1
|
Shinada M, Suzuki H, Hanyu M, Igarashi C, Matsumoto H, Takahashi M, Hihara F, Tachibana T, Sogawa C, Zhang MR, Higashi T, Sato H, Kurihara H, Yoshii Y, Doi Y. Trace Metal Impurities Effects on the Formation of [ 64Cu]Cu-diacetyl-bis( N4-methylthiosemicarbazone) ([ 64Cu]Cu-ATSM). Pharmaceuticals (Basel) 2023; 17:10. [PMID: 38275997 PMCID: PMC10821298 DOI: 10.3390/ph17010010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 12/15/2023] [Accepted: 12/19/2023] [Indexed: 01/27/2024] Open
Abstract
[64Cu]Cu-diacetyl-bis(N4-methylthiosemicarbazone) ([64Cu]Cu-ATSM) is a radioactive hypoxia-targeting therapeutic agent being investigated in clinical trials for malignant brain tumors. For the quality management of [64Cu]Cu-ATSM, understanding trace metal impurities' effects on the chelate formation of 64Cu and ATSM is important. In this study, we conducted coordination chemistry studies on metal-ATSM complexes. First, the effects of nonradioactive metal ions (Cu2+, Ni2+, Zn2+, and Fe2+) on the formation of [64Cu]Cu-ATSM were evaluated. When the amount of Cu2+ or Ni2+ added was 1.2 mol or 288 mol, equivalent to ATSM, the labeling yield of [64Cu]Cu-ATSM fell below 90%. Little effect was observed even when excess amounts of Zn2+ or Fe2+ were added to the ATSM. Second, these metals were reacted with ATSM, and chelate formation was measured using ultraviolet-visible (UV-Vis) absorption spectra. UV-Vis spectra showed a rapid formation of Cu2+ and the ATSM complex upon mixing. The rate of chelate formation by Ni2+ and ATSM was lower than that by Cu-ATSM. Zn2+ and Fe2+ showed much slower reactions with the ATSM than Ni2+. Trace amounts of Ni2+, Zn2+, and Fe2+ showed little effect on [64Cu]Cu-ATSM' quality, while the concentration of impurity Cu2+ must be controlled. These results can provide process management tools for radiopharmaceuticals.
Collapse
Affiliation(s)
- Mitsuhiro Shinada
- Faculty of Science, Toho University, Funabashi 274-8510, Japan; (M.T.); (T.T.); (Y.D.)
- Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan; (H.S.); (M.H.); (C.I.); (H.M.); (F.H.); (C.S.); (M.-R.Z.); (T.H.)
- Kanagawa Cancer Center, Kanagawa 241-8515, Japan; (H.S.); (H.K.)
| | - Hisashi Suzuki
- Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan; (H.S.); (M.H.); (C.I.); (H.M.); (F.H.); (C.S.); (M.-R.Z.); (T.H.)
| | - Masayuki Hanyu
- Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan; (H.S.); (M.H.); (C.I.); (H.M.); (F.H.); (C.S.); (M.-R.Z.); (T.H.)
| | - Chika Igarashi
- Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan; (H.S.); (M.H.); (C.I.); (H.M.); (F.H.); (C.S.); (M.-R.Z.); (T.H.)
- Kanagawa Cancer Center, Kanagawa 241-8515, Japan; (H.S.); (H.K.)
| | - Hiroki Matsumoto
- Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan; (H.S.); (M.H.); (C.I.); (H.M.); (F.H.); (C.S.); (M.-R.Z.); (T.H.)
- Kanagawa Cancer Center, Kanagawa 241-8515, Japan; (H.S.); (H.K.)
| | - Masashi Takahashi
- Faculty of Science, Toho University, Funabashi 274-8510, Japan; (M.T.); (T.T.); (Y.D.)
- Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan; (H.S.); (M.H.); (C.I.); (H.M.); (F.H.); (C.S.); (M.-R.Z.); (T.H.)
| | - Fukiko Hihara
- Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan; (H.S.); (M.H.); (C.I.); (H.M.); (F.H.); (C.S.); (M.-R.Z.); (T.H.)
| | - Tomoko Tachibana
- Faculty of Science, Toho University, Funabashi 274-8510, Japan; (M.T.); (T.T.); (Y.D.)
- Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan; (H.S.); (M.H.); (C.I.); (H.M.); (F.H.); (C.S.); (M.-R.Z.); (T.H.)
| | - Chizuru Sogawa
- Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan; (H.S.); (M.H.); (C.I.); (H.M.); (F.H.); (C.S.); (M.-R.Z.); (T.H.)
| | - Ming-Rong Zhang
- Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan; (H.S.); (M.H.); (C.I.); (H.M.); (F.H.); (C.S.); (M.-R.Z.); (T.H.)
| | - Tatsuya Higashi
- Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan; (H.S.); (M.H.); (C.I.); (H.M.); (F.H.); (C.S.); (M.-R.Z.); (T.H.)
| | - Hidemitsu Sato
- Kanagawa Cancer Center, Kanagawa 241-8515, Japan; (H.S.); (H.K.)
| | - Hiroaki Kurihara
- Kanagawa Cancer Center, Kanagawa 241-8515, Japan; (H.S.); (H.K.)
| | - Yukie Yoshii
- Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, Chiba 263-8555, Japan; (H.S.); (M.H.); (C.I.); (H.M.); (F.H.); (C.S.); (M.-R.Z.); (T.H.)
- Kanagawa Cancer Center, Kanagawa 241-8515, Japan; (H.S.); (H.K.)
| | - Yoshihiro Doi
- Faculty of Science, Toho University, Funabashi 274-8510, Japan; (M.T.); (T.T.); (Y.D.)
| |
Collapse
|
2
|
Huynh TT, Sreekumar S, Mpoy C, Rogers BE. A comparison of 64Cu-labeled bi-terminally PEGylated A20FMDV2 peptides targeting integrin α νβ 6. Oncotarget 2022; 13:360-372. [PMID: 35186193 PMCID: PMC8849274 DOI: 10.18632/oncotarget.28197] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 02/07/2022] [Indexed: 11/25/2022] Open
Abstract
Expression of epithelial-specific integrin ανβ6 is up-regulated in various aggressive cancers and serves as a prognostic marker. Integrin-targeted PET imaging probes have been successfully developed and tested in the clinic. Radiotracers based on the peptide A20FMDV2 derived from foot-and-mouth disease virus represent specific and selective PET ligands for imaging ανβ6-positive cancers. The present study aims to describe the radiolabeling, in vitro and in vivo evaluation of a bi-terminally PEGylated A20FMDV2 conjugated with DOTA or PCTA for 64Cu radiolabeling. Stability studies showed radiolabeled complexes remained stable up to 24 h in PBS and human serum. In vitro cell assays in CaSki cervical cancer cells and BxPC-3 pancreatic cancer cells confirmed that the peptides displayed high affinity for αvβ6 with Kd values of ~50 nM. Biodistribution studies revealed that [64Cu] Cu-PCTA-(PEG28)2-A20FMDV2 exhibited higher tumor uptake (1.63 ± 0.53 %ID/g in CaSki and 3.86 ± 0.58 %ID/g in BxPC-3 at 1 h) when compared to [64Cu]Cu-DOTA-(PEG28)2-A20FMDV2 (0.95 ± 0.29 %ID/g in CaSki and 2.12 ± 0.83 %ID/g in BxPC-3 at 1 h) . However, higher tumor uptake was accompanied by increased radioactive uptake in normal organs. Therefore, both peptides are appropriate for imaging ανβ6-positive lesions although further optimization is needed to improve tumor-to-normal-tissue ratios.
Collapse
Affiliation(s)
- Truc T Huynh
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, USA.,Department of Chemistry, Washington University, St. Louis, MO, USA
| | - Sreeja Sreekumar
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, USA
| | - Cedric Mpoy
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, USA
| | - Buck E Rogers
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO, USA
| |
Collapse
|
3
|
Alirezapour B, Ashkezari M, Fini M, Rasaee M, Mohammadnejad J, Paknejad M, Maadi E, Yousefnia H, Zolghadri S. Preparation and preclinical characterization of 111In-DTPA-Anti-MUC1 as a radioimmunoconjugate for diagnosis of breast cancer by single-photon emission computed tomography. J Cancer Res Ther 2022; 18:158-167. [DOI: 10.4103/jcrt.jcrt_730_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
|
4
|
Miranda ACC, dos Santos SN, Fuscaldi LL, Balieiro LM, Bellini MH, Guimarães MICC, de Araújo EB. Radioimmunotheranostic Pair Based on the Anti-HER2 Monoclonal Antibody: Influence of Chelating Agents and Radionuclides on Biological Properties. Pharmaceutics 2021; 13:971. [PMID: 34198999 PMCID: PMC8309196 DOI: 10.3390/pharmaceutics13070971] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 06/18/2021] [Accepted: 06/24/2021] [Indexed: 11/17/2022] Open
Abstract
The oncogene HER2 is an important molecular target in oncology because it is associated with aggressive disease and the worst prognosis. The development of non-invasive imaging techniques and target therapies using monoclonal antibodies is a rapidly developing field. Thus, this work proposes the study of the radioimmunotheranostic pair, [111In]In-DTPA-trastuzumab and [177Lu]Lu-DOTA-trastuzumab, evaluating the influence of the chelating agents and radionuclides on the biological properties of the radioimmunoconjugates (RICs). The trastuzumab was immunoconjugated with the chelators DTPA and DOTA and radiolabeled with [111In]InCl3 and [177Lu]LuCl3, respectively. The stability of the RICs was evaluated in serum, and the immunoreactive and internalization fractions were determined in SK-BR-3 breast cancer cells. The in vivo pharmacokinetics and dosimetry quantification and the ex vivo biodistribution were performed in normal and SK-BR-3 tumor-bearing mice. The data showed that there was no influence of the chelating agents and radionuclides on the immunoreactive and internalization fractions of RICs. In contrast, they influenced the stability of RICs in serum, as well as the pharmacokinetics, dosimetry and biodistribution profiles. Therefore, the results showed that the nature of the chelating agent and radionuclide could influence the biological properties of the radioimmunotheranostic pair.
Collapse
Affiliation(s)
- Ana Cláudia Camargo Miranda
- Hospital Israelita Albert Einstein, Instituto Israelita de Ensino e Pesquisa, Sao Paulo 05652-900, Brazil
- Instituto de Pesquisas Energéticas e Nucleares, IPEN/CNEN, Sao Paulo 05508-000, Brazil; (S.N.d.S.); (L.M.B.); (M.H.B.); (E.B.d.A.)
| | - Sofia Nascimento dos Santos
- Instituto de Pesquisas Energéticas e Nucleares, IPEN/CNEN, Sao Paulo 05508-000, Brazil; (S.N.d.S.); (L.M.B.); (M.H.B.); (E.B.d.A.)
| | - Leonardo Lima Fuscaldi
- Departamento de Ciências Fisiológicas, Faculdade de Ciências Médicas da Santa Casa de São Paulo, Sao Paulo 01221-020, Brazil;
| | - Luiza Mascarenhas Balieiro
- Instituto de Pesquisas Energéticas e Nucleares, IPEN/CNEN, Sao Paulo 05508-000, Brazil; (S.N.d.S.); (L.M.B.); (M.H.B.); (E.B.d.A.)
| | - Maria Helena Bellini
- Instituto de Pesquisas Energéticas e Nucleares, IPEN/CNEN, Sao Paulo 05508-000, Brazil; (S.N.d.S.); (L.M.B.); (M.H.B.); (E.B.d.A.)
| | - Maria Inês Calil Cury Guimarães
- Instituto de Radiologia do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Sao Paulo 05403-911, Brazil;
| | - Elaine Bortoleti de Araújo
- Instituto de Pesquisas Energéticas e Nucleares, IPEN/CNEN, Sao Paulo 05508-000, Brazil; (S.N.d.S.); (L.M.B.); (M.H.B.); (E.B.d.A.)
| |
Collapse
|
5
|
Abstract
Immuno-positron emission tomography (immunoPET) is a paradigm-shifting molecular imaging modality combining the superior targeting specificity of monoclonal antibody (mAb) and the inherent sensitivity of PET technique. A variety of radionuclides and mAbs have been exploited to develop immunoPET probes, which has been driven by the development and optimization of radiochemistry and conjugation strategies. In addition, tumor-targeting vectors with a short circulation time (e.g., Nanobody) or with an enhanced binding affinity (e.g., bispecific antibody) are being used to design novel immunoPET probes. Accordingly, several immunoPET probes, such as 89Zr-Df-pertuzumab and 89Zr-atezolizumab, have been successfully translated for clinical use. By noninvasively and dynamically revealing the expression of heterogeneous tumor antigens, immunoPET imaging is gradually changing the theranostic landscape of several types of malignancies. ImmunoPET is the method of choice for imaging specific tumor markers, immune cells, immune checkpoints, and inflammatory processes. Furthermore, the integration of immunoPET imaging in antibody drug development is of substantial significance because it provides pivotal information regarding antibody targeting abilities and distribution profiles. Herein, we present the latest immunoPET imaging strategies and their preclinical and clinical applications. We also emphasize current conjugation strategies that can be leveraged to develop next-generation immunoPET probes. Lastly, we discuss practical considerations to tune the development and translation of immunoPET imaging strategies.
Collapse
Affiliation(s)
- Weijun Wei
- Department of Nuclear Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
- Departments of Radiology and Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Room 7137, Madison, Wisconsin 53705, United States
| | - Zachary T Rosenkrans
- Department of Pharmaceutical Sciences, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Jianjun Liu
- Department of Nuclear Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Gang Huang
- Department of Nuclear Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
- Shanghai Key Laboratory of Molecular Imaging, Shanghai University of Medicine and Health Sciences, Shanghai 201318, China
| | - Quan-Yong Luo
- Department of Nuclear Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, China
| | - Weibo Cai
- Departments of Radiology and Medical Physics, University of Wisconsin-Madison, 1111 Highland Avenue, Room 7137, Madison, Wisconsin 53705, United States
- Department of Pharmaceutical Sciences, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
- University of Wisconsin Carbone Cancer Center, Madison, Wisconsin 53705, United States
| |
Collapse
|
6
|
Leygue N, Enel M, Diallo A, Mestre-Voegtlé B, Galaup C, Picard C. Efficient Synthesis of a Family of Bifunctional Chelators Based on the PCTA[12] Macrocycle Suitable for Bioconjugation. European J Org Chem 2019. [DOI: 10.1002/ejoc.201900280] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Nadine Leygue
- SPCMIB; UMR 5068 CNRS-Université Paul Sabatier-Toulouse III; 118 route de Narbonne 31062 Toulouse France
| | - Morgane Enel
- SPCMIB; UMR 5068 CNRS-Université Paul Sabatier-Toulouse III; 118 route de Narbonne 31062 Toulouse France
| | - Abdel Diallo
- SPCMIB; UMR 5068 CNRS-Université Paul Sabatier-Toulouse III; 118 route de Narbonne 31062 Toulouse France
| | - Béatrice Mestre-Voegtlé
- SPCMIB; UMR 5068 CNRS-Université Paul Sabatier-Toulouse III; 118 route de Narbonne 31062 Toulouse France
| | - Chantal Galaup
- SPCMIB; UMR 5068 CNRS-Université Paul Sabatier-Toulouse III; 118 route de Narbonne 31062 Toulouse France
| | - Claude Picard
- SPCMIB; UMR 5068 CNRS-Université Paul Sabatier-Toulouse III; 118 route de Narbonne 31062 Toulouse France
| |
Collapse
|
7
|
Ahmedova A, Todorov B, Burdzhiev N, Goze C. Copper radiopharmaceuticals for theranostic applications. Eur J Med Chem 2018; 157:1406-1425. [DOI: 10.1016/j.ejmech.2018.08.051] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 08/15/2018] [Accepted: 08/18/2018] [Indexed: 12/12/2022]
|
8
|
Enel M, Leygue N, Saffon N, Galaup C, Picard C. Facile Access to the 12-Membered Macrocyclic Ligand PCTA and Its Derivatives with Carboxylate, Amide, and Phosphinate Ligating Functionalities. European J Org Chem 2018. [DOI: 10.1002/ejoc.201800066] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Morgane Enel
- CNRS; Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique (SPCMIB); UMR-5068; 118 Route de Narbonne 31062 Toulouse cedex 9 France
- Université de Toulouse; UPS; Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique (SPCMIB); 118 route de Narbonne 31062 Toulouse cedex 9 France
| | - Nadine Leygue
- CNRS; Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique (SPCMIB); UMR-5068; 118 Route de Narbonne 31062 Toulouse cedex 9 France
- Université de Toulouse; UPS; Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique (SPCMIB); 118 route de Narbonne 31062 Toulouse cedex 9 France
| | - Nathalie Saffon
- Institut de Chimie de Toulouse (FR 2599); 118 Route de Narbonne 31062 Toulouse cedex 9 France
| | - Chantal Galaup
- CNRS; Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique (SPCMIB); UMR-5068; 118 Route de Narbonne 31062 Toulouse cedex 9 France
- Université de Toulouse; UPS; Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique (SPCMIB); 118 route de Narbonne 31062 Toulouse cedex 9 France
| | - Claude Picard
- CNRS; Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique (SPCMIB); UMR-5068; 118 Route de Narbonne 31062 Toulouse cedex 9 France
- Université de Toulouse; UPS; Laboratoire de Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique (SPCMIB); 118 route de Narbonne 31062 Toulouse cedex 9 France
| |
Collapse
|
9
|
Mansour N, Paquette M, Ait-Mohand S, Dumulon-Perreault V, Guérin B. Evaluation of a novel GRPR antagonist for prostate cancer PET imaging: [ 64 Cu]-DOTHA 2 -PEG-RM26. Nucl Med Biol 2018; 56:31-38. [DOI: 10.1016/j.nucmedbio.2017.10.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 10/17/2017] [Accepted: 10/18/2017] [Indexed: 02/08/2023]
|
10
|
Čepa A, Ráliš J, Král V, Paurová M, Kučka J, Humajová J, Lázníček M, Lebeda O. In vitro evaluation of the monoclonal antibody 64Cu-IgG M75 against human carbonic anhydrase IX and its in vivo imaging. Appl Radiat Isot 2017; 133:9-13. [PMID: 29272822 DOI: 10.1016/j.apradiso.2017.12.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 08/30/2017] [Accepted: 12/14/2017] [Indexed: 11/26/2022]
Abstract
Specific oncology diagnostics requires new types of the selective radiopharmaceuticals, particularly those suitable for the molecular PET imaging. The aim of this work is to present a new, specific PET-immunodiagnostic radiopharmaceutical based on the monoclonal antibody IgG M75 targeting human carbonic anhydrase IX labelled with 64Cu (T½ = 12.70h) and its in vitro and in vivo evaluation. The antibody IgG M75 was conjugated with a non-commercial copper-specific chelator "phosphinate" and then labelled with the positron emitter 64Cu. Stability of the labelled conjugated was tested in human serum. The immunoreactivity of the labelled conjugate was evaluated in vitro on a suitable cell cultures of the colorectal carcinoma (HT-29) and its imaging properties were estimated in vivo on a mouse model with inoculated colorectal carcinoma HT-29 imaged on a µPET/CT. The tested radioimmunoconjugate was obtained in a specific activity of 0.25-0.5 MBq/µg. In vitro uptake experiments revealed specific binding to the HT-29 cells (45 ± 2.8% of the total added activity) and the measured KD value was found to be 9.2nM. Imaging clearly demonstrated significant uptake of the labelled monoclonal antibody in the tumour at 18h post administration. The radioimmunoconjugate 64Cu-PS-IgG M75 seems to be a suitable candidate for PET diagnostics of hypoxic tumours expressing human carbonic anhydrase IX.
Collapse
Affiliation(s)
- Adam Čepa
- Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Králové, Charles University in Prague, Czech Republic; Nuclear Physics Institute of the CAS, Czech Republic
| | - Jan Ráliš
- Nuclear Physics Institute of the CAS, Czech Republic
| | - Vlastimil Král
- Institute of Molecular Genetics of the CAS, Czech Republic
| | - Monika Paurová
- Department of Inorganic Chemistry, Faculty of Science, Charles University in Prague, Czech Republic
| | - Jan Kučka
- Institute of Macromolecular Chemistry of the CAS, Czech Republic
| | - Jana Humajová
- Institute of Biophysics and Informatics, 1st Medical Faculty, Charles University in Prague, Czech Republic
| | - Milan Lázníček
- Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Králové, Charles University in Prague, Czech Republic
| | - Ondřej Lebeda
- Nuclear Physics Institute of the CAS, Czech Republic.
| |
Collapse
|
11
|
Gillet R, Roux A, Brandel J, Huclier-Markai S, Camerel F, Jeannin O, Nonat AM, Charbonnière LJ. A Bispidol Chelator with a Phosphonate Pendant Arm: Synthesis, Cu(II) Complexation, and 64Cu Labeling. Inorg Chem 2017; 56:11738-11752. [DOI: 10.1021/acs.inorgchem.7b01731] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Raphaël Gillet
- Laboratoire d’Ingénierie
Moléculaire Appliquée à l’Analyse, Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Amandine Roux
- Laboratoire d’Ingénierie
Moléculaire Appliquée à l’Analyse, Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Jérémy Brandel
- Laboratoire de Reconnaissance et Procédés
de Séparation Moléculaire, Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Sandrine Huclier-Markai
- GIP Arronax, 1 rue Aronnax, CS 10112, F-44817 Saint-Herblain, France
- Subatech Laboratory, UMR 6457, Ecole des Mines de Nantes, IN2P3/CNRS, Université de Nantes, 4 rue Alfred Kastler, F-44307 Nantes, France
| | - Franck Camerel
- Laboratoire Matière Condensée et Systèmes
Électroactifs, Institut des Sciences Chimiques de Rennes, UMR-CNRS 6226, 263 Avenue du Général Leclerc, CS
74205, F-35042 Rennes Cedex, France
| | - Olivier Jeannin
- Laboratoire Matière Condensée et Systèmes
Électroactifs, Institut des Sciences Chimiques de Rennes, UMR-CNRS 6226, 263 Avenue du Général Leclerc, CS
74205, F-35042 Rennes Cedex, France
| | - Aline M. Nonat
- Laboratoire d’Ingénierie
Moléculaire Appliquée à l’Analyse, Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Loïc J. Charbonnière
- Laboratoire d’Ingénierie
Moléculaire Appliquée à l’Analyse, Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| |
Collapse
|
12
|
Sai KKS, Sattiraju A, Almaguel FG, Xuan A, Rideout S, Krishnaswamy RS, Zhang J, Herpai DM, Debinski W, Mintz A. Peptide-based PET imaging of the tumor restricted IL13RA2 biomarker. Oncotarget 2017; 8:50997-51007. [PMID: 28881623 PMCID: PMC5584224 DOI: 10.18632/oncotarget.16549] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 02/27/2017] [Indexed: 11/25/2022] Open
Abstract
Peptides that target cancer cell surface receptors are promising platforms to deliver diagnostic and therapeutic payloads specifically to cancer but not normal tissue. IL13RA2 is a tumor-restricted receptor found to be present in several aggressive malignancies, including in the vast majority of high-grade gliomas and malignant melanoma. This receptor has been successfully targeted for diagnostic and therapeutic purposes using modified IL-13 ligand and more recently using a specific peptide, Pep-1L. In the current work, we establish the in vitro and in vivo tumor binding properties of radiolabeled Pep-1L, designed for tumor imaging. We radiolabeled Pep-1L with Copper-64 and demonstrated specific cell uptake in the IL13RA2-over expressing G48 glioblastoma cell line having abundant IL13RA2 expression. [64Cu]Pep-1L binding was blocked by unlabeled ligand, demonstrating specificity. To demonstrate in vivo tumor uptake, we intravenously injected into tumor-bearing mice and demonstrated that [64Cu]Pep-1L specifically bound tumors at 24 hours, which was significantly blocked (3-fold) by pre-injecting unlabeled peptide. To further demonstrate specificity of Pep-1L towards IL13RA2 in vivo, we exploited an IL13RA2-inducible melanoma tumor model that does not express receptor at baseline but expresses abundant receptor after treatment with doxycycline. We injected [64Cu]Pep-1L into mice bearing IL13RA2-inducible melanoma tumors and performed in vivo PET/CT and post-necropsy biodistribution studies and found that tumors that were induced to express IL13RA2 receptor by doxycycline pretreatment bound radiolabeled Pep-1L 3-4 fold greater than uninduced tumors, demonstrating receptor specificity. This work demonstrates that [64Cu]Pep-1L selectively binds hIL13RA2-expressing tumors and validates Pep-1L as an effective platform to deliver diagnostics and therapeutics to IL13RA2-expressing cancers.
Collapse
Affiliation(s)
| | - Anirudh Sattiraju
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Frankis G Almaguel
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Ang Xuan
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Stephanie Rideout
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | | | - JoAnn Zhang
- MicroPET/CT Imaging Section, TriFoil Imaging, Chatsworth, CA, USA
| | - Denise M Herpai
- Department of Cancer Biology, Brain Tumor Center of Excellence, Wake Forest School of Medicine, Winston Salem, NC, USA
| | - Waldemar Debinski
- Department of Cancer Biology, Brain Tumor Center of Excellence, Wake Forest School of Medicine, Winston Salem, NC, USA
| | - Akiva Mintz
- Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| |
Collapse
|
13
|
Moreau M, Poty S, Vrigneaud JM, Walker P, Guillemin M, Raguin O, Oudot A, Bernhard C, Goze C, Boschetti F, Collin B, Brunotte F, Denat F. MANOTA: a promising bifunctional chelating agent for copper-64 immunoPET. Dalton Trans 2017; 46:14659-14668. [DOI: 10.1039/c7dt01772c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A comparison of four bifunctional chelating agents showed superior behaviour of a new NOTA derivative for 64Cu labelling of antibody fragments.
Collapse
|
14
|
Le Fur M, Beyler M, Lepareur N, Fougère O, Platas-Iglesias C, Rousseaux O, Tripier R. Pyclen Tri-n-butylphosphonate Ester as Potential Chelator for Targeted Radiotherapy: From Yttrium(III) Complexation to 90Y Radiolabeling. Inorg Chem 2016; 55:8003-12. [PMID: 27486673 DOI: 10.1021/acs.inorgchem.6b01135] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Mariane Le Fur
- Université de Bretagne Occidentale, UMR-CNRS 6521, UFR des Sciences et Techniques, 6 Avenue Victor le Gorgeu, CS 93837, 29238 Brest Cedex 3, France
| | - Maryline Beyler
- Université de Bretagne Occidentale, UMR-CNRS 6521, UFR des Sciences et Techniques, 6 Avenue Victor le Gorgeu, CS 93837, 29238 Brest Cedex 3, France
| | - Nicolas Lepareur
- Département de Médecine Nucléaire, Centre Eugène Marquis, INSERM U991, Avenue de la Bataille Flandres-Dunkerque,
CS 44229, 35042 Rennes Cedex, France
| | - Olivier Fougère
- Guerbet Group, Centre de Recherche d’Aulnay-sous-Bois, BP 57400, 95943 Roissy CdG Cedex, France
| | - Carlos Platas-Iglesias
- Centro de Investigaciones
Científicas Avanzadas (CICA) and Departamento de Química
Fundamental, Universidade da Coruña, Campus da Zapateira-Rúa da
Fraga 10, 15008 A Coruña, Spain
| | - Olivier Rousseaux
- Guerbet Group, Centre de Recherche d’Aulnay-sous-Bois, BP 57400, 95943 Roissy CdG Cedex, France
| | - Raphaël Tripier
- Université de Bretagne Occidentale, UMR-CNRS 6521, UFR des Sciences et Techniques, 6 Avenue Victor le Gorgeu, CS 93837, 29238 Brest Cedex 3, France
| |
Collapse
|
15
|
Gai Y, Sun L, Hui W, Ouyang Q, Anderson CJ, Xiang G, Ma X, Zeng D. New Bifunctional Chelator p-SCN-PhPr-NE3TA for Copper-64: Synthesis, Peptidomimetic Conjugation, Radiolabeling, and Evaluation for PET Imaging. Inorg Chem 2016; 55:6892-901. [PMID: 27347690 DOI: 10.1021/acs.inorgchem.6b00395] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Bifunctional chelators play an important role in developing metallic radionuclide-based radiopharmaceuticals. In this study, a new bifunctional ligand, p-SCN-PhPr-NE3TA, was synthesized and conjugated to a very late antigen-4 targeting peptidomimetic, LLP2A, for evaluating its application in (64)Cu-based positron emission tomography (PET) imaging. The new ligand exhibited strong selective coordination of Cu(II), leading to a robust Cu complex, even in the presence of 10-fold Fe(III). The LLP2A conjugate of p-SCN-PhPr-NE3TA was prepared and successfully labeled with (64)Cu under mild conditions. The conjugate (64)Cu-NE3TA-PEG4-LLP2A showed significantly higher specific activity, compared with (64)Cu-NOTA-PEG4-LLP2A, while maintaining comparable serum stability. Subsequent biodistribution studies and PET imaging in mice bearing B16F10 xenografts confirmed its favorable in vivo performance and high tumor uptake with low background, rendering p-SCN-PhPr-NE3TA a promising bifunctional chelator for (64)Cu-based radiopharmaceuticals.
Collapse
Affiliation(s)
- Yongkang Gai
- School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology , 13 Hangkong Road, Wuhan 430030, China.,Department of Radiology, University of Pittsburgh , Pittsburgh, Pennsylvania 15219, United States
| | - Lingyi Sun
- Department of Radiology, University of Pittsburgh , Pittsburgh, Pennsylvania 15219, United States
| | - Wenqi Hui
- College of Pharmacy, The Third Military Medical University , Chongqing 400038, China
| | - Qin Ouyang
- College of Pharmacy, The Third Military Medical University , Chongqing 400038, China
| | - Carolyn J Anderson
- Department of Radiology, University of Pittsburgh , Pittsburgh, Pennsylvania 15219, United States.,Departments of Pharmacology & Chemical Biology and Bioengineering, University of Pittsburgh , Pittsburgh, Pennsylvania 15219, United States
| | - Guangya Xiang
- School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology , 13 Hangkong Road, Wuhan 430030, China
| | - Xiang Ma
- School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology , 13 Hangkong Road, Wuhan 430030, China
| | - Dexing Zeng
- Department of Radiology, University of Pittsburgh , Pittsburgh, Pennsylvania 15219, United States
| |
Collapse
|
16
|
Krasikova RN, Aliev RA, Kalmykov SN. The next generation of positron emission tomography radiopharmaceuticals labeled with non-conventional radionuclides. MENDELEEV COMMUNICATIONS 2016. [DOI: 10.1016/j.mencom.2016.03.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
|
17
|
Dale AV, An GI, Pandya DN, Ha YS, Bhatt N, Soni N, Lee H, Ahn H, Sarkar S, Lee W, Huynh PT, Kim JY, Gwon MR, Kim SH, Park JG, Yoon YR, Yoo J. Synthesis and Evaluation of New Generation Cross-Bridged Bifunctional Chelator for 64Cu Radiotracers. Inorg Chem 2015; 54:8177-86. [DOI: 10.1021/acs.inorgchem.5b01386] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ajit V. Dale
- Department of Molecular Medicine, BK21 Plus KNU Biomedical
Convergence Program, Kyungpook National University, Daegu 700-422, South Korea
| | - Gwang Il An
- Molecular
Imaging Research Center, Korea Institute of Radiological and Medical Sciences, Seoul 139-706, South Korea
| | - Darpan N. Pandya
- Department of Molecular Medicine, BK21 Plus KNU Biomedical
Convergence Program, Kyungpook National University, Daegu 700-422, South Korea
| | - Yeong Su Ha
- Department of Molecular Medicine, BK21 Plus KNU Biomedical
Convergence Program, Kyungpook National University, Daegu 700-422, South Korea
| | - Nikunj Bhatt
- Department of Molecular Medicine, BK21 Plus KNU Biomedical
Convergence Program, Kyungpook National University, Daegu 700-422, South Korea
| | - Nisarg Soni
- Department of Molecular Medicine, BK21 Plus KNU Biomedical
Convergence Program, Kyungpook National University, Daegu 700-422, South Korea
| | - Hochun Lee
- Department of Energy Systems Engineering, Daegu Gyeongbuk Institute of Science & Technology, Daegu 711-873, South Korea
| | - Heesu Ahn
- Department of Molecular Medicine, BK21 Plus KNU Biomedical
Convergence Program, Kyungpook National University, Daegu 700-422, South Korea
| | - Swarbhanu Sarkar
- Department of Molecular Medicine, BK21 Plus KNU Biomedical
Convergence Program, Kyungpook National University, Daegu 700-422, South Korea
| | - Woonghee Lee
- Department of Molecular Medicine, BK21 Plus KNU Biomedical
Convergence Program, Kyungpook National University, Daegu 700-422, South Korea
| | - Phuong Tu Huynh
- Department of Molecular Medicine, BK21 Plus KNU Biomedical
Convergence Program, Kyungpook National University, Daegu 700-422, South Korea
| | - Jung Young Kim
- Molecular
Imaging Research Center, Korea Institute of Radiological and Medical Sciences, Seoul 139-706, South Korea
| | - Mi-Ri Gwon
- Department
of Biomedical Science and Clinical Trial Center, BK21 PLUS, KNU Bio-Medical
Convergence Program, Kyungpook National University Graduate School and Hospital, Daegu 700-422, South Korea
| | - Sung Hong Kim
- Analysis Research Division, Daegu Center, Korea Basic Science Institute, Daegu 702-701, South Korea
| | - Jae Gyu Park
- Pohang Center for Evaluation of Biomaterials, Pohang Technopark Foundation, Gyeongbuk 790-834, South Korea
| | - Young-Ran Yoon
- Department
of Biomedical Science and Clinical Trial Center, BK21 PLUS, KNU Bio-Medical
Convergence Program, Kyungpook National University Graduate School and Hospital, Daegu 700-422, South Korea
| | - Jeongsoo Yoo
- Department of Molecular Medicine, BK21 Plus KNU Biomedical
Convergence Program, Kyungpook National University, Daegu 700-422, South Korea
| |
Collapse
|
18
|
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] [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
| |
Collapse
|
19
|
Enrique MA, Mariana OR, Mirshojaei SF, Ahmadi A. Multifunctional radiolabeled nanoparticles: strategies and novel classification of radiopharmaceuticals for cancer treatment. J Drug Target 2014; 23:191-201. [DOI: 10.3109/1061186x.2014.988216] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
20
|
Ait-Mohand S, Denis C, Tremblay G, Paquette M, Guérin B. Development of Bifunctional Chelates Bearing Hydroxamate Arms for Highly Efficient 64Cu Radiolabeling. Org Lett 2014; 16:4512-5. [DOI: 10.1021/ol5020575] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Samia Ait-Mohand
- Department
of Nuclear Medicine and Radiobiology, Université de Sherbrooke, 3001 12th
North Avenue Sherbrooke, Quebec J1H 5N4, Canada
| | - Céline Denis
- Department
of Nuclear Medicine and Radiobiology, Université de Sherbrooke, 3001 12th
North Avenue Sherbrooke, Quebec J1H 5N4, Canada
| | - Geneviève Tremblay
- Department
of Nuclear Medicine and Radiobiology, Université de Sherbrooke, 3001 12th
North Avenue Sherbrooke, Quebec J1H 5N4, Canada
| | - Michel Paquette
- Department
of Nuclear Medicine and Radiobiology, Université de Sherbrooke, 3001 12th
North Avenue Sherbrooke, Quebec J1H 5N4, Canada
| | - Brigitte Guérin
- Department
of Nuclear Medicine and Radiobiology, Université de Sherbrooke, 3001 12th
North Avenue Sherbrooke, Quebec J1H 5N4, Canada
- Centre d’imagerie moléculaire de Sherbrooke (CIMS), 3001 12th North Avenue Sherbrooke, Quebec J1H 5N4, Canada
| |
Collapse
|
21
|
Zeng D, Ouyang Q, Cai Z, Xie XQ, Anderson CJ. New cross-bridged cyclam derivative CB-TE1K1P, an improved bifunctional chelator for copper radionuclides. Chem Commun (Camb) 2014; 50:43-5. [PMID: 24141371 DOI: 10.1039/c3cc45928d] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A new cross-bridged cyclam chelator, CB-TE1K1P, was developed for copper-based radiopharmaceuticals, and this chelator can be labelled with (64)Cu under mild conditions in high specific activity. DBCO-PEG4-CB-TE1K1P was synthesized for conjugation to proteins, while Dde-CB-TE1K1P((t)Bu2)-OH was synthesized for solid-phase peptide synthesis. Examples of the conjugation chemistry, radiolabelling and serum stability of each are presented.
Collapse
Affiliation(s)
- Dexing Zeng
- Department of Radiology, University of Pittsburgh, 100 Technology Drive, Suite 452F, Pittsburgh, PA 15219, USA.
| | | | | | | | | |
Collapse
|
22
|
Cai Z, Anderson CJ. Chelators for copper radionuclides in positron emission tomography radiopharmaceuticals. J Labelled Comp Radiopharm 2014; 57:224-30. [PMID: 24347474 PMCID: PMC4277819 DOI: 10.1002/jlcr.3165] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Accepted: 10/29/2013] [Indexed: 12/27/2022]
Abstract
The development of chelating agents for copper radionuclides in positron emission tomography radiopharmaceuticals has been a highly active and important area of study in recent years. The rapid evolution of chelators has resulted in highly specific copper chelators that can be readily conjugated to biomolecules and efficiently radiolabeled to form stable complexes in vivo. Chelators are not only designed for conjugation to monovalent biomolecules but also for incorporation into multivalent targeting ligands such as theranostic nanoparticles. These advancements have strengthened the role of copper radionuclides in the fields of nuclear medicine and molecular imaging. This review emphasizes developments of new copper chelators that have most greatly advanced the field of copper-based radiopharmaceuticals over the past 5 years.
Collapse
Affiliation(s)
- Zhengxin Cai
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Carolyn J. Anderson
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA 15219, USA
| |
Collapse
|
23
|
Banerjee SR, Pullambhatla M, Foss CA, Nimmagadda S, Ferdani R, Anderson CJ, Mease RC, Pomper MG. ⁶⁴Cu-labeled inhibitors of prostate-specific membrane antigen for PET imaging of prostate cancer. J Med Chem 2014; 57:2657-69. [PMID: 24533799 PMCID: PMC3983358 DOI: 10.1021/jm401921j] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Indexed: 01/15/2023]
Abstract
Prostate-specific membrane antigen (PSMA) is a well-recognized target for identification and therapy of a variety of cancers. Here we report five (64)Cu-labeled inhibitors of PSMA, [(64)Cu]3-7, which are based on the lysine-glutamate urea scaffold and utilize a variety of macrocyclic chelators, namely NOTA(3), PCTA(4), Oxo-DO3A(5), CB-TE2A(6), and DOTA(7), in an effort to determine which provides the most suitable pharmacokinetics for in vivo PET imaging. [(64)Cu]3-7 were prepared in high radiochemical yield (60-90%) and purity (>95%). Positron emission tomography (PET) imaging studies of [(64)Cu]3-7 revealed specific accumulation in PSMA-expressing xenografts (PSMA+ PC3 PIP) relative to isogenic control tumor (PSMA- PC3 flu) and background tissue. The favorable kinetics and high image contrast provided by CB-TE2A chelated [(64)Cu]6 suggest it as the most promising among the candidates tested. That could be due to the higher stability of [(64)Cu]CB-TE2A as compared with [(64)Cu]NOTA, [(64)Cu]PCTA, [(64)Cu]Oxo-DO3A, and [(64)Cu]DOTA chelates in vivo.
Collapse
Affiliation(s)
- Sangeeta Ray Banerjee
- Russell
H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins Medical Institutions, 1550 Orleans Street, Baltimore, Maryland 21287, United States
| | - Mrudula Pullambhatla
- Russell
H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins Medical Institutions, 1550 Orleans Street, Baltimore, Maryland 21287, United States
| | - Catherine A. Foss
- Russell
H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins Medical Institutions, 1550 Orleans Street, Baltimore, Maryland 21287, United States
| | - Sridhar Nimmagadda
- Russell
H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins Medical Institutions, 1550 Orleans Street, Baltimore, Maryland 21287, United States
| | - Riccardo Ferdani
- Department
of Radiology, University of Pittsburgh Medical
Center, Pittsburgh, Pennsylvania 15219, United States
| | - Carolyn J. Anderson
- Department
of Radiology, University of Pittsburgh Medical
Center, Pittsburgh, Pennsylvania 15219, United States
| | - Ronnie C. Mease
- Russell
H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins Medical Institutions, 1550 Orleans Street, Baltimore, Maryland 21287, United States
| | - Martin G. Pomper
- Russell
H. Morgan Department of Radiology and Radiological Sciences, Johns Hopkins Medical Institutions, 1550 Orleans Street, Baltimore, Maryland 21287, United States
| |
Collapse
|
24
|
Ramogida CF, Orvig C. Tumour targeting with radiometals for diagnosis and therapy. Chem Commun (Camb) 2013; 49:4720-39. [PMID: 23599005 DOI: 10.1039/c3cc41554f] [Citation(s) in RCA: 177] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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.
Collapse
Affiliation(s)
- Caterina F Ramogida
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, Canada V6T 1Z1
| | | |
Collapse
|
25
|
Abstract
Radiometals comprise many useful radioactive isotopes of various metallic elements. When properly harnessed, these have valuable emission properties that can be used for diagnostic imaging techniques, such as single photon emission computed tomography (SPECT, e.g.(67)Ga, (99m)Tc, (111)In, (177)Lu) and positron emission tomography (PET, e.g.(68)Ga, (64)Cu, (44)Sc, (86)Y, (89)Zr), as well as therapeutic applications (e.g.(47)Sc, (114m)In, (177)Lu, (90)Y, (212/213)Bi, (212)Pb, (225)Ac, (186/188)Re). A fundamental critical component of a radiometal-based radiopharmaceutical is the chelator, the ligand system that binds the radiometal ion in a tight stable coordination complex so that it can be properly directed to a desirable molecular target in vivo. This article is a guide for selecting the optimal match between chelator and radiometal for use in these systems. The article briefly introduces a selection of relevant and high impact radiometals, and their potential utility to the fields of radiochemistry, nuclear medicine, and molecular imaging. A description of radiometal-based radiopharmaceuticals is provided, and several key design considerations are discussed. The experimental methods by which chelators are assessed for their suitability with a variety of radiometal ions is explained, and a large selection of the most common and most promising chelators are evaluated and discussed for their potential use with a variety of radiometals. Comprehensive tables have been assembled to provide a convenient and accessible overview of the field of radiometal chelating agents.
Collapse
Affiliation(s)
- Eric W Price
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, CanadaV6T 1Z1.
| | | |
Collapse
|
26
|
Yapp DT, Ferreira CL, Gill RK, Boros E, Wong MQ, Mandel D, Jurek P, Kiefer GE. Imaging Tumor Vasculature Noninvasively with Positron Emission Tomography and RGD Peptides Labeled with Copper 64 Using the Bifunctonal Chelates DOTA, Oxo-DO3A. and PCTA. Mol Imaging 2013. [DOI: 10.2310/7290.2012.00044] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Affiliation(s)
- Donald T.T. Yapp
- From Department of Experimental Therapeutics, BC Cancer Agency, Vancouver, BC; Nordion, Vancouver, BC; TRIUMF, Vancouver, BC; Department of Chemistry, University of British Columbia, Vancouver, BC; and Macrocyclics, Dallas, TX
| | - Cara L. Ferreira
- From Department of Experimental Therapeutics, BC Cancer Agency, Vancouver, BC; Nordion, Vancouver, BC; TRIUMF, Vancouver, BC; Department of Chemistry, University of British Columbia, Vancouver, BC; and Macrocyclics, Dallas, TX
| | - Rajanvir K. Gill
- From Department of Experimental Therapeutics, BC Cancer Agency, Vancouver, BC; Nordion, Vancouver, BC; TRIUMF, Vancouver, BC; Department of Chemistry, University of British Columbia, Vancouver, BC; and Macrocyclics, Dallas, TX
| | - Eszter Boros
- From Department of Experimental Therapeutics, BC Cancer Agency, Vancouver, BC; Nordion, Vancouver, BC; TRIUMF, Vancouver, BC; Department of Chemistry, University of British Columbia, Vancouver, BC; and Macrocyclics, Dallas, TX
| | - May Q. Wong
- From Department of Experimental Therapeutics, BC Cancer Agency, Vancouver, BC; Nordion, Vancouver, BC; TRIUMF, Vancouver, BC; Department of Chemistry, University of British Columbia, Vancouver, BC; and Macrocyclics, Dallas, TX
| | - Derek Mandel
- From Department of Experimental Therapeutics, BC Cancer Agency, Vancouver, BC; Nordion, Vancouver, BC; TRIUMF, Vancouver, BC; Department of Chemistry, University of British Columbia, Vancouver, BC; and Macrocyclics, Dallas, TX
| | - Paul Jurek
- From Department of Experimental Therapeutics, BC Cancer Agency, Vancouver, BC; Nordion, Vancouver, BC; TRIUMF, Vancouver, BC; Department of Chemistry, University of British Columbia, Vancouver, BC; and Macrocyclics, Dallas, TX
| | - Garry E. Kiefer
- From Department of Experimental Therapeutics, BC Cancer Agency, Vancouver, BC; Nordion, Vancouver, BC; TRIUMF, Vancouver, BC; Department of Chemistry, University of British Columbia, Vancouver, BC; and Macrocyclics, Dallas, TX
| |
Collapse
|
27
|
Measurement of the rate of copper(II) exchange for 64Cu complexes of bifunctional chelators. Inorganica Chim Acta 2012. [DOI: 10.1016/j.ica.2012.07.012] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
28
|
Marciniak A, Cebrat M, Czyżnikowska Ż, Brasuń J. Novel short-chain analogues of somatostatin as ligands for Cu(II) ions. Role of the metal ion binding on the spatial structure of the ligand. J Inorg Biochem 2012; 117:10-7. [PMID: 23078770 DOI: 10.1016/j.jinorgbio.2012.08.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 08/27/2012] [Accepted: 08/31/2012] [Indexed: 01/05/2023]
Abstract
In this paper we present the studies on coordination abilities of two short-chain analogues of somatostatin with free N-terminal and protected amino group towards copper (II) ions. The octreotide is the most popular analogue of the somatostatin (peptide hormone) used in medicine. Somatostatin analogues are used in diagnosis and treatment of the neuroendocrine tumors. Both analyzed analogues are characterized by the presence of two His instead of Cys residues in characteristic fragment of native peptide. We characterize coordination abilities of the ligands using potentiometric and spectroscopic methods. His-analogues of somatostatin are effective ligands for copper (II) ions. Both peptides are able to form the complexes with the cyclic structure.
Collapse
Affiliation(s)
- Aleksandra Marciniak
- Department of Inorganic Chemistry, Wroclaw Medical University, Szewska 38, 50-139 Wroclaw, Poland
| | | | | | | |
Collapse
|
29
|
Bartholomä MD. Recent developments in the design of bifunctional chelators for metal-based radiopharmaceuticals used in Positron Emission Tomography. Inorganica Chim Acta 2012. [DOI: 10.1016/j.ica.2012.01.061] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
30
|
Ferreira CL, Holley I, Bensimon C, Jurek P, Kiefer GE. Pharmacokinetic Modulation of Radiolabeled Chelates Facilitated by Phosphonate Ester Coordinating Groups. Mol Pharm 2012; 9:2180-6. [DOI: 10.1021/mp300024c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Cara L. Ferreira
- Nordion, 4004 Wesbrook
Mall, Vancouver, British Columbia, Canada V6T 2A3
| | - Ian Holley
- Nordion, 4004 Wesbrook
Mall, Vancouver, British Columbia, Canada V6T 2A3
| | - Corinne Bensimon
- Nordion, 4004 Wesbrook
Mall, Vancouver, British Columbia, Canada V6T 2A3
| | - Paul Jurek
- Macrocyclics, 1309 Record Crossing, Dallas,
Texas 75235, USA
| | - Garry E. Kiefer
- Macrocyclics, 1309 Record Crossing, Dallas,
Texas 75235, USA
| |
Collapse
|
31
|
Cooper MS, Ma MT, Sunassee K, Shaw KP, Williams JD, Paul RL, Donnelly PS, Blower PJ. Comparison of (64)Cu-complexing bifunctional chelators for radioimmunoconjugation: labeling efficiency, specific activity, and in vitro/in vivo stability. Bioconjug Chem 2012; 23:1029-39. [PMID: 22471317 PMCID: PMC4756438 DOI: 10.1021/bc300037w] [Citation(s) in RCA: 170] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
High radiolabeling efficiency, preferably to high specific activity, and good stability of the radioimmunoconjugate are essential features for a successful immunoconjugate for imaging or therapy. In this study, the radiolabeling efficiency, in vitro stability, and biodistribution of immunoconjugates with eight different bifunctional chelators labeled with (64)Cu were compared. The anti-CD20 antibody, rituximab, was conjugated to four macrocyclic bifunctional chelators (p-SCN-Bn-DOTA, p-SCN-Bn-Oxo-DO3A, p-SCN-NOTA, and p-SCN-PCTA), three DTPA derivatives (p-SCN-Bn-DTPA, p-SCN-CHX-A″-DTPA, and ITC-2B3M-DTPA), and a macrobicyclic hexamine (sarcophagine) chelator (sar-CO2H) = (1-NH2-8-NHCO(CH2)3CO2H)sar where sar = sarcophagine = 3,6,10,13,16,19-hexaazabicyclo[6.6.6]icosane). Radiolabeling efficiency under various conditions, in vitro stability in serum at 37 °C, and in vivo biodistribution and imaging in normal mice over 48 h were studied. All chelators except sar-CO2H were conjugated to rituximab by thiourea bond formation with an average of 4.9 ± 0.9 chelators per antibody molecule. Sar-CO2H was conjugated to rituximab by amide bond formation with 0.5 chelators per antibody molecule. Efficiencies of (64)Cu radiolabeling were dependent on the concentration of immunoconjugate. Notably, the (64)Cu-NOTA-rituximab conjugate demonstrated the highest radiochemical yield (95%) under very dilute conditions (31 nM NOTA-rituximab conjugate). Similarly, sar-CO-rituximab, containing 1/10th the number of chelators per antibody compared to that of other conjugates, retained high labeling efficiency (98%) at an antibody concentration of 250 nM. In contrast to the radioimmunoconjugates containing DTPA derivatives, which demonstrated poor serum stability, all macrocyclic radioimmunoconjugates were very stable in serum with <6% dissociation of (64)Cu over 48 h. In vivo biodistribution profiles in normal female Balb/C mice were similar for all the macrocyclic radioimmunoconjugates with most of the activity remaining in the blood pool up to 48 h. While all the macrocyclic bifunctional chelators are suitable for molecular imaging using (64)Cu-labeled antibody conjugates, NOTA and sar-CO2H show significant advantages over the others in that they can be radiolabeled rapidly at room temperature, under dilute conditions, resulting in high specific activity.
Collapse
Affiliation(s)
- Maggie S. Cooper
- King’s College London, Division of Imaging Sciences and Biomedical Engineering, 4 Floor Lambeth Wing, St. Thomas’ Hospital, SE1 7EH, London
| | - Michelle T. Ma
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Melbourne, Victoria, 3010, Australia
| | - Kavitha Sunassee
- King’s College London, Division of Imaging Sciences and Biomedical Engineering, 4 Floor Lambeth Wing, St. Thomas’ Hospital, SE1 7EH, London
| | - Karen P. Shaw
- King’s College London, Division of Imaging Sciences and Biomedical Engineering, 4 Floor Lambeth Wing, St. Thomas’ Hospital, SE1 7EH, London
| | - Jennifer D. Williams
- King’s College London, Division of Imaging Sciences and Biomedical Engineering, 4 Floor Lambeth Wing, St. Thomas’ Hospital, SE1 7EH, London
| | - Rowena L. Paul
- King’s College London, Division of Imaging Sciences and Biomedical Engineering, 4 Floor Lambeth Wing, St. Thomas’ Hospital, SE1 7EH, London
| | - Paul S. Donnelly
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Melbourne, Victoria, 3010, Australia
| | - Philip J. Blower
- King’s College London, Division of Imaging Sciences and Biomedical Engineering, 4 Floor Lambeth Wing, St. Thomas’ Hospital, SE1 7EH, London
| |
Collapse
|
32
|
Suzuki H, Kanai A, Uehara T, Guerra Gomez FL, Hanaoka H, Arano Y. Facile synthesis and evaluation of C-functionalized benzyl-1-oxa-4,7,10-triazacyclododecane-N,N′,N″-triacetic acid as chelating agent for 111In-labeled polypeptides. Bioorg Med Chem 2012; 20:978-84. [DOI: 10.1016/j.bmc.2011.11.046] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Revised: 11/19/2011] [Accepted: 11/21/2011] [Indexed: 10/14/2022]
|
33
|
Shi J, Liu TW, Chen J, Green D, Jaffray D, Wilson BC, Wang F, Zheng G. Transforming a Targeted Porphyrin Theranostic Agent into a PET Imaging Probe for Cancer. Am J Cancer Res 2011; 1:363-70. [PMID: 21938264 PMCID: PMC3177245 DOI: 10.7150/thno/v01p0363] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Accepted: 08/27/2011] [Indexed: 12/29/2022] Open
Abstract
Porphyrin based photosensitizers are useful agents for photodynamic therapy (PDT) and fluorescence imaging of cancer. Porphyrins are also excellent metal chelators forming highly stable metallo-complexes making them efficient delivery vehicles for radioisotopes. Here we investigated the possibility of incorporating (64)Cu into a porphyrin-peptide-folate (PPF) probe developed previously as folate receptor (FR) targeted fluorescent/PDT agent, and evaluated the potential of turning the resulting (64)Cu-PPF into a positron emission tomography (PET) probe for cancer imaging. Noninvasive PET imaging followed by radioassay evaluated the tumor accumulation, pharmacokinetics and biodistribution of (64)Cu-PPF. (64)Cu-PPF uptake in FR-positive tumors was visible on small-animal PET images with high tumor-to-muscle ratio (8.88 ± 3.60) observed after 24 h. Competitive blocking studies confirmed the FR-mediated tracer uptake by the tumor. The ease of efficient (64)Cu-radiolabeling of PPF while retaining its favorable biodistribution, pharmacokinetics and selective tumor uptake, provides a robust strategy to transform tumor-targeted porphyrin-based photosensitizers into PET imaging probes.
Collapse
|
34
|
Ait-Mohand S, Fournier P, Dumulon-Perreault V, Kiefer GE, Jurek P, Ferreira CL, Bénard F, Guérin B. Evaluation of 64Cu-labeled bifunctional chelate-bombesin conjugates. Bioconjug Chem 2011; 22:1729-35. [PMID: 21761921 DOI: 10.1021/bc2002665] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Several bifunctional chelates (BFCs) were investigated as carriers of (64)Cu for PET imaging. The most widely used chelator for (64)Cu labeling of BFCs is DOTA (1,4,7,10-tetraazacyclododecane-N,N',N″,N'''-tretraacetic acid), even though this complex exhibits only moderate in vivo stability. In this study, we prepared a series of alternative chelator-peptide conjugates labeled with (64)Cu, measured in vitro receptor binding affinities in human breast cancer T47D cells expressing the gastrin-releasing peptide receptor (GRPR) and compared their in vivo stability in mice. DOTA-, NOTA-(1,4,7-triazacyclononane-1,4,7-triacetic acid), PCTA-(3,6,9,15-tetraazabicyclo[9.3.1]pentadeca-1(15),11,13-triene-3,6,9-triacetic acid), and Oxo-DO3A-(1-oxa-4,7,10-triazacyclododecane-4,7,10-triacetic acid) peptide conjugates were prepared using H(2)N-Aoc-[d-Tyr(6),βAla(11),Thi(13),Nle(14)]bombesin(6-14) (BBN) as a peptide template. The BBN moiety was selected since it binds with high affinity to the GRPR, which is overexpressed on human breast cancer cells. A convenient synthetic approach for the attachment of aniline-BFC to peptides on solid support is also presented. To facilitate the attachment of the aniline-PCTA and aniline-Oxo-DO3A to the peptide via an amide bond, a succinyl spacer was introduced at the N-terminus of BBN. The partially protected aniline-BFC (p-H(2)N-Bn-PCTA(Ot-Bu)(3) or p-H(2)N-Bn-DO3A(Ot-Bu)(3)) was then coupled to the resulting N-terminal carboxylic acid preactivated with DEPBT/ClHOBt on resin. After cleavage and purification, the peptide-conjugates were labeled with (64)Cu using [(64)Cu]Cu(OAc)(2) in 0.1 M ammonium acetate buffer at 100 °C for 15 min. Labeling efficacy was >90% for all peptides; Oxo-DO3A-BBN was incubated an additional 150 min at 100 °C to achieve this high yield. Specific activities varied from 76 to 101 TBq/mmol. Competition assays on T47D cells showed that all BFC-BBN complexes retained high affinity for the GRPR. All BFC-BBN (64)Cu-conjugates were stable for over 20 h when incubated at 37 °C in mouse plasma samples. However, in vivo, only 37% of the (64)Cu/Oxo-DO3A complex remained intact after 20 h while the (64)Cu/DOTA-BBN complex was completely demetalated. In contrast, both (64)Cu/NOTA- and (64)Cu/PCTA-BBN conjugates remained stable during the 20 h time period. Our results indicate that it is possible to successfully conjugate aniline-BFC with peptide on solid support. Our data also show that (64)Cu-labeled NOTA- and PCTA-BBN peptide conjugates are promising radiotracers for PET imaging of many human cancers overexpressing the GRP receptor.
Collapse
Affiliation(s)
- Samia Ait-Mohand
- Centre d'imagerie moléculaire de Sherbrooke, Department of Nuclear Medicine and Radiobiology, Université de Sherbrooke, 3001, 12th North Avenue Sherbrooke, Qubec, Canada, J1H 5N4
| | | | | | | | | | | | | | | |
Collapse
|
35
|
Rockey WM, Huang L, Kloepping KC, Baumhover NJ, Giangrande PH, Schultz MK. Synthesis and radiolabeling of chelator-RNA aptamer bioconjugates with copper-64 for targeted molecular imaging. Bioorg Med Chem 2011; 19:4080-90. [PMID: 21658962 DOI: 10.1016/j.bmc.2011.05.010] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Revised: 05/04/2011] [Accepted: 05/09/2011] [Indexed: 12/14/2022]
Abstract
Ribonucleic acid (RNA) aptamers with high affinity and specificity for cancer-specific cell-surface antigens are promising reagents for targeted molecular imaging of cancer using positron emission tomography (PET). For this application, aptamers must be conjugated to chelators capable of coordinating PET-radionuclides (e.g., copper-64, (64)Cu) to enable radiolabeling for in vivo imaging of tumors. This study investigates the choice of chelator and radiolabeling parameters such as pH and temperature for the development of (64)Cu-labeled RNA-based targeted agents for PET imaging. The characterization and optimization of labeling conditions are described for four chelator-aptamer complexes. Three commercially available bifunctional macrocyclic chelators (1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid mono N-hydroxysuccinimide [DOTA-NHS]; S-2-(4-isothiocyanatobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid [p-SCN-Bn-NOTA]; and p-SCN-Bn-3,6,9,15-tetraazabicyclo [9.3.1]pentadeca-1(15),11,13-triene-3,6,9-triacetic acid [p-SCN-Bn-PCTA]), as well as the polyamino-macrocyclic diAmSar (3,6,10,13,16,19-hexaazabicyclo[6.6.6] icosane-1,8-diamine) were conjugated to A10-3.2, a RNA aptamer which has been shown to bind specifically to a prostate cancer-specific cell-surface antigen (PSMA). Although a commercial bifunctional version of diAmSar was not available, RNA conjugation with this chelator was achieved in a two-step reaction by the addition of a disuccinimidyl suberate linker. Radiolabeling parameters (e.g., pH, temperature, and time) for each chelator-RNA conjugate were assessed in order to optimize specific activity and RNA stability. Furthermore, the radiolabeled chelator-coupled RNA aptamers were evaluated for binding specificity to their target antigen. In summary, key parameters were established for optimal radiolabeling of RNA aptamers for eventual PET imaging with (64)Cu.
Collapse
Affiliation(s)
- William M Rockey
- Department of Radiation Oncology, University of Iowa, Iowa City, IA 52242, United States
| | | | | | | | | | | |
Collapse
|
36
|
Cai H, Li Z, Huang CW, Shahinian AH, Wang H, Park R, Conti PS. Evaluation of copper-64 labeled AmBaSar conjugated cyclic RGD peptide for improved microPET imaging of integrin alphavbeta3 expression. Bioconjug Chem 2011; 21:1417-24. [PMID: 20666401 DOI: 10.1021/bc900537f] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recently, we have developed a new cage-like bifunctional chelator 4-((8-amino-3,6,10,13,16,19-hexaazabicyclo [6.6.6] icosane-1-ylamino) methyl) benzoic acid (AmBaSar) for copper-64 labeling and synthesized the positron emission tomography (PET) tracer (64)Cu-AmBaSar-RGD. In this study, we further evaluate the biological property of this new AmBaSar chelator by using (64)Cu-AmBaSar-RGD as the model compound. In vitro and in vivo stability, lipophilicity, cell binding and uptake, microPET imaging, receptor blocking experiments, and biodistribution studies of (64)Cu-AmBaSar-RGD were investigated, and the results were directly compared with the established radiotracer (64)Cu-DOTA-RGD. The (64)Cu-AmBaSar-RGD was obtained with high radiochemical yield (> or =95%) and purity (> or =99%) under mild conditions (pH 5.0-5.5 and 23-37 degrees C) in less than 30 min. For in vitro studies, the radiochemical purity of (64)Cu-AmBaSar-RGD was more than 97% in PBS or FBS and 95% in mouse serum after 24 h of incubation. The log P value of (64)Cu-AmBaSar-RGD was -2.44 +/- 0.12. For in vivo studies, (64)Cu-AmBaSar-RGD and (64)Cu-DOTA-RGD have demonstrated comparable tumor uptake at selected time points on the basis of microPET imaging. The integrin alpha(v)beta(3) receptor specificity was confirmed by blocking experiments for both tracers. Compared with (64)Cu-DOTA-RGD, (64)Cu-AmBaSar-RGD demonstrated much lower liver accumulation in both microPET imaging and biodistribution studies. Metabolic studies also directly supported the observation that (64)Cu-AmBaSar-RGD was more stable in vivo than (64)Cu-DOTA-RGD. In summary, the in vitro and in vivo evaluations of the (64)Cu-AmBaSar-RGD have demonstrated its improved Cu-chelation stability compared with that of the established tracer (64)Cu-DOTA-RGD. The AmBaSar chelator will also have general applications for (64)Cu labeling of various bioactive molecules in high radiochemical yield and high in vivo stability.
Collapse
Affiliation(s)
- Hancheng Cai
- Molecular Imaging Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | | | | | | | | | | | | |
Collapse
|
37
|
Lattuada L, Barge A, Cravotto G, Giovenzana GB, Tei L. The synthesis and application of polyamino polycarboxylic bifunctional chelating agents. Chem Soc Rev 2011; 40:3019-49. [DOI: 10.1039/c0cs00199f] [Citation(s) in RCA: 139] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
|
38
|
Uppal R, Catana C, Ay I, Benner T, Sorensen AG, Caravan P. Bimodal thrombus imaging: simultaneous PET/MR imaging with a fibrin-targeted dual PET/MR probe--feasibility study in rat model. Radiology 2010; 258:812-20. [PMID: 21177389 DOI: 10.1148/radiol.10100881] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To image thrombus by using magnetic resonance (MR) imaging and positron emission tomography (PET) simultaneously in a rat arterial thrombus model with a dual PET/MR probe. MATERIALS AND METHODS Animal studies were approved by the institutional animal use committee. A dual PET/MR probe was synthesized by means of partial exchange of gadolinium for copper 64 ((64)Cu) in the fibrin-targeted MR probe EP-2104R. A preformed 25-mm thrombus was injected into the right internal carotid artery of a rat. Imaging was performed with a clinical 3.0-T MR imager with an MR-compatible human PET imager. Rats (n = 5) were imaged prior to and after systemic administration of the dual probe by using simultaneous PET/MR. The organ distribution of (64)Cu and gadolinium was determined ex vivo (n = 8), 2 hours after injection by using well counting and inductively coupled plasma mass spectrometry, respectively. Signal intensity ratios (SIRs) between the thrombus-containing and contralateral vessel were computed from PET images and MR data before and after probe administration. RESULTS The dual probe was synthesized with greater than 98% radiochemical purity. Thrombus enhancement was observed in all five animals at both MR (SIR([postprobe])/SIR([preprobe]) = 1.71 ± 0.35, P = .0053) and PET (SIR = 1.85 ± 0.48, P = .0087) after injection of the dual PET/MR probe. Ex vivo analysis at 2 hours after injection showed the highest (64)Cu and gadolinium concentrations, after the excretory organs (kidney and liver), to be in the thrombus. CONCLUSION A fibrin-targeted dual PET/MR probe enables simultaneous, direct MR and PET imaging of thrombus.
Collapse
Affiliation(s)
- Ritika Uppal
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 Thirteenth Street, Suite 2301, Charlestown, MA 02129, USA
| | | | | | | | | | | |
Collapse
|
39
|
Yoshida C, Tsuji AB, Sudo H, Sugyo A, Sogawa C, Inubushi M, Uehara T, Fukumura T, Koizumi M, Arano Y, Saga T. Development of positron emission tomography probe of 64Cu-labeled anti-C-kit 12A8 Fab to measure protooncogene C-kit expression. Nucl Med Biol 2010; 38:331-7. [PMID: 21492781 DOI: 10.1016/j.nucmedbio.2010.10.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2010] [Revised: 09/02/2010] [Accepted: 10/12/2010] [Indexed: 12/25/2022]
Abstract
INTRODUCTION C-kit is an important diagnostic and therapeutic target molecule for several malignancies, and c-kit-targeted drugs have been used clinically. Because abundant c-kit expression in tumors is a prerequisite for successful c-kit-targeted therapy, imaging of c-kit expression is expected to play a pivotal role in the therapeutic decision for each patient. We evaluated (64)Cu-labeled Fab of anti-c-kit antibody 12A8 as a positron emission tomography (PET) imaging probe. METHODS (111)In- or (125)I-Labeled 12A8 Fab was evaluated in vitro by cell binding, competitive inhibition and cellular internalization assays, and in vivo by biodistribution in mice bearing c-kit-expressing and -non-expressing tumors. Next, Fab fragment was labeled with the positron emitter (64)Cu and evaluated by PET. RESULTS Radiolabeled 12A8 Fab showed specific binding to c-kit-expressing cells with high affinity and internalized into cells after binding to c-kit on cell surface. Although tumor accumulation of [(111)In]Fab was lower than that of [(111)In]IgG, the faster blood clearance of [(111)In]Fab provided higher tumor-to-blood ratio at 6 h postinjection onwards. Blood clearance of (64)Cu-labeled 12A8 Fab was slower than that of [(111)In]Fab, but PET using [(64)Cu]Fab clearly visualized the tumor at 6 h postinjection onwards. CONCLUSION The (64)Cu-labeled 12A8 Fab could be used for c-kit-specific PET imaging and might help in selecting appropriate patients for c-kit-targeted treatments.
Collapse
Affiliation(s)
- Chisato Yoshida
- Diagnostic Imaging Group, Molecular Imaging Center, National Institute of Radiological Sciences, Inage-ku, Chiba 263-8555, Japan
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Li Z, Conti PS. Radiopharmaceutical chemistry for positron emission tomography. Adv Drug Deliv Rev 2010; 62:1031-51. [PMID: 20854860 DOI: 10.1016/j.addr.2010.09.007] [Citation(s) in RCA: 144] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Revised: 09/11/2010] [Accepted: 09/13/2010] [Indexed: 12/13/2022]
Abstract
Molecular imaging is an emerging technology that allows the visualization of interactions between molecular probes and biological targets. Molecules that either direct or are subject to homeostatic controls in biological systems could be labeled with the appropriate radioisotopes for the quantitative measurement of selected molecular interactions during normal tissue homeostasis and again after perturbations of the normal state. In particular, positron emission tomography (PET) offers picomolar sensitivity and is a fully translational technique that requires specific probes radiolabeled with a usually short-lived positron-emitting radionuclide. PET has provided the capability of measuring biological processes at the molecular and metabolic levels in vivo by the detection of the gamma rays formed as a result of the annihilation of the positrons emitted. Despite the great wealth of information that such probes can provide, the potential of PET strongly depends on the availability of suitable PET radiotracers. However, the development of new imaging probes for PET is far from trivial and radiochemistry is a major limiting factor for the field of PET. In this review, we provided an overview of the most common chemical approaches for the synthesis of PET-labeled molecules and highlighted the most recent developments and trends. The discussed PET radionuclides include ¹¹C (t₁(/)₂=20.4min), ¹³N (t₁(/)₂=9.9min), ¹⁵O (t₁(/)₂=2min), ⁶⁸Ga (t₁(/)₂=68min), ¹⁸F (t₁(/)₂=109.8min), ⁶⁴Cu (t₁(/)₂=12.7h), and ¹²⁴I (t₁(/)₂=4.12d).
Collapse
|
41
|
Comparison of bifunctional chelates for (64)Cu antibody imaging. Eur J Nucl Med Mol Imaging 2010; 37:2117-26. [PMID: 20552190 DOI: 10.1007/s00259-010-1506-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Accepted: 05/19/2010] [Indexed: 01/27/2023]
Abstract
PURPOSE Improved bifunctional chelates (BFCs) are needed to facilitate efficient (64)Cu radiolabeling of monoclonal antibodies (mAbs) under mild conditions and to yield stable, target-specific agents. The utility of two novel BFCs, 1-Oxa-4,7,10-triazacyclododecane-5-S-(4-isothiocyanatobenzyl)-4,7,10-triacetic acid (p-SCN-Bn-Oxo-DO3A) and 3,6,9,15-tetraazabicyclo[9.3.1]pentadeca-1(15),11,13-triene-4-S-(4-isothiocyanatobenzyl)-3,6,9-triacetic acid (p-SCN-Bn-PCTA), for mAb imaging with (64)Cu were compared to the commonly used S-2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraazacyclododecane-tetraacetic acid (p-SCN-Bn-DOTA). METHODS The BFCs were conjugated to trastuzumab, which targets the HER2/neu receptor. (64)Cu radiolabeling of the conjugates was optimized. Receptor binding was analyzed using flow cytometry and radioassays. Finally, PET imaging and biodistribution studies were done in mice bearing either HER2/neu-positive or HER2/neu-negative tumors. RESULTS (64)Cu-Oxo-DO3A- and PCTA-trastuzumab were prepared at room temperature in >95% radiochemical yield (RCY) in <30 min, compared to only 88% RCY after 2 h for the preparation of (64)Cu-DOTA-trastuzumab under the same conditions. Cell studies confirmed that the immunoreactivity of the mAb was retained for each of the bioconjugates. In vivo studies showed that (64)Cu-Oxo-DO3A- and PCTA-trastuzumab had higher uptake than the (64)Cu-DOTA-trastuzumab at 24 h in HER2/neu-positive tumors, resulting in higher tumor to background ratios and better tumor images. By 40 h all three of the (64)Cu-BFC-trastuzumab conjugates allowed for clear visualization of the HER2/neu-positive tumors but not the negative control tumor. CONCLUSION The antibody conjugates of PCTA and Oxo-DO3A were shown to have superior (64)Cu radiolabeling efficiency and stability compared to the analogous DOTA conjugate. In addition, (64)Cu-PCTA and Oxo-DO3A antibody conjugates may facilitate earlier imaging with greater target to background ratios than the analogous (64)Cu-DOTA antibody conjugates.
Collapse
|
42
|
Ferreira CL, Lamsa E, Woods M, Duan Y, Fernando P, Bensimon C, Kordos M, Guenther K, Jurek P, Kiefer GE. Evaluation of Bifunctional Chelates for the Development of Gallium-Based Radiopharmaceuticals. Bioconjug Chem 2010; 21:531-6. [DOI: 10.1021/bc900443a] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Cara L. Ferreira
- MDS Nordion, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3, Ottawa Heart Institute, Ottawa, Ontario, Canada, MDS Nordion, Kanata, Ontario, Canada, and Macrocyclics, Dallas, Texas
| | - Eric Lamsa
- MDS Nordion, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3, Ottawa Heart Institute, Ottawa, Ontario, Canada, MDS Nordion, Kanata, Ontario, Canada, and Macrocyclics, Dallas, Texas
| | - Michael Woods
- MDS Nordion, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3, Ottawa Heart Institute, Ottawa, Ontario, Canada, MDS Nordion, Kanata, Ontario, Canada, and Macrocyclics, Dallas, Texas
| | - Yin Duan
- MDS Nordion, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3, Ottawa Heart Institute, Ottawa, Ontario, Canada, MDS Nordion, Kanata, Ontario, Canada, and Macrocyclics, Dallas, Texas
| | - Pasan Fernando
- MDS Nordion, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3, Ottawa Heart Institute, Ottawa, Ontario, Canada, MDS Nordion, Kanata, Ontario, Canada, and Macrocyclics, Dallas, Texas
| | - Corinne Bensimon
- MDS Nordion, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3, Ottawa Heart Institute, Ottawa, Ontario, Canada, MDS Nordion, Kanata, Ontario, Canada, and Macrocyclics, Dallas, Texas
| | - Myra Kordos
- MDS Nordion, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3, Ottawa Heart Institute, Ottawa, Ontario, Canada, MDS Nordion, Kanata, Ontario, Canada, and Macrocyclics, Dallas, Texas
| | - Katharina Guenther
- MDS Nordion, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3, Ottawa Heart Institute, Ottawa, Ontario, Canada, MDS Nordion, Kanata, Ontario, Canada, and Macrocyclics, Dallas, Texas
| | - Paul Jurek
- MDS Nordion, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3, Ottawa Heart Institute, Ottawa, Ontario, Canada, MDS Nordion, Kanata, Ontario, Canada, and Macrocyclics, Dallas, Texas
| | - Garry E. Kiefer
- MDS Nordion, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3, Ottawa Heart Institute, Ottawa, Ontario, Canada, MDS Nordion, Kanata, Ontario, Canada, and Macrocyclics, Dallas, Texas
| |
Collapse
|
43
|
Cai H, Li Z, Huang CW, Park R, Shahinian AH, Conti PS. An improved synthesis and biological evaluation of a new cage-like bifunctional chelator, 4-((8-amino-3,6,10,13,16,19-hexaazabicyclo[6.6.6]icosane-1-ylamino)methyl)benzoic acid, for 64Cu radiopharmaceuticals. Nucl Med Biol 2009; 37:57-65. [PMID: 20122669 DOI: 10.1016/j.nucmedbio.2009.09.001] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2009] [Revised: 08/29/2009] [Accepted: 09/01/2009] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Stable attachment of (64)Cu(2+) to a targeting molecule usually requires the use of a bifunctional chelator (BFC). Sarcophagine (Sar) ligands rapidly coordinate (64)Cu(2+) within the multiple macrocyclic rings comprising the cage structure under mild conditions, providing high stability in vivo. Previously, we have designed a new versatile cage-like BFC Sar ligand, 4-((8-amino-3,6,10,13,16,19-hexaazabicyclo[6.6.6]icosane-1-ylamino)methyl)benzoic acid (AmBaSar), for (64)Cu radiopharmaceuticals. Here we report the improved synthesis of AmBaSar, (64)Cu(2+) labeling conditions and its biological evaluation compared with the known BFC 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (DOTA). METHODS The AmBaSar was synthesized in four steps starting from (1,8-diamine-Sar) cobalt(III) pentachloride ([Co(DiAmSar)]Cl(5)) using an improved synthetic method. The AmBaSar was labeled with (64)Cu(2+) in pH 5.0 ammonium acetate buffer solution at room temperature, followed by analysis and purification with HPLC. The in vitro stability of (64)Cu-AmBaSar complex was evaluated in phosphate buffered saline (PBS), fetal bovine serum and mouse blood. The microPET imaging and biodistribution studies of (64)Cu-AmBaSar were performed in Balb/c mice, and the results were compared with (64)Cu-DOTA. RESULTS The AmBaSar was readily prepared and characterized by MS and (1)H NMR. The radiochemical yield of (64)Cu-AmBaSar was >or=98% after 30 min of incubation at 25 degrees C. The (64)Cu-AmBaSar complex was analyzed and purified by HPLC with a retention time of 17.9 min. The radiochemical purity of (64)Cu-AmBaSar was more than 97% after 26 h of incubation in PBS or serum. The biological evaluation of (64)Cu-AmBaSar in normal mouse demonstrated renal clearance as the primary mode of excretion, with improved stability in vivo compared to (64)Cu-DOTA. CONCLUSIONS The new cage-like BFC AmBaSar was prepared using a simplified synthetic method. The (64)Cu-AmBaSar complex could be obtained rapidly with high radiochemical yield (>/=98%) under mild conditions. In vitro and in vivo evaluation of AmBaSar demonstrated its promising potential for preparation of (64)Cu radiopharmaceuticals.
Collapse
Affiliation(s)
- Hancheng Cai
- Molecular Imaging Center, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | | | | | | | | | | |
Collapse
|
44
|
Cai H, Fissekis J, Conti PS. Synthesis of a novel bifunctional chelator AmBaSar based on sarcophagine for peptide conjugation and (64)Cu radiolabelling. Dalton Trans 2009:5395-400. [PMID: 19565091 DOI: 10.1039/b902210d] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Copper-64 shows promise as both a suitable PET imaging and therapeutic radionuclide due to its nuclear characteristics. Stable attachment of radioactive (64)Cu(2+) to targeted imaging probes requires the use of a bifunctional chelator. Sarcophagine (Sar) ligands coordinate the metal ion (64)Cu(2+) within the multiple macrocyclic rings comprising the cage structure, yielding extraordinarily stable complexes that are inert to dissociation of the metal ion in vivo. Several (64)Cu labelled RGD derivatives have been applied in imaging of the alpha(nu)beta(3) integrin receptor expression during tumour angiogenesis. In order to design and develop novel molecular imaging probes containing RGD and Sar ligands, we designed a novel versatile Sar cage-like bifunctional chelator named AmBaSar, synthesized using a conventional synthetic strategy. Conjugation with the cyclic peptide RGD, and subsequent labelling with (64)Cu, provided a new PET probe (64)Cu-AmBaSar-RGD for imaging the alpha(nu)beta(3) integrin receptor.
Collapse
Affiliation(s)
- Hancheng Cai
- Department of Radiology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA
| | | | | |
Collapse
|
45
|
Brasuń J, Matera-Witkiewicz A, Ołdziej S, Pratesi A, Ginanneschi M, Messori L. Impact of ring size on the copper(II) coordination abilities of cyclic tetrapeptides. J Inorg Biochem 2009; 103:813-7. [PMID: 19329186 DOI: 10.1016/j.jinorgbio.2009.02.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2008] [Revised: 02/10/2009] [Accepted: 02/12/2009] [Indexed: 11/28/2022]
Abstract
A new, 14-membered, tetraza cyclic tetrapeptide containing histidine and lysine side-chains, c(beta(3)homoLysdHisbeta-AlaHis), was designed, synthesized and characterized; its copper(II) binding properties were investigated in dependence of pH by potentiometric and spectroscopic methods. In line with previous studies of similar systems, the progressive involvement of amide nitrogens in copper(II) coordination was evidenced for pH values greater than 6. At physiological pH the dominant species consists of a copper(II) center coordinated by two amide nitrogens, an imidazole nitrogen and a water molecule. In contrast, at pH values higher than 8.7, a copper(II) coordination environment consisting of four amide nitrogens in the equatorial plane and the axial imidazole ligands is formed as clearly indicated by spectroscopic data and theoretical calculations. The behavior of this 14-membered cyclic tetrapeptide is compared to that of its 12-membered cyclic analog, particular attention being paid to the effects of ring size on the respective copper(II) binding abilities.
Collapse
Affiliation(s)
- Justyna Brasuń
- Department of Inorganic Chemistry, Wrocław Medical University, Poland.
| | | | | | | | | | | |
Collapse
|