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Merdzo I, Travagin F, Boccalon M, Alessio E, Lattuada L, Baranyai Z, Giovenzana GB. TRASUTA: The Effect of the Structural Rigidity of a Mesocyclic AAZTA-like Chelating Agent on the Thermodynamic, Kinetic, and Structural Properties of Some Divalent Metal and Ga 3+ Complexes. Inorg Chem 2024; 63:12525-12537. [PMID: 38905138 DOI: 10.1021/acs.inorgchem.4c01413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/23/2024]
Abstract
Mesocyclic chelating agents such as AAZTA and its derivatives have been recently reported to overcome the relatively low thermodynamic stability of metal complexes of acyclic chelating agents and the slow complexation kinetics of macrocyclic chelating agents. This work reports the preparation of a spirobicyclic hexadentate AAZTA-like chelating agent (TRASUTA) and the investigation of the thermodynamic, kinetic, and structural properties of the corresponding chelates with the PET-relevant Ga3+ and selected metal ions. A combination of analytical techniques allowed identification of a coordination isomerization process, involving the coordinating side arms and the inversion of a nitrogen atom and leading to lower thermodynamic and kinetic inertness with respect to mononuclear mesocyclic analogues. The bicyclic system of TRASUTA retains significant dynamics despite the conformational constraint imposed by the spiro-fusion, resulting in a lower stability of the corresponding metal chelates.
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Affiliation(s)
- Ileana Merdzo
- Bracco Imaging Spa, AREA Science Park, ed. Q─S.S. 14 Km 163,5, Basovizza 34149, (TS), Italy
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via L. Giorgieri 1, Trieste 34127, (TS), Italy
| | - Fabio Travagin
- Dipartimento di Scienze del Farmaco, Università Degli Studi Del Piemonte Orientale, Largo Donegani 2/3, Novara 28100, (NO), Italy
| | - Mariangela Boccalon
- Bracco Imaging Spa, AREA Science Park, ed. Q─S.S. 14 Km 163,5, Basovizza 34149, (TS), Italy
| | - Enzo Alessio
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via L. Giorgieri 1, Trieste 34127, (TS), Italy
| | - Luciano Lattuada
- Bracco Imaging Spa, Bracco Research Centre, Via Ribes 5, Colleretto Giacosa 10010, (TO), Italy
| | - Zsolt Baranyai
- Bracco Imaging Spa, AREA Science Park, ed. Q─S.S. 14 Km 163,5, Basovizza 34149, (TS), Italy
| | - Giovanni B Giovenzana
- Dipartimento di Scienze del Farmaco, Università Degli Studi Del Piemonte Orientale, Largo Donegani 2/3, Novara 28100, (NO), Italy
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Wang R, Jin W, Luo Y, Hong H, Zhao R, Li L, Yan L, Qiao J, Ploessl K, Zhu L, Kung HF. Novel [ 68Ga/ 177Lu]Ga/Lu-AZ-093 as PSMA-Targeting Agent for Diagnosis and Radiotherapy. Mol Pharm 2024; 21:3256-3267. [PMID: 38856975 DOI: 10.1021/acs.molpharmaceut.4c00020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Prostate-specific membrane antigen (PSMA) overexpressed in prostate cancer cells can serve as a target for imaging and radioligand therapy (RLT). Previously, [68Ga]Ga-P16-093, containing a Ga(III) chelator, N,N'-bis[2-hydroxy-5-(carboxyethyl)benzyl]ethylenediamine-N,N'-diacetic acid (HBED-CC), displayed excellent PSMA-targeting properties and showed a high tumor uptake and retention useful for diagnosis in prostate cancer patients. Recently, [177Lu]Lu-PSMA-617 has been approved by the U.S. food and drug administration (FDA) for the treatment of prostate cancer patients. Derivatives of PSMA-093 using AAZTA (6-amino-6-methylperhydro-1,4-diazepinetetraacetic acid), as the chelator, were designed as alternative agents forming complexes with both diagnostic and therapeutic radiometals, such as gallium-68 (log K = 22.18) or lutetium-177 (log K = 21.85). The aim of this study is to evaluate AAZTA-Gly-O-(methylcarboxy)-Tyr-Phe-Lys-NH-CO-NH-Glu (designated as AZ-093, 1) leading to a gallium-68/lutetium-177 theranostic pair as potential PSMA targeting agents. Synthesis of the desired precursor, AZ-093, 1, was effectively accomplished. Labeling with either [68Ga]GaCl3 or [177Lu]LuCl3 in a sodium acetate buffer solution (pH 4-5) at 50 °C in 5 to 15 min produced either [68Ga]Ga-1 or [177Lu]Lu-1 with high yields and excellent radiochemical purities. Results of in vitro binding studies, cell uptake, and retention (using PSMA-positive prostate carcinoma cells line, 22Rv1-FOLH1-oe) were comparable to that of [68Ga]Ga-P16-093 and [177Lu]Lu-PSMA-617, respectively. Specific cellular uptake was determined with or without the competitive blocking agent (2 μM of "cold" PSMA-11). Cellular binding and internalization showed a time-dependent increase over 2 h at 37 °C in the PSMA-positive cells. The cell uptakes were completely blocked by the "cold" PSMA-11 suggesting that they are competing for the same PSMA binding sites. In the mouse model with implanted PSMA-positive tumor cells, both [68Ga]Ga-1 and [177Lu]Lu-1 displayed excellent uptake and retention in the tumor. Results indicate that [68Ga]Ga/[177Lu]Lu-1 (68Ga]Ga/[177Lu]Lu-AZ-093) is potentially useful as PSMA-targeting agent for both diagnosis and radiotherapy of prostate cancer.
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Affiliation(s)
- Ran Wang
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
- Department of Nuclear Medicine, The Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen 518107, China
| | - Wenbin Jin
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, Guangdong 518000, China
| | - Yang Luo
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Haiyan Hong
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Ruiyue Zhao
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Linlin Li
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Li Yan
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Jinping Qiao
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Karl Ploessl
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Five Eleven Pharma Inc., Philadelphia, Pennsylvania 19104, United States
| | - Lin Zhu
- Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Hank F Kung
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Five Eleven Pharma Inc., Philadelphia, Pennsylvania 19104, United States
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Phipps MD, Cingoranelli S, Bhupathiraju NVSDK, Younes A, Cao M, Sanders VA, Neary MC, Daveny MH, Cutler CS, Lopez GE, Saini S, Parker CC, Fernandez SR, Lewis JS, Lapi SE, Francesconi LC, Deri MA. Sc-HOPO: A Potential Construct for Use in Radioscandium-Based Radiopharmaceuticals. Inorg Chem 2023; 62:20567-20581. [PMID: 36724083 PMCID: PMC10390652 DOI: 10.1021/acs.inorgchem.2c03931] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Three isotopes of scandium─43Sc, 44Sc, and 47Sc─have attracted increasing attention as potential candidates for use in imaging and therapy, respectively, as well as for possible theranostic use as an elementally matched pair. Here, we present the octadentate chelator 3,4,3-(LI-1,2-HOPO) (or HOPO), an effective chelator for hard cations, as a potential ligand for use in radioscandium constructs with simple radiolabeling under mild conditions. HOPO forms a 1:1 Sc-HOPO complex that was fully characterized, both experimentally and theoretically. [47Sc]Sc-HOPO exhibited good stability in chemical and biological challenges over 7 days. In healthy mice, [43,47Sc]Sc-HOPO cleared the body rapidly with no signs of demetalation. HOPO is a strong candidate for use in radioscandium-based radiopharmaceuticals.
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Affiliation(s)
- Michael D Phipps
- Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY 10016
- Department of Chemistry, City University of New York Hunter College, 695 Park Avenue, New York, New York 10065
- Department of Chemistry, Lehman College of the City University of New York, Bronx, NY 10468
- Medical Isotope Research & Production Laboratory, Collider-Accelerator Division, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Shelbie Cingoranelli
- Department of Radiology, University of Alabama at Birmingham, Birmingham, AL 35294
| | | | - Ali Younes
- Department of Chemistry, City University of New York Hunter College, 695 Park Avenue, New York, New York 10065
| | - Minhua Cao
- Department of Chemistry, City University of New York Hunter College, 695 Park Avenue, New York, New York 10065
| | - Vanessa A. Sanders
- Medical Isotope Research & Production Laboratory, Collider-Accelerator Division, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Michelle C. Neary
- Department of Chemistry, City University of New York Hunter College, 695 Park Avenue, New York, New York 10065
| | - Matthew H. Daveny
- Department of Chemistry, City University of New York Hunter College, 695 Park Avenue, New York, New York 10065
| | - Cathy S. Cutler
- Medical Isotope Research & Production Laboratory, Collider-Accelerator Division, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Gustavo E. Lopez
- Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY 10016
- Department of Chemistry, Lehman College of the City University of New York, Bronx, NY 10468
| | - Shefali Saini
- Department of Radiology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Candace C. Parker
- Department of Radiology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Solana R. Fernandez
- Department of Radiology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Jason S. Lewis
- Program in Molecular Pharmacology and Chemistry, Memorial Sloan Kettering Cancer Center, New York, NY 10065
| | - Suzanne E. Lapi
- Department of Radiology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Lynn C. Francesconi
- Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY 10016
- Department of Chemistry, City University of New York Hunter College, 695 Park Avenue, New York, New York 10065
| | - Melissa A. Deri
- Ph.D. Program in Chemistry, The Graduate Center of the City University of New York, New York, NY 10016
- Department of Chemistry, Lehman College of the City University of New York, Bronx, NY 10468
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Kilian K, Pyrzyńska K. Scandium Radioisotopes-Toward New Targets and Imaging Modalities. Molecules 2023; 28:7668. [PMID: 38005390 PMCID: PMC10675654 DOI: 10.3390/molecules28227668] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 11/15/2023] [Accepted: 11/15/2023] [Indexed: 11/26/2023] Open
Abstract
The concept of theranostics uses radioisotopes of the same or chemically similar elements to label biological ligands in a way that allows the use of diagnostic and therapeutic radiation for a combined diagnosis and treatment regimen. For scandium, radioisotopes -43 and -44 can be used as diagnostic markers, while radioisotope scandium-47 can be used in the same configuration for targeted therapy. This work presents the latest achievements in the production and processing of radioisotopes and briefly characterizes solutions aimed at increasing the availability of these radioisotopes for research and clinical practice.
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Affiliation(s)
- Krzysztof Kilian
- Heavy Ion Laboratory, University of Warsaw, Pasteura 5a, 02-093 Warsaw, Poland
| | - Krystyna Pyrzyńska
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland;
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[111In]In/[177Lu]Lu-AAZTA5-LM4 SST2R-Antagonists in Cancer Theranostics: From Preclinical Testing to First Patient Results. Pharmaceutics 2023; 15:pharmaceutics15030776. [PMID: 36986637 PMCID: PMC10053881 DOI: 10.3390/pharmaceutics15030776] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 02/23/2023] [Accepted: 02/24/2023] [Indexed: 03/03/2023] Open
Abstract
Aiming to expand the application of the SST2R-antagonist LM4 (DPhe-c[DCys-4Pal-DAph(Cbm)-Lys-Thr-Cys]-DTyr-NH2) beyond [68Ga]Ga-DATA5m-LM4 PET/CT (DATA5m, (6-pentanoic acid)-6-(amino)methy-1,4-diazepinetriacetate), we now introduce AAZTA5-LM4 (AAZTA5, 1,4-bis(carboxymethyl)-6-[bis(carboxymethyl)]amino-6-[pentanoic-acid]perhydro-1,4-diazepine), allowing for the convenient coordination of trivalent radiometals of clinical interest, such as In-111 (for SPECT/CT) or Lu-177 (for radionuclide therapy). After labeling, the preclinical profiles of [111In]In-AAZTA5-LM4 and [177Lu]Lu-AAZTA5-LM4 were compared in HEK293-SST2R cells and double HEK293-SST2R/wtHEK293 tumor-bearing mice using [111In]In-DOTA-LM3 and [177Lu]Lu-DOTA-LM3 as references. The biodistribution of [177Lu]Lu-AAZTA5-LM4 was additionally studied for the first time in a NET patient. Both [111In]In-AAZTA5-LM4 and [177Lu]Lu-AAZTA5-LM4 displayed high and selective targeting of the HEK293-SST2R tumors in mice and fast background clearance via the kidneys and the urinary system. This pattern was reproduced for [177Lu]Lu-AAZTA5-LM4 in the patient according to SPECT/CT results in a monitoring time span of 4–72 h pi. In view of the above, we may conclude that [177Lu]Lu-AAZTA5-LM4 shows promise as a therapeutic radiopharmaceutical candidate for SST2R-expressing human NETs, based on previous [68Ga]Ga-DATA5m-LM4 PET/CT, but further studies are needed to fully assess its clinical value. Furthermore, [111In]In-AAZTA5-LM4 SPECT/CT may represent a legitimate alternative diagnostic option in cases where PET/CT is not available.
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Modern Developments in Bifunctional Chelator Design for Gallium Radiopharmaceuticals. MOLECULES (BASEL, SWITZERLAND) 2022; 28:molecules28010203. [PMID: 36615397 PMCID: PMC9822085 DOI: 10.3390/molecules28010203] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/19/2022] [Accepted: 12/19/2022] [Indexed: 12/28/2022]
Abstract
The positron-emitting radionuclide gallium-68 has become increasingly utilised in both preclinical and clinical settings with positron emission tomography (PET). The synthesis of radiochemically pure gallium-68 radiopharmaceuticals relies on careful consideration of the coordination chemistry. The short half-life of 68 min necessitates rapid quantitative radiolabelling (≤10 min). Desirable radiolabelling conditions include near-neutral pH, ambient temperatures, and low chelator concentrations to achieve the desired apparent molar activity. This review presents a broad overview of the requirements of an efficient bifunctional chelator in relation to the aqueous coordination chemistry of gallium. Developments in bifunctional chelator design and application are then presented and grouped according to eight categories of bifunctional chelator: the macrocyclic chelators DOTA and TACN; the acyclic HBED, pyridinecarboxylates, siderophores, tris(hydroxypyridinones), and DTPA; and the mesocyclic diazepines.
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Horváth D, Vágner A, Szikra D, Trencsényi G, Demitri N, Guidolin N, Maiocchi A, Ghiani S, Travagin F, Giovenzana GB, Baranyai Z. Boosting Bismuth(III) Complexation for Targeted α-Therapy (TAT) Applications with the Mesocyclic Chelating Agent AAZTA. Angew Chem Int Ed Engl 2022; 61:e202207120. [PMID: 36073561 PMCID: PMC9828418 DOI: 10.1002/anie.202207120] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Indexed: 01/12/2023]
Abstract
Targeted α therapy (TAT) is a promising tool in the therapy of cancer. The radionuclide 213 BiIII shows favourable physical properties for this application, but the fast and stable chelation of this metal ion remains challenging. Herein, we demonstrate that the mesocyclic chelator AAZTA quickly coordinates BiIII at room temperature, leading to a robust complex. A comprehensive study of the structural, thermodynamic and kinetic properties of [Bi(AAZTA)]- is reported, along with bifunctional [Bi(AAZTA-C4-COO- )]2- and the targeted agent [Bi(AAZTA-C4-TATE)]- , which incorporates the SSR agonist Tyr3 -octreotate. An unexpected increase in the stability and kinetic inertness of the metal chelate was observed for the bifunctional derivative and was maintained for the peptide conjugate. A cyclotron-produced 205/206 Bi mixture was used as a model of 213 Bi in labelling, stability, and biodistribution experiments, allowing the efficiency of [213 Bi(AAZTA-C4-TATE)]- to be estimated. High accumulation in AR42J tumours and reduced kidney uptake were observed with respect to the macrocyclic chelate [213 Bi(DOTA-TATE)]- .
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Affiliation(s)
- Dávid Horváth
- Department of Physical ChemistryUniversity of DebrecenEgyetem tér 14010DebrecenHungary
| | | | - Dezsö Szikra
- Scanomed Ltd.Nagyerdei Krt. 984032DebrecenHungary,Medical Imaging ClinicUniversity of DebrecenNagyerdei krt. 984032DebrecenHungary
| | - György Trencsényi
- Scanomed Ltd.Nagyerdei Krt. 984032DebrecenHungary,Medical Imaging ClinicUniversity of DebrecenNagyerdei krt. 984032DebrecenHungary
| | - Nicola Demitri
- Elettra-Sincrotrone TriesteS.S. 14 Km 163.5 in Area Science Park34149Basovizza (TS)Italy
| | - Nicol Guidolin
- Bracco Imaging SpaBracco Research CentreVia Ribes 510010Colleretto Giacosa (TO)Italy
| | - Alessandro Maiocchi
- Bracco Imaging SpaBracco Research CentreVia Ribes 510010Colleretto Giacosa (TO)Italy
| | - Simona Ghiani
- Bracco Imaging SpaBracco Research CentreVia Ribes 510010Colleretto Giacosa (TO)Italy
| | - Fabio Travagin
- Dipartimento di Scienze del FarmacoUniversità del Piemonte OrientaleLargo Donegani 2/328100NovaraItaly
| | - Giovanni B. Giovenzana
- Dipartimento di Scienze del FarmacoUniversità del Piemonte OrientaleLargo Donegani 2/328100NovaraItaly
| | - Zsolt Baranyai
- Bracco Imaging SpaBracco Research CentreVia Ribes 510010Colleretto Giacosa (TO)Italy
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8
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Horváth D, Vágner A, Szikra D, Trencsényi G, Demitri N, Guidolin N, Maiocchi A, Ghiani S, Travagin F, Giovenzana GB, Baranyai Z. Boosting Bismuth(III) Complexation for Targeted α‐Therapy (TAT) Applications with the Mesocyclic Chelating Agent AAZTA. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202207120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Dávid Horváth
- University of Debrecen Department of Physical Chemistry HUNGARY
| | | | | | | | - Nicola Demitri
- Elettra Sincrotrone Trieste SCpA Elettra Sincrotrone Trieste SCpA ITALY
| | | | | | | | - Fabio Travagin
- Universita degli Studi del Piemonte Orientale Amedeo Avogadro Dipartimento di Scienze del Farmaco ITALY
| | - Giovanni Battista Giovenzana
- Università degli Studi del Piemonte Orientale Amedeo Avogadro Facoltà di Farmacia: Universita degli Studi del Piemonte Orientale Amedeo Avogadro Dipartimento di Scienze del Farmaco Dipartimento di Scienze del Farmaco Largo Donegani 2/3Via Bovio 6 28100 Novara ITALY
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9
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Aldrich KE, Popov IA, Root HD, Batista ER, Greer SM, Kozimor SA, Lilley LM, Livshits MY, Mocko V, Janicke MT, Scott BL, Stein BW, Yang P. Synthesis, solid-state, solution, and theoretical characterization of an "in-cage" scandium-NOTA complex. Dalton Trans 2022; 51:9994-10005. [PMID: 35739082 DOI: 10.1039/d1dt03887g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Developing chelators that strongly and selectively bind rare-earth elements (Sc, Y, La, and lanthanides) represents a longstanding fundamental challenge in inorganic chemistry. Solving these challenges is becoming more important because of increasing use of rare-earth elements in numerous technologies, ranging from paramagnets to luminescent materials. Within this context, we interrogated the complexation chemistry of the scandium(III) (Sc3+) trication with the hexadentate 1,4,7-triazacyclononane-1,4,7-triacetic acid (H3NOTA) chelator. This H3NOTA chelator is often regarded as an underperformer for complexing Sc3+. A common assumption is that metalation does not fully encapsulate Sc3+ within the NOTA3- macrocycle, leaving Sc3+ on the periphery of the chelate and susceptible to demetalation. Herein, we developed a synthetic approach that contradicted those assumptions. We confirmed that our procedure forced Sc3+ into the NOTA3- binding pocket by using single crystal X-ray diffraction to determine the Na[Sc(NOTA)(OOCCH3)] structure. Density functional theory (DFT) and 45Sc nuclear magnetic resonance (NMR) spectroscopy showed Sc3+ encapsulation was retained when the crystals were dissolved. Solution-phase and DFT studies revealed that [Sc(NOTA)(OOCCH3)]1- could accommodate an additional H2O capping ligand. Thermodynamic properties associated with the Sc-OOCCH3 and Sc-H2O capping ligand interactions demonstrated that these capping ligands occupied critical roles in stabilizing the [Sc(NOTA)] chelation complex.
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Affiliation(s)
| | - Ivan A Popov
- Los Alamos National Laboratory, Los Alamos, NM, USA. .,Department of Chemistry, The University of Akron, Akron, Ohio 44325-3601, USA
| | | | | | | | | | | | | | | | | | - Brian L Scott
- Los Alamos National Laboratory, Los Alamos, NM, USA.
| | | | - Ping Yang
- Los Alamos National Laboratory, Los Alamos, NM, USA.
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Fersing C, Masurier N, Rubira L, Deshayes E, Lisowski V. AAZTA-Derived Chelators for the Design of Innovative Radiopharmaceuticals with Theranostic Applications. Pharmaceuticals (Basel) 2022; 15:234. [PMID: 35215346 PMCID: PMC8879111 DOI: 10.3390/ph15020234] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 02/12/2022] [Accepted: 02/14/2022] [Indexed: 02/06/2023] Open
Abstract
With the development of 68Ga and 177Lu radiochemistry, theranostic approaches in modern nuclear medicine enabling patient-centered personalized medicine applications have been growing in the last decade. In conjunction with the search for new relevant molecular targets, the design of innovative chelating agents to easily form stable complexes with various radiometals for theranostic applications has gained evident momentum. Initially conceived for magnetic resonance imaging applications, the chelating agent AAZTA features a mesocyclic seven-membered diazepane ring, conferring some of the properties of both acyclic and macrocyclic chelating agents. Described in the early 2000s, AAZTA and its derivatives exhibited interesting properties once complexed with metals and radiometals, combining a fast kinetic of formation with a slow kinetic of dissociation. Importantly, the extremely short coordination reaction times allowed by AAZTA derivatives were particularly suitable for short half-life radioelements (i.e., 68Ga). In view of these particular characteristics, the scope of this review is to provide a survey on the design, synthesis, and applications in the nuclear medicine/radiopharmacy field of AAZTA-derived chelators.
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Affiliation(s)
- Cyril Fersing
- Nuclear Medicine Department, Institut Régional du Cancer de Montpellier (ICM), University Montpellier, 34298 Montpellier, France; (L.R.); (E.D.)
- IBMM, University Montpellier, CNRS, ENSCM, 34293 Montpellier, France; (N.M.); (V.L.)
| | - Nicolas Masurier
- IBMM, University Montpellier, CNRS, ENSCM, 34293 Montpellier, France; (N.M.); (V.L.)
| | - Léa Rubira
- Nuclear Medicine Department, Institut Régional du Cancer de Montpellier (ICM), University Montpellier, 34298 Montpellier, France; (L.R.); (E.D.)
| | - Emmanuel Deshayes
- Nuclear Medicine Department, Institut Régional du Cancer de Montpellier (ICM), University Montpellier, 34298 Montpellier, France; (L.R.); (E.D.)
- Institut de Recherche en Cancérologie de Montpellier (IRCM), INSERM U1194, Institut Régional du Cancer de Montpellier (ICM), University of Montpellier, 34298 Montpellier, France
| | - Vincent Lisowski
- IBMM, University Montpellier, CNRS, ENSCM, 34293 Montpellier, France; (N.M.); (V.L.)
- Department of Pharmacy, Lapeyronie Hospital, CHU Montpellier, 191 Av. du Doyen Gaston Giraud, 34295 Montpellier, France
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11
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Chakravarty R, Chakraborty S. A review of advances in the last decade on targeted cancer therapy using 177Lu: focusing on 177Lu produced by the direct neutron activation route. AMERICAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 2021; 11:443-475. [PMID: 35003885 PMCID: PMC8727880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 10/09/2021] [Indexed: 06/14/2023]
Abstract
Lutetium-177 [T½ = 6.76 d; Eβ (max) = 0.497 MeV; maximum tissue range ~2.5 mm; 208 keV γ-ray] is one of the most important theranostic radioisotope used for the management of various oncological and non-oncological disorders. The present review chronicles the advancement in the last decade in 177Lu-radiopharmacy with a focus on 177Lu produced via direct 176Lu (n, γ) 177Lu nuclear reaction in medium flux research reactors. The specific nuances of 177Lu production by various routes are described and their pros and cons are discussed. Lutetium, is the last element in the lanthanide series. Its chemistry plays a vital role in the preparation of a wide variety of radiopharmaceuticals which demonstrate appreciable in vivo stability. Traditional bifunctional chelators (BFCs) that are used for 177Lu-labeling are discussed and the upcoming ones are highlighted. Research efforts that resulted in the growth of various 177Lu-based radiopharmaceuticals in preclinical and clinical settings are provided. This review also summarizes the results of clinical studies with potent 177Lu-based radiopharmaceuticals that have been prepared using medium specific activity 177Lu produced by direct neutron activation route in research reactors. Overall, the review amply demonstrates the practicality of the medium specific activity 177Lu towards formulation of various clinically useful radiopharmaceuticals, especially for the benefit of millions of cancer patients in developing countries with limited reactor facilities.
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Affiliation(s)
- Rubel Chakravarty
- Radiopharmaceuticals Division, Bhabha Atomic Research Centre Trombay, Mumbai 400085, India
- Homi Bhabha National Institute Anushaktinagar, Mumbai 400094, India
| | - Sudipta Chakraborty
- Radiopharmaceuticals Division, Bhabha Atomic Research Centre Trombay, Mumbai 400085, India
- Homi Bhabha National Institute Anushaktinagar, Mumbai 400094, India
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12
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Vaughn BA, Loveless CS, Cingoranelli SJ, Schlyer D, Lapi SE, Boros E. Evaluation of 177Lu and 47Sc Picaga-Linked, Prostate-Specific Membrane Antigen-Targeting Constructs for Their Radiotherapeutic Efficacy and Dosimetry. Mol Pharm 2021; 18:4511-4519. [PMID: 34714082 DOI: 10.1021/acs.molpharmaceut.1c00711] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Lu-177-based, targeted radiotherapeutics/endoradiotherapies are an emerging clinical tool for the management of various cancers. The chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) remains the workhorse for such applications but can limit apparent molar activity or efficient charge modulation, which can impact target binding and, as a consequence, target efficacy. Previously, our lab had developed the small, rare earth selective bifunctional chelator, picaga, as an efficient bifunctional chelator for scandium and lutetium isotopes. Here, we assess the performance of these constructs for therapy in prostate-specific membrane antigen (PSMA)-expressing tumor xenografts. To assess the viability of picaga conjugates in conjunction with long in vivo circulation, a picaga conjugate functionalized with a serum albumin binding moiety, 177Lu-picaga-Alb53-PSMA, was also synthesized. A directly comparative, low, single 3.7 MBq dose treatment study with Lu-PSMA-617 was conducted. Treatment with 177Lu-picaga-Alb53-PSMA resulted in tumor regression and lengthened median survival (54 days) when compared with the vehicle (16 days), 47Sc-picaga-DUPA-, 177Lu-picaga-DUPA-, and 177Lu-PSMA-617-treated cohorts (21, 23, and 21 days, respectively).
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Affiliation(s)
- Brett A Vaughn
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York 11794, United States
| | - C Shaun Loveless
- Department of Radiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| | - Shelbie J Cingoranelli
- Department of Radiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| | - David Schlyer
- Brookhaven National Laboratory, Upton, New York 11973, United States.,Department of Biomedical Engineering, Stony Brook University, Stony Brook, New York 11794, United States
| | - Suzanne E Lapi
- Department of Radiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| | - Eszter Boros
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York 11794, United States
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13
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Sneddon D, Cornelissen B. Emerging chelators for nuclear imaging. Curr Opin Chem Biol 2021; 63:152-162. [PMID: 34051509 DOI: 10.1016/j.cbpa.2021.03.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 02/28/2021] [Accepted: 03/09/2021] [Indexed: 11/25/2022]
Abstract
Chelators are necessary in nuclear medicine imaging to direct an inorganic radionuclide, a radiometal, to a desired target; unfortunately, there is no 'one-size-fits-all' chelator. As the toolbox of radiometals is expanding, new chelators are required to prevent off-target side effects. 1,4,7,10-Tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) is the current gold standard chelator for several radiometals, but typically, chelation requires harsh conditions, making it unsuitable to label biological vectors. The ideal chelator would allow labelling under mild conditions (near-neutral pH and low temperatures [∼37 °C]) and be both thermodynamically and kinetically stable. Over the past 2-3 years, several exciting chelators have been developed that have superior properties to make them worth investigating for future clinical applications.
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Affiliation(s)
- Deborah Sneddon
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, OX3 7LE, United Kingdom.
| | - Bart Cornelissen
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, OX3 7LE, United Kingdom
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14
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Travagin F, Lattuada L, Giovenzana GB. AAZTA: The rise of mesocyclic chelating agents for metal coordination in medicine. Coord Chem Rev 2021. [DOI: 10.1016/j.ccr.2021.213908] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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15
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Klasen B, Lemcke D, Mindt TL, Gasser G, Rösch F. Development and in vitro evaluation of new bifunctional 89Zr-chelators based on the 6-amino-1,4-diazepane scaffold for immuno-PET applications. Nucl Med Biol 2021; 102-103:12-23. [PMID: 34242949 DOI: 10.1016/j.nucmedbio.2021.06.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 06/15/2021] [Accepted: 06/25/2021] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Combination of hydroxamate bearing side chains with the 6-amino-1,4-diazepane scaffold provides a promising strategy for fast and stable 89Zr-labeling of antibodies. Following this approach, we hereby present the development, labeling kinetics and in vitro complex stability of three resulting bifunctional chelator derivatives both stand-alone and coupled to a model protein in comparison to different linear deferoxamine (DFO) derivatives. METHODS The novel 89Zr-chelator Hy3ADA5 was prepared via amide-coupling of separately synthesized 6-amino-1,4-diazepane-6-pentanoic acid and hydroxamate-containing side chains. Two further bifunctional derivatives were synthesized by extending the resulting system with either a squaramide- or p-isothiocyanatophenyl moiety for simplified binding to proteins. After coupling to a model antibody and purification, the resulting immunoconjugates as well as the unbound chelator derivatives were 89Zr-labeled at room temperature (RT) and neutral pH. For comparison, different DFO derivatives were analogously coupled, purified and radiolabeled. In vitro complex stability of the resulting radioconjugates was investigated in phosphate buffered saline (PBS) and human serum at 37 °C over a period of 7 days. RESULTS 89Zr-labeling of the novel unbound Hy3ADA5 derivatives indicated rapid complexation kinetics resulting in high radiochemical conversions (RCC) of 84-94% after 90 min. Similar or even faster radiolabeling with slightly increased maximum yields was obtained using the DFO-analogues. Initially, [89Zr]Zr-DFO*-p-Ph-NCS showed a delayed formation, nevertheless reaching almost quantitative complexation. Radiolabeling of the corresponding immunoconjugates Hy3ADA5-SA-mAb and Hy3ADA5-p-Ph-NCS-mAb resulted in 82.0 ± 1.1 and 89.2 ± 0.7% RCC, respectively after 90 min representing high but slightly lower labeling efficiency compared to the DFO- and DFO*-functionalized analogues. All examined radioimmunoconjugates showed very high in vitro complex stability both in human serum and PBS, providing no significant release of the radiometal. In the case of unbound chelators, however, the p-Ph-NCS-functionalized derivatives indicated considerable instability in human serum already after 1 h. CONCLUSION The novel chelator derivatives based on hydroxamate-functionalized 6-amino-1,4-diazepane revealed fast and high yielding 89Zr-labeling kinetics as well as high in vitro complex stability both stand-alone and coupled to an antibody. Therefore, Hy3ADA5 represents a promising tool for radiolabeling of biomolecules such as antibodies at mild conditions for immuno-PET applications.
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Affiliation(s)
- Benedikt Klasen
- Department of Chemistry - TRIGA site, Johannes Gutenberg University Mainz, Germany.
| | - Daniel Lemcke
- Department of Chemistry - TRIGA site, Johannes Gutenberg University Mainz, Germany
| | - Thomas L Mindt
- Ludwig Boltzmann Institute Applied Diagnostics, General Hospital Vienna, Austria; Department of Inorganic Chemistry, Faculty of Chemistry, University of Vienna, Austria
| | - Gilles Gasser
- Chimie ParisTech, PSL University, CNRS, Institute of Chemistry for Life and Health Sciences, Laboratory for Inorganic Chemical Biology, Paris, France
| | - Frank Rösch
- Department of Chemistry - TRIGA site, Johannes Gutenberg University Mainz, Germany.
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Grus T, Lahnif H, Klasen B, Moon ES, Greifenstein L, Roesch F. Squaric Acid-Based Radiopharmaceuticals for Tumor Imaging and Therapy. Bioconjug Chem 2021; 32:1223-1231. [PMID: 34170116 DOI: 10.1021/acs.bioconjchem.1c00305] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Targeting vectors bound to a chelator represent a significant fraction of radiopharmaceuticals used nowadays for diagnostic and therapeutic purposes in nuclear medicine. The use of squaramides as coupling units for chelator and targeting vector helps to circumvent the disadvantages of several common coupling methods. This review gives an overview of the use of squaric acid diesters (SADE) as linking agents. It focuses on the conjugation of cyclic chelators, e.g., DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid), as well as hybrid chelators like AAZTA5 (6-pentanoic acid-6-amino-1,4-diazepine tetracetic acid) or DATA5m (6-pentanoic acid-6-amino-1,4-diazapine-triacetate) to different targeting vectors, e.g., prostate-specific membrane antigen inhibitors (KuE; PSMAi), fibroblast activation protein inhibitors (FAPi), and monoclonal antibodies (mAbs). An overview of the synthesis, radiolabeling, and in vitro and in vivo behavior of the described structures is given. The unique properties of SADE enable a fast and simple conjugation of chelators to biomolecules, peptides, and small molecules under mild conditions. Furthermore, SA-containing conjugates could not only display similar in vitro characteristics in terms of binding affinity when compared to reference compounds, but may even induce beneficial effects on the pharmacokinetic properties of these radiopharmaceuticals.
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Affiliation(s)
- Tilmann Grus
- Department of Chemistry - TRIGA site, Johannes Gutenberg University Mainz, 55128 Mainz, Germany
| | - Hanane Lahnif
- Department of Chemistry - TRIGA site, Johannes Gutenberg University Mainz, 55128 Mainz, Germany
| | - Benedikt Klasen
- Department of Chemistry - TRIGA site, Johannes Gutenberg University Mainz, 55128 Mainz, Germany
| | - Euy-Sung Moon
- Department of Chemistry - TRIGA site, Johannes Gutenberg University Mainz, 55128 Mainz, Germany
| | - Lukas Greifenstein
- Department of Chemistry - TRIGA site, Johannes Gutenberg University Mainz, 55128 Mainz, Germany
| | - Frank Roesch
- Department of Chemistry - TRIGA site, Johannes Gutenberg University Mainz, 55128 Mainz, Germany
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In Vitro Evaluation of the Squaramide-Conjugated Fibroblast Activation Protein Inhibitor-Based Agents AAZTA 5.SA.FAPi and DOTA.SA.FAPi. Molecules 2021; 26:molecules26123482. [PMID: 34201111 PMCID: PMC8226449 DOI: 10.3390/molecules26123482] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/21/2021] [Accepted: 06/04/2021] [Indexed: 12/17/2022] Open
Abstract
Recently, the first squaramide-(SA) containing FAP inhibitor-derived radiotracers were introduced. DATA5m.SA.FAPi and DOTA.SA.FAPi with their non-radioactive complexes showed high affinity and selectivity for FAP. After a successful preclinical study with [68Ga]Ga-DOTA.SA.FAPi, the first patient studies were realized for both compounds. Here, we present a new squaramide-containing compound targeting FAP, based on the AAZTA5 chelator 1,4-bis-(carboxylmethyl)-6-[bis-(carboxymethyl)-amino-6-pentanoic-acid]-perhydro-1,4-diazepine. For this molecule (AAZTA5.SA.FAPi), complexation with radionuclides such as gallium-68, scandium-44, and lutetium-177 was investigated, and the in vitro properties of the complexes were characterized and compared with those of DOTA.SA.FAPi. AAZTA5.SA.FAPi and its derivatives labelled with non-radioactive isotopes demonstrated similar excellent inhibitory potencies compared to the previously published SA.FAPi ligands, i.e., sub-nanomolar IC50 values for FAP and high selectivity indices over the serine proteases PREP and DPPs. Labeling with all three radiometals was easier and faster with AAZTA5.SA.FAPi compared to the corresponding DOTA analogue at ambient temperature. Especially, scandium-44 labeling with the AAZTA derivative resulted in higher specific activities. Both DOTA.SA.FAPi and AAZTA5.SA.FAPi showed sufficiently high stability in different media. Therefore, these FAP inhibitor agents could be promising for theranostic approaches targeting FAP.
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18
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Mikolajczak R, Huclier-Markai S, Alliot C, Haddad F, Szikra D, Forgacs V, Garnuszek P. Production of scandium radionuclides for theranostic applications: towards standardization of quality requirements. EJNMMI Radiopharm Chem 2021; 6:19. [PMID: 34036449 PMCID: PMC8149571 DOI: 10.1186/s41181-021-00131-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 03/26/2021] [Indexed: 01/23/2023] Open
Abstract
In the frame of "precision medicine", the scandium radionuclides have recently received considerable interest, providing personalised adjustment of radiation characteristics to optimize the efficiency of medical care or therapeutic benefit for particular groups of patients. Radionuclides of scandium, namely scandium-43 and scandium-44 (43/44Sc) as positron emitters and scandium-47 (47Sc), beta-radiation emitter, seem to fit ideally into the concept of theranostic pair. This paper aims to review the work on scandium isotopes production, coordination chemistry, radiolabeling, preclinical studies and the very first clinical studies. Finally, standardized procedures for scandium-based radiopharmaceuticals have been proposed as a basis to pave the way for elaboration of the Ph.Eur. monographs for perspective scandium radionuclides.
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Affiliation(s)
- R Mikolajczak
- Radioisotope Centre POLATOM, National Centre for Nuclear Research, Andrzej Soltan 7, 05-400, Otwock, Poland
| | - S Huclier-Markai
- Laboratoire Subatech, UMR 6457, IMT Nantes Atlantique /CNRS-IN2P3 / Université de Nantes, 4 Rue A. Kastler, BP 20722, 44307, Nantes Cedex 3, France.
- ARRONAX GIP, 1 rue Aronnax, 44817, Nantes Cedex, France.
| | - C Alliot
- ARRONAX GIP, 1 rue Aronnax, 44817, Nantes Cedex, France
- CRCINA, Inserm / CNRS / Université de Nantes, 8 quai Moncousu, 44007, Nantes Cedex 1, France
| | - F Haddad
- Laboratoire Subatech, UMR 6457, IMT Nantes Atlantique /CNRS-IN2P3 / Université de Nantes, 4 Rue A. Kastler, BP 20722, 44307, Nantes Cedex 3, France
- ARRONAX GIP, 1 rue Aronnax, 44817, Nantes Cedex, France
| | - D Szikra
- Faculty of Medicine, Department of Medical Imaging, Division of Nuclear Medicine and Translational Imaging, University of Debrecen, Nagyerdei krt. 98, Debrecen, 4032, Hungary
- Scanomed Ltd., Nagyerdei krt. 98, Debrecen, 4032, Hungary
| | - V Forgacs
- Faculty of Medicine, Department of Medical Imaging, Division of Nuclear Medicine and Translational Imaging, University of Debrecen, Nagyerdei krt. 98, Debrecen, 4032, Hungary
| | - P Garnuszek
- Radioisotope Centre POLATOM, National Centre for Nuclear Research, Andrzej Soltan 7, 05-400, Otwock, Poland
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Klasen B, Moon ES, Rösch F. AAZTA 5-squaramide ester competing with DOTA-, DTPA- and CHX-A″-DTPA-analogues: Promising tool for 177Lu-labeling of monoclonal antibodies under mild conditions. Nucl Med Biol 2021; 96-97:80-93. [PMID: 33839678 DOI: 10.1016/j.nucmedbio.2021.03.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 01/12/2021] [Accepted: 03/20/2021] [Indexed: 12/17/2022]
Abstract
BACKGROUND Combining the advantages of both cyclic and acyclic chelator systems, AAZTA (1,4-bis(carboxymethyl)-6-[bis(carboxymethyl)]amino-6-methylperhydro-1,4-diazepine) is well suited for complexation of various diagnostic and therapeutic radiometals such as gallium-68, scandium-44 and lutetium-177 under mild conditions. Due to its specificity for primary amines and pH dependent binding properties, squaric acid (SA) represents an excellent tool for selective coupling of the appropriate chelator to different target vectors. Therefore, the aim of this study was to evaluate radiolabeling properties of the novel bifunctional AAZTA5-SA being coupled to a model antibody (bevacizumab) in comparison to DOTA-SA, DTPA-p-Bn-SA and CHX-A″-DTPA-p-Bn-SA using the therapeutic nuclide lutetium-177. METHODS AND RESULTS As proof-of-concept, bevacizumab was first functionalized with AAZTA5-SA, DOTA-SA, DTPA-p-Bn-SA or CHX-A″-DTPA-p-Bn-SA. After purification via fractionated size exclusion chromatography (SEC), the corresponding immunoconjugates were subsequently radiolabeled with lutetium-177 at pH 7 and room temperature (RT) as well as 37 °C. After 90 min, labeling of AAZTA5-SA-mAb resulted in almost quantitative radiochemical yields (RCY) of >98% and >99%, respectively. Formation of [177Lu]Lu-DTPA-p-Bn-SA-mAb indicated rapid labeling kinetics reaching similar yields at RT already after 30 min. Fast but incomplete radiolabeling of the CHX-A″-analogue could be observed with a yield of 74% after 10 min and no further significant increase. In contrast, 177Lu-labeling of DOTA-SA-mAb showed negligible radiochemical yields of <2% both at room temperature and 37 °C. In vitro complex stability measurements of [177Lu]Lu-AAZTA5-SA-mAb at 37 °C indicated >94% protein bound activity in human serum and >92% in phosphate buffered saline (PBS), respectively within 15 days. [177Lu]Lu-DTPA-p-Bn-SA-mAb and [177Lu]Lu-CHX-A″-DTPA-p-Bn-SA-mAb revealed similar to even slightly higher in vitro stability in both media. CONCLUSION Coupling of AAZTA5-SA to the monoclonal antibody bevacizumab allowed for 177Lu-labeling with almost quantitative radiochemical yields both at room temperature and 37 °C. Within 15 days, the resulting radioconjugate indicated very high in vitro complex stability both in human serum and PBS. Therefore, AAZTA5-SA is a promising tool for 177Lu-labeling of sensitive biomolecules such as antibodies for theranostic applications.
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Affiliation(s)
- Benedikt Klasen
- Department of Chemistry - TRIGA site, Johannes Gutenberg University, Mainz, Germany.
| | - Euy Sung Moon
- Department of Chemistry - TRIGA site, Johannes Gutenberg University, Mainz, Germany.
| | - Frank Rösch
- Department of Chemistry - TRIGA site, Johannes Gutenberg University, Mainz, Germany.
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Vaughn BA, Koller AJ, Boros E. Aqueous chemistry of the smallest rare earth: Comprehensive characterization of radioactive and non-radioactive scandium complexes for biological applications. Methods Enzymol 2021; 651:343-371. [PMID: 33888209 DOI: 10.1016/bs.mie.2021.01.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The aqueous chemistry of scandium(III) is of emerging interest for biological applications, specifically in nuclear medicine, as radioactive isotopes of scandium are becoming more readily accessible. In contrast to other rare earths, Sc3+ has no d or f electrons, limiting characterization of corresponding coordination complexes to spectroscopic techniques that do not rely on the characteristic electronic transitions of f-elements or transition metal ions. Herein, we provide a comprehensive overview on characterization techniques suitable to elucidate the solution behavior of small and macromolecular complexes of the smallest rare earth.
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Affiliation(s)
- Brett A Vaughn
- Department of Chemistry, Stony Brook University, Stony Brook, NY, United States
| | - Angus J Koller
- Department of Chemistry, Stony Brook University, Stony Brook, NY, United States
| | - Eszter Boros
- Department of Chemistry, Stony Brook University, Stony Brook, NY, United States.
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21
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Vaughn BA, Koller AJ, Chen Z, Ahn SH, Loveless CS, Cingoranelli SJ, Yang Y, Cirri A, Johnson CJ, Lapi SE, Chapman KW, Boros E. Homologous Structural, Chemical, and Biological Behavior of Sc and Lu Complexes of the Picaga Bifunctional Chelator: Toward Development of Matched Theranostic Pairs for Radiopharmaceutical Applications. Bioconjug Chem 2020; 32:1232-1241. [PMID: 33284001 DOI: 10.1021/acs.bioconjchem.0c00574] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The radioactive isotopes scandium-44/47 and lutetium-177 are gaining relevance for radioimaging and radiotherapy, resulting in a surge of studies on their coordination chemistry and subsequent applications. Although the trivalent ions of these elements are considered close homologues, dissimilar chemical behavior is observed when they are complexed by large ligand architectures due to discrepancies between Lu(III) and Sc(III) ions with respect to size, chemical hardness, and Lewis acidity. Here, we demonstrate that Lu and Sc complexes of 1,4-bis(methoxycarbonyl)-7-[(6-carboxypyridin-2-yl)methyl]-1,4,7-triazacyclononane (H3mpatcn) and its corresponding bioconjugate picaga-DUPA can be employed to promote analogous structural features and, subsequently, biological properties for coordination complexes of these ions. The close homology was evidenced using potentiometric methods, computational modeling, variable temperature mass spectrometry, and pair distribution function analysis of X-ray scattering data. Radiochemical labeling, in vitro stability, and biodistribution studies with Sc-47 and Lu-177 indicate that the 7-coordinate ligand environment of the bifunctional picaga ligand is compatible with biological applications and the future investigation of β-emitting, picaga-chelated Sc and Lu isotopes for radiotherapy.
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Affiliation(s)
- Brett A Vaughn
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York 11794, United States
| | - Angus J Koller
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York 11794, United States
| | - Zhihengyu Chen
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York 11794, United States
| | - Shin Hye Ahn
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York 11794, United States
| | - C Shaun Loveless
- Department of Radiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| | - Shelbie J Cingoranelli
- Department of Radiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| | - Yi Yang
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York 11794, United States
| | - Anthony Cirri
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York 11794, United States
| | - Christopher J Johnson
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York 11794, United States
| | - Suzanne E Lapi
- Department of Radiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, United States
| | - Karena W Chapman
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York 11794, United States
| | - Eszter Boros
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, New York 11794, United States
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Hofstetter M, Moon ES, D'Angelo F, Geissbühler L, Alberts I, Afshar-Oromieh A, Rösch F, Rominger A, Gourni E. Effect of the versatile bifunctional chelator AAZTA 5 on the radiometal labelling properties and the in vitro performance of a gastrin releasing peptide receptor antagonist. EJNMMI Radiopharm Chem 2020; 5:29. [PMID: 33258012 PMCID: PMC7704979 DOI: 10.1186/s41181-020-00115-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 11/23/2020] [Indexed: 12/24/2022] Open
Abstract
Background Gastrin Releasing Peptide receptor (GRPr)-based radioligands have shown great promise for diagnostic imaging of GRPr-positive cancers, such as prostate and breast. The present study aims at developing and evaluating a versatile GRPr-based probe for both PET/SPECT imaging as well as intraoperative and therapeutic applications. The influence of the versatile chelator AAZTA5 on the radiometal labelling properties and the in vitro performance of the generated radiotracers were thoroughly investigated. The GRPr-based antagonist D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH2 was functionalized with the chelator 6-[Bis (carboxymethyl)amino]-1,4-bis (carboyxmethyl)-6-methyl-1,4-diazepane (AAZTA5) through the spacer 4-amino-1-carboxymethyl-piperidine (Pip) to obtain AAZTA5-Pip-D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH2 (LF1). LF1 was radiolabelled with gallium-68 (PET), indium-111 (SPECT, intraoperative applications) and lutetium-177 (therapy, SPECT). In vitro evaluation included stability studies, determination of lipophilicity, protein-binding studies, determination of Kd and Bmax as well as internalization studies using the epithelial human prostate cancer cell line PC3. In vitro monotherapy as well as combination therapy studies were further performed to assess its applicability as a theranostic compound. Results LF1 was labelled with gallium-68, indium-111 and lutetium-177 within 5 min at room temperature (RT). The apparent molar activities (Am) were ranging between 50 and 60 GBq/μmol for the 68Ga-labelled LF1, 10–20 GBq/μmol for the 111In- and 177Lu-labelled LF1. The radiotracers were stable for a period of 4 h post labeling exhibiting a hydrophilic profile with an average of a LogDoctanol/PBS of − 3, while the bound activity to the human serum protein was approximately 10%. 68/natGa-LF1, 177/natLu-LF1 and 111/natIn-LF1 exhibited high affinity for the PC3 cells, with Kd values of 16.3 ± 2.4 nM, 10.3 ± 2.73 nM and 5.2 ± 1.9 nM, respectively, and the required concentration of the radiotracers to saturate the receptors (Bmax) was between 0.5 and 0.8 nM which corresponds to approximately 4 × 105 receptors per cell. Low specific internalization rate was found in cell culture, while the total specific cell surface bound uptake always exceeded the internalized activity. In vitro therapy studies showed that inhibition of PC3 cells growth is somewhat more efficient when combination of 177Lu-labelled LF1 with rapamycin is applied compared to 177Lu-laballed LF1 alone. Conclusion Encouraged by these promising in vitro data, preclinical evaluation of the LF1 precursor are planned in tumour models in vivo.
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Affiliation(s)
- Michael Hofstetter
- Department of Nuclear Medicine, Inselspital, Bern University Hospital, Freiburgstr. 18, 3010, Bern, Switzerland
| | - Euy Sung Moon
- Department of Chemistry - TRIGA site, Johannes Gutenberg - University Mainz, Mainz, Germany
| | - Fabio D'Angelo
- Department of Nuclear Medicine, Inselspital, Bern University Hospital, Freiburgstr. 18, 3010, Bern, Switzerland
| | - Lucien Geissbühler
- Department of Nuclear Medicine, Inselspital, Bern University Hospital, Freiburgstr. 18, 3010, Bern, Switzerland
| | - Ian Alberts
- Department of Nuclear Medicine, Inselspital, Bern University Hospital, Freiburgstr. 18, 3010, Bern, Switzerland
| | - Ali Afshar-Oromieh
- Department of Nuclear Medicine, Inselspital, Bern University Hospital, Freiburgstr. 18, 3010, Bern, Switzerland
| | - Frank Rösch
- Department of Chemistry - TRIGA site, Johannes Gutenberg - University Mainz, Mainz, Germany
| | - Axel Rominger
- Department of Nuclear Medicine, Inselspital, Bern University Hospital, Freiburgstr. 18, 3010, Bern, Switzerland
| | - Eleni Gourni
- Department of Nuclear Medicine, Inselspital, Bern University Hospital, Freiburgstr. 18, 3010, Bern, Switzerland.
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Sinnes JP, Bauder-Wüst U, Schäfer M, Moon ES, Kopka K, Rösch F. 68Ga, 44Sc and 177Lu-labeled AAZTA 5-PSMA-617: synthesis, radiolabeling, stability and cell binding compared to DOTA-PSMA-617 analogues. EJNMMI Radiopharm Chem 2020; 5:28. [PMID: 33242189 PMCID: PMC7691401 DOI: 10.1186/s41181-020-00107-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 10/19/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The AAZTA chelator and in particular its bifunctional derivative AAZTA5 was recently investigated to demonstrate unique capabilities to complex diagnostic and therapeutic trivalent radiometals under mild conditions. This study presents a comparison of 68Ga, 44Sc and 177Lu-labeled AAZTA5-PSMA-617 with DOTA-PSMA-617 analogues. We evaluated the radiolabeling characteristics, in vitro stability of the radiolabeled compounds and evaluated their binding affinity and internalization behavior on LNCaP tumor cells in direct comparison to the radiolabeled DOTA-conjugated PSMA-617 analogs. RESULTS AAZTA5 was synthesized in a five-step synthesis and coupled to the PSMA-617 backbone on solid phase. Radiochemical evaluation of AAZTA5-PSMA-617 with 68Ga, 44Sc and 177Lu achieved quantitative radiolabeling of > 99% after less than 5 min at room temperature. Stabilities against human serum, PBS buffer and EDTA and DTPA solutions were analyzed. While there was a small degradation of the 68Ga complex over 2 h in human serum, PBS and EDTA/DTPA, the 44Sc and 177Lu complexes were stable at 2 h and remained stable over 8 h and 1 day. For all three compounds, i.e. [natGa]Ga-AAZTA5-PSMA-617, [natSc]Sc-AAZTA5-PSMA-617 and [natLu]Lu-AAZTA5-PSMA-617, in vitro studies on PSMA-positive LNCaP cells were performed in direct comparison to radiolabeled DOTA-PSMA-617 yielding the corresponding inhibition constants (Ki). Ki values were in the range of 8-31 nM values which correspond with those of [natGa]Ga-DOTA-PSMA-617, [natSc]Sc-DOTA-PSMA-617 and [natLu]Lu-DOTA-PSMA-617, i.e. 5-7 nM, respectively. Internalization studies demonstrated cellular membrane to internalization ratios for the radiolabeled 68Ga, 44Sc and 177Lu-AAZTA5-PSMA-617 tracers (13-20%IA/106 cells) in the same range as the ones of the three radiolabeled DOTA-PSMA-617 tracers (17-20%IA/106 cells) in the same assay. CONCLUSIONS The AAZTA5-PSMA-617 structure proved fast and quantitative radiolabeling with all three radiometal complexes at room temperature, excellent stability with 44Sc, very high stability with 177Lu and medium stability with 68Ga in human serum, PBS and EDTA/DTPA solutions. All three AAZTA5-PSMA-617 tracers showed binding affinities and internalization ratios in LNCaP cells comparable with that of radiolabeled DOTA-PSMA-617 analogues. Therefore, the exchange of the chelator DOTA with AAZTA5 within the PSMA-617 binding motif has no negative influence on in vitro LNCaP cell binding characteristics. In combination with the faster and milder radiolabeling features, AAZTA5-PSMA-617 thus demonstrates promising potential for in vivo application for theranostics of prostate cancer.
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Affiliation(s)
- Jean-Philippe Sinnes
- Johannes Gutenberg-University Mainz, Department of Chemistry/ TRIGA, Fritz-Strassmann-Weg 2, 55128, Mainz, Germany
| | - Ulrike Bauder-Wüst
- German Cancer Research Center (DKFZ), Division of Radiopharmaceutical Chemistry, Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
| | - Martin Schäfer
- German Cancer Research Center (DKFZ), Division of Radiopharmaceutical Chemistry, Im Neuenheimer Feld 280, 69120, Heidelberg, Germany
| | - Euy Sung Moon
- Johannes Gutenberg-University Mainz, Department of Chemistry/ TRIGA, Fritz-Strassmann-Weg 2, 55128, Mainz, Germany
| | - Klaus Kopka
- German Cancer Research Center (DKFZ), Division of Radiopharmaceutical Chemistry, Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.,German Cancer Research Center (DKFZ), Division of Radiopharmaceutical Chemistry and German Cancer Consortium (DKTK), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.,New address: Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, 01328, Dresden, Germany
| | - Frank Rösch
- Johannes Gutenberg-University Mainz, Department of Chemistry/ TRIGA, Fritz-Strassmann-Weg 2, 55128, Mainz, Germany.
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Eychenne R, Bouvry C, Bourgeois M, Loyer P, Benoist E, Lepareur N. Overview of Radiolabeled Somatostatin Analogs for Cancer Imaging and Therapy. Molecules 2020; 25:E4012. [PMID: 32887456 PMCID: PMC7504749 DOI: 10.3390/molecules25174012] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 08/28/2020] [Accepted: 09/01/2020] [Indexed: 12/19/2022] Open
Abstract
Identified in 1973, somatostatin (SST) is a cyclic hormone peptide with a short biological half-life. Somatostatin receptors (SSTRs) are widely expressed in the whole body, with five subtypes described. The interaction between SST and its receptors leads to the internalization of the ligand-receptor complex and triggers different cellular signaling pathways. Interestingly, the expression of SSTRs is significantly enhanced in many solid tumors, especially gastro-entero-pancreatic neuroendocrine tumors (GEP-NET). Thus, somatostatin analogs (SSAs) have been developed to improve the stability of the endogenous ligand and so extend its half-life. Radiolabeled analogs have been developed with several radioelements such as indium-111, technetium-99 m, and recently gallium-68, fluorine-18, and copper-64, to visualize the distribution of receptor overexpression in tumors. Internal metabolic radiotherapy is also used as a therapeutic strategy (e.g., using yttrium-90, lutetium-177, and actinium-225). With some radiopharmaceuticals now used in clinical practice, somatostatin analogs developed for imaging and therapy are an example of the concept of personalized medicine with a theranostic approach. Here, we review the development of these analogs, from the well-established and authorized ones to the most recently developed radiotracers, which have better pharmacokinetic properties and demonstrate increased efficacy and safety, as well as the search for new clinical indications.
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Affiliation(s)
- Romain Eychenne
- UPS, CNRS, SPCMIB (Laboratoire de Synthèse et Physico-Chimie de Molécules d’Intérêt Biologique)—UMR 5068, Université de Toulouse, F-31062 Toulouse, France; (R.E.); (E.B.)
- Groupement d’Intérêt Public ARRONAX, 1 Rue Aronnax, F-44817 Saint Herblain, France;
- CNRS, CRCINA (Centre de Recherche en Cancérologie et Immunologie Nantes—Angers)—UMR 1232, ERL 6001, Inserm, Université de Nantes, F-44000 Nantes, France
| | - Christelle Bouvry
- Comprehensive Cancer Center Eugène Marquis, Rennes, F-35000, France;
- CNRS, ISCR (Institut des Sciences Chimiques de Rennes)—UMR 6226, Univ Rennes, F-35000 Rennes, France
| | - Mickael Bourgeois
- Groupement d’Intérêt Public ARRONAX, 1 Rue Aronnax, F-44817 Saint Herblain, France;
- CNRS, CRCINA (Centre de Recherche en Cancérologie et Immunologie Nantes—Angers)—UMR 1232, ERL 6001, Inserm, Université de Nantes, F-44000 Nantes, France
| | - Pascal Loyer
- INRAE, Institut NUMECAN (Nutrition, Métabolismes et Cancer)—UMR_A 1341, UMR_S 1241, Inserm, Univ Rennes, F-35000 Rennes, France;
| | - Eric Benoist
- UPS, CNRS, SPCMIB (Laboratoire de Synthèse et Physico-Chimie de Molécules d’Intérêt Biologique)—UMR 5068, Université de Toulouse, F-31062 Toulouse, France; (R.E.); (E.B.)
| | - Nicolas Lepareur
- Comprehensive Cancer Center Eugène Marquis, Rennes, F-35000, France;
- INRAE, Institut NUMECAN (Nutrition, Métabolismes et Cancer)—UMR_A 1341, UMR_S 1241, Inserm, Univ Rennes, F-35000 Rennes, France;
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Rosar F, Buchholz HG, Michels S, Hoffmann MA, Piel M, Waldmann CM, Rösch F, Reuss S, Schreckenberger M. Image quality analysis of 44Sc on two preclinical PET scanners: a comparison to 68Ga. EJNMMI Phys 2020; 7:16. [PMID: 32166581 PMCID: PMC7067939 DOI: 10.1186/s40658-020-0286-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 03/03/2020] [Indexed: 11/10/2022] Open
Abstract
Background 44Sc has been increasingly investigated as a potential alternative to 68Ga in the development of tracers for positron emission tomography (PET). The lower mean positron energy of 44Sc (0.63 MeV) compared to 68Ga (0.83 MeV) can result in better spatial image resolutions. However, high-energy γ-rays (1157 keV) are emitted at high rates (99.9%) during 44Sc decay, which can reduce image quality. Therefore, we investigated the impact of these physical properties and performed an unbiased performance evaluation of 44Sc and 68Ga with different imaging phantoms (image quality phantom, Derenzo phantom, and three-rod phantom) on two preclinical PET scanners (Mediso nanoScan PET/MRI, Siemens microPET Focus 120). Results Despite the presence of high-energy γ-rays in 44Sc decay, a higher image resolution of small structures was observed with 44Sc when compared to 68Ga. Structures as small as 1.3 mm using the Mediso system, and as small as 1.0 mm using the Siemens system, could be visualized and analyzed by calculating full width at half maximum. Full widths at half maxima were similar for both isotopes. For image quality comparison, we calculated recovery coefficients in 1–5 mm rods and spillover ratios in either air, water, or bone-equivalent material (Teflon). Recovery coefficients for 44Sc were significantly higher than those for 68Ga. Despite the lower positron energy, 44Sc-derived spillover ratio (SOR) values were similar or slightly higher to 68Ga-derived SOR values. This may be attributed to the higher background caused by the additional γ-rays. On the Siemens system, an overestimation of scatter correction in the central part of the phantom was observed causing a virtual disappearance of spillover inside the three-rod phantom. Conclusion Based on these findings, 44Sc appears to be a suitable alternative to 68Ga. The superior image resolution makes it an especially strong competitor in preclinical settings. The additional γ-emissions have a small impact on the imaging resolution but cause higher background noises and can effect an overestimation of scatter correction, depending on the PET system and phantom.
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Affiliation(s)
- Florian Rosar
- Department of Nuclear Medicine, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany. .,Department of Nuclear Medicine, Saarland University Medical Center, Homburg, Germany.
| | - Hans-Georg Buchholz
- Department of Nuclear Medicine, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Sebastian Michels
- Department of Nuclear Medicine, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Manuela A Hoffmann
- Department of Nuclear Medicine, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Markus Piel
- Institute of Nuclear Chemistry, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Christopher M Waldmann
- Department of Nuclear Medicine, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Frank Rösch
- Institute of Nuclear Chemistry, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Stefan Reuss
- Department of Nuclear Medicine, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Mathias Schreckenberger
- Department of Nuclear Medicine, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
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Rangger C, Haubner R. Radiolabelled Peptides for Positron Emission Tomography and Endoradiotherapy in Oncology. Pharmaceuticals (Basel) 2020; 13:E22. [PMID: 32019275 PMCID: PMC7169460 DOI: 10.3390/ph13020022] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 01/14/2020] [Accepted: 01/16/2020] [Indexed: 02/07/2023] Open
Abstract
This review deals with the development of peptide-based radiopharmaceuticals for the use with positron emission tomography and peptide receptor radiotherapy. It discusses the pros and cons of this class of radiopharmaceuticals as well as the different labelling strategies, and summarises approaches to optimise metabolic stability. Additionally, it presents different target structures and addresses corresponding tracers, which are already used in clinical routine or are being investigated in clinical trials.
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Affiliation(s)
| | - Roland Haubner
- Department of Nuclear Medicine, Medical University of Innsbruck, Anichstrasse 35, 6020 Innsbruck, Austria;
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Vaughn BA, Ahn SH, Aluicio-Sarduy E, Devaraj J, Olson AP, Engle J, Boros E. Chelation with a twist: a bifunctional chelator to enable room temperature radiolabeling and targeted PET imaging with scandium-44. Chem Sci 2020; 11:333-342. [PMID: 32953004 PMCID: PMC7472660 DOI: 10.1039/c9sc04655k] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Accepted: 11/17/2019] [Indexed: 01/16/2023] Open
Abstract
Scandium-44 has emerged as an attractive, novel PET radioisotope with ideal emission properties and half-life (t 1/2 = 3.97 h, E mean β+ = 632 keV) well matched to the pharmacokinetics of small molecules, peptides and small biologics. Conjugates of the current gold-standard chelator for 44Sc, 1,4,7,10-tetraaza-cyclododecane-1,4,7,10-tetraacetic acid (DOTA), require heating to achieve radiochemical complexation, limiting application of this isotope in conjunction with temperature-sensitive biologics. To establish Sc(iii) isotopes as broadly applicable tools for nuclear medicine, development of alternative bifunctional chelators is required. To address this need, we characterized the Sc(iii)-chelation properties of the small-cavity triaza-macrocycle-based, picolinate-functionalized chelator H3mpatcn. Spectroscopic and radiochemical studies establish the [Sc(mpatcn)] complex as kinetically inert and appropriate for biological applications. A proof-of-concept bifunctional conjugate targeting the prostate-specific membrane antigen (PSMA), picaga-DUPA, chelates 44Sc to form 44Sc(picaga)-DUPA at room temperature with an apparent molar activity of 60 MBq μmol-1 and formation of inert RRR-Λ and SSS-Δ-twist isomers. Sc(picaga)-DUPA exhibits a K i of 1.6 nM for PSMA, comparable to the 18F-based imaging probe DCFPyL (K i = 1.1 nM) currently in phase 3 clinical trials for imaging prostate cancer. Finally, we successfully employed 44Sc(picaga)-DUPA to image PSMA-expressing tumors in a preclinical mouse model, establishing the picaga bifunctional chelator as an optimal choice for the 44Sc PET nuclide.
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Affiliation(s)
- Brett A Vaughn
- Department of Chemistry , Stony Brook University , 100 Nicolls Road , Stony Brook , 11790 , New York , USA .
| | - Shin Hye Ahn
- Department of Chemistry , Stony Brook University , 100 Nicolls Road , Stony Brook , 11790 , New York , USA .
| | - Eduardo Aluicio-Sarduy
- Medical Physics Department , University of Wisconsin-Madison , 1111 Highland Avenue , Madison , 53705 , Wisconsin , USA
| | - Justin Devaraj
- Department of Chemistry , Stony Brook University , 100 Nicolls Road , Stony Brook , 11790 , New York , USA .
| | - Aeli P Olson
- Medical Physics Department , University of Wisconsin-Madison , 1111 Highland Avenue , Madison , 53705 , Wisconsin , USA
| | - Jonathan Engle
- Medical Physics Department , University of Wisconsin-Madison , 1111 Highland Avenue , Madison , 53705 , Wisconsin , USA
| | - Eszter Boros
- Department of Chemistry , Stony Brook University , 100 Nicolls Road , Stony Brook , 11790 , New York , USA .
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