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Timmers EM, Fransen PM, González García Á, Schoenmakers SMC, Magana JR, Peeters JW, Tennebroek R, van Casteren I, Tuinier R, Janssen HM, Voets IK. Co-assembly of precision polyurethane ionomers reveals role of and interplay between individual components. Polym Chem 2021; 12:2891-2903. [PMID: 34046093 PMCID: PMC8129887 DOI: 10.1039/d1py00079a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 03/25/2021] [Indexed: 11/21/2022]
Abstract
Industrial and household products, such as paints, inks and cosmetics usually consist of mixtures of macromolecules that are disperse in composition, in size and in monomer sequence. Identifying structure-function relationships for these systems is complicated, as particular macromolecular components cannot be investigated individually. For this study, we have addressed this issue, and have synthesized a series of five sequence-defined polyurethanes (PUs): one neutral-hydrophobic, one single-charged hydrophilic, one single-charged hydrophobic and two double-charged amphiphilic PUs (one symmetric and one asymmetric). These novel precision PUs - that were prepared by using stepwise coupling-deprotection synthetic protocols - have a defined composition, size and monomer sequence, where the chosen sequences were inspired by those that are abundantly formed in the production of industrial waterborne PU dispersions. By performing dynamic light scattering experiments (DLS), self-consistent field (SCF) computations and cryogenic transmission electron microscopy (cryo-TEM), we have elucidated the behavior in aqueous solution of the individual precision PUs, as well as of binary and ternary mixtures of the PU sequences. The double-charged PU sequences ('hosts') were sufficiently amphiphilic to yield single-component micellar solutions, whereas the two more hydrophobic sequences did not micellize on their own, and gave precipitates or ill-defined larger aggregates. Both the neutral-hydrophobic PU and the hydrophilic single-charged PU were successfully incorporated in the host micelles as guests, respectively increasing and reducing the micelle radius upon incorporation. SCF computations indicated that double-charged symmetric PUs stretch whilst double-charged asymmetric PUs are expelled from the core to accommodate hydrophobic PU guests within the micelles. For the ternary mixture of the double-charged symmetric and asymmetric hosts and the neutral-hydrophobic guest we have found an improved colloidal stability, as compared to those for binary mixtures of either host and hydrophobic guest. In another ternary mixture of precision PUs, with all three components not capable of forming micelles on their own, we see that the ensemble of molecules produces stable micellar solutions. Taken together, we find that the interplay between PU-molecules in aqueous dispersions promotes the formation of stable micellar hydrocolloids.
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Affiliation(s)
- Elizabeth M Timmers
- Laboratory of Self-Organizing Soft Matter, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven The Netherlands
- Laboratory of Macro-Organic Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven The Netherlands
- Institute for Complex Molecular Systems, Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven The Netherlands
| | | | - Álvaro González García
- Institute for Complex Molecular Systems, Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven The Netherlands
- Laboratory of Physical Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven The Netherlands
- Van 't Hoff Laboratory for Physical and Colloid Chemistry, Department of Chemistry and Debye Institute for Nanomaterials Science, Utrecht University Padualaan 8 3584 CH Utrecht The Netherlands
| | - Sandra M C Schoenmakers
- Laboratory of Macro-Organic Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven The Netherlands
- Institute for Complex Molecular Systems, Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven The Netherlands
| | - Jose Rodrigo Magana
- Laboratory of Self-Organizing Soft Matter, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven The Netherlands
- Laboratory of Macro-Organic Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven The Netherlands
- Institute for Complex Molecular Systems, Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven The Netherlands
| | - Joris W Peeters
- SyMO-Chem B.V. Den Dolech 2 5612 AZ Eindhoven The Netherlands
| | - Ronald Tennebroek
- DSM Resins and Functional Materials Sluisweg 12 5145 PE Waalwijk The Netherlands
| | - Ilse van Casteren
- DSM Resins and Functional Materials Sluisweg 12 5145 PE Waalwijk The Netherlands
| | - Remco Tuinier
- Institute for Complex Molecular Systems, Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven The Netherlands
- Laboratory of Physical Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven The Netherlands
- Van 't Hoff Laboratory for Physical and Colloid Chemistry, Department of Chemistry and Debye Institute for Nanomaterials Science, Utrecht University Padualaan 8 3584 CH Utrecht The Netherlands
| | - Henk M Janssen
- SyMO-Chem B.V. Den Dolech 2 5612 AZ Eindhoven The Netherlands
| | - Ilja K Voets
- Laboratory of Self-Organizing Soft Matter, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven The Netherlands
- Institute for Complex Molecular Systems, Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven The Netherlands
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Timmers E, Fransen PM, Magana JR, Janssen HM, Voets IK. Micellization of Sequence-Controlled Polyurethane Ionomers in Mixed Aqueous Solvents. Macromolecules 2021; 54:2376-2382. [PMID: 33814615 PMCID: PMC8016144 DOI: 10.1021/acs.macromol.0c02107] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 12/28/2020] [Indexed: 12/22/2022]
Abstract
While the impact of compositional parameters such as block length and ionic content on the micellization of (polymeric) amphiphiles is widely investigated, the influence of monomer sequence has received far less attention until recently. Here, we report the synthesis of two sequence-controlled polyurethane ionomers (PUIs) prepared via a stepwise coupling-deprotection strategy, and compare their solution association in aqueous-organic mixtures. The two PUIs are highly similar in mass and overall composition, yet differ markedly in the sequence of building blocks. PUI-A2 comprises a polytetrahydrofuran (pTHF) block connected to an alternation of isophorone diamine (IPDA) and dimethylolpropionic acid (DMPA) units that together are also arranged in a blockwise manner. The result is a macromolecular structure with a comparatively hydrophobic tail (pTHF) and a hydrophilic headgroup, which structure is reminiscent of those of traditional surfactants, albeit much larger in size. PUI-S2 instead resembles a bolaamphiphilic architecture with a pTHF midblock connected on either end to a singly charged segment comprising DMPA and IPDA. We detect micellization below a threshold cosolvent volume fraction (φsolv) of 0.4 in aqueous-organic mixtures with tetrahydrofuran (THF), ethanol, and isopropyl alcohol. We use scattering tools to compare the aggregation number (N agg) and hydrodynamic radius (R h) of PUI-S2 and PUI-A2 micelles. Irrespective of the solvent composition, we observe in the micellar window of φsolv < 0.4, lower N agg for PUI-S2 micelles compared to PUI-A2, which we attribute to packing restraints associated with its bolaamphiphilic architecture. The increase in micellar size with increasing φsolv is much more pronounced for PUI-S2 than for PUI-A2. The micellar mass decreases with increasing φsolv for both PUIs; the effect is modest for PUI-S2 compared to PUI-A2 and is not observed in the most apolar cosolvent studied (THF). Upon the approach of the micellization boundary φsolv ≈ 0.4, both types of PUI micelles become less compact in structure, as (in most cases) PUIs are released and as micellar dimensions increase.
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Affiliation(s)
- Elizabeth
M. Timmers
- Laboratory
of Self-Organizing Soft Matter, Department of Chemical Engineering
and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands
- Laboratory
of Macro-Organic Chemistry, Department of Chemical Engineering and
Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands
- Institute
for Complex Molecular Systems, Eindhoven
University of Technology, 5600MB Eindhoven, The Netherlands
| | - P. Michel Fransen
- Laboratory
of Macro-Organic Chemistry, Department of Chemical Engineering and
Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands
- SyMO-Chem
B.V., Den Dolech 2, 5612 AZ Eindhoven, The Netherlands
| | - Jose Rodrigo Magana
- Laboratory
of Self-Organizing Soft Matter, Department of Chemical Engineering
and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands
- Laboratory
of Macro-Organic Chemistry, Department of Chemical Engineering and
Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands
- Institute
for Complex Molecular Systems, Eindhoven
University of Technology, 5600MB Eindhoven, The Netherlands
| | - Henk M. Janssen
- Laboratory
of Macro-Organic Chemistry, Department of Chemical Engineering and
Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands
- SyMO-Chem
B.V., Den Dolech 2, 5612 AZ Eindhoven, The Netherlands
| | - Ilja K. Voets
- Laboratory
of Self-Organizing Soft Matter, Department of Chemical Engineering
and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands
- Laboratory
of Macro-Organic Chemistry, Department of Chemical Engineering and
Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands
- Institute
for Complex Molecular Systems, Eindhoven
University of Technology, 5600MB Eindhoven, The Netherlands
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Timmers EM, Magana JR, Schoenmakers SMC, Fransen PM, Janssen HM, Voets IK. Sequence of Polyurethane Ionomers Determinative for Core Structure of Surfactant-Copolymer Complexes. Int J Mol Sci 2020; 22:E337. [PMID: 33396960 PMCID: PMC7795199 DOI: 10.3390/ijms22010337] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/20/2020] [Accepted: 12/23/2020] [Indexed: 01/04/2023] Open
Abstract
The core of micelles self-assembled from amphiphiles is hydrophobic and contains little water, whereas complex coacervate core micelles co-assembled from oppositely charged hydrophilic polymers have a hydrophilic core with a high water content. Co-assembly of ionic surfactants with ionic-neutral copolymers yields surfactant-copolymer complexes known to be capable of solubilizing both hydrophilic and hydrophobic cargo within the mixed core composed of a coacervate phase with polyelectrolyte-decorated surfactant micelles. Here we formed such complexes from asymmetric (PUI-A2) and symmetric (PUI-S2), sequence-controlled polyurethane ionomers and poly(N-methyl-2-vinylpyridinium iodide)29-b-poly(ethylene oxide)204 copolymers. The complexes with PUI-S2 were 1.3-fold larger in mass and 1.8-fold larger in radius of gyration than the PUI-A2 complexes. Small-angle X-ray scattering revealed differences in the packing of the similarly sized PUI micelles within the core of the complexes. The PUI-A2 micelles were arranged in a more ordered fashion and were spaced further apart from each other (10 nm vs. 6 nm) than the PUI-S2 micelles. Hence, this work shows that the monomer sequence of amphiphiles can be varied to alter the internal structure of surfactant-copolymer complexes. Since the structure of the micellar core may affect both the cargo loading and release, our findings suggest that these properties may be tuned through control of the monomer sequence of the micellar constituents.
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Affiliation(s)
- Elizabeth M. Timmers
- Laboratory of Self-Organizing Soft Matter, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands; (E.M.T.); (J.R.M.)
- Laboratory of Macro-Organic Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands;
- Institute for Complex Molecular Systems, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Jose Rodrigo Magana
- Laboratory of Self-Organizing Soft Matter, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands; (E.M.T.); (J.R.M.)
- Laboratory of Macro-Organic Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands;
- Institute for Complex Molecular Systems, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Sandra M. C. Schoenmakers
- Laboratory of Macro-Organic Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands;
- Institute for Complex Molecular Systems, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - P. Michel Fransen
- SyMO-Chem B.V., Den Dolech 2, 5612 AZ Eindhoven, The Netherlands; (P.M.F.); (H.M.J.)
| | - Henk M. Janssen
- SyMO-Chem B.V., Den Dolech 2, 5612 AZ Eindhoven, The Netherlands; (P.M.F.); (H.M.J.)
| | - Ilja K. Voets
- Laboratory of Self-Organizing Soft Matter, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands; (E.M.T.); (J.R.M.)
- Laboratory of Macro-Organic Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands;
- Institute for Complex Molecular Systems, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
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Shalgunov V, van Wieringen JP, Janssen HM, Fransen PM, Dierckx RAJO, Michel MC, Booij J, Elsinga PH. Synthesis and evaluation in rats of homologous series of [(18)F]-labeled dopamine D 2/3 receptor agonists based on the 2-aminomethylchroman scaffold as potential PET tracers. EJNMMI Res 2015. [PMID: 26205538 PMCID: PMC4512978 DOI: 10.1186/s13550-015-0119-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Background Agonist positron emission tomography (PET) tracers for dopamine D2/3 receptors (D2/3Rs) offer greater sensitivity to changes in endogenous dopamine levels than D2/3R antagonist tracers. D2/3R agonist tracers currently available for clinical research are labeled with the short-lived isotope carbon-11, which limits their use. We aimed to develop high-affinity D2R agonists amenable for labeling with the longer-living fluorine-18. Here, we report the evaluation as potential PET tracers of two homologous series of [18F]fluorinated tracers based on the 2-aminomethylchroman-7-ol (AMC) scaffold: (R)-2-((4-(2-fluoroalkoxy)benzylamino)methyl)chroman-7-ols (AMC13 homologues) and (R)-2-((2-(4-(4-(fluoroalkoxy)phenyl)piperazin-1-yl)ethylamino)methyl)chroman-7-ols (AMC15 homologues). We varied the length of the 18F-fluoroalkyl chain in these structures to balance brain penetration and non-specific binding of the radioligands by adjusting their lipophilicity. Methods The tracers were evaluated in brain slices of Sprague-Dawley rats by in vitro autoradiography and in living rats by microPET imaging and ex vivo autoradiography. PET data were analyzed with one- and two-tissue compartmental models (1TCM/2TCM), simplified reference tissue model (SRTM), and Logan graphical analysis. Specificity of binding was tested by blocking D2/3R with raclopride. Results Homologues with a shorter fluoroalkyl chain consistently showed greater D2/3R-specific-to-total binding ratios in the striatum than those with longer chains. The fluoroethoxy homologue of AMC13 ([18F]FEt-AMC13) demonstrated the highest degree of D2/3R-specific binding among the evaluated tracers: mean striatum-to-cerebellum uptake ratio reached 4.4 in vitro and 2.1/2.8 in vivo/ex vivo (PET/autoradiography). Striatal binding potential (BPND) relative to cerebellum was 0.51–0.63 depending on the estimation method. Radiometabolites of [18F]FEt-AMC13 did not enter the brain. In vitro, application of 10 μmol/L raclopride reduced D2/3R-specific binding of [18F]FEt-AMC13 in the striatum by 81 %. In vivo, pre-treatment with 1 mg/kg (2.9 μmol/kg) raclopride led to 17–39 % decrease in D2/3R-specific binding in the striatum. Conclusions Varying the length of the [18F]fluoroalkyl chain helped improve the characteristics of the original candidate tracers. Further modifications of the current lead [18F]FEt-AMC13 can provide an agonist radiopharmaceutical suitable for D2/3R imaging by PET. Electronic supplementary material The online version of this article (doi:10.1186/s13550-015-0119-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Vladimir Shalgunov
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands,
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Shalgunov V, van Wieringen JP, Janssen HM, Fransen PM, Dierckx RAJO, Michel MC, Booij J, Elsinga PH. Synthesis and evaluation in rats of the dopamine D2/3 receptor agonist 18F-AMC20 as a potential radioligand for PET. J Nucl Med 2014; 56:133-9. [PMID: 25476538 DOI: 10.2967/jnumed.114.145466] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
UNLABELLED Dopamine D(2/3) receptor (D(2/3)R) agonist PET tracers are better suited for the imaging of synaptic dopaminergic neurotransmission than D(2/3)R antagonists and may also offer the opportunity to study in vivo the high-affinity state of D(2/3)R (D(2/3)RHigh). With the aim to develop (18)F-labeled D2/3R agonists suitable for widespread clinical application, we report here on the synthesis and in vitro and in vivo evaluation of a D(2/3)R agonist ligand from the aminomethyl chromane (AMC) class-(R)-2-[(4-(18)F-fluorobenzylamino)methyl]chroman-7-ol ((18)F- AMC20: ). METHODS In vitro affinities of AMC20: toward dopaminergic receptor subtypes were measured in membrane homogenates prepared from HEK293 cells expressing human dopamine receptors. Agonism of AMC20: was assessed in the arrestin recruitment assay in Chinese hamster ovary-K(1) cells expressing the long isoform of D(2)R (D(2)RLong). D(2/3)R-specific binding of (18)F- AMC20: was evaluated in brain slices of Sprague-Dawley rats by in vitro autoradiography and in living rats by in vivo small-animal PET imaging and ex vivo autoradiography. PET data were analyzed with 1- and 2-tissue compartmental models, the simplified reference tissue model, and Logan graphical analysis. Specificity of binding was tested by blocking D(2/3)R with raclopride (coincubation with 10 μM in vitro, administration of 1.0 mg/kg in vivo). RESULTS In membrane homogenates, AMC20: demonstrated picomolar affinity at D(2)RHigh (mean inhibition constant [K(i)] = 85 pM) and excellent selectivity against the low-affinity state of D(2)R (D(2)RLow) (mean K(i) = 84 nM, 988-fold selectivity) and D(1)-like receptors (mean K(i) = 5,062 nM at D1R). The efficacy of AMC20: was 90% of that of dopamine in the arrestin recruitment assay. Up to 70% of total binding of (18)F- AMC20: in the D2/3R-rich striatum in rat brain slices was D(2/3)R-specific; in living rats, the uptake ratio between the striatum and the D(2/3)R-poor cerebellum reached 2.0-2.5, depending on the measurement method. Radiometabolites of (18)F- AMC20: did not enter the brain. Striatal binding potential of (18)F- AMC20: varied between 0.49 and 0.59 depending on the estimation method. Pretreatment with 1 mg of raclopride per kilogram reduced the apparent specific binding of (18)F- AMC20: in the striatum. CONCLUSION (18)F- AMC20: shows specific binding to D(2/3)R in the striatum of living rats. Further optimization of the chemical structure of (18)F- AMC20: can lead to (18)F-labeled D(2/3) agonist PET tracers more suitable for in vivo clinical application.
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Affiliation(s)
- Vladimir Shalgunov
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Jan-Peter van Wieringen
- Department of Nuclear Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | | | | | - Rudi A J O Dierckx
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Martin C Michel
- Department of Pharmacology, Johannes Gutenberg University, Mainz, Germany
| | - Jan Booij
- Department of Nuclear Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Philip H Elsinga
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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van Wieringen JP, Shalgunov V, Janssen HM, Fransen PM, Janssen AGM, Michel MC, Booij J, Elsinga PH. Synthesis and characterization of a novel series of agonist compounds as potential radiopharmaceuticals for imaging dopamine D₂/₃ receptors in their high-affinity state. J Med Chem 2014; 57:391-410. [PMID: 24325578 DOI: 10.1021/jm401384w] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Imaging of dopamine D2/3 receptors (D2/3R) can shed light on the nature of several neuropsychiatric disorders in which dysregulation of D2/3R signaling is involved. Agonist D2/3 tracers for PET/SPECT imaging are considered to be superior to antagonists because they are more sensitive to dopamine concentrations and may selectively label the high-affinity receptor state. Carbon-11-labeled D2/3R agonists have been developed, but these short-lived tracers can be used only in centers with a cyclotron. Here, we report the development of a series of novel D2R agonist compounds based on the 2-aminomethylchromane (AMC) scaffold that provides ample opportunities for the introduction of longer-lived [(18)F] or [(123)I]. Binding experiments showed that several AMC compounds have a high affinity and selectivity for D2/3R and act as agonists. Two fluorine-containing compounds were [(18)F]-labeled, and both displayed specific binding to striatal D2/3R in rat brain slices in vitro. These findings encourage further in vivo evaluations.
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Affiliation(s)
- Jan-Peter van Wieringen
- Department of Nuclear Medicine, Academic Medical Center, University of Amsterdam , Amsterdam, The Netherlands
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Orselli E, Albuquerque RQ, Fransen PM, Fröhlich R, Janssen HM, De Cola L. 1,2,3-Triazolyl-pyridine derivatives as chelating ligands for blue iridium(iii) complexes. Photophysics and electroluminescent devices. ACTA ACUST UNITED AC 2008. [DOI: 10.1039/b805324c] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Tack F, Bakker A, Maes S, Dekeyser N, Bruining M, Elissen-Roman C, Janicot M, Janssen HM, De Waal BFM, Fransen PM, Lou X, Meijer EW, Arien A, Brewster ME. Dendrimeric poly(propylene-imines) as effective delivery agents for DNAzymes: dendrimer synthesis, stability and oligonucleotide complexation. J Control Release 2007; 116:e24-6. [PMID: 17718950 DOI: 10.1016/j.jconrel.2006.09.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- F Tack
- Oncology Discovery Research and Early Development, Johnson and Johnson Pharmaceutical Research and Development, Beerse, Belgium
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Tack F, Bakker A, Maes S, Dekeyser N, Bruining M, Elissen-Roman C, Janicot M, Brewster M, Janssen HM, De Waal BFM, Fransen PM, Lou X, Meijer EW. Modified poly(propylene imine) dendrimers as effective transfection agents for catalytic DNA enzymes (DNAzymes). J Drug Target 2006; 14:69-86. [PMID: 16608734 DOI: 10.1080/10611860600635665] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The major bottleneck in gene therapy remains the issue of delivery. In this work, various modified poly(propylene imine) (PPI) dendrimers are introduced as gene transfection agents. Commercially available PPI-dendrimers have been modified (i) at the exterior primary amines with acetyl groups or glycol gallate (PEG-like) groups, and (ii) at the interior tertiary amines with methyl iodide (MeI) or MeCl to produce multiple quaternized cationic sites in the core of the dendrimer. The prepared materials have been tested with respect to their binding capabilities to DNA, their toxicity in cell cultures, their in vitro transfection efficiency and their in vivo delivery possibilities. In all cases, a 33-mer oligonucleotide (DNAzyme) was used. Polyacrylamide gel electrophoresis (PAGE) studies have demonstrated strong but reversible binding, where the quarternized and higher generation dendrimer species have shown more potent binding. Typically, for the modified fourth PPI-dendrimers, binding is observed at a concentration of about 4 microM DNA and a dendrimer-DNA charge ratio of around 2:1-1:1. All the tested PPI-dendrimers display a low cellular toxicity, especially when higher serum contents are used in the culture medium. For example, most of the prepared fourth generation PPI-dendrimers are not or hardly toxic up to at least 20 microM in 20% serum. An in vitro characterization has revealed a high dendrimer-mediated intracellular uptake of the DNAzyme: all the tested fourth generation PPI-dendrimers display transfection efficiencies close to or exceeding 80%, even when the concentration of serum in the medium is increased from 10 to 40%. Finally, the potential of using modified PPI-dendrimers for in vivo gene therapy experiments is demonstrated. Injecting a G4-PEG(MeI)-ssDNA complex intravenously into Nude mice has resulted in a high nuclear uptake as confirmed by co-localization studies.
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Affiliation(s)
- Frederik Tack
- Erasmus University, Department of Experimental Surgical Oncology, Rotterdam, The Netherlands
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