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Hoerres R, Hennkens HM. 1,4,7-Triazacyclononane-Based Chelators for the Complexation of [ 186Re]Re- and [ 99mTc]Tc-Tricarbonyl Cores. Inorg Chem 2023; 62:20688-20698. [PMID: 37683190 PMCID: PMC10732151 DOI: 10.1021/acs.inorgchem.3c01934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Indexed: 09/10/2023]
Abstract
Metal complexes with the general formula [MI(CO)3(k3-L)]+, where M = Re, 186Re, or 99mTc and L = 1,4,7-triazacyclononane (TACN), NOTA, or NODAGA chelators, have previously been conjugated to peptide-based biological targeting vectors and investigated as potential theranostic radiopharmaceuticals. The promising results demonstrated by these bioconjugate complexes prompted our exploration of other TACN-based chelators for suitability for (radio)labeling with the [M(CO)3]+ core. In this work, we investigated the role of the TACN pendant arms in complexation of the [M(CO)3]+ core through (radio)labeling of TACN chelators bearing acid, ester, mixed acid-ester, or no pendant functional groups. The chelators were synthesized from TACN, characterized, and (radio)labeled with nonradioactive Re-, [186Re]Re-, and [99mTc]Tc-tricarbonyl cores. The nonfunctionalized (3), diacid (4), and monoacid monoester (7 and 8) chelators underwent direct labeling, while the diester (M-5 and M-6) complexes required indirect synthesis from M-4. All six chelators demonstrated stable radiometal coordination. The ester-bearing derivatives, which exhibited more lipophilic character than their acid-bearing counterparts, were prone to ester hydrolysis over time, making them less suitable for radiopharmaceutical development. These studies confirmed that the TACN pendant functional groups were key to efficient labeling with the [M(CO)3]+ core, with ionizable pendant arms favored over nonionizable pendant arms.
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Affiliation(s)
- Rebecca Hoerres
- Department
of Chemistry, University of Missouri, Columbia, Missouri 65211, United States
| | - Heather M. Hennkens
- Department
of Chemistry, University of Missouri, Columbia, Missouri 65211, United States
- Research
Reactor Center, University of Missouri, Columbia, Missouri 65211, United States
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Qiao Z, Xu J, Gonzalez R, Miao Y. Effects of Polyethylene Glycol and 8-Aminooctanoic Acid Linkers on Melanoma Uptake of [ 99mTc]Tc-Tricarbonyl-NOTA-Conjugated Lactam-Cyclized α-MSH Peptides. Bioconjug Chem 2023; 34:934-940. [PMID: 37140963 PMCID: PMC10192115 DOI: 10.1021/acs.bioconjchem.3c00164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The purpose of this study was to evaluate the effect of linkers on tumor targeting and biodistribution of [99mTc]Tc(CO)3-NOTA-PEG2Nle-CycMSHhex {[99mTc]Tc(CO)3-1,4,7-triazacyclononane-1,4,7-triyl-triacetic acid-polyethylene glycol-Nle-c[Asp-His-d-Phe-Arg-Trp-Lys]-CONH2} and [99mTc]Tc(CO)3-NOTA-AocNle-CycMSHhex {[99mTc]Tc(CO)3-NOTA-8-aminooctanoic acid-Nle-CycMSHhex} on B16/F10 melanoma-bearing mice. NOTA-PEG2Nle-CycMSHhex and NOTA-AocNle-CycMSHhex were synthesized and radiolabeled with [99mTc]Tc via the {[99mTc]Tc(CO)3(OH2)3}+ intermediate. The biodistribution of [99mTc]Tc(CO)3-NOTA-PEG2Nle-CycMSHhex and [99mTc]Tc(CO)3-NOTA-AocNle-CycMSHhex was determined on B16/F10 melanoma-bearing C57 mice. The melanoma imaging property of [99mTc]Tc(CO)3-NOTA-PEG2Nle-CycMSHhex was determined on B16/F10 melanoma-bearing C57 mice. [99mTc]Tc(CO)3-NOTA-PEG2Nle-CycMSHhex and [99mTc]Tc(CO)3-NOTA-AocNle-CycMSHhex were readily prepared with more than 90% radiochemical yields and exhibited MC1R-specific binding on B16/F10 melanoma cells. [99mTc]Tc(CO)3-NOTA-PEG2Nle-CycMSHhex exhibited a higher tumor uptake than [99mTc]Tc(CO)3-NOTA-AocNle-CycMSHhex at 2, 4, and 24 h postinjection. The tumor uptake of [99mTc]Tc(CO)3-NOTA-PEG2Nle-CycMSHhex was 13.63 ± 1.13, 31.93 ± 2.57, 20.31 ± 3.23, and 1.33 ± 0.15% ID/g at 0.5, 2, 4, and 24 h postinjection, respectively. The tumor uptake of [99mTc]Tc(CO)3-NOTA-PEG2Nle-CycMSHhex was 1.6 and 3.4 times the tumor uptake of [99mTc]Tc(CO)3-NOTA-AocNle-CycMSHhex at 2 and 4 h postinjection, respectively. Meanwhile, the normal organ uptake of [99mTc]Tc(CO)3-NOTA-PEG2Nle-CycMSHhex was lower than 1.8% ID/g at 2 h postinjection. The renal uptake of [99mTc]Tc(CO)3-NOTA-PEG2Nle-CycMSHhex was only 1.73 ± 0.37, 0.73 ± 0.14, and 0.03 ± 0.01% ID/g at 2, 4, and 24 h postinjection, respectively. [99mTc]Tc(CO)3-NOTA-PEG2Nle-CycMSHhex showed high tumor to normal organ uptake ratios at 2 h postinjection. Single-photon emission computed tomography imaging revealed that the B16/F10 melanoma lesions could be clearly visualized by [99mTc]Tc(CO)3-NOTA-PEG2Nle-CycMSHhex at 2 h postinjection. Overall, the high tumor uptake and low kidney uptake of [99mTc]Tc(CO)3-NOTA-PEG2Nle-CycMSHhex highlighted its potential for melanoma imaging and warranted the future evaluation of [188Re]Re(CO)3-NOTA-PEG2Nle-CycMSHhex for melanoma therapy.
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Affiliation(s)
- Zheng Qiao
- Department of Radiology, University of Colorado Denver, Aurora, CO 80045, USA
| | - Jingli Xu
- Department of Radiology, University of Colorado Denver, Aurora, CO 80045, USA
| | - Rene Gonzalez
- Department of Medical Oncology, University of Colorado Denver, Aurora, CO 80045, USA
| | - Yubin Miao
- Department of Radiology, University of Colorado Denver, Aurora, CO 80045, USA
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Sidorenko GV, Miroslavov AE, Tyupina MY. Technetium(I) carbonyl complexes for nuclear medicine: Coordination-chemical aspect. Coord Chem Rev 2023. [DOI: 10.1016/j.ccr.2022.214911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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4
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Crișan G, Moldovean-Cioroianu NS, Timaru DG, Andrieș G, Căinap C, Chiș V. Radiopharmaceuticals for PET and SPECT Imaging: A Literature Review over the Last Decade. Int J Mol Sci 2022; 23:ijms23095023. [PMID: 35563414 PMCID: PMC9103893 DOI: 10.3390/ijms23095023] [Citation(s) in RCA: 60] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2022] [Revised: 04/23/2022] [Accepted: 04/28/2022] [Indexed: 02/04/2023] Open
Abstract
Positron emission tomography (PET) uses radioactive tracers and enables the functional imaging of several metabolic processes, blood flow measurements, regional chemical composition, and/or chemical absorption. Depending on the targeted processes within the living organism, different tracers are used for various medical conditions, such as cancer, particular brain pathologies, cardiac events, and bone lesions, where the most commonly used tracers are radiolabeled with 18F (e.g., [18F]-FDG and NA [18F]). Oxygen-15 isotope is mostly involved in blood flow measurements, whereas a wide array of 11C-based compounds have also been developed for neuronal disorders according to the affected neuroreceptors, prostate cancer, and lung carcinomas. In contrast, the single-photon emission computed tomography (SPECT) technique uses gamma-emitting radioisotopes and can be used to diagnose strokes, seizures, bone illnesses, and infections by gauging the blood flow and radio distribution within tissues and organs. The radioisotopes typically used in SPECT imaging are iodine-123, technetium-99m, xenon-133, thallium-201, and indium-111. This systematic review article aims to clarify and disseminate the available scientific literature focused on PET/SPECT radiotracers and to provide an overview of the conducted research within the past decade, with an additional focus on the novel radiopharmaceuticals developed for medical imaging.
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Affiliation(s)
- George Crișan
- Faculty of Physics, Babeş-Bolyai University, Str. M. Kogălniceanu 1, 400084 Cluj-Napoca, Romania; (G.C.); (N.S.M.-C.); (D.-G.T.)
- Department of Nuclear Medicine, County Clinical Hospital, Clinicilor 3-5, 400006 Cluj-Napoca, Romania;
| | | | - Diana-Gabriela Timaru
- Faculty of Physics, Babeş-Bolyai University, Str. M. Kogălniceanu 1, 400084 Cluj-Napoca, Romania; (G.C.); (N.S.M.-C.); (D.-G.T.)
| | - Gabriel Andrieș
- Department of Nuclear Medicine, County Clinical Hospital, Clinicilor 3-5, 400006 Cluj-Napoca, Romania;
| | - Călin Căinap
- The Oncology Institute “Prof. Dr. Ion Chiricuţă”, Republicii 34-36, 400015 Cluj-Napoca, Romania;
| | - Vasile Chiș
- Faculty of Physics, Babeş-Bolyai University, Str. M. Kogălniceanu 1, 400084 Cluj-Napoca, Romania; (G.C.); (N.S.M.-C.); (D.-G.T.)
- Institute for Research, Development and Innovation in Applied Natural Sciences, Babeș-Bolyai University, Str. Fântânele 30, 400327 Cluj-Napoca, Romania
- Correspondence:
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Charles A, Khosrashahi FN, Ma L, Munindradasa C, Hoerres R, Lydon JD, Kelley SP, Guthrie J, Rotsch D, Medvedev D, Cutler CS, Li Y, Wilbur DS, Hennkens HM, Jurisson SS. Evaluation of 186WS 2 target material for production of high specific activity 186Re via proton irradiation: separation, radiolabeling and recovery/recycling. RADIOCHIM ACTA 2022. [DOI: 10.1515/ract-2021-1138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Enriched tungsten disulfide (186WS2) was evaluated at increasing proton beam currents (20–50 μA) and times (up to 4 h) on a GE PETtrace cyclotron for production of high specific activity (HSA) 186Re. The HSA 186Re was separated from the irradiated target as [186Re][ReO4]– by a liquid–liquid extraction method and radiolabeled with a new N2S2 ligand (222-MAMA-N-ethylpropionate). The enriched 186W was recovered from the extraction process, analyzed for purity and enrichment, and converted back to the disulfide (186WS2). The results demonstrate that the 186WS2 is an easily pressed target material that can withstand relatively high currents and can be readily recovered and recycled. The 186Re produced was isolated in high specific activity and readily formed the radiotracers [186Re][ReO(222-MAMA-N-ethylpropionate)] and [186Re][Re(CO)3(OH2)3] +.
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Affiliation(s)
- Anster Charles
- Department of Chemistry , University of Missouri , Columbia , MO , USA
| | | | - Li Ma
- Department of Chemistry , University of Missouri , Columbia , MO , USA
| | | | - Rebecca Hoerres
- Department of Chemistry , University of Missouri , Columbia , MO , USA
| | - John D. Lydon
- University of Missouri Research Reactor Center (MURR) , Columbia , MO , USA
| | - Steven P. Kelley
- Department of Chemistry , University of Missouri , Columbia , MO , USA
| | - James Guthrie
- University of Missouri Research Reactor Center (MURR) , Columbia , MO , USA
| | | | - Dmitri Medvedev
- Collider Accelerator Department , Brookhaven National Laboratory , Upton , NY , USA
| | - Cathy S. Cutler
- Collider Accelerator Department , Brookhaven National Laboratory , Upton , NY , USA
| | - Yawen Li
- Department of Radiation Oncology , University of Washington , Seattle , WA , USA
| | - D. Scott Wilbur
- Department of Radiation Oncology , University of Washington , Seattle , WA , USA
| | - Heather M. Hennkens
- Department of Chemistry , University of Missouri , Columbia , MO , USA
- University of Missouri Research Reactor Center (MURR) , Columbia , MO , USA
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Melis DR, Burgoyne AR, Ooms M, Gasser G. Bifunctional chelators for radiorhenium: past, present and future outlook. RSC Med Chem 2022; 13:217-245. [PMID: 35434629 PMCID: PMC8942221 DOI: 10.1039/d1md00364j] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 01/14/2022] [Indexed: 01/16/2023] Open
Abstract
Targeted radionuclide therapy (TRNT) is an ever-expanding field of nuclear medicine that provides a personalised approach to cancer treatment while limiting toxicity to normal tissues. It involves the radiolabelling of a biological targeting vector with an appropriate therapeutic radionuclide, often facilitated by the use of a bifunctional chelator (BFC) to stably link the two entities. The radioisotopes of rhenium, 186Re (t 1/2 = 90 h, 1.07 MeV β-, 137 keV γ (9%)) and 188Re (t 1/2 = 16.9 h, 2.12 MeV β-, 155 keV γ (15%)), are particularly attractive for radiotherapy because of their convenient and high-abundance β--particle emissions as well as their imageable γ-emissions and chemical similarity to technetium. As a transition metal element with multiple oxidation states and coordination numbers accessible for complexation, there is great opportunity available when it comes to developing novel BFCs for rhenium. The purpose of this review is to provide a recap on some of the past successes and failings, as well as show some more current efforts in the design of BFCs for 186/188Re. Future use of these radionuclides for radiotherapy depends on their cost-effective availability and this will also be discussed. Finally, bioconjugation strategies for radiolabelling biomolecules with 186/188Re will be touched upon.
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Affiliation(s)
- Diana R Melis
- SCK CEN, Belgian Nuclear Research Centre Boeretang 200 BE-2400 Mol Belgium +1 865 341 1413 +32 14 33 32 83
- Chimie ParisTech, Laboratory for Inorganic Chemical Biology, PSL University F-75005 Paris France www.gassergroup.com +33 1 44 27 56 02
| | - Andrew R Burgoyne
- SCK CEN, Belgian Nuclear Research Centre Boeretang 200 BE-2400 Mol Belgium +1 865 341 1413 +32 14 33 32 83
| | - Maarten Ooms
- SCK CEN, Belgian Nuclear Research Centre Boeretang 200 BE-2400 Mol Belgium +1 865 341 1413 +32 14 33 32 83
| | - Gilles Gasser
- Chimie ParisTech, Laboratory for Inorganic Chemical Biology, PSL University F-75005 Paris France www.gassergroup.com +33 1 44 27 56 02
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Kankanamalage PH, Hoerres R, Ho KV, Anderson CJ, Gallazzi F, Hennkens HM. p-NCS-Bn-NODAGA as a bifunctional chelator for radiolabeling with the 186Re/99mTc-tricarbonyl core: Radiochemistry with model complexes and a GRPR-targeting peptide. Nucl Med Biol 2022; 108-109:1-9. [DOI: 10.1016/j.nucmedbio.2022.01.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 01/19/2022] [Accepted: 01/27/2022] [Indexed: 12/30/2022]
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8
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Rizvi SFA, Ahmad M, Munib F, Zhang H. Preclinical assessment of Alzheimer's disease using novel designed
99m
Tc‐labeled RGD‐based pro‐apoptotic cyclic peptide as a promising SPECT agent. Appl Organomet Chem 2022. [DOI: 10.1002/aoc.6569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Syed Faheem Askari Rizvi
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering Lanzhou University Lanzhou China
| | - Munir Ahmad
- Department of Nuclear Medicine Institute of Nuclear Medicine and Oncology (INMOL) Lahore Pakistan
| | - Farzana Munib
- Department of Nuclear Medicine Institute of Nuclear Medicine and Oncology (INMOL) Lahore Pakistan
| | - Haixia Zhang
- State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering Lanzhou University Lanzhou China
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Lazniewska J, Agostino M, Hickey SM, Parkinson-Lawrence E, Stagni S, Massi M, Brooks DA, Plush SE. Spectroscopic and Molecular Docking Study of the Interaction between Neutral Re(I) Tetrazolate Complexes and Bovine Serum Albumin. Chemistry 2021; 27:11406-11417. [PMID: 33960039 DOI: 10.1002/chem.202101307] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Indexed: 11/08/2022]
Abstract
Re(I) complexes have potential in biomedical sciences as imaging agents, diagnostics and therapeutics. Thus, it is crucial to understand how Re(I) complexes interact with carrier proteins, like serum albumins. Here, two neutral Re(I) complexes were used (fac-[Re(CO)3 (1,10-phenanthroline)L], in which L is either 4-cyanophenyltetrazolate (1) or 4-methoxycarbonylphenyltetrazole ester (2), to study the interactions with bovine serum albumin (BSA). Spectroscopic measurements, calculations of thermodynamic and Förster resonance energy transfer parameters, as well as molecular modelling, were performed to study differential binding between BSA and complex 1 and 2. Induced-fit docking combined with quantum-polarised ligand docking were employed in what is believed to be a first for a Re(I) complex as a ligand for BSA. Our findings provide a basis for other molecular interaction studies and suggest that subtle functional group alterations at the terminal region of the Re(I) complex have a significant impact on the ability of this class of compounds to interact with BSA.
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Affiliation(s)
- Joanna Lazniewska
- Clinical and Health Sciences, University of South Australia North Terrace, Adelaide, SA 5000, Australia
| | - Mark Agostino
- Curtin Health Innovation Research Institute Curtin Institute for Computation and Curtin Medical School, Curtin University, Kent Street, Perth, WA 6102, Australia
| | - Shane M Hickey
- Clinical and Health Sciences, University of South Australia North Terrace, Adelaide, SA 5000, Australia
| | - Emma Parkinson-Lawrence
- Clinical and Health Sciences, University of South Australia North Terrace, Adelaide, SA 5000, Australia
| | - Stefano Stagni
- Department of Industrial Chemistry ''Toso Montanari'', University of Bologna, Viale del Risorgimento 4, Bologna, Italy
| | - Massimiliano Massi
- Department of Chemistry, Curtin University, Kent Street, Perth, WA 6102, Australia
| | - Douglas A Brooks
- Clinical and Health Sciences, University of South Australia North Terrace, Adelaide, SA 5000, Australia
| | - Sally E Plush
- Clinical and Health Sciences, University of South Australia North Terrace, Adelaide, SA 5000, Australia
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SPECT Imaging of SST2-Expressing Tumors with 99mTc-Based Somatostatin Receptor Antagonists: The Role of Tetraamine, HYNIC, and Spacers. Pharmaceuticals (Basel) 2021; 14:ph14040300. [PMID: 33800582 PMCID: PMC8065591 DOI: 10.3390/ph14040300] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 03/24/2021] [Accepted: 03/25/2021] [Indexed: 12/24/2022] Open
Abstract
[99mTc]Tc-HYNIC-TOC is the most widely used 99mTc-labeled somatostatin receptor (SST) agonist for the SPECT imaging of SST-expressing tumors, such as neuroendocrine tumors. Recently, radiolabeled SST antagonists have shown improved diagnostic efficacy over agonists. 99mTc-labeled SST antagonists are lacking in clinical practice. Surprisingly, when [99mTc]Tc-HYNIC was conjugated to the SST2 antagonist SS01, SST2 imaging was not feasible. This was not the case when [99mTc]Tc-N4 was conjugated to SS01. Here, we assessed the introduction of different spacers (X: β-Ala, Ahx, Aun and PEG4) among HYNIC and SS01 with the aim of restoring the affinity of HYNIC conjugates. In addition, we used the alternative antagonist JR11 for determining the suitability of HYNIC with 99mTc-labeled SST2 antagonists. We performed a head-to-head comparison of the N4 conjugates of SS01 and JR11. [99mTc]Tc-HYNIC-TOC was used as a reference, and HEK-SST2 cells were used for in vitro and in vivo evaluation. EDDA was used as a co-ligand for all [99mTc]Tc-HYNIC conjugates. The introduction of Ahx restored, to a great extent, the SST2-mediated cellular uptake of the [99mTc]Tc-HYNIC-X conjugates (X: spacer), albeit lower than the corresponding [99mTc]Tc-N4-conjugates. SPECT/CT images showed that all 99mTc-labeled conjugates accumulated in the tumor and kidneys with [99mTc]Tc-HYNIC-PEG4-SS01, [99mTc]Tc-N4-SS01 and [99mTc]Tc-N4-JR11 having notably higher kidney uptake. Biodistribution studies showed similar or better tumor-to-non-tumor ratios for the [99mTc]Tc-HYNIC-Ahx conjugates, compared to the [99mTc]Tc-N4 counterparts. The [99mTc]Tc-HYNIC-Ahx conjugates of SS01 and JR11 were comparable to [99mTc]Tc-HYNIC-TOC as imaging agents. HYNIC is a suitable chelator for the development of 99mTc-labeled SST2 antagonists when a spacer of appropriate length, such as Ahx, is used.
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Makris G, Bandari RP, Kuchuk M, Jurisson SS, Smith CJ, Hennkens HM. Development and Preclinical Evaluation of 99mTc- and 186Re-Labeled NOTA and NODAGA Bioconjugates Demonstrating Matched Pair Targeting of GRPR-Expressing Tumors. Mol Imaging Biol 2021; 23:52-61. [PMID: 32886303 DOI: 10.1007/s11307-020-01537-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 08/10/2020] [Accepted: 08/26/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE The goal of this work was to develop hydrophilic gastrin-releasing peptide receptor (GRPR)-targeting complexes of the general formula fac-[M(CO)3(L)]+ [M = natRe, 99mTc, 186Re; L: NOTA for 1, NODAGA for 2] conjugated to a powerful GRPR peptide antagonist (DPhe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH2) via a 6-aminohexanoic acid linker. PROCEDURES Metallated-peptides were prepared employing the [M(OH2)3(CO)3]+ [M = Re, 99mTc, 186Re] precursors. Re-1/2 complexes were characterized with HR-MS. IC50 studies were performed for peptides 1/2 and their respective Re-1/2 complexes in a binding assay utilizing GRPR-expressing human PC-3 prostate cancer cells and [125I]I-Tyr4-BBN as the competing ligand. The 99mTc/186Re-complexes were identified by HPLC co-injection with their Re-analogues. All tracers were challenged in vitro at 37 °C against cysteine/histidine (phosphate-buffered saline 10 mM, pH 7.4) and rat serum. Biodistribution and micro-SPECT/CT imaging of [99mTc]Tc-1/2 and [186Re]Re-2 were performed in PC-3 tumor-bearing ICR SCID mice. RESULTS High in vitro receptor affinity (IC50 2-3 nM) was demonstrated for all compounds. The 99mTc/186Re-tracers were found to be hydrophilic (log D7.4 ≤ - 1.35) and highly stable. Biodistribution in PC-3 xenografted mice revealed good tumor uptake (%ID/g at 1 h: 4.3 ± 0.7 for [99mTc]Tc-1, 8.3 ± 0.9 for [99mTc]Tc-2 and 4.2 ± 0.8 for [186Re]Re-2) with moderate retention over 24 h. Rapid renal clearance was observed for [99mTc]Tc-2 and [186Re]Re-2 (> 84 % at 4 h), indicating favorable pharmacokinetics. Micro-SPECT/CT images for the 99mTc-tracers clearly visualized PC-3 tumors in agreement with the biodistribution data and with superior imaging properties found for [99mTc]Tc-2. CONCLUSIONS [99mTc]Tc-2 shows promise for further development as a GRPR-imaging agent. [186Re]Re-2 demonstrated very similar in vivo behavior to [99mTc]Tc-2, and further studies are therefore justified to explore the theranostic potential of our approach for targeting of GRPR-positive cancers.
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Affiliation(s)
- George Makris
- Research Reactor Center, University of Missouri, Columbia, MO, 65211, USA
| | - Rajendra P Bandari
- Research Service, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, 65201, USA
| | - Marina Kuchuk
- Research Reactor Center, University of Missouri, Columbia, MO, 65211, USA
| | - Silvia S Jurisson
- Department of Chemistry, University of Missouri, Columbia, MO, 65211, USA
| | - Charles J Smith
- Research Reactor Center, University of Missouri, Columbia, MO, 65211, USA
- Research Service, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, 65201, USA
- Department of Radiology, University of Missouri School of Medicine, Columbia, MO, 65212, USA
| | - Heather M Hennkens
- Research Reactor Center, University of Missouri, Columbia, MO, 65211, USA.
- Department of Chemistry, University of Missouri, Columbia, MO, 65211, USA.
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12
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Fani M, Weingaertner V, Kolenc Peitl P, Mansi R, Gaonkar RH, Garnuszek P, Mikolajczak R, Novak D, Simoncic U, Hubalewska-Dydejczyk A, Rangger C, Kaeopookum P, Decristoforo C. Selection of the First 99mTc-Labelled Somatostatin Receptor Subtype 2 Antagonist for Clinical Translation-Preclinical Assessment of Two Optimized Candidates. Pharmaceuticals (Basel) 2020; 14:19. [PMID: 33379299 PMCID: PMC7824897 DOI: 10.3390/ph14010019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 12/22/2020] [Accepted: 12/23/2020] [Indexed: 02/01/2023] Open
Abstract
Recently, radiolabelled antagonists targeting somatostatin receptors subtype 2 (SST2) in neuroendocrine neoplasms demonstrated certain superior properties over agonists. Within the ERA-PerMED project "TECANT" two 99mTc-Tetramine (N4)-derivatized SST2 antagonists (TECANT-1 and TECANT-2) were studied for the selection of the best candidate for clinical translation. Receptor-affinity, internalization and dissociation studies were performed in human embryonic kidney-293 (HEK293) cells transfected with the human SST2 (HEK-SST2). Log D, protein binding and stability in human serum were assessed. Biodistribution and SPECT/CT studies were carried out in nude mice bearing HEK-SST2 xenografts, together with dosimetric estimations from mouse-to-man. [99mTc]Tc-TECANT-1 showed higher hydrophilicity and lower protein binding than [99mTc]-TECANT-2, while stability was comparable. Both radiotracers revealed similar binding affinity, while [99mTc]Tc-TECANT-1 had higher cellular uptake (>50%, at 2 h/37 °C) and lower dissociation rate (<30%, at 2 h/37 °C). In vivo, [99mTc]Tc-TECANT-1 showed lower blood values, kidney and muscles uptake, whereas tumour uptake was comparable to [99mTc]Tc-TECANT-2. SPECT/CT imaging confirmed the biodistribution results, providing the best tumour-to-background image contrast for [99mTc]Tc-TECANT-1 at 4 h post-injection (p.i.). The estimated radiation dose amounted to approximately 6 µSv/MBq for both radiotracers. This preclinical study provided the basis of selection of [99mTc]Tc-TECANT-1 for clinical translation of the first 99mTc-based SST2 antagonist.
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Affiliation(s)
- Melpomeni Fani
- Division of Radiopharmaceutical Chemistry, University Hospital Basel, Universitätsspital Basel, CH-4031 Basel, Switzerland; (M.F.); (R.M.); (R.H.G.)
| | - Viktoria Weingaertner
- Department of Nuclear Medicine, Medical University Innsbruck, 6020 Innsbruck, Austria; (V.W.); (C.R.); (P.K.)
| | - Petra Kolenc Peitl
- Department of Nuclear Medicine, University Medical Centre Ljubljana, University of Ljubljana, 1000 Ljubljana, Slovenia; (P.K.P.); (D.N.)
| | - Rosalba Mansi
- Division of Radiopharmaceutical Chemistry, University Hospital Basel, Universitätsspital Basel, CH-4031 Basel, Switzerland; (M.F.); (R.M.); (R.H.G.)
| | - Raghuvir H. Gaonkar
- Division of Radiopharmaceutical Chemistry, University Hospital Basel, Universitätsspital Basel, CH-4031 Basel, Switzerland; (M.F.); (R.M.); (R.H.G.)
| | - Piotr Garnuszek
- Radioisotope Centre POLATOM, National Centre for Nuclear Research, 05-400 Otwock, Poland; (P.G.); (R.M.)
| | - Renata Mikolajczak
- Radioisotope Centre POLATOM, National Centre for Nuclear Research, 05-400 Otwock, Poland; (P.G.); (R.M.)
| | - Doroteja Novak
- Department of Nuclear Medicine, University Medical Centre Ljubljana, University of Ljubljana, 1000 Ljubljana, Slovenia; (P.K.P.); (D.N.)
| | - Urban Simoncic
- Faculty of Mathematics and Physics, University of Ljubljana, 1000 Ljubljana, Slovenia;
| | | | - Christine Rangger
- Department of Nuclear Medicine, Medical University Innsbruck, 6020 Innsbruck, Austria; (V.W.); (C.R.); (P.K.)
| | - Piriya Kaeopookum
- Department of Nuclear Medicine, Medical University Innsbruck, 6020 Innsbruck, Austria; (V.W.); (C.R.); (P.K.)
| | - Clemens Decristoforo
- Department of Nuclear Medicine, Medical University Innsbruck, 6020 Innsbruck, Austria; (V.W.); (C.R.); (P.K.)
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Qiao Z, Xu J, Gonzalez R, Miao Y. Novel [ 99mTc]-Tricarbonyl-NOTA-Conjugated Lactam-Cyclized Alpha-MSH Peptide with Enhanced Melanoma Uptake and Reduced Renal Uptake. Mol Pharm 2020; 17:3581-3588. [PMID: 32663011 DOI: 10.1021/acs.molpharmaceut.0c00606] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The purpose of this study was to examine the melanoma targeting and imaging properties of 99mTc(CO)3-NOTA-GGNle-CycMSHhex {1,4,7-triazacyclononane-1,4,7-triyl-triacetic acid-GlyGlyNle-c[Asp-His-DPhe-Arg-Trp-Lys]-CONH2} and 99mTc(CO)3-NODAGA-GGNle-CycMSHhex {1,4,7-triazacyclononane,1-gluteric acid-4,7-acetic acid-GlyGlyNle-c[Asp-His-DPhe-Arg-Trp-Lys]-CONH2} on B16/F10 melanoma-bearing C57 mice to demonstrate the feasibility of NOTA/NODAGA as metal chelators for 99mTc(CO)3+ radiolabeling. NOTA/NODAGA-GGNle-CycMSHhex were synthesized using fluorenylmethoxycarbonyl (Fmoc) chemistry. The melanocortin-1 (MC1) receptor binding affinities of the peptides were determined on B16/F10 melanoma cells. The biodistribution of 99mTc(CO)3-NOTA-GGNle-CycMSHhex and 99mTc(CO)3-NODAGA-GGNle-CycMSHhex were determined on B16/F10 melanoma-bearing C57 mice at 2 h postinjection to select a lead peptide for further evaluation. The melanoma targeting and imaging properties of 99mTc(CO)3-NOTA-GGNle-CycMSHhex and 99mTc(CO)3-NODAGA-GGNle-CycMSHhex were determined on B16/F10 melanoma-bearing C57 mice. The IC50 values of NOTA/NODAGA-GGNle-CycMSHhex were 0.8 ± 0.1 and 0.9 ± 0.1 nM on B16/F10 cells. 99mTc(CO)3-NOTA-GGNle-CycMSHhex and 99mTc(CO)3-NODAGA-GGNle-CycMSHhex were readily prepared via the [99mTc(CO)3(OH2)3]+ intermediate and displayed MC1R-specific binding on B16/F10 cells. 99mTc(CO)3-NOTA-GGNle-CycMSHhex was further evaluated as a lead peptide because of its higher tumor uptake (19.76 ± 3.62% ID/g) and lower kidney uptake (1.59 ± 0.52% ID/g) at 2 h postinjection than 99mTc(CO)3-NODAGA-GGNle-CycMSHhex. The B16/F10 melanoma uptake of 99mTc(CO)3-NOTA-GGNle-CycMSHhex was 16.07 ± 4.47, 19.76 ± 3.62, 11.30 ± 2.81, and 3.16 ± 2.28% ID/g at 0.5, 2, 4, and 24 h postinjection, respectively. 99mTc(CO)3-NOTA-GGNle-CycMSHhex showed high tumor to normal organ uptake ratios after 2 h postinjection. The B16/F10 melanoma lesions were clearly visualized by SPECT/CT using 99mTc(CO)3-NOTA-GGNle-CycMSHhex as an imaging probe at 2 h postinjection. High tumor uptake, low kidney uptake, and fast urinary clearance of 99mTc(CO)3-NOTA-GGNle-CycMSHhex highlighted its potential for melanoma imaging and facilitated the evaluation of 188Re(CO)3-NOTA-GGNle-CycMSHhex for melanoma therapy.
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14
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Duatti A. Review on 99mTc radiopharmaceuticals with emphasis on new advancements. Nucl Med Biol 2020; 92:202-216. [PMID: 32475681 DOI: 10.1016/j.nucmedbio.2020.05.005] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 05/07/2020] [Accepted: 05/18/2020] [Indexed: 02/06/2023]
Abstract
Rapid imaging acquisition, high spatial resolution and sensitivity, powered by advancements in solid-state detector technology, are significantly changing the perspective of single photon emission tomography (SPECT). In particular, this evolutionary step is fueling a rediscovery of technetium-99m, a still unique radionuclide within the nuclear medicine scenario because of its ideal nuclear properties and easy preparation of its radiopharmaceuticals that does not require a costly infrastructure and complex procedures. Scope of this review is to show that the arsenal of technetium-99m radiopharmaceuticals is already equipped with imaging agents that may complement and integrate the role played by analogous tracers developed for positron emission tomography (PET). These include, in particular, somatostatin (SST) and prostate-specific membrane antigen (PSMA) receptor targeting agents, and a number of peptide-derived radiopharmaceuticals. Additionally, these recent technological developments, combined with new myocardial perfusion tracers having more favorable biodistribution and pharmacokinetic properties as compared to current commercial agents, may also reinvigorate the prevailing position still hold by technetium-99m radiopharmaceuticals in nuclear cardiology.
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Affiliation(s)
- Adriano Duatti
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Ferrara, Italy.
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15
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Shi S, Yao L, Li L, Wu Z, Zha Z, Kung HF, Zhu L, Fang DC. Synthesis of novel technetium-99m tricarbonyl-HBED-CC complexes and structural prediction in solution by density functional theory calculation. ROYAL SOCIETY OPEN SCIENCE 2019; 6:191247. [PMID: 31827858 PMCID: PMC6894603 DOI: 10.1098/rsos.191247] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 10/04/2019] [Indexed: 06/10/2023]
Abstract
HBED-CC (N,N'-bis[2-hydroxy-5-(carboxyethyl)benzyl]ethylene diamine-N,N'-diacetic acid, L1 ) is a common bifunctional chelating agent in preparation of 68Ga-radiopharmaceuticals. Due to its high stability constant for the Ga3+ complex (logKGaL = 38.5) and its acyclic structure, it is well known for a rapid and efficient radiolabelling at ambient temperature with Gallium-68 and its high in vivo stability. [99mTc][Tc(CO)3(H2O)3]+ is an excellent precursor for radiolabelling of biomolecules. The aim of this study was to develop a novel preparation method of 99mTc-HBED-CC complexes. In this study, HBED-CC-NI (2,2'-(ethane-1,2-diylbis((2-hydroxy-5-(3-((2-(2-nitro-1H-imidazol-1-yl)ethyl)amino)-3-oxopropyl)benzyl)-azanediyl))-diacetic acid, L2 ), a derivative of HBED-CC, was designed and synthesized. Both L1 and L2 were radiolabelled by [99mTc][Tc(CO)3(H2O)3]+ successfully for the first time. In order to explore the coordination mode of metal and chelates, non-radioactive Re(CO)3 L1 and Re(CO)3 L2 were synthesized and characterized spectroscopically. Tc(CO)3 L1 and Tc(CO)3 L2 in solution were calculated by density functional theory and were analysed with radio-HPLC chromatograms. It showed that [99mTc]Tc(CO)3 L2 forms two stable diastereomers in solution, which is similar to those of [68Ga]Ga-HBED-CC complexes. Natural bond orbital analysis through the natural population charges revealed a charge transfer between [99mTc][Tc(CO)3]+ and L1 or L2 . The experimental results showed that tricarbonyl technetium might form stable complex with HBED-CC derivatives, which is useful for the future application of using HBED-CC as a bifunctional chelating agent in developing new 99mTc-radiopharmaceuticals as diagnostic imaging agents.
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Affiliation(s)
- Shengyu Shi
- College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Lifeng Yao
- College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
- College of Chemistry and Chemical Engineering, Qujing Normal University, Qujing 655011, People's Republic of China
| | - Linlin Li
- College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Zehui Wu
- Beijing Institute of Brain Disorders, Capital Medical University, Beijing 100069, People's Republic of China
| | - Zhihao Zha
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hank F. Kung
- Beijing Institute of Brain Disorders, Capital Medical University, Beijing 100069, People's Republic of China
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Lin Zhu
- College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
| | - De-Cai Fang
- College of Chemistry, Beijing Normal University, Beijing 100875, People's Republic of China
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16
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Okoye NC, Baumeister JE, Najafi Khosroshahi F, Hennkens HM, Jurisson SS. Chelators and metal complex stability for radiopharmaceutical applications. RADIOCHIM ACTA 2019. [DOI: 10.1515/ract-2018-3090] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Diagnostic and therapeutic nuclear medicine relies heavily on radiometal nuclides. The most widely used and well-known radionuclide is technetium-99m (99mTc), which has dominated diagnostic nuclear medicine since the advent of the 99Mo/99mTc generator in the 1960s. Since that time, many more radiometals have been developed and incorporated into potential radiopharmaceuticals. One critical aspect of radiometal-containing radiopharmaceuticals is their stability under in vivo conditions. The chelator that is coordinated to the radiometal is a key factor in determining radiometal complex stability. The chelators that have shown the most promise and are under investigation in the development of diagnostic and therapeutic radiopharmaceuticals over the last 5 years are discussed in this review.
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Affiliation(s)
| | | | | | - Heather M. Hennkens
- Department of Chemistry , University of Missouri , Columbia, MO 65211 , USA
- University of Missouri Research Reactor Center , Columbia, MO 65211 , USA
| | - Silvia S. Jurisson
- Department of Chemistry , University of Missouri , Columbia, MO 65211 , USA
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17
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Rust L, Payne KM, Carniato F, Botta M, Woods M. Differences in the Relaxometric Properties of Regioisomeric Benzyl-DOTA Bifunctional Chelators: Implications for Molecular Imaging. Bioconjug Chem 2019; 30:1530-1538. [PMID: 31050414 DOI: 10.1021/acs.bioconjchem.9b00223] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The bifunctional chelator S-2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraazacyclododecane- N, N', N″, N‴-1,4,7,10-tetraacetate (IB-DOTA) is on paper the most attractive of the commercially available bifunctional chelators for magnetic resonance imaging (MRI) applications. The preserved DOTA scaffold is known to produce extremely kinetically and thermodynamically robust chelates with the Gd3+ ion. Also, ligation through four acetate pendant arms should ensure that the rapid water exchange kinetics so, crucial to the function of an MRI contrast agent are retained. However, upon ligation of the Gd3+ ion, IB-DOTA differentiates into two distinct isomers defined by the positions of the benzylic substituent (corner or side). A relaxometric analysis of these two isomers revealed marked differences in the property and behavior of the two chelates. Most notably the side isomer is found to be substantially more likely to aggregate in aqueous solution than its corner counterpart. This aggregation results in higher relaxivity for the side isomer versus the corner isomer, an observation that potentially obscures the impact of differences in water exchange kinetics between the two isomers. The side isomer is composed of a significant fraction of a twisted square antiprismatic coordination geometry that exchanges water more rapidly than optimal (τM = 7 ns) for maximizing relaxivity. The impact of this excessively fast exchange is not observed in the relaxivity of the side isomer only because in isolation this chelate tumbles much more slowly than the corner isomer. However, this situation is not expected to persist when the chelate is employed in a typical bioconjugate. These results imply that the corner isomer of IB-DOTA may represent a better choice of bifunctional chelator for bioconjugation applications in which a large macromolecule is to be tagged for MRI applications.
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Affiliation(s)
- Lauren Rust
- Department of Chemistry , Portland State University , 1719 SW 10th Avenue , Portland , Oregon 97201 , United States
| | - Katherine M Payne
- Department of Chemistry , Portland State University , 1719 SW 10th Avenue , Portland , Oregon 97201 , United States
| | - Fabio Carniato
- Dipartimento di Scienze e Innovazione Tecnologica , Università del Piemonte Orientale "Amedeo Avogadro" , Viale T. Michel 11 , I-15121 Alessandria , Italy
| | - Mauro Botta
- Dipartimento di Scienze e Innovazione Tecnologica , Università del Piemonte Orientale "Amedeo Avogadro" , Viale T. Michel 11 , I-15121 Alessandria , Italy
| | - Mark Woods
- Department of Chemistry , Portland State University , 1719 SW 10th Avenue , Portland , Oregon 97201 , United States.,Advanced Imaging Research Center , Oregon Health and Science University , 3181 SW Sam Jackson Park Road , Portland , Oregon 97239 , United States
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18
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Makris G, Kuchuk M, Gallazzi F, Jurisson SS, Smith CJ, Hennkens HM. Somatostatin receptor targeting with hydrophilic [99mTc/186Re]Tc/Re-tricarbonyl NODAGA and NOTA complexes. Nucl Med Biol 2019; 71:39-46. [DOI: 10.1016/j.nucmedbio.2019.04.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 03/26/2019] [Accepted: 04/23/2019] [Indexed: 02/08/2023]
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Ishizaki A, Mishiro K, Shiba K, Hanaoka H, Kinuya S, Odani A, Ogawa K. Fundamental study of radiogallium-labeled aspartic acid peptides introducing octreotate derivatives. Ann Nucl Med 2019; 33:244-251. [PMID: 30604401 DOI: 10.1007/s12149-018-01326-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 12/20/2018] [Indexed: 01/10/2023]
Abstract
OBJECTIVE Somatostatin receptors are highly expressed in neuroendocrine tumors, and many radiolabeled somatostatin analogs for diagnosis and treatment have been developed. To simultaneously detect not only primary cancer but also bone metastases, this study aimed to develop a positron emission tomography probe using generator-produced nuclide Gallium-68 (T1/2 = 68 min), in which a carrier for primary cancer, a carrier for bone metastases lesions, and a stable gallium complex are introduced into the one molecule. Based on this strategy, the somatostatin receptor-targeted peptide, [Tyr3]-octreotate (TATE), aspartic acid peptide (Dn) with high binding affinity for hydroxyapatite, and Ga-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) as a stable gallium complex were selected. The novel complexes, Ga-DOTA-Dn-TATE (n = 0, 2, 5, 8, or 11), were designed, synthesized, and evaluated. The radiogallium complexes were prepared using the easy-to-handle radioisotope 67Ga due to relatively long half-life. METHODS The radiogallium complex precursor DOTA-Dn-TATE was synthesized by the Fmoc-based solid-phase method and by the air oxidation method to form the disulfide bond. [67Ga]Ga-DOTA-Dn-TATE was synthesized by reacting DOTA-Dn-TATE and 67Ga. Hydroxyapatite binding assays, in vitro cellular uptake experiments in AR42J tumor cells, in biodistribution experiments in AR42J tumor-bearing mice, were performed using [67Ga]Ga-DOTA-Dn-TATE. RESULTS The radiochemical purities of [67Ga]Ga-DOTA-Dn-TATE were > 96.0%. In in vitro and in vivo experiments, [67Ga]Ga-DOTA-D11-TATE had a high affinity for hydroxyapatite and highly accumulated in bone. However, the uptake of [67Ga]Ga-DOTA-D11-TATE into somatostatin receptor-positive AR42J cells was lower than that of [67Ga]Ga-DOTA-TATE, and the accumulation of [67Ga]Ga-DOTA-D11-TATE in tumor was significantly low. CONCLUSION Ga-DOTA-D11-TATE may not be recognized by somatostatin receptor by the introduction of D11, and the charge adjustment may be important for somatostatin receptor-positive cell uptake.
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Affiliation(s)
- Atsushi Ishizaki
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Kenji Mishiro
- Institute for Frontier Science Initiative, Kanazawa University, Kakuma-machi, Kanazawa, Japan
| | - Kazuhiro Shiba
- Advanced Science Research Center, Kanazawa University, Kanazawa, Japan
| | - Hirofumi Hanaoka
- Department of Bioimaging Information Analysis, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Seigo Kinuya
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Akira Odani
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Kazuma Ogawa
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan. .,Institute for Frontier Science Initiative, Kanazawa University, Kakuma-machi, Kanazawa, Japan.
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