK adsorbed to the surface of poloxamer particles. The CRL1005/BAK/pDNA formulation significantly enhanced antigen-specific cellular and humoral immune responses, and increased transgene levels in muscle and serum. The complexity of the formulation was reduced by replacing the commercial BAK, which is a mixture of four alkyl chains, with a C14 BAK homolog. The substitution yielded an analytically preferable formulation with equivalent physical characteristics and immunogenicity. CONCLUSIONS The results suggest that the CRL1005/BAK/pDNA formulation may enhance immunogenicity by improving the delivery of pDNA-based vaccines. This formulation is currently being evaluated for the prevention of CMV-associated disease in a phase 2 clinical trial.
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Affiliation(s)
- Jukka Hartikka
- Vical Incorporated, 10390 Pacific Center Court, San Diego, CA 92121-4340, USA.
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34
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Amado E, Kerth A, Blume A, Kressler J. Infrared reflection absorption spectroscopy coupled with Brewster angle microscopy for studying interactions of amphiphilic triblock copolymers with phospholipid monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:10041-10053. [PMID: 18698867 DOI: 10.1021/la801768m] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Novel water-soluble amphiphilic triblock copolymers poly(glycerol monomethacrylate)-b-poly(propylene oxide)-b-poly(glycerol monomethacrylate) (PGMA-b-PPO-b-PGMA) were synthesized because of their expected enhanced ability to interact with biological membranes compared to the well-known poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (PEO-b-PPO-b-PEO) block copolymers. Their bulkier hydrophilic PGMA blocks might induce a disturbance in the packing of liquid-crystalline lipid bilayers in addition to the effect caused by the hydrophobic PPO block alone. To gain a better insight into the polymer-membrane interactions at the molecular level, the adsorption kinetics and concomitant interactions of (PGMA14)(2-)PPO(34) with model membranes of dipalmitoylphosphatidylcholine (DPPC) and dimyristoylphosphatidylcholine (DMPC) were monitored using infrared reflection absorption spectroscopy (IRRAS) coupled with Brewster angle microscopy (BAM) and surface pressure (pi) measurements. The maximum penetration surface pressure of ca. 39 mN/m suggests that (PGMA14)(2-)PPO(34) is able to insert into lipid monolayers even above the so-called monolayer-bilayer equivalent pressure of 30-35 mN/m. Copolymer adsorption to a liquid-expanded DPPC-d62 monolayer proceeds in a two-step mechanism: (i) initially only the more hydrophobic PPO middle block penetrates the lipid monolayer; (ii) following the liquid-expanded-liquid-condensed (LE-LC) phase transition, the bulky PGMA hydrophilic blocks are dragged into the headgroup region as the PPO block inserts further into the fatty acid region. The adsorption kinetics is considerably faster for DMPC-d54 monolayers due to their higher fluidity. Copolymer adsorption to an LC-DPPC-d62 monolayer leads to a change in the monolayer packing by forcing the lipid alkyl chains into a more vertical orientation, their tilt angle with respect to the surface normal being reduced from initially 30 degrees +/- 3 degrees to 18 degrees +/- 3 degrees. BAM images rule out macroscopic phase separation and show that coalescence of DPPC-d62 LC domains takes place at relatively low surface pressures of pi > or = 23 mN/m, suggesting that (PGMA14)(2-)PPO (34) partitions into both LE as well as LC domains.
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Affiliation(s)
- Elkin Amado
- Department of Chemistry, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
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Sommer K, Kaiser S, Krylova OO, Kressler J, Pohl P, Busse K. Influence of amphiphilic block copolymer induced changes in membrane ion conductance on the reversal of multidrug resistance. J Med Chem 2008; 51:4253-9. [PMID: 18588278 DOI: 10.1021/jm800177c] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Block copolymers are able to reverse multidrug resistance (MDR) of tumor cells by a yet unknown mechanism. The drug efflux system's direct and indirect inhibition mediated by polymer P-glycoprotein (Pgp) interactions or adenosine triphosphate (ATP) depletion, respectively, may be involved in MDR reversal as well as damage to the membrane barrier caused by polymer insertion into the membrane. To test the latter hypothesis, cellular drug accumulation was monitored in the presence of both overexpressed fluorescently labeled Pgp and different block copolymers. Therefore, a new triblock copolymer (poly(ethylene oxide)- block-poly(hexafluoropropylene oxide)- block-poly(ethylene oxide)) was designed and synthesized by combined polymerization and polymer analogous reaction. Its administration induced drug uptake, whereas control cells with high Pgp expression levels showed no drug accumulation. Drug uptake was even more pronounced in the presence of another triblock copolymer: (poly(perfluorohexylethyl methacrylate)- block-poly(ethylene oxide)- block-poly(perfluorohexylethyl methacrylate). The latter polymer's lack of ionophoric activity suggests that ion transport facilitation by polymers is not a determinative factor for MDR reversal.
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Affiliation(s)
- Klaus Sommer
- Johannes Kepler Universitat, Fachbereich Physik, Institut fur Biophysik, Altenbergerstrasse 69, 4040 Linz, Austria
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Gau-Racine J, Lal J, Zeghal M, Auvray L. PEO−PPO Block Copolymer Vectors Do Not Interact Directly with DNA but with Lipid Membranes. J Phys Chem B 2007; 111:9900-7. [PMID: 17661502 DOI: 10.1021/jp0687302] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Small angle neutron (SANS) and light scattering was used to study the interaction between fragments of double stranded deoxyribonucleic acid (DNA) and a synthetic triblock [poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide)] amphiphilic polymer, known as L64, a potential vector for gene therapy. The mechanism of action of this vector is yet unknown. The contrast variation method was used to separate the partial structure factors of the different components in mixtures of triblock and DNA. It has been found that the copolymer and DNA molecules exhibit repulsive interactions. Further, the interaction between the copolymer and a model lipid membrane was investigated in order to explain the action of the vector. Electrical measurements on black lipid membranes indicated that the main effect of L64 as a vector is to permeabilize the cell's membrane.
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Affiliation(s)
- Jocelyne Gau-Racine
- Laboratoire MPI-LRP, UMR CNRS 7581, Université d'Evry Val d'Essonne, 91025 Evry cedex, France.
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Seelig A, Gerebtzoff G. Enhancement of drug absorption by noncharged detergents through membrane and P-glycoprotein binding. Expert Opin Drug Metab Toxicol 2006; 2:733-52. [PMID: 17014392 DOI: 10.1517/17425255.2.5.733] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Noncharged detergents are used as excipients in drug formulations. Until recently, they were considered as inert compounds, enhancing drug absorption essentially by improving drug solubility. However, many detergents insert into lipid membranes, although to different extents, and change the lateral packing density of membranes at high concentrations. Moreover, they bind to the efflux transporter P-glycoprotein (P-gp) and most likely to related transporters and metabolising enzymes with overlapping substrate specificities. If their affinity to P-gp is higher than that of the coadministered drug they act as modulators or inhibitors of P-gp and enhance drug absorption. Inhibition of P-gp and related proteins can, however, cause severe side effects. This paper first reviews the membrane binding propensity of different noncharged detergents (including poloxamers) and discusses their ability to bind to P-gp. Second, literature data on drug uptake enhancement by noncharged detergents, obtained in vivo and in vitro, are analysed at the molecular level. The present analysis provides the tools for an approximate and simple prior estimate of the membrane and P-gp binding ability of noncharged detergents based on a modular binding approach.
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Affiliation(s)
- Anna Seelig
- Biozentrum, Biophysical Chemistry, University of Basel, Klingelbergstrasse 70, CH-4057 Basel, Switzerland.
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Abstract
This critical review covers synthetic ion channels and pores created between January 2004 and December 2005 comprehensively. The discussion of a rich collection of structural motifs may particularly appeal to organic, biological, supramolecular and polymer chemists. Functions addressed include ion selectivity and molecular recognition, as well as responsiveness to light, heat, voltage and membrane composition. The practical applications involved concern certain topics in medicinal chemistry (antibiotics, drug delivery), catalysis and sensing. An introduction to principles and methods is provided for the non-specialist; some new sources of inspiration from fields beyond chemistry are highlighted.
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Affiliation(s)
- Adam L Sisson
- Department of Organic Chemistry, University of Geneva, Geneva, Switzerland
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Valeeva Y, Dorodnykh T, Alexandrova N, Zubin E, Kachalova A, Volkov E, Gottikh M, Melik-Nubarov N. Block copolymers of Pluronics and poly-(2-dimethylamino+ethyl methacrylate) for delivery of oligonucleotides into tumor cells. J Drug Deliv Sci Technol 2006. [DOI: 10.1016/s1773-2247(06)50046-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Sutachan JJ, Montoya G JV, Xu F, Chen D, Blanck TJJ, Recio-Pinto E. Pluronic F-127 affects the regulation of cytoplasmic Ca2+ in neuronal cells. Brain Res 2006; 1068:131-7. [PMID: 16387285 DOI: 10.1016/j.brainres.2005.11.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2005] [Revised: 10/31/2005] [Accepted: 11/09/2005] [Indexed: 01/28/2023]
Abstract
Fura-2 is one of the most widely used cytoplasmic Ca2+ ([Ca2+]cyt) sensors. In studies using isolated dorsal root ganglion (DRG) neurons, the loading of Fura-2 AM is often facilitated by the use of pluronic F-127. In preliminary studies, we detected that the use of pluronic F-127 appeared to be affecting the depolarization-evoked [Ca2+]cyt transient in DRG neurons. To determine whether this was the case, we conducted a systematic study. Adult rat DRG neurons were cultured, and their response to 50 mM KCl was measured in sister cultured cells (isolated on the same day) that were loaded with 5 microM Fura-2AM in the absence or in the presence of 0.02% pluronic F-127. In the absence of pluronic F-127, the KCl-evoked [Ca2+]cyt transient changed with time, being wider on day 1 than on day 2 after plating. On day 2, the KCl-evoked [Ca2+]cyt transient was wider in neurons Fura-2 loaded in the presence of pluronic F-127. These results indicate that pluronic F-127 significantly alters depolarization-evoked [Ca2+]cyt transients, which may reflect alteration in regulation of [Ca2+]cyt in neuronal cells.
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Affiliation(s)
- Jhon-Jairo Sutachan
- Department of Anesthesiology, New York University School of Medicine, 550 First Avenue, RR605, New York, NY 10016, USA
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Pavlov D, Alexandrova N, Krylova O, Pohl P, Melik-Nubarov N. Effect of block architecture on the ability of polyalkylene oxides to overcome multidrug resistance of tumor cells. J Drug Deliv Sci Technol 2006. [DOI: 10.1016/s1773-2247(06)50048-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Exner AA, Krupka TM, Scherrer K, Teets JM. Enhancement of carboplatin toxicity by Pluronic block copolymers. J Control Release 2005; 106:188-97. [PMID: 15951044 DOI: 10.1016/j.jconrel.2005.04.015] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2005] [Revised: 04/25/2005] [Accepted: 04/26/2005] [Indexed: 11/20/2022]
Abstract
The objective of this study was to examine the effects of three Pluronic triblock copolymers (F127, P85, or L61) on the cytotoxicity of carboplatin to the DHB/K12/TRb rat colorectal carcinoma cell line. Studies to determine the dependence of the sensitization effect on Pluronic dose were carried out for polymer concentrations ranging from 0.0001-10% (w/w). To establish the carboplatin toxicity and its potential enhancement by Pluronic, the drug was delivered to cells in doses ranging from 0-0.5% (w/w) in the presence of Pluronic at a constant concentration. These treatment groups were compared to control groups receiving carboplatin alone. Cell cytotoxicity resulting from the treatments was determined with a mitochondrial enzyme activity assay (WST-1), while cell morphology was examined with May-Grünwald and Giemsa staining. Results indicate that the greatest enhancement of carboplatin toxicity was induced by P85, where the inhibitory concentration (IC(50)) was reduced by 50% (from 0.096 mg/mL for carboplatin alone to 0.048 mg/mL in presence of P85). L61 was toxic to the cells with or without drug (viability<3.5%), while F127 exhibited no sensitizing effect and in some cases increased the cell viability to 130% over the untreated control. The WST-1 results were confirmed by trypan blue exclusion cell counts at 0 and 24 h post treatment. Data conclusively demonstrate that Pluronic P85 is the optimal agent for increased cytotoxicity of carboplatin in this cell line and can potentially be used not only as a drug delivery scheme but also as a chemosensitizing agent in future cancer therapy.
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Affiliation(s)
- Agata A Exner
- Department of Radiology, University Hospitals of Cleveland, Case Western Reserve University School of Medicine, 11100 Euclid Avenue, Cleveland, OH 44106-5056, USA.
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Kabanov A, Zhu J, Alakhov V. Pluronic Block Copolymers for Gene Delivery. NON-VIRAL VECTORS FOR GENE THERAPY, SECOND EDITION: PART 1 2005; 53PA:231-261. [PMID: 16243066 DOI: 10.1016/s0065-2660(05)53009-8] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Amphiphilic block copolymers of poly(ethylene oxide) and poly(propylene oxide) called Pluronic or poloxamer are commercially available pharmaceutical excipients. They recently attracted considerable attention in gene delivery applications. First, they were shown to increase the transfection with adenovirus and lentivirus vectors. Second, they were shown to increase expression of genes delivered into cells using non-viral vectors. Third, the conjugates of Pluronic with polycations, were used as DNA-condensing agents to form polyplexes. Finally, it was demonstrated that they can increase regional expression of the naked DNA after its injection in the skeletal and cardiac muscles or tumor. Therefore, there is substantial evidence that Pluronic block copolymers can improve gene expression with different delivery routes and different types of vectors, including naked DNA. These results and possible mechanisms of Pluronic effects are discussed. At least in some cases, Pluronic can act as biological adjuvants by activating selected signaling pathways, such as NF-kappaB, and upregulating the transcription of the genes.
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Affiliation(s)
- Alexander Kabanov
- Department of Pharmaceutical Sciences and Center for Drug Delivery and Nanomedicine, College of Pharmacy, University of Nebraska Medical Center Omaha, Nebraska 68198
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Melik-Nubarov N, Krylova O. The Control of Membrane Properties by Synthetic Polymers. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/s1554-4516(05)02005-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
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