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Koller AJ, Glaser O, DeLuca MC, Motz RN, Amason EK, Carbo-Bague I, Mixdorf JC, Guzei IA, Aluicio-Sarduy E, Śmiłowicz D, Barnhart TE, Ramogida CF, Nolan EM, Engle JW, Boros E. "Off-Label Use" of the Siderophore Enterobactin Enables Targeted Imaging of Cancer with Radioactive Ti (IV). Angew Chem Int Ed Engl 2024; 63:e202319578. [PMID: 38442302 DOI: 10.1002/anie.202319578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 02/27/2024] [Accepted: 03/04/2024] [Indexed: 03/07/2024]
Abstract
The development of inert, biocompatible chelation methods is required to harness the emerging positron emitting radionuclide 45Ti for radiopharmaceutical applications. Herein, we evaluate the Ti(IV)-coordination chemistry of four catechol-based, hexacoordinate chelators using synthetic, structural, computational, and radiochemical approaches. The siderophore enterobactin (Ent) and its synthetic mimic TREN-CAM readily form mononuclear Ti(IV) species in aqueous solution at neutral pH. Radiolabeling studies reveal that Ent and TREN-CAM form mononuclear complexes with the short-lived, positron-emitting radionuclide 45Ti(IV), and do not transchelate to plasma proteins in vitro and exhibit rapid renal clearance in naïve mice. These features guide efforts to target the 45Ti isotope to prostate cancer tissue through the design, synthesis, and evaluation of Ent-DUPA, a small molecule conjugate composed of a prostate specific membrane antigen (PSMA) targeting peptide and a monofunctionalized Ent scaffold. The [45Ti][Ti(Ent-DUPA)]2- complex forms readily at room temperature. In a tumor xenograft model in mice, selective tumor tissue accumulation (8±5 %, n=5), and low off-target uptake in other organs is observed. Overall, this work demonstrates targeted imaging with 45Ti(IV), provides a foundation for advancing the application of 45Ti in nuclear medicine, and reveals that Ent can be repurposed as a 45Ti-complexing cargo for targeted nuclear imaging applications.
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Affiliation(s)
- Angus J Koller
- Department of Chemistry, Stony Brook University, Stony Brook, New York, 11794, United States
| | - Owen Glaser
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin, 53706, United States
| | - Molly C DeLuca
- Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin, 53705, United States
| | - Rachel N Motz
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, United States
| | - Edith K Amason
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin, 53706, United States
| | - Imma Carbo-Bague
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada
| | - Jason C Mixdorf
- Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin, 53705, United States
| | - Ilia A Guzei
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin, 53706, United States
| | - Eduardo Aluicio-Sarduy
- Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin, 53705, United States
| | - Dariusz Śmiłowicz
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin, 53706, United States
| | - Todd E Barnhart
- Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin, 53705, United States
| | - Caterina F Ramogida
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada
| | - Elizabeth M Nolan
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, United States
| | - Jonathan W Engle
- Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Madison, Wisconsin, 53705, United States
| | - Eszter Boros
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin, 53706, United States
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2
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Harriswangler C, McNeil BL, Brandariz I, Valencia L, Esteban-Gómez D, Ramogida CF, Platas-Iglesias C. Incorporation of Carboxylate Pendant Arms into 18-Membered Macrocycles: Effects on [ nat/203Pb]Pb(II) Complexation. Chemistry 2024:e202400434. [PMID: 38466910 DOI: 10.1002/chem.202400434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 03/04/2024] [Accepted: 03/11/2024] [Indexed: 03/13/2024]
Abstract
We present a detailed investigation on the coordination chemistry of [nat/203Pb]Pb(II) with chelators H4PYTA and H4CHX-PYTA. These chelators belong to the family of ligands derived from the 18-membered macrocyclic backbone PYAN and present varying degrees of rigidity due to the presence of either ethyl or cyclohexyl spacers. A complete study of the stable Pb(II) complexes is carried out via NMR, X-Ray crystallography, stability constant determination and computational studies. While these studies indicated that Pb(II) complexation is achieved, and the thermodynamic stability of the resulting complexes is very high, a certain degree of fluxionality does exist in both cases. Nevertheless, radiolabeling studies were carried out using SPECT (single photon emission computed tomography) compatible isotope lead-203 (203Pb, t1/2=51.9 h), and while both chelators complex the radioisotope, the incorporation of carboxylate pendant arms appears to be detrimental towards the stability of the complexes when compared to the previously described amide analogues. Additionally, incorporation of a cyclohexyl spacer does not improve the kinetic inertness of the system.
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Affiliation(s)
- Charlene Harriswangler
- Centro Interdisciplinar de Química e Bioloxía (CICA) and Departamento de Química, Universidade da Coruña, Campus da Zapateira-Rúa da Fraga 10, 15001, A Coruña, Spain
| | - Brooke L McNeil
- Department of Chemistry, Simon Fraser University, 8888 University Drive, V5A 1S6, Burnaby, British Columbia, Canada
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, V6T 2A3, Vancouver, British Columbia, Canada
| | - Isabel Brandariz
- Centro Interdisciplinar de Química e Bioloxía (CICA) and Departamento de Química, Universidade da Coruña, Campus da Zapateira-Rúa da Fraga 10, 15001, A Coruña, Spain
| | - Laura Valencia
- Departamento de Química Inorgánica, Facultad de Ciencias, Universidade de Vigo, As Lagoas, Marcosende, 36310, Pontevedra, Spain
| | - David Esteban-Gómez
- Centro Interdisciplinar de Química e Bioloxía (CICA) and Departamento de Química, Universidade da Coruña, Campus da Zapateira-Rúa da Fraga 10, 15001, A Coruña, Spain
| | - Caterina F Ramogida
- Department of Chemistry, Simon Fraser University, 8888 University Drive, V5A 1S6, Burnaby, British Columbia, Canada
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, V6T 2A3, Vancouver, British Columbia, Canada
| | - Carlos Platas-Iglesias
- Centro Interdisciplinar de Química e Bioloxía (CICA) and Departamento de Química, Universidade da Coruña, Campus da Zapateira-Rúa da Fraga 10, 15001, A Coruña, Spain
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3
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Randhawa P, Carbo-Bague I, Davey PRWJ, Chen S, Merkens H, Uribe CF, Zhang C, Tosato M, Bénard F, Radchenko V, Ramogida CF. Exploration of commercial cyclen-based chelators for mercury-197 m/g incorporation into theranostic radiopharmaceuticals. Front Chem 2024; 12:1292566. [PMID: 38389726 PMCID: PMC10881723 DOI: 10.3389/fchem.2024.1292566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 01/23/2024] [Indexed: 02/24/2024] Open
Abstract
A comprehensive investigation of the Hg2+ coordination chemistry and 197m/gHg radiolabeling capabilities of cyclen-based commercial chelators, namely, DOTA and DOTAM (aka TCMC), along with their bifunctional counterparts, p-SCN-Bn-DOTA and p-SCN-Bn-TCMC, was conducted to assess the suitability of these frameworks as bifunctional chelators for the 197m/gHg2+ theranostic pair. Radiolabeling studies revealed that TCMC and DOTA exhibited low radiochemical yields (0%-6%), even when subjected to harsh conditions (80°C) and high ligand concentrations (10-4 M). In contrast, p-SCN-Bn-TCMC and p-SCN-Bn-DOTA demonstrated significantly higher 197m/gHg radiochemical yields (100% ± 0.0% and 70.9% ± 1.1%, respectively) under the same conditions. The [197 m/gHg]Hg-p-SCN-Bn-TCMC complex was kinetically inert when challenged against human serum and glutathione. To understand the differences in labeling between the commercial chelators and their bifunctional counterparts, non-radioactive natHg2+ complexes were assessed using NMR spectroscopy and DFT calculations. The NMR spectra of Hg-TCMC and Hg-p-SCN-Bn-TCMC suggested binding of the Hg2+ ion through the cyclen backbone framework. DFT studies indicated that binding of the Hg2+ ion within the backbone forms a thermodynamically stable product. However, competition can form between isothiocyanate binding and binding through the macrocycle, which was experimentally observed. The isothiocyanate bound coordination product was dominant at the radiochemical scale as, in comparison, the macrocycle bound product was seen at the NMR scale, agreeing with the DFT result. Furthermore, a bioconjugate of TCMC (TCMC-PSMA) targeting prostate-specific membrane antigen was synthesized and radiolabeled, resulting in an apparent molar activity of 0.089 MBq/nmol. However, the complex demonstrated significant degradation over 24 h when exposed to human serum and glutathione. Subsequently, cell binding assays were conducted, revealing a Ki value ranging from 19.0 to 19.6 nM. This research provides crucial insight into the effectiveness of current commercial chelators in the context of 197m/gHg2+ radiolabeling. It underscores the necessity for the development of specific and customized chelators to these unique "soft" radiometals to advance 197m/gHg2+ radiopharmaceuticals.
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Affiliation(s)
- Parmissa Randhawa
- Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada
| | - Imma Carbo-Bague
- Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada
| | - Patrick R W J Davey
- Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada
| | - Shaohuang Chen
- Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada
| | - Helen Merkens
- Department of Molecular Oncology, BC Cancer, Vancouver, BC, Canada
| | - Carlos F Uribe
- Department of Molecular Oncology, BC Cancer, Vancouver, BC, Canada
| | - Chengcheng Zhang
- Department of Molecular Oncology, BC Cancer, Vancouver, BC, Canada
| | - Marianna Tosato
- Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada
| | - François Bénard
- Department of Molecular Oncology, BC Cancer, Vancouver, BC, Canada
| | - Valery Radchenko
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada
- Department of Chemistry, University of British Columbia, Vancouver, BC, Canada
| | - Caterina F Ramogida
- Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada
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4
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Tosato M, Randhawa P, Lazzari L, McNeil BL, Dalla Tiezza M, Zanoni G, Mancin F, Orian L, Ramogida CF, Di Marco V. Tuning the Softness of the Pendant Arms and the Polyazamacrocyclic Backbone to Chelate the 203Pb/ 212Pb Theranostic Pair. Inorg Chem 2024; 63:1745-1758. [PMID: 38230993 PMCID: PMC10828988 DOI: 10.1021/acs.inorgchem.3c02610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 12/18/2023] [Accepted: 12/20/2023] [Indexed: 01/18/2024]
Abstract
A series of macrocyclic ligands were considered for the chelation of Pb2+: 1,4,7,10-tetrakis[2-(methylsulfanyl)ethyl]-1,4,7,10-tetraazacyclododecane (DO4S), 1,4,7-tris[2-(methylsulfanyl)ethyl]-1,4,7,10-tetraazacyclododecane (DO3S), 1,4,7-tris[2-(methylsulfanyl)ethyl]-10-acetamido-1,4,7,10-tetraazacyclododecane (DO3SAm), 1,7-bis[2-(methylsulfanyl)ethyl]-1,4,7,10-tetraazacyclododecane-4,10-diacetic acid (DO2A2S), 1,5,9-tris[2-(methylsulfanyl)ethyl]-1,5,9-triazacyclododecane (TACD3S), 1,4,7,10-tetrakis[2-(methylsulfanyl)ethyl]-1,4,7,10-tetrazacyclotridecane (TRI4S), and 1,4,8,11-tetrakis[2-(methylsulfanyl)ethyl]-1,4,8,11-tetrazacyclotetradecane (TE4S). The equilibrium, the acid-mediated dissociation kinetics, and the structural properties of the Pb2+ complexes formed by these chelators were examined by UV-Visible and nuclear magnetic resonance (NMR) spectroscopies, combined with potentiometry and density functional theory (DFT) calculations. The obtained results indicated that DO4S, DO3S, DO3SAm, and DO2A2S were able to efficiently chelate Pb2+ and that the most suitable macrocyclic scaffold for Pb2+ is 1,4,7,10-tetrazacyclododecane. NMR spectroscopy gave insights into the solution structures of the Pb2+ complexes, and 1H-207Pb interactions confirmed the involvement of S and/or O donors in the metal coordination sphere. Highly fluxional solution behavior was discovered when Pb2+ was coordinated to symmetric ligands (i.e., DO4S and DO2A2S) while the introduction of structural asymmetry in DO3S and DO3SAm slowed down the intramolecular dynamics. The ligand ability to chelate [203Pb]Pb2+ under highly dilute reaction conditions was explored through radiolabeling experiments. While DO4S and DO3S possessed modest performance, DO3SAm and DO2A2S demonstrated high complexation efficiency under mild reaction conditions (pH = 7, 5 min reaction time). The [203Pb]Pb2+ complexes' integrity in human serum over 24 h was appreciably good for [203Pb][Pb(DO4S)]2+ (80 ± 5%) and excellent for [203Pb][Pb(DO3SAm)]2+ (93 ± 1%) and [203Pb][Pb(DO2A2S)] (94 ± 1%). These results reveal the promise of DO2A2S and DO3SAm as chelators in cutting-edge theranostic [203/212Pb]Pb2+ radiopharmaceuticals.
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Affiliation(s)
- Marianna Tosato
- Department
of Chemical Sciences, University of Padova, 35131 Padova, Italy
- Radiopharmaceutical
Chemistry Section, Nuclear Medicine Unit, AUSL-IRCCS Reggio Emilia, 42122 Reggio Emilia, Italy
- Department
of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
- Life
Sciences Division, TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - Parmissa Randhawa
- Department
of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
- Life
Sciences Division, TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - Luca Lazzari
- Department
of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | - Brooke L. McNeil
- Department
of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
- Life
Sciences Division, TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - Marco Dalla Tiezza
- Department
of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | - Giordano Zanoni
- Department
of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | - Fabrizio Mancin
- Department
of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | - Laura Orian
- Department
of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | - Caterina F. Ramogida
- Department
of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
- Life
Sciences Division, TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - Valerio Di Marco
- Department
of Chemical Sciences, University of Padova, 35131 Padova, Italy
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5
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Carbo-Bague I, Saini S, Cingoranelli SJ, Davey PRWJ, Tosato M, Lapi SE, Ramogida CF. Evaluation of a novel hexadentate 1,2-hydroxypyridinone-based acyclic chelate, HOPO-O 6-C4, for 43Sc/ 47Sc, 68Ga, and 45Ti radiopharmaceuticals. Nucl Med Biol 2024; 128-129:108872. [PMID: 38262310 DOI: 10.1016/j.nucmedbio.2023.108872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 12/11/2023] [Accepted: 12/19/2023] [Indexed: 01/25/2024]
Abstract
INTRODUCTION Chelators play a crucial role in the development of metal-based radiopharmaceuticals, and with the continued interest in 68Ga and increasing availability of new radiometals such as 43Sc/47Sc and 45Ti, there is a growing demand for tailored chelators that can form stable complexes with these metals. This work reports the synthesis and characterization of a hexadentate tris-1,2-hydroxypyridonone chelator HOPO-O6-C4 and its in vitro and in vivo evaluation with the above mentioned radiometals. METHODS To investigate the affinity of HOPO-O6-C4, macroscopic studies were performed with Sc3+, and Ga3+ followed by DFT structural optimization of the Sc3+, Ga3+ and Ti4+ complexes. Further tracer studies with 43Sc (and 47Sc), 45Ti, and 68Ga were performed to determine the potential for positron emission tomography (PET) imaging with these complexes. In vitro stability studies followed by in vivo imaging and biodistribution studies were performed to understand the kinetic stability of the resultant radiometal-complexes of HOPO-O6-C4. RESULTS Promising radiolabeling results with HOPO-O6-C4 were obtained with 43Sc, 47Sc, 45Ti, and 68Ga radionuclides; rapid radiolabeling was observed at 37 °C and pH 7 in under 30-min. Apparent molar activity measurements were performed for radiolabeling of HOPO-O6-C4 with 43Sc (4.9 ± 0.26 GBq/μmol), 47Sc (1.58 ± 0.01 GBq/μmol), 45Ti (11.5 ± 1.6 GBq/μmol) and 68Ga (5.74 ± 0.7 GBq/μmol), respectively. Preclinical in vivo imaging studies resulted in promising results with [68Ga]Ga-HOPO-O6-C4 indicating a rapid clearance through hepatic excretion route and no decomplexation whereas [43Sc]Sc-HOPO-O6-C4, [47Sc]Sc-HOPO-O6-C4 and [45Ti]Ti-HOPO-O6-C4 showed modest and significant evidence of decomplexation, respectively. CONCLUSIONS The tris-1,2-HOPO chelator HOPO-O6-C4 is a promising scaffold for elaboration into a 68Ga- based radiopharmaceutical.
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Affiliation(s)
- Imma Carbo-Bague
- Department of Chemistry, Simon Fraser University, 8888 University Dr, Burnaby, BC V5A 1S6, Canada; Life Sciences, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
| | - Shefali Saini
- Department of Radiology, University of Alabama at Birmingham, 1824 6th Ave South, Birmingham, AL 35294, USA
| | - Shelbie J Cingoranelli
- Department of Radiology, University of Alabama at Birmingham, 1824 6th Ave South, Birmingham, AL 35294, USA
| | - Patrick R W J Davey
- Department of Chemistry, Simon Fraser University, 8888 University Dr, Burnaby, BC V5A 1S6, Canada; Life Sciences, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
| | - Marianna Tosato
- Department of Chemistry, Simon Fraser University, 8888 University Dr, Burnaby, BC V5A 1S6, Canada; Life Sciences, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
| | - Suzanne E Lapi
- Department of Radiology, University of Alabama at Birmingham, 1824 6th Ave South, Birmingham, AL 35294, USA.
| | - Caterina F Ramogida
- Department of Chemistry, Simon Fraser University, 8888 University Dr, Burnaby, BC V5A 1S6, Canada; Life Sciences, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada.
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6
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Carbo-Bague I, Li C, McNeil BL, Gao Y, McDonagh AW, Van de Voorde M, Ooms M, Kunz P, Yang H, Radchenko V, Schreckenbach G, Ramogida CF. Comparative Study of a Decadentate Acyclic Chelate, HOPO-O 10, and Its Octadentate Analogue, HOPO-O 8, for Radiopharmaceutical Applications. Inorg Chem 2023; 62:20549-20566. [PMID: 36608341 DOI: 10.1021/acs.inorgchem.2c03671] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [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: 01/07/2023]
Abstract
Radiolanthanides and actinides are aptly suited for the diagnosis and treatment of cancer via nuclear medicine because they possess unique chemical and physical properties (e.g., radioactive decay emissions). These rare radiometals have recently shown the potential to selectively deliver a radiation payload to cancer cells. However, their clinical success is highly dependent on finding a suitable ligand for stable chelation and conjugation to a disease-targeting vector. Currently, the commercially available chelates exploited in the radiopharmaceutical design do not fulfill all of the requirements for nuclear medicine applications, and there is a need to further explore their chemistry to rationally design highly specific chelates. Herein, we describe the rational design and chemical development of a novel decadentate acyclic chelate containing five 1,2-hydroxypyridinones, 3,4,3,3-(LI-1,2-HOPO), referred to herein as HOPO-O10, based on the well-known octadentate ligand 3,4,3-(LI-1,2-HOPO), referred to herein as HOPO-O8, a highly efficient chelator for 89Zr[Zr4+]. Analysis by 1H NMR spectroscopy and mass spectrometry of the La3+ and Tb3+ complexes revealed that HOPO-O10 forms bimetallic complexes compared to HOPO-O8, which only forms monometallic species. The radiolabeling properties of both chelates were screened with [135La]La3+, [155/161Tb]Tb3+, [225Ac]Ac3+ and, [227Th]Th4+. Comparable high specific activity was observed for the [155/161Tb]Tb3+ complexes, outperforming the gold-standard 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid, yet HOPO-O10 surpassed HOPO-O8 with higher [227Th]Th4+ affinity and improved complex stability in a human serum challenge assay. A comprehensive analysis of the decadentate and octadentate chelates was performed with density functional theory for the La3+, Ac3+, Eu3+, Tb3+, Lu3+, and Th4+ complexes. The computational simulations demonstrated the enhanced stability of Th4+-HOPO-O10 over Th4+-HOPO-O8. This investigation reveals the potential of HOPO-O10 for the stable chelation of large tetravalent radioactinides for nuclear medicine applications and provides insight for further chelate development.
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Affiliation(s)
- Imma Carbo-Bague
- Department of Chemistry, Simon Fraser University, Burnaby, British ColumbiaV5A 1S6, Canada
| | - Cen Li
- Department of Chemistry, University of Manitoba, Winnipeg, ManitobaR3T 2N2, Canada
| | - Brooke L McNeil
- Department of Chemistry, Simon Fraser University, Burnaby, British ColumbiaV5A 1S6, Canada
- Life Sciences Division, TRIUMF, Vancouver, British ColumbiaV6T 2A3, Canada
| | - Yang Gao
- Department of Chemistry, University of Manitoba, Winnipeg, ManitobaR3T 2N2, Canada
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, Sichuan610054, China
| | - Anthony W McDonagh
- Department of Chemistry, Simon Fraser University, Burnaby, British ColumbiaV5A 1S6, Canada
| | | | - Maarten Ooms
- NURA Research Group, Belgian Nuclear Research Center, SCK CEN, 2400Mol, Belgium
| | - Peter Kunz
- Department of Chemistry, Simon Fraser University, Burnaby, British ColumbiaV5A 1S6, Canada
- Accelerator Division, TRIUMF, Vancouver, British ColumbiaV6T 2A3, Canada
| | - Hua Yang
- Department of Chemistry, Simon Fraser University, Burnaby, British ColumbiaV5A 1S6, Canada
- Life Sciences Division, TRIUMF, Vancouver, British ColumbiaV6T 2A3, Canada
| | - Valery Radchenko
- Life Sciences Division, TRIUMF, Vancouver, British ColumbiaV6T 2A3, Canada
- Department of Chemistry, University of British Columbia, Vancouver, British ColumbiaV6T 1Z1, Canada
| | - Georg Schreckenbach
- Department of Chemistry, University of Manitoba, Winnipeg, ManitobaR3T 2N2, Canada
| | - Caterina F Ramogida
- Department of Chemistry, Simon Fraser University, Burnaby, British ColumbiaV5A 1S6, Canada
- Life Sciences Division, TRIUMF, Vancouver, British ColumbiaV6T 2A3, Canada
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7
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Kostelnik TI, Olson AP, Grundmane A, Ellison PA, Mynerich J, Chen S, Marinova A, Randhawa P, Karaivanov D, Aluicio-Sarduy E, Barnhart TE, Orvig C, Ramogida CF, Hoehr C, Filosofov D, Engle JW, Radchenko V. Production and radiochemistry of antimony-120m: Efforts toward Auger electron therapy with 119Sb. Nucl Med Biol 2023; 122-123:108352. [PMID: 37390607 DOI: 10.1016/j.nucmedbio.2023.108352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/23/2023] [Accepted: 05/30/2023] [Indexed: 07/02/2023]
Abstract
Targeted Meitner-Auger Therapy (TMAT) has potential for personalized treatment thanks to its subcellular dosimetric selectivity, which is distinct from the dosimetry of β- and α particle emission based Targeted Radionuclide Therapy (TRT). To date, most clinical and preclinical TMAT studies have used commercially available radionuclides. These studies showed promising results despite using radionuclides with theoretically suboptimal photon to electron ratios, decay kinetics, and electron emission spectra. Studies using radionuclides whose decay characteristics are considered more optimal are therefore important for evaluation of the full potential of Meitner-Auger therapy; 119Sb is among the best such candidates. In the present work, we develop radiochemical purification of 120Sb from irradiated natural tin targets for TMAT studies with 119Sb.
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Affiliation(s)
- Thomas I Kostelnik
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Aeli P Olson
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - Aivija Grundmane
- Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Paul A Ellison
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - Jenasee Mynerich
- Faculty of Science, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada
| | - Shaohuang Chen
- Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Atanaska Marinova
- Dzhelepov Laboratory of Nuclear Problems, Joint Institute for Nuclear Research, Dubna 141980, Russian Federation
| | - Parmissa Randhawa
- Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Dimitar Karaivanov
- Dzhelepov Laboratory of Nuclear Problems, Joint Institute for Nuclear Research, Dubna 141980, Russian Federation
| | - Eduardo Aluicio-Sarduy
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - Todd E Barnhart
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - Chris Orvig
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | | | - Cornelia Hoehr
- Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia V8W 2Y2, Canada; Department of Computer Science, Mathematics, Physics, and Statistics, University of British Columbia Okanagan, Kelowna, British Columbia V1V 1V7, Canada
| | - Dmitry Filosofov
- Dzhelepov Laboratory of Nuclear Problems, Joint Institute for Nuclear Research, Dubna 141980, Russian Federation
| | - Jonathan W Engle
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI 53705, United States
| | - Valery Radchenko
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada.
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8
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McNeil BL, Mastroianni SA, McNeil SW, Zeisler S, Kumlin J, Borjian S, McDonagh AW, Cross M, Schaffer P, Ramogida CF. Optimized production, purification, and radiolabeling of the 203Pb/ 212Pb theranostic pair for nuclear medicine. Sci Rep 2023; 13:10623. [PMID: 37391445 PMCID: PMC10313663 DOI: 10.1038/s41598-023-37313-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 06/20/2023] [Indexed: 07/02/2023] Open
Abstract
TRIUMF is one of the only laboratories in the world able to produce both lead-203 (203Pb, t1/2 = 51.9 h) and 212Pb (t1/2 = 10.6 h) onsite via its 13 and 500 MeV cyclotrons, respectively. Together, 203Pb and 212Pb form an element-equivalent theranostic pair that potentiate image-guided, personalized cancer treatment, using 203Pb as a single-photon emission computed tomography (SPECT) source, and 212Pb for targeted alpha therapy. In this study, improvements to 203Pb production were accomplished by manufacturing electroplated, silver-backed thallium (Tl) targets to improve target thermal stability, which allow for higher currents during irradiation. We implemented a novel, two-column purification method that employs selective Tl precipitation (203Pb only) alongside extraction and anion exchange chromatography to elute high specific activity and chemical purity 203/212Pb in a minimal volume of dilute acid, without the need for evaporation. Optimization of the purification method translated to improvements in radiolabeling yields and apparent molar activity of lead chelators TCMC (S-2-(4-Isothiocyanatobenzyl)-1,4,7,10-tetraaza-1,4,7,10-tetra(2-carbamoylmethyl)cyclododecane) and Crypt-OH, a derivative of a [2.2.2]-cryptand.
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Affiliation(s)
- Brooke L McNeil
- Life Sciences Division, TRIUMF, Vancouver, BC, V6T 2A3, Canada
- Department of Chemistry, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
| | | | - Scott W McNeil
- Life Sciences Division, TRIUMF, Vancouver, BC, V6T 2A3, Canada
| | | | | | | | - Anthony W McDonagh
- Department of Chemistry, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
| | | | - Paul Schaffer
- Life Sciences Division, TRIUMF, Vancouver, BC, V6T 2A3, Canada
- Department of Chemistry, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
- ARTMS Inc., Burnaby, BC, V5A 4N5, Canada
- Department of Radiology, University of British Columbia, 2775 Laurel St, Vancouver, BC, V5Z 1M9, Canada
| | - Caterina F Ramogida
- Life Sciences Division, TRIUMF, Vancouver, BC, V6T 2A3, Canada.
- Department of Chemistry, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada.
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9
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Randhawa P, Gower-Fry KL, Stienstra CMK, Tosato M, Chen S, Gao Y, McDonagh AW, Di Marco V, Radchenko V, Schreckenbach G, Ramogida CF. Selective Chelation of the Exotic Meitner-Auger Emitter Mercury-197 m/g with Sulfur-Rich Macrocyclic Ligands: Towards the Future of Theranostic Radiopharmaceuticals. Chemistry 2023; 29:e202203815. [PMID: 36701527 DOI: 10.1002/chem.202203815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 01/25/2023] [Accepted: 01/26/2023] [Indexed: 01/27/2023]
Abstract
Mercury-197 m/g are a promising pair of radioactive isomers for incorporation into a theranostic as they can be used as a diagnostic agent using SPECT imaging and a therapeutic via Meitner-Auger electron emissions. However, the current absence of ligands able to stably coordinate 197m/g Hg to a tumour-targeting vector precludes their use in vivo. To address this, we report herein a series of sulfur-rich chelators capable of incorporating 197m/g Hg into a radiopharmaceutical. 1,4,7,10-Tetrathia-13-azacyclopentadecane (NS4 ) and its derivatives, (2-(1,4,7,10-tetrathia-13-azacyclopentadecan-13-yl)acetic acid (NS4 -CA) and N-benzyl-2-(1,4,7,10-tetrathia-13-azacyclopentadecan-13-yl)acetamide (NS4 -BA), were designed, synthesized and analyzed for their ability to coordinate Hg2+ through a combination of theoretical (DFT) and experimental coordination chemistry studies (NMR and mass spectrometry) as well as 197m/g Hg radiolabeling studies and in vitro stability assays. The development of stable ligands for 197m/g Hg reported herein is extremely impactful as it would enable their use for in vivo imaging and therapy, leading to personalized treatments for cancer.
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Affiliation(s)
- Parmissa Randhawa
- Department of Chemistry, Simon Fraser University, 8888 University Drive, V5A 1S6, Burnaby, British Columbia, Canada.,Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, V6T 2A3, Vancouver, British Columbia, Canada
| | - K Lexi Gower-Fry
- Department of Chemistry, Simon Fraser University, 8888 University Drive, V5A 1S6, Burnaby, British Columbia, Canada.,Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, V6T 2A3, Vancouver, British Columbia, Canada
| | - Cailum M K Stienstra
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, V6T 2A3, Vancouver, British Columbia, Canada
| | - Marianna Tosato
- Department of Chemistry, Simon Fraser University, 8888 University Drive, V5A 1S6, Burnaby, British Columbia, Canada.,Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, V6T 2A3, Vancouver, British Columbia, Canada.,Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131, Padova, Italy
| | - Shaohuang Chen
- Department of Chemistry, Simon Fraser University, 8888 University Drive, V5A 1S6, Burnaby, British Columbia, Canada.,Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, V6T 2A3, Vancouver, British Columbia, Canada
| | - Yang Gao
- Department of Chemistry, University of Manitoba, 140 Dysart Rd, R3T 2N2, Winnipeg, Manitoba, Canada.,Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, 610054, Chengdu, Sichuan, P. R. China
| | - Anthony W McDonagh
- Department of Chemistry, Simon Fraser University, 8888 University Drive, V5A 1S6, Burnaby, British Columbia, Canada
| | - Valerio Di Marco
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131, Padova, Italy
| | - Valery Radchenko
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, V6T 2A3, Vancouver, British Columbia, Canada.,Department of Chemistry, University of British Columbia, 2036 Main Mall, V6T 1Z1, Vancouver, British Columbia, Canada
| | - Georg Schreckenbach
- Department of Chemistry, University of Manitoba, 140 Dysart Rd, R3T 2N2, Winnipeg, Manitoba, Canada
| | - Caterina F Ramogida
- Department of Chemistry, Simon Fraser University, 8888 University Drive, V5A 1S6, Burnaby, British Columbia, Canada.,Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, V6T 2A3, Vancouver, British Columbia, Canada
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10
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Chen S, Bas M, Happel S, Randhawa P, McNeil S, Kurakina E, Zeisler S, Maskell K, Hoehr C, Ramogida CF, Radchenko V. Determination of distribution coefficients of mercury and gold on selected extraction chromatographic resins - towards an improved separation method of mercury-197 from proton-irradiated gold targets. J Chromatogr A 2023; 1688:463717. [PMID: 36565656 DOI: 10.1016/j.chroma.2022.463717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 12/11/2022] [Accepted: 12/12/2022] [Indexed: 12/15/2022]
Abstract
Radioisotope mercury-197g (197gHg, half-life: 64.14 h) along with its metastable isomer (197mHg, half-life: 23.8 h) are potential candidates for targeted Meitner-Auger electron therapy due to their suitable decay properties. Their production can be achieved via proton irradiation of a natural gold target, but the number of studies surrounding their separation from an irradiated gold target is limited. This study focuses on the determination of distribution coefficients (Kd) of gold (III) and mercury (II) on seven extraction chromatographic resins. Mercury Kd were measured by means of radiotracers and Inductively Coupled Plasma Mass Spectrometry (ICP_MS); values obtained from the two methods were generally in good agreement. These results can provide insight on Hg and Au chemistry and aid in the design of improved separation system(s).
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Affiliation(s)
- Shaohuang Chen
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada; Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
| | - Marine Bas
- TrisKem International SAS, 3 Rue des Champs Géons ZAC de L'Éperon, Bruz, Brittany 35170, France
| | - Steffen Happel
- TrisKem International SAS, 3 Rue des Champs Géons ZAC de L'Éperon, Bruz, Brittany 35170, France
| | - Parmissa Randhawa
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada; Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
| | - Scott McNeil
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - Elena Kurakina
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - Stefan Zeisler
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - Keiran Maskell
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada; Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
| | - Cornelia Hoehr
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada; Department of Physics and Astronomy, University of Victoria, 3800 Finnerty Road, Victoria, British Columbia V8P 5C2, Canada; Department of Computer Science, Mathematics, Physics and Statistics, University of British Columbia Okanagan, 3187 University Way, Kelowna, British Columbia V1V 1V7, Canada
| | - Caterina F Ramogida
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada; Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
| | - Valery Radchenko
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada; Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada.
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11
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McNeil BL, Kadassery KJ, McDonagh AW, Zhou W, Schaffer P, Wilson JJ, Ramogida CF. Evaluation of the Effect of Macrocyclic Ring Size on [ 203Pb]Pb(II) Complex Stability in Pyridyl-Containing Chelators. Inorg Chem 2022; 61:9638-9649. [PMID: 35704752 DOI: 10.1021/acs.inorgchem.2c01114] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
As an element-equivalent theranostic pair, lead-203 (203Pb, 100% EC, half-life = 51.92 h) and lead-212 (212Pb, 100% β-, half-life = 10.64 h), through the emission of γ rays and an α particle in its decay chain, respectively, can aid in the development of personalized targeted radionuclide treatment for advanced and currently untreatable cancers. With these isotopes currently being used in clinical trials, an understanding of the relationship between the chelator structure, ability to incorporate the radiometal, and metal-complex stability is needed to help design appropriate chelators for clinical use. Herein, we report an investigation into the effect of ring size in macrocyclic chelators where pyridine, an intermediate Lewis base, acts as an electron donor toward lead. Crown-4Py (4,7,13,16-tetrakis(pyridin-2-ylmethyl)-1,10-dioxa-4,7,13,16-tetraazacyclooctadecane), cyclen-4Py (1,4,7,10-tetrakis(pyridin-2-ylmethyl)-1,4,7,10-tetraazacyclododecane), and NOON-2Py (7,16-bis(pyridin-2-ylmethyl)-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane) were synthesized and analyzed for their ability to coordinate Pb2+. Metal complex stability was investigated via [203Pb]Pb2+ radiolabeling studies, 1H NMR spectroscopy, X-ray crystallography, and potentiometry. With the smallest macrocyclic backbone, cyclen-4Py had the highest radiochemical yield, while, in descending order, crown-4Py and NOON-2Py had the lowest. Thermodynamic stability constants (log KML) of 19.95(3), 13.29(5), and 11.67 for [Pb(Cyclen-4Py)]2+, [Pb(Crown-4Py)]2+, and [Pb(NOON-2Py)]2+, respectively, correlated with their radiochemical yields. The X-ray crystal structure of the least stable complexes [Pb(NOON-2Py)]2+ revealed a hemidirected Pb2+ center, as reflected by a void within the coordination sphere, and [Pb(Crown-4Py)]2+ showed an average Pb-N pyridine interatomic distance of >3 Å. By contrast, the crystal structure of [Pb(Cyclen-4Py)]2+ showed shorter Pb-N pyridine interactions, and in solution, only one highly symmetric isomer existed for this complex, whereas conformational flexibility was observed for both [Pb(Crown-4Py)]2+ and [Pb(NOON-2Py)]2+ at the NMR timescale. This study illustrates the importance of the macrocyclic backbone size when incorporating bulky electron-donor groups into the design of a macrocyclic chelator as it affects the accessibility of lead to the donor arms. Our results show that cyclen-4Py is a promising chelator for future studies with this theranostic pair.
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Affiliation(s)
- Brooke L McNeil
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.,Life Sciences Division, TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - Karthika J Kadassery
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca New York, 14853-1301 United States
| | - Anthony W McDonagh
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Wen Zhou
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Paul Schaffer
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.,Life Sciences Division, TRIUMF, Vancouver, British Columbia V6T 2A3, Canada.,Department of Radiology, The University of British Columbia, Vancouver, British Columbia V5Z 1M9, Canada
| | - Justin J Wilson
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca New York, 14853-1301 United States
| | - Caterina F Ramogida
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.,Life Sciences Division, TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
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12
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McDonagh AW, McNeil BL, Rousseau J, Roberts RJ, Merkens H, Yang H, Bénard F, Ramogida CF. Development of a multi faceted platform containing a tetrazine, fluorophore and chelator: synthesis, characterization, radiolabeling, and immuno-SPECT imaging. EJNMMI Radiopharm Chem 2022; 7:12. [PMID: 35666363 PMCID: PMC9170845 DOI: 10.1186/s41181-022-00164-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 05/23/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Combining optical (fluorescence) imaging with nuclear imaging has the potential to offer a powerful tool in personal health care, where nuclear imaging offers in vivo functional whole-body visualization, and the fluorescence modality may be used for image-guided tumor resection. Varying chemical strategies have been exploited to fuse both modalities into one molecular entity. When radiometals are employed in nuclear imaging, a chelator is typically inserted into the molecule to facilitate radiolabeling; the availability of the chelator further expands the potential use of these platforms for targeted radionuclide therapy if a therapeutic radiometal is employed. Herein, a novel mixed modality scaffold which contains a tetrazine (Tz)--for biomolecule conjugation, fluorophore-for optical imaging, and chelator-for radiometal incorporation, in one construct is presented. The novel platform was characterized for its fluorescence properties, radiolabeled with single-photon emission computed tomography (SPECT) isotope indium-111 (111In3+) and therapeutic alpha emitter actinium-225 (225Ac3+). Both radiolabels were conjugated in vitro to trans-cyclooctene (TCO)-modified trastuzumab; biodistribution and immuno-SPECT imaging of the former conjugate was assessed. RESULTS Key to the success of the platform synthesis was incorporation of a 4,4'-dicyano-BODIPY fluorophore. The route gives access to an advanced intermediate where final chelator-incorporated compounds can be easily accessed in one step prior to radiolabeling or biomolecule conjugation. The DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) conjugate was prepared, displayed good fluorescence properties, and was successfully radiolabeled with 111In & 225Ac in high radiochemical yield. Both complexes were then separately conjugated in vitro to TCO modified trastuzumab through an inverse electron demand Diels-Alder (IEDDA) reaction with the Tz. Pilot small animal in vivo immuno-SPECT imaging with [111In]In-DO3A-BODIPY-Tz-TCO-trastuzumab was also conducted and exhibited high tumor uptake (21.2 ± 5.6%ID/g 6 days post-injection) with low uptake in non-target tissues. CONCLUSIONS The novel platform shows promise as a multi-modal probe for theranostic applications. In particular, access to an advanced synthetic intermediate where tailored chelators can be incorporated in the last step of synthesis expands the potential use of the scaffold to other radiometals. Future studies including validation of ex vivo fluorescence imaging and exploiting the pre-targeting approach available through the IEDDA reaction are warranted.
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Affiliation(s)
- Anthony W McDonagh
- Department of Chemistry, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
| | - Brooke L McNeil
- Department of Chemistry, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada.,Life Sciences Division, TRIUMF, Vancouver, BC, V6T 2A3, Canada
| | - Julie Rousseau
- Department of Molecular Oncology, BC Cancer, Vancouver, BC, V5Z 1L3, Canada
| | - Ryan J Roberts
- Department of Chemistry, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada
| | - Helen Merkens
- Department of Molecular Oncology, BC Cancer, Vancouver, BC, V5Z 1L3, Canada
| | - Hua Yang
- Department of Chemistry, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada.,Life Sciences Division, TRIUMF, Vancouver, BC, V6T 2A3, Canada
| | - François Bénard
- Department of Molecular Oncology, BC Cancer, Vancouver, BC, V5Z 1L3, Canada
| | - Caterina F Ramogida
- Department of Chemistry, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada. .,Life Sciences Division, TRIUMF, Vancouver, BC, V6T 2A3, Canada.
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13
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Miller C, Rousseau J, Ramogida CF, Celler A, Rahmim A, Uribe CF. Implications of physics, chemistry and biology for dosimetry calculations using theranostic pairs. Theranostics 2022; 12:232-259. [PMID: 34987643 PMCID: PMC8690938 DOI: 10.7150/thno.62851] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 10/18/2021] [Indexed: 12/15/2022] Open
Abstract
Theranostics is an emerging paradigm that combines imaging and therapy in order to personalize patient treatment. In nuclear medicine, this is achieved by using radiopharmaceuticals that target identical molecular targets for both imaging (using emitted gamma rays) and radiopharmaceutical therapy (using emitted beta, alpha or Auger-electron particles) for the treatment of various diseases, such as cancer. If the therapeutic radiopharmaceutical cannot be imaged quantitatively, a “theranostic pair” imaging surrogate can be used to predict the absorbed radiation doses from the therapeutic radiopharmaceutical. However, theranostic dosimetry assumes that the pharmacokinetics and biodistributions of both radiopharmaceuticals in the pair are identical or very similar, an assumption that still requires further validation for many theranostic pairs. In this review, we consider both same-element and different-element theranostic pairs and attempt to determine if factors exist which may cause inaccurate dose extrapolations in theranostic dosimetry, either intrinsic (e.g. chemical differences) or extrinsic (e.g. injecting different amounts of each radiopharmaceutical) to the radiopharmaceuticals. We discuss the basis behind theranostic dosimetry and present common theranostic pairs and their therapeutic applications in oncology. We investigate general factors that could create alterations in the behavior of the radiopharmaceuticals or the quantitative accuracy of imaging them. Finally, we attempt to determine if there is evidence showing some specific pairs as suitable for theranostic dosimetry. We show that there are a variety of intrinsic and extrinsic factors which can significantly alter the behavior among pairs of radiopharmaceuticals, even if they belong to the same chemical element. More research is needed to determine the impact of these factors on theranostic dosimetry estimates and on patient outcomes, and how to correctly account for them.
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14
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Yang H, Wilson JJ, Orvig C, Li Y, Wilbur DS, Ramogida CF, Radchenko V, Schaffer P. Harnessing α-Emitting Radionuclides for Therapy: Radiolabeling Method Review. J Nucl Med 2022; 63:5-13. [PMID: 34503958 PMCID: PMC8717181 DOI: 10.2967/jnumed.121.262687] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 08/05/2021] [Indexed: 11/16/2022] Open
Abstract
Targeted α-therapy (TAT) is an emerging powerful tool treating late-stage cancers for which therapeutic options are limited. At the core of TAT are targeted radiopharmaceuticals, where isotopes are paired with targeting vectors to enable tissue- or cell-specific delivery of α-emitters. DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) and DTPA (diethylenetriamine pentaacetic acid) are commonly used to chelate metallic radionuclides but have limitations. Significant efforts are underway to develop effective stable chelators for α-emitters and are at various stages of development and community adoption. Isotopes such as 149Tb, 212/213Bi, 212Pb (for 212Bi), 225Ac, and 226/227Th have found suitable chelators, although further studies, especially in vivo studies, are required. For others, including 223Ra, 230U, and, arguably 211At, the ideal chemistry remains elusive. This review summarizes the methods reported to date for the incorporation of 149Tb, 211At, 212/213Bi, 212Pb (for 212Bi), 223Ra, 225Ac, 226/227Th, and 230U into radiopharmaceuticals, with a focus on new discoveries and remaining challenges.
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Affiliation(s)
- Hua Yang
- Life Sciences Division, TRIUMF, Vancouver, British Columbia, Canada;
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Justin J Wilson
- Chemistry and Chemical Biology, Cornell University, Ithaca, New York
| | - Chris Orvig
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada
| | - Yawen Li
- Department of Radiation Oncology, University of Washington, Seattle, Washington
| | - D Scott Wilbur
- Department of Radiation Oncology, University of Washington, Seattle, Washington
| | - Caterina F Ramogida
- Life Sciences Division, TRIUMF, Vancouver, British Columbia, Canada
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Valery Radchenko
- Life Sciences Division, TRIUMF, Vancouver, British Columbia, Canada
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada; and
| | - Paul Schaffer
- Life Sciences Division, TRIUMF, Vancouver, British Columbia, Canada
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada
- Department of Radiology, University of British Columbia, Vancouver, British Columbia, Canada
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15
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Hu A, Brown V, MacMillan SN, Radchenko V, Yang H, Wharton L, Ramogida CF, Wilson JJ. Chelating the Alpha Therapy Radionuclides 225Ac 3+ and 213Bi 3+ with 18-Membered Macrocyclic Ligands Macrodipa and Py-Macrodipa. Inorg Chem 2021; 61:801-806. [PMID: 34965102 DOI: 10.1021/acs.inorgchem.1c03670] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The radionuclides 225Ac3+ and 213Bi3+ possess favorable physical properties for targeted alpha therapy (TAT), a therapeutic approach that leverages α radiation to treat cancers. A chelator that effectively binds and retains these radionuclides is required for this application. The development of ligands for this purpose, however, is challenging because the large ionic radii and charge-diffuse nature of these metal ions give rise to weaker metal-ligand interactions. In this study, we evaluated two 18-membered macrocyclic chelators, macrodipa and py-macrodipa, for their ability to complex 225Ac3+ and 213Bi3+. Their coordination chemistry with Ac3+ was probed computationally and with Bi3+ experimentally via NMR spectroscopy and X-ray crystallography. Furthermore, radiolabeling studies were conducted, revealing the efficient incorporation of both 225Ac3+ and 213Bi3+ by py-macrodipa that matches or surpasses the well-known chelators macropa and DOTA. Incubation in human serum at 37 °C showed that ∼90% of the 225Ac3+-py-macrodipa complex dissociates after 1 d. The Bi3+-py-macrodipa complex possesses remarkable kinetic inertness reflected by an EDTA transchelation challenge study, surpassing that of Bi3+-macropa. This work establishes py-macrodipa as a valuable candidate for 213Bi3+ TAT, providing further motivation for its implementation within new radiopharmaceutical agents.
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Affiliation(s)
- Aohan Hu
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Victoria Brown
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Samantha N MacMillan
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Valery Radchenko
- Life Sciences Division, TRIUMF, Vancouver, British Columbia V6T 2A3, Canada.,Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Hua Yang
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.,Life Sciences Division, TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - Luke Wharton
- Life Sciences Division, TRIUMF, Vancouver, British Columbia V6T 2A3, Canada.,Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Caterina F Ramogida
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.,Life Sciences Division, TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - Justin J Wilson
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
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16
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Hu A, Aluicio-Sarduy E, Brown V, MacMillan SN, Becker KV, Barnhart TE, Radchenko V, Ramogida CF, Engle JW, Wilson JJ. Py-Macrodipa: A Janus Chelator Capable of Binding Medicinally Relevant Rare-Earth Radiometals of Disparate Sizes. J Am Chem Soc 2021; 143:10429-10440. [PMID: 34190542 DOI: 10.1021/jacs.1c05339] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Nuclear medicine leverages different types of radiometals for disease diagnosis and treatment, but these applications usually require them to be stably chelated. Given the often-disparate chemical properties of these radionuclides, it is challenging to find a single chelator that binds all of them effectively. Toward addressing this problem, we recently reported a macrocyclic chelator macrodipa with an unprecedented "dual-size-selectivity" pattern for lanthanide (Ln3+) ions, characterized by its high affinity for both the large and the small Ln3+ ( J. Am. Chem. Soc, 2020, 142, 13500). Here, we describe a second-generation "macrodipa-type" ligand, py-macrodipa. Its coordination chemistry with Ln3+ was thoroughly investigated experimentally and computationally. These studies reveal that the Ln3+-py-macrodipa complexes exhibit enhanced thermodynamic and kinetic stabilities compared to Ln3+-macrodipa, while retaining the unusual dual-size selectivity. Nuclear medicine applications of py-macrodipa for chelating radiometals with disparate chemical properties were assessed using the therapeutic 135La3+ and diagnostic 44Sc3+ radiometals representing the two size extremes within the rare-earth series. Radiolabeling and stability studies demonstrate that the rapidly formed complexes of these radionuclides with py-macrodipa are highly stable in human serum. Thus, in contrast to gold standard chelators like DOTA and macropa, py-macrodipa can be harnessed for the simultaneous, efficient binding of radiometals with disparate ionic radii like La3+ and Sc3+, signifying a substantial achievement in nuclear medicine. This concept could enable the facile incorporation of a breadth of medicinally relevant radiometals into chemically identical radiopharmaceutical agents. The fundamental coordination chemistry learned from py-macrodipa provides valuable insight for future chelator development.
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Affiliation(s)
- Aohan Hu
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Eduardo Aluicio-Sarduy
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Victoria Brown
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | - Samantha N MacMillan
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Kaelyn V Becker
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.,Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Todd E Barnhart
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Valery Radchenko
- Life Sciences Division, TRIUMF, Vancouver, British Columbia V6T 2A3, Canada.,Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Caterina F Ramogida
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.,Life Sciences Division, TRIUMF, Vancouver, British Columbia V6T 2A3, Canada
| | - Jonathan W Engle
- Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.,Department of Radiology, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Justin J Wilson
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
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17
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McDonagh AW, McNeil BL, Patrick BO, Ramogida CF. Synthesis and Evaluation of Bifunctional [2.2.2]-Cryptands for Nuclear Medicine Applications. Inorg Chem 2021; 60:10030-10037. [PMID: 34159785 DOI: 10.1021/acs.inorgchem.1c01274] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
For the first time, synthesis of bifunctional [2.2.2]-cryptands (CRYPT) and demonstration of radiolabeling with lead(II) (Pb2+) isotopes are disclosed herein. The synthesis is convenient and high-yielding and gives access to three distinct bifunctional handles (azide (-N3), isothiocyanate (-NCS), and tetrazine (-Tz)) that can enable the construction of radioimmunoconjugates for targeted and pretargeted therapy. Proof-of-principle CRYPT radiolabeling was successful with lead-203 ([203Pb]Pb2+) and demonstrated complexation efficiency superior to that of DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) and efficiency comparable to that of the current industry standard TCMC (1,4,7,10-tetraaza-1,4,7,10-tetra-(2-carbamoylmethyl)-cyclododecane). In vitro human serum stability assays demonstrated excellent [203Pb]Pb-CRYPT stability over 72 h (91.7 ± 0.56%; n = 3). [203Pb]Pb-CRYPT-radioimmunoconjugates were synthesized from the corresponding CRYPT-immunoconjugate or by conjugating [203Pb]Pb-Tz-CRYPT to transcyclooctene modified trastuzumab (TCO-trastuzumab) via the inverse electron-demand Diels-Alder (IEEDA) reaction. This investigation reveals the potential for CRYPT ligands to become new industry standards for therapeutic and diagnostic radiometals in radiopharmaceutical elaboration.
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Affiliation(s)
- Anthony W McDonagh
- Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - Brooke L McNeil
- Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada.,Life Sciences Division, TRIUMF, Vancouver, BC V6T 2A3, Canada
| | - Brian O Patrick
- Department of Chemistry, University of British Columbia, Vancouver, BC V6T 1Z1, Canada
| | - Caterina F Ramogida
- Department of Chemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada.,Life Sciences Division, TRIUMF, Vancouver, BC V6T 2A3, Canada
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18
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Fiszbein DJ, Brown V, Thiele NA, Woods JJ, Wharton L, MacMillan SN, Radchenko V, Ramogida CF, Wilson JJ. Tuning the Kinetic Inertness of Bi 3+ Complexes: The Impact of Donor Atoms on Diaza-18-Crown-6 Ligands as Chelators for 213Bi Targeted Alpha Therapy. Inorg Chem 2021; 60:9199-9211. [PMID: 34102841 DOI: 10.1021/acs.inorgchem.1c01269] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The radionuclide 213Bi can be applied for targeted α therapy (TAT): a type of nuclear medicine that harnesses α particles to eradicate cancer cells. To use this radionuclide for this application, a bifunctional chelator (BFC) is needed to attach it to a biological targeting vector that can deliver it selectively to cancer cells. Here, we investigated six macrocyclic ligands as potential BFCs, fully characterizing the Bi3+ complexes by NMR spectroscopy, mass spectrometry, and elemental analysis. Solid-state structures of three complexes revealed distorted coordination geometries about the Bi3+ center arising from the stereochemically active 6s2 lone pair. The kinetic properties of the Bi3+ complexes were assessed by challenging them with a 1000-fold excess of the chelating agent diethylenetriaminepentaacetic acid (DTPA). The most kinetically inert complexes contained the most basic pendent donors. Density functional theory (DFT) and quantum theory of atoms in molecules (QTAIM) calculations were employed to investigate this trend, suggesting that the kinetic inertness is not correlated with the extent of the 6s2 lone pair stereochemical activity, but with the extent of covalency between pendent donors. Lastly, radiolabeling studies of 213Bi (30-210 kBq) with three of the most promising ligands showed rapid formation of the radiolabeled complexes at room temperature within 8 min for ligand concentrations as low as 10-7 M, corresponding to radiochemical yields of >80%, thereby demonstrating the promise of this ligand class for use in 213Bi TAT.
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Affiliation(s)
- David J Fiszbein
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Victoria Brown
- Department of Chemistry, Simon Fraser University, 8888 University Dr, Burnaby, BC V5A 1S6 Canada
| | - Nikki A Thiele
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Joshua J Woods
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States.,Robert F. Smith School for Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Luke Wharton
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 Canada.,Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
| | - Samantha N MacMillan
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Valery Radchenko
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 Canada.,Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada
| | - Caterina F Ramogida
- Department of Chemistry, Simon Fraser University, 8888 University Dr, Burnaby, BC V5A 1S6 Canada.,Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 Canada
| | - Justin J Wilson
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
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19
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McNeil BL, Robertson AKH, Fu W, Yang H, Hoehr C, Ramogida CF, Schaffer P. Production, purification, and radiolabeling of the 203Pb/ 212Pb theranostic pair. EJNMMI Radiopharm Chem 2021; 6:6. [PMID: 33527221 PMCID: PMC7851237 DOI: 10.1186/s41181-021-00121-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 01/11/2021] [Indexed: 11/26/2022] Open
Abstract
Background Lead-212 (212Pb, t1/2 = 10.6 h) and lead-203 (203Pb, t1/2 = 51.9 h) are an element-equivalent, or a matched theranostic radioisotope pair that show great potential for application in targeted radionuclide therapy (TRT) and single-photon emission computed tomography (SPECT), respectively. At TRIUMF we have produced both 203Pb and 212Pb using TRIUMF’s TR13 (13 MeV) and 500 MeV cyclotrons, and subsequently purified and evaluated both radioisotopes using a series of pyridine-modified DOTA analogues in comparison to the commercially available chelates DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) and TCMC (1,4,7,10-tetraaza-1,4,7,10-tetra(2-carbamoylmethyl)cyclododecane). Results Proton irradiation (12.8 MeV) of natural and enriched thallium-203 (203Tl) targets gave 203Pb saturation yields of 134 ± 25 and 483 ± 3 MBq/μA, respectively. Thorium-228 (228Th, t1/2 = 1.9 y), a by-product of 232Th proton spallation on TRIUMF’s main 500 MeV beamline (beamline 1A, BL1A), was recovered to build a 228Th/212Pb generator with the ability to deliver up to 9–10 MBq of 212Pb daily. Both lead isotopes were purified via solid phase extraction chromatography (Pb resin), and isolated in an acetate form ([203/212Pb]Pb(OAc)2) suitable for direct radiolabeling of chelators and bioconjugates. A series of cyclen-based chelators (herein referred to as DOTA-1Py, -2Py, and -3Py) along with established chelates DOTA and TCMC were evaluated for their ability to complex both 203Pb and 212Pb. All chelates incorporated 212Pb/203Pb efficiently, with higher radiolabeling yields observed for the 212Pb-complexes. Conclusion The production of 203Pb and 212Pb was established using TRIUMF 13 MeV and 500 MeV cyclotrons, respectively. Both production methods provided radiometals suitable for subsequent radiolabeling reactions using known and novel chelates. Furthermore, the novel chelate DOTA-3Py may be a good candidate for biomolecule conjugation and further theranostic 212Pb/203Pb studies. Supplementary Information The online version contains supplementary material available at 10.1186/s41181-021-00121-4.
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Affiliation(s)
- Brooke L McNeil
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada.,Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada
| | - Andrew K H Robertson
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada.,Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada
| | - Winnie Fu
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada
| | - Hua Yang
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada
| | | | - Caterina F Ramogida
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada. .,Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada.
| | - Paul Schaffer
- Life Sciences Division, TRIUMF, Vancouver, BC, Canada. .,Department of Chemistry, Simon Fraser University, Burnaby, BC, Canada. .,Department of Radiology, University of British Columbia, Vancouver, BC, Canada.
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20
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Randhawa P, Olson AP, Chen S, Gower-Fry KL, Hoehr C, Engle JW, Ramogida CF, Radchenko V. Meitner-Auger Electron Emitters for Targeted Radionuclide Therapy: Mercury-197m/g and Antimony-119. Curr Radiopharm 2021; 14:394-419. [PMID: 33430758 PMCID: PMC8521447 DOI: 10.2174/1874471014999210111201630] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 10/12/2020] [Accepted: 10/26/2020] [Indexed: 11/22/2022]
Abstract
Targeted Radionuclide Therapies (TRTs) based on Auger emitting radionuclides have the potential to deliver extremely selective therapeutic payloads on the cellular level. However, to fully exploit this potential, suitable radionuclides need to be applied in combination with appropriate delivery systems. In this review, we summarize the state-of-the-art production, purification, chelation and applications of two promising candidates for Targeted Auger Therapy, namely antimony- 119 (119Sb) and mercury-197 (197Hg). Both radionuclides have great potential to become efficient tools for TRT. We also highlight our current progress on the production of both radionuclides at TRIUMF and the University of Wisconsin.
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Affiliation(s)
| | - Aeli P. Olson
- Medical Physics and Radiology, University of Wisconsin, Madison, WI, USA
| | - Shaohuang Chen
- Chemistry, Simon Fraser University, Burnaby, BC, Canada
- Life Sciences, TRIUMF, Vancouver, BC, Canada
| | | | | | - Jonathan W. Engle
- Medical Physics and Radiology, University of Wisconsin, Madison, WI, USA
| | - Caterina F. Ramogida
- Chemistry, Simon Fraser University, Burnaby, BC, Canada
- Life Sciences, TRIUMF, Vancouver, BC, Canada
| | - Valery Radchenko
- Life Sciences, TRIUMF, Vancouver, BC, Canada
- Chemistry, Science, University of British Columbia, BC, Canada
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21
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Kunz P, Andreoiu C, Brown V, Cervantes M, Even J, Garcia FH, Gottberg A, Lassen J, Radchenko V, Ramogida CF, Robertson AKH, Schaffer P, Sothilingam R. Medical isotope collection from ISAC targets. EPJ Web Conf 2020. [DOI: 10.1051/epjconf/202022906003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The ISAC facility (Isotope Separation and Acceleration) at TRIUMF has recently started to provide isotopes for pre-clinical nuclear medicine studies. By irradiating ISOL (Isotope Separation OnLine) targets with a 480 MeV proton beam from the TRIUMF H- cyclotron, the facility can deliver a large variety of radioactive isotope beams (RIB) for research in the fields of nuclear astrophysics, nuclear structure and material science with half-lives down to a few milliseconds via an electrostatic beamline network. For the collection of medical isotopes, typically with half-lives in the range of hours or days, we have developed a compact apparatus for the implantation of mass-separated RIB on a target disc at energies between 20-55 keV. In this paper, we also discuss two different retrieval methods of the implanted activity from the implantation target: by chemical etching of the target surface and by recoil collection of implanted alpha emitters.
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22
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Ramogida CF, Robertson AKH, Jermilova U, Zhang C, Yang H, Kunz P, Lassen J, Bratanovic I, Brown V, Southcott L, Rodríguez-Rodríguez C, Radchenko V, Bénard F, Orvig C, Schaffer P. Evaluation of polydentate picolinic acid chelating ligands and an α-melanocyte-stimulating hormone derivative for targeted alpha therapy using ISOL-produced 225Ac. EJNMMI Radiopharm Chem 2019; 4:21. [PMID: 31659557 PMCID: PMC6684685 DOI: 10.1186/s41181-019-0072-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 07/18/2019] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Actinium-225 (225Ac, t1/2 = 9.9 d) is a promising candidate radionuclide for use in targeted alpha therapy (TAT), though the currently limited global supply has hindered the development of a suitable Ac-chelating ligand and 225Ac-radiopharmaceuticals towards the clinic. We at TRIUMF have leveraged our Isotope Separation On-Line (ISOL) facility to produce 225Ac and use the resulting radioactivity to screen a number of potential 225Ac-radiopharmaceutical compounds. RESULTS MBq quantities of 225Ac and parent radium-225 (225Ra, t1/2 = 14.8 d) were produced and separated using solid phase extraction DGA resin, resulting in a radiochemically pure 225Ac product in > 98% yield and in an amenable form for radiolabeling of ligands and bioconjugates. Of the many polydentate picolinic acid ("pa") containing ligands evaluated (H4octapa [N4O4], H4CHXoctapa [N4O4], p-NO2-Bn-H4neunpa [N5O4], and H6phospa [N4O4]), all out-performed the current gold standard, DOTA for 225Ac radiolabeling ability at ambient temperature. Moreover, a melanocortin 1 receptor-targeting peptide conjugate, DOTA-modified cyclized α-melanocyte-stimulating hormone (DOTA-CycMSH), was radiolabeled with 225Ac and proof-of-principle biodistribution studies using B16F10 tumour-bearing mice were conducted. At 2 h post-injection, tumour-to-blood ratios of 20.4 ± 3.4 and 4.8 ± 2.4 were obtained for the non-blocking (molar activity [M.A.] > 200 kBq/nmol) and blocking (M.A. = 1.6 kBq/nmol) experiment, respectively. CONCLUSION TRIUMF's ISOL facility is able to provide 225Ac suitable for preclinical screening of radiopharmaceutical compounds; [225Ac(octapa)]-, [225Ac(CHXoctapa)]-, and [225Ac(DOTA-CycMSH)] may be good candidates for further targeted alpha therapy studies.
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Affiliation(s)
- Caterina F Ramogida
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada. .,Department of Chemistry, Simon Fraser University, 8888 University Dr, Burnaby, BC, V5A 1S6, Canada.
| | - Andrew K H Robertson
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada.,Department of Physics & Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC, V6T 1Z1, Canada
| | - Una Jermilova
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - Chengcheng Zhang
- Department of Molecular Oncology, BC Cancer Research Centre, 675 West 10th Ave, Vancouver, BC, V5Z 1L3, Canada
| | - Hua Yang
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - Peter Kunz
- Accelerator Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - Jens Lassen
- Accelerator Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - Ivica Bratanovic
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - Victoria Brown
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - Lily Southcott
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada
| | - Cristina Rodríguez-Rodríguez
- Department of Physics & Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC, V6T 1Z1, Canada.,Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Valery Radchenko
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada.,Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, V6T 1Z1, Canada
| | - François Bénard
- Department of Molecular Oncology, BC Cancer Research Centre, 675 West 10th Ave, Vancouver, BC, V5Z 1L3, Canada.,Department of Functional Imaging, BC Cancer, 600 West 10th Ave, Vancouver, BC, V5Z 4E6, Canada.,Department of Radiology, University of British Columbia, 2775 Laurel St, Vancouver, BC, V5Z 1M9, Canada
| | - Chris Orvig
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, V6T 1Z1, Canada
| | - Paul Schaffer
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3, Canada. .,Department of Chemistry, Simon Fraser University, 8888 University Dr, Burnaby, BC, V5A 1S6, Canada. .,Department of Radiology, University of British Columbia, 2775 Laurel St, Vancouver, BC, V5Z 1M9, Canada.
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23
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Wang X, Jaraquemada-Peláez MDG, Rodríguez-Rodríguez C, Cao Y, Buchwalder C, Choudhary N, Jermilova U, Ramogida CF, Saatchi K, Häfeli UO, Patrick BO, Orvig C. H4octox: Versatile Bimodal Octadentate Acyclic Chelating Ligand for Medicinal Inorganic Chemistry. J Am Chem Soc 2018; 140:15487-15500. [DOI: 10.1021/jacs.8b09964] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Xiaozhu Wang
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - María de Guadalupe Jaraquemada-Peláez
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Cristina Rodríguez-Rodríguez
- Center for Comparative Medicine, 4145 Wesbrook Mall, Vancouver, British Columbia V6T 1W5, Canada
- Department of Physics and Astronomy, University of British Columbia, 6224 Agronomy Road, Vancouver, British Columbia V6T 1Z1, Canada
| | - Yang Cao
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Christian Buchwalder
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Neha Choudhary
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - Una Jermilova
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - Caterina F. Ramogida
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada
| | - Katayoun Saatchi
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Urs O. Häfeli
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, British Columbia V6T 1Z3, Canada
| | - Brian O. Patrick
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Chris Orvig
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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24
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Dias GM, Ramogida CF, Rousseau J, Zacchia NA, Hoehr C, Schaffer P, Lin KS, Bénard F. 89 Zr for antibody labeling and in vivo studies – A comparison between liquid and solid target production. Nucl Med Biol 2018; 58:1-7. [DOI: 10.1016/j.nucmedbio.2017.11.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 10/10/2017] [Accepted: 11/15/2017] [Indexed: 11/30/2022]
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25
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Comba P, Jermilova U, Orvig C, Patrick BO, Ramogida CF, Rück K, Schneider C, Starke M. Octadentate Picolinic Acid-Based Bispidine Ligand for Radiometal Ions. Chemistry 2017; 23:15945-15956. [DOI: 10.1002/chem.201702284] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Indexed: 11/10/2022]
Affiliation(s)
- Peter Comba
- Universität Heidelberg; Anorganisch-Chemisches Institut and Interdisciplinary Center for Scientific Computing, INF 270, D-; 69120 Heidelberg Germany
| | - Una Jermilova
- Life Sciences Division; TRIUMF; 4004 Wesbrook Mall Vancouver V6T 2A3 British Columbia Canada
| | - Chris Orvig
- Medicinal Inorganic Chemistry Group; University of British Columbia; Department of Chemistry; 2036 Main Mall Vancouver V6T 1Z1 British Columbia Canada
| | - Brian O. Patrick
- Medicinal Inorganic Chemistry Group; University of British Columbia; Department of Chemistry; 2036 Main Mall Vancouver V6T 1Z1 British Columbia Canada
| | - Caterina F. Ramogida
- Life Sciences Division; TRIUMF; 4004 Wesbrook Mall Vancouver V6T 2A3 British Columbia Canada
| | - Katharina Rück
- Universität Heidelberg; Anorganisch-Chemisches Institut and Interdisciplinary Center for Scientific Computing, INF 270, D-; 69120 Heidelberg Germany
| | - Christina Schneider
- Universität Heidelberg; Anorganisch-Chemisches Institut and Interdisciplinary Center for Scientific Computing, INF 270, D-; 69120 Heidelberg Germany
| | - Miriam Starke
- Universität Heidelberg; Anorganisch-Chemisches Institut and Interdisciplinary Center for Scientific Computing, INF 270, D-; 69120 Heidelberg Germany
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Thiele NA, Brown V, Kelly JM, Amor‐Coarasa A, Jermilova U, MacMillan SN, Nikolopoulou A, Ponnala S, Ramogida CF, Robertson AKH, Rodríguez‐Rodríguez C, Schaffer P, Williams C, Babich JW, Radchenko V, Wilson JJ. An Eighteen‐Membered Macrocyclic Ligand for Actinium‐225 Targeted Alpha Therapy. Angew Chem Int Ed Engl 2017; 56:14712-14717. [DOI: 10.1002/anie.201709532] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Indexed: 01/19/2023]
Affiliation(s)
- Nikki A. Thiele
- Chemistry and Chemical Biology Cornell University Ithaca NY 14853 USA
| | - Victoria Brown
- Life Science Division, TRIUMF Vancouver BC V6T 2A3 Canada
| | | | | | - Una Jermilova
- Life Science Division, TRIUMF Vancouver BC V6T 2A3 Canada
| | | | | | | | | | | | - Cristina Rodríguez‐Rodríguez
- Fac. of Pharmaceutical Sciences, Dept. of Physics and Astronomy and Centre for Comparative Medicine University of British Columbia Vancouver BC V6T 1W5 Canada
| | - Paul Schaffer
- Life Science Division, TRIUMF Vancouver BC V6T 2A3 Canada
| | | | | | | | - Justin J. Wilson
- Chemistry and Chemical Biology Cornell University Ithaca NY 14853 USA
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27
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Thiele NA, Brown V, Kelly JM, Amor‐Coarasa A, Jermilova U, MacMillan SN, Nikolopoulou A, Ponnala S, Ramogida CF, Robertson AKH, Rodríguez‐Rodríguez C, Schaffer P, Williams C, Babich JW, Radchenko V, Wilson JJ. An Eighteen‐Membered Macrocyclic Ligand for Actinium‐225 Targeted Alpha Therapy. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201709532] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Nikki A. Thiele
- Chemistry and Chemical Biology Cornell University Ithaca NY 14853 USA
| | - Victoria Brown
- Life Science Division, TRIUMF Vancouver BC V6T 2A3 Canada
| | | | | | - Una Jermilova
- Life Science Division, TRIUMF Vancouver BC V6T 2A3 Canada
| | | | | | | | | | | | - Cristina Rodríguez‐Rodríguez
- Fac. of Pharmaceutical Sciences, Dept. of Physics and Astronomy and Centre for Comparative Medicine University of British Columbia Vancouver BC V6T 1W5 Canada
| | - Paul Schaffer
- Life Science Division, TRIUMF Vancouver BC V6T 2A3 Canada
| | | | | | | | - Justin J. Wilson
- Chemistry and Chemical Biology Cornell University Ithaca NY 14853 USA
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28
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Spreckelmeyer S, Ramogida CF, Rousseau J, Arane K, Bratanovic I, Colpo N, Jermilova U, Dias GM, Dude I, Jaraquemada-Peláez MDG, Bénard F, Schaffer P, Orvig C. p-NO 2-Bn-H 4neunpa and H 4neunpa-Trastuzumab: Bifunctional Chelator for Radiometalpharmaceuticals and 111In Immuno-Single Photon Emission Computed Tomography Imaging. Bioconjug Chem 2017; 28:2145-2159. [PMID: 28683198 DOI: 10.1021/acs.bioconjchem.7b00311] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Potentially nonadentate (N5O4) bifunctional chelator p-SCN-Bn-H4neunpa and its immunoconjugate H4neunpa-trastuzumab for 111In radiolabeling are synthesized. The ability of p-SCN-Bn-H4neunpa and H4neunpa-trastuzumab to quantitatively radiolabel 111InCl3 at an ambient temperature within 15 or 30 min, respectively, is presented. Thermodynamic stability determination with In3+, Bi3+, and La3+ resulted in high conditional stability constant (pM) values. In vitro human serum stability assays have demonstrated both 111In complexes to have high stability over 5 days. Mouse biodistribution of [111In][In(p-NO2-Bn-neunpa)]-, compared to that of [111In][In(p-NH2-Bn-CHX-A″-diethylenetriamine pentaacetic acid (DTPA))]2-, at 1, 4, and 24 h shows fast clearance of both complexes from the mice within 24 h. In a second mouse biodistribution study, the immunoconjugates 111In-neunpa-trastuzumab and 111In-CHX-A″-DTPA-trastuzumab demonstrate a similar distribution profile but with slightly lower tumor uptake of 111In-neunpa-trastuzumab compared to that of 111In-CHX-A″-DTPA-trastuzumab. These results were also confirmed by immuno-single photon emission computed tomography (immuno-SPECT) imaging in vivo. These initial investigations reveal the acyclic bifunctional chelator p-SCN-Bn-H4neunpa to be a promising chelator for 111In (and other radiometals) with high in vitro stability and also show H4neunpa-trastuzumab to be an excellent 111In chelator with promising biodistribution in mice.
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Affiliation(s)
- Sarah Spreckelmeyer
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada.,Department of Pharmacokinetics, Toxicology and Targeting, Research Institute of Pharmacy, University of Groningen , Antonius Deusinglaan 1, Groningen 9713 AV, The Netherlands
| | - Caterina F Ramogida
- Life Sciences Division, TRIUMF , 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - Julie Rousseau
- BC Cancer Agency , 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - Karen Arane
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Ivica Bratanovic
- Life Sciences Division, TRIUMF , 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - Nadine Colpo
- BC Cancer Agency , 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - Una Jermilova
- Life Sciences Division, TRIUMF , 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - Gemma M Dias
- BC Cancer Agency , 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - Iulia Dude
- BC Cancer Agency , 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - Maria de Guadalupe Jaraquemada-Peláez
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - François Bénard
- BC Cancer Agency , 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - Paul Schaffer
- Life Sciences Division, TRIUMF , 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - Chris Orvig
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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Robertson AKH, Ramogida CF, Rodríguez-Rodríguez C, Blinder S, Kunz P, Sossi V, Schaffer P. Multi-isotope SPECT imaging of the 225Ac decay chain: feasibility studies. Phys Med Biol 2017; 62:4406-4420. [PMID: 28362640 DOI: 10.1088/1361-6560/aa6a99] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Effective use of the [Formula: see text] decay chain in targeted internal radioimmunotherapy requires the retention of both [Formula: see text] and progeny isotopes at the target site. Imaging-based pharmacokinetic tests of these pharmaceuticals must therefore separately yet simultaneously image multiple isotopes that may not be colocalized despite being part of the same decay chain. This work presents feasibility studies demonstrating the ability of a microSPECT/CT scanner equipped with a high energy collimator to simultaneously image two components of the [Formula: see text] decay chain: [Formula: see text] (218 keV) and [Formula: see text] (440 keV). Image quality phantoms were used to assess the performance of two collimators for simultaneous [Formula: see text] and [Formula: see text] imaging in terms of contrast and noise. A hotrod resolution phantom containing clusters of thin rods with diameters ranging between 0.85 and 1.70 mm was used to assess resolution. To demonstrate ability to simultaneously image dynamic [Formula: see text] and [Formula: see text] activity distributions, a phantom containing a [Formula: see text] generator from [Formula: see text] was imaged. These tests were performed with two collimators, a high-energy ultra-high resolution (HEUHR) collimator and an ultra-high sensitivity (UHS) collimator. Values consistent with activity concentrations determined independently via gamma spectroscopy were observed in high activity regions of the images. In hotrod phantom images, the HEUHR collimator resolved all rods for both [Formula: see text] and [Formula: see text] images. With the UHS collimator, no rods were resolvable in [Formula: see text] images and only rods ⩾1.3 mm were resolved in [Formula: see text] images. After eluting the [Formula: see text] generator, images accurately visualized the reestablishment of transient equilibrium of the [Formula: see text] decay chain. The feasibility of evaluating the pharmacokinetics of the [Formula: see text] decay chain in vivo has been demonstrated. This presented method requires the use of a high-performance high-energy collimator.
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Affiliation(s)
- A K H Robertson
- Life Sciences Division, TRIUMF, 4004 Wesbrook Mall, Vancouver BC, V6T 2A3, Canada. Department of Physics and Astronomy, University of British Columbia (UBC), 6224 Agronomy Road, Vancouver BC, V6T 1Z1, Canada
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Weekes DM, Ramogida CF, Jaraquemada-Peláez MDG, Patrick BO, Apte C, Kostelnik TI, Cawthray JF, Murphy L, Orvig C. Dipicolinate Complexes of Gallium(III) and Lanthanum(III). Inorg Chem 2016; 55:12544-12558. [DOI: 10.1021/acs.inorgchem.6b02357] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- David M. Weekes
- Medicinal Inorganic Chemistry Group, Department
of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Caterina F. Ramogida
- Medicinal Inorganic Chemistry Group, Department
of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Maria de Guadalupe Jaraquemada-Peláez
- Medicinal Inorganic Chemistry Group, Department
of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Brian O. Patrick
- Medicinal Inorganic Chemistry Group, Department
of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Chirag Apte
- Medicinal Inorganic Chemistry Group, Department
of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Thomas I. Kostelnik
- Medicinal Inorganic Chemistry Group, Department
of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Jacqueline F. Cawthray
- Medicinal Inorganic Chemistry Group, Department
of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Lisa Murphy
- Medicinal Inorganic Chemistry Group, Department
of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Chris Orvig
- Medicinal Inorganic Chemistry Group, Department
of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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31
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Ramogida CF, Boros E, Patrick BO, Zeisler SK, Kumlin J, Adam MJ, Schaffer P, Orvig C. Evaluation of H2CHXdedpa, H2dedpa- and H2CHXdedpa-N,N′-propyl-2-NI ligands for 64Cu(ii) radiopharmaceuticals. Dalton Trans 2016; 45:13082-90. [DOI: 10.1039/c6dt00932h] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Hexadentate acyclic chelate H2CHXdedpa and related N,N′-alkylated ligands are radiolabeled with radioactive 64Cu(ii) under mild conditions forming kinetically inert complexes.
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Affiliation(s)
- Caterina F. Ramogida
- Medicinal Inorganic Chemistry Group
- Department of Chemistry
- University of British Columbia
- Vancouver
- Canada
| | - Eszter Boros
- Medicinal Inorganic Chemistry Group
- Department of Chemistry
- University of British Columbia
- Vancouver
- Canada
| | - Brian O. Patrick
- Medicinal Inorganic Chemistry Group
- Department of Chemistry
- University of British Columbia
- Vancouver
- Canada
| | | | | | | | | | - Chris Orvig
- Medicinal Inorganic Chemistry Group
- Department of Chemistry
- University of British Columbia
- Vancouver
- Canada
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Ramogida CF, Pan J, Ferreira CL, Patrick BO, Rebullar K, Yapp DTT, Lin KS, Adam MJ, Orvig C. Nitroimidazole-Containing H2dedpa and H2CHXdedpa Derivatives as Potential PET Imaging Agents of Hypoxia with (68)Ga. Inorg Chem 2015; 54:4953-65. [PMID: 25928800 DOI: 10.1021/acs.inorgchem.5b00554] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
(68)Ga is an attractive radiometal for use in positron emission tomography (PET) imaging. The success of (68)Ga-based agents is dependent on a chelator that exhibits rapid radiometal incorporation, and strong kinetic inertness to prevent transchelation of (68)Ga in vivo. The linear chelating agents H2dedpa (1,2-[[6-carboxypyridin-2-yl]methylamino]ethane) and H2CHXdedpa (CHX = cyclohexyl/cyclohexane) (N4O2) have recently been developed that bind Ga(3+) quickly and under mild conditions, ideal properties to be incorporated into a (68)Ga PET imaging agent. Herein, nitroimidazole (NI) derivatives of H2dedpa and H2CHXdedpa to investigate specific targeting of hypoxic tumor cells are investigated, given that NI can be reduced and retained exclusively in hypoxic cells. Nine N,N'-bis-alkylated derivatives of H2dedpa and H2CHXdedpa have been synthesized; they have been screened for their ability to bind gallium, and cyclic voltammetry of nonradioactive complexes was performed to probe the redox cycling mechanism of NI. The compounds were radiolabeled with (67)Ga and (68)Ga and show promising radiolabeling efficiencies (>99%) when labeled at 10(-5) M for 10 min at room temperature. Moreover, stability studies (via apo-transferrin challenge, 37 °C) show that the (67)Ga complexes exhibit exceptional stability (86-99% intact) after 2 h. In vitro uptake studies under hypoxic (0.5% O2) and normoxic (21% O2) conditions in three cancerous cell lines [HT-29 (colon), LCC6(HER-2) (breast), and CHO (Chinese hamster ovarian)] were performed. Of the four H2dedpa or H2CHXdedpa NI derivatives tested, all showed preferential uptake in hypoxic cells compared to normoxic cells with hypoxic/normoxic ratios as high as 7.9 ± 2.7 after 120 min. The results suggest that these novel bis-alkylated NI-containing H2dedpa and H2CHXdedpa ligands would be ideal candidates for further testing in vivo for PET imaging of hypoxia with (68)Ga.
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Affiliation(s)
- Caterina F Ramogida
- †Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada.,‡TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - Jinhe Pan
- §BC Cancer Agency, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - Cara L Ferreira
- ∥Nordion, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - Brian O Patrick
- †Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Karla Rebullar
- †Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Donald T T Yapp
- §BC Cancer Agency, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - Kuo-Shyan Lin
- §BC Cancer Agency, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada
| | - Michael J Adam
- ‡TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - Chris Orvig
- †Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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Ramogida CF, Cawthray JF, Boros E, Ferreira CL, Patrick BO, Adam MJ, Orvig C. H2CHXdedpa and H4CHXoctapa—Chiral Acyclic Chelating Ligands for 67/68Ga and 111In Radiopharmaceuticals. Inorg Chem 2015; 54:2017-31. [DOI: 10.1021/ic502942a] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Caterina F. Ramogida
- Medicinal Inorganic
Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - Jacqueline F. Cawthray
- Medicinal Inorganic
Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Eszter Boros
- Medicinal Inorganic
Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - Cara L. Ferreira
- Nordion, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - Brian O. Patrick
- Medicinal Inorganic
Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Michael J. Adam
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia V6T 2A3, Canada
| | - Chris Orvig
- Medicinal Inorganic
Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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Abstract
Use of radiometals in nuclear oncology is a rapidly growing field and encompasses a broad spectrum of radiotracers for imaging via PET (positron emission tomography) or SPECT (single-photon emission computed tomography) and therapy via α, β(-), or Auger electron emission. This feature article opens with a brief introduction to the imaging and therapy modalities exploited in nuclear medicine, followed by a discussion of the multi-component strategy used in radiopharmaceutical development, known as the bifunctional chelate (BFC) method. The modular assembly is dissected into its individual components and each is discussed separately. The concepts and knowledge unique to metal-based designs are outlined, giving insight into how these radiopharmaceuticals are evaluated for use in vivo. Imaging nuclides (64)Cu, (68)Ga, (86)Y, (89)Zr, and (111)In, and therapeutic nuclides (90)Y, (177)Lu, (225)Ac, (213)Bi, (188)Re, and (212)Pb will be the focus herein. Finally, key examples have been extracted from the literature to give the reader a sense of breadth of the field.
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Affiliation(s)
- Caterina F Ramogida
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, Canada V6T 1Z1
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Price EW, Zeglis BM, Cawthray JF, Ramogida CF, Ramos N, Lewis JS, Adam MJ, Orvig C. H(4)octapa-trastuzumab: versatile acyclic chelate system for 111In and 177Lu imaging and therapy. J Am Chem Soc 2013; 135:12707-21. [PMID: 23901833 PMCID: PMC3787943 DOI: 10.1021/ja4049493] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A bifunctional derivative of the versatile acyclic chelator H4octapa, p-SCN-Bn-H4octapa, has been synthesized for the first time. The chelator was conjugated to the HER2/neu-targeting antibody trastuzumab and labeled in high radiochemical purity and specific activity with the radioisotopes (111)In and (177)Lu. The in vivo behavior of the resulting radioimmunoconjugates was investigated in mice bearing ovarian cancer xenografts and compared to analogous radioimmunoconjugates employing the ubiquitous chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA). The H4octapa-trastuzumab conjugates displayed faster radiolabeling kinetics with more reproducible yields under milder conditions (15 min, RT, ~94-95%) than those based on DOTA-trastuzumab (60 min, 37 °C, ~50-88%). Further, antibody integrity was better preserved in the (111)In- and (177)Lu-octapa-trastuzumab constructs, with immunoreactive fractions of 0.99 for each compared to 0.93-0.95 for (111)In- and (177)Lu-DOTA-trastuzumab. These results translated to improved in vivo biodistribution profiles and SPECT imaging results for (111)In- and (177)Lu-octapa-trastuzumab compared to (111)In- and (177)Lu-DOTA-trastuzumab, with increased tumor uptake and higher tumor-to-tissue activity ratios.
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MESH Headings
- Animals
- Antibodies, Monoclonal, Humanized/chemistry
- Antibodies, Monoclonal, Humanized/therapeutic use
- Antineoplastic Agents/chemistry
- Antineoplastic Agents/therapeutic use
- Chelating Agents/chemistry
- Chelating Agents/therapeutic use
- Ethylamines/chemistry
- Ethylamines/pharmacology
- Female
- Heterocyclic Compounds, 1-Ring/chemistry
- Heterocyclic Compounds, 1-Ring/therapeutic use
- Humans
- Indium Radioisotopes/chemistry
- Indium Radioisotopes/therapeutic use
- Lutetium/chemistry
- Lutetium/therapeutic use
- Mice
- Mice, Nude
- Models, Molecular
- Molecular Structure
- Neoplasm Transplantation
- Neoplasms, Experimental/diagnosis
- Neoplasms, Experimental/drug therapy
- Pyridines/chemistry
- Pyridines/pharmacology
- Radiopharmaceuticals/chemistry
- Radiopharmaceuticals/therapeutic use
- Tissue Distribution
- Trastuzumab
- Tumor Cells, Cultured
- Xenograft Model Antitumor Assays
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Affiliation(s)
- Eric W. Price
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada, V6T 1Z1
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada, V6T 2A3
| | - Brian M. Zeglis
- Department of Radiology and Program in Molecular Pharmacology and Chemistry, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York, 10065, United States of America
| | - Jacqueline F. Cawthray
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada, V6T 1Z1
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada, V6T 2A3
| | - Caterina F. Ramogida
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada, V6T 1Z1
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada, V6T 2A3
| | - Nicholas Ramos
- Department of Radiology and Program in Molecular Pharmacology and Chemistry, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York, 10065, United States of America
| | - Jason S. Lewis
- Department of Radiology and Program in Molecular Pharmacology and Chemistry, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York, 10065, United States of America
| | - Michael J. Adam
- TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada, V6T 2A3
| | - Chris Orvig
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada, V6T 1Z1
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Dunn TJ, Chiang L, Ramogida CF, Hazin K, Webb MI, Katz MJ, Storr T. Class III Delocalization and Exciton Coupling in a Bimetallic Bis-ligand Radical Complex. Chemistry 2013; 19:9606-18. [DOI: 10.1002/chem.201300798] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Indexed: 11/07/2022]
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Dunn TJ, Chiang L, Ramogida CF, Webb MI, Savard D, Sakaguchi M, Ogura T, Shimazaki Y, Storr T. Non-innocent ligand behaviour of a bimetallic Cu complex employing a bridging catecholate. Dalton Trans 2012; 41:7905-14. [DOI: 10.1039/c2dt30444a] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [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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Dunn TJ, Ramogida CF, Simmonds C, Paterson A, Wong EWY, Chiang L, Shimazaki Y, Storr T. Non-Innocent Ligand Behavior of a Bimetallic Ni Schiff-Base Complex Containing a Bridging Catecholate. Inorg Chem 2011; 50:6746-55. [DOI: 10.1021/ic200785g] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Tim J. Dunn
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A-1S6, Canada
| | - Caterina F. Ramogida
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A-1S6, Canada
| | - Curtis Simmonds
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A-1S6, Canada
| | - Alisa Paterson
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A-1S6, Canada
| | - Edwin W. Y. Wong
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A-1S6, Canada
| | - Linus Chiang
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A-1S6, Canada
| | - Yuichi Shimazaki
- College of Science, Ibaraki University, Bunkyo, Mito 310-8512, Japan
| | - Tim Storr
- Department of Chemistry, Simon Fraser University, Burnaby, British Columbia V5A-1S6, Canada
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Shimazaki Y, Arai N, Dunn TJ, Yajima T, Tani F, Ramogida CF, Storr T. Influence of the chelate effect on the electronic structure of one-electron oxidized group 10 metal(ii)-(disalicylidene)diamine complexes. Dalton Trans 2011; 40:2469-79. [DOI: 10.1039/c0dt01574a] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [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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