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Pretze M, Michler E, Runge R, Wetzig K, Tietze K, Brandt F, Schultz MK, Kotzerke J. Influence of the Molar Activity of 203/212Pb-PSC-PEG 2-TOC on Somatostatin Receptor Type 2-Binding and Cell Uptake. Pharmaceuticals (Basel) 2023; 16:1605. [PMID: 38004470 PMCID: PMC10675797 DOI: 10.3390/ph16111605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 11/06/2023] [Accepted: 11/10/2023] [Indexed: 11/26/2023] Open
Abstract
(1) Background: In neuroendocrine tumors (NETs), somatostatin receptor subtype 2 is highly expressed, which can be targeted by a radioactive ligand such as [177Lu]Lu-1,4,7,10-tetraazacyclododecane-N,N',N″,N‴,-tetraacetic acid-[Tyr3,Thr8]-octreotide (177Lu-DOTA-TOC) and, more recently, by a lead specific chelator (PSC) containing 203/212Pb-PSC-PEG2-TOC (PSC-TOC). The molar activity (AM) can play a crucial role in tumor uptake, especially in receptor-mediated uptake, such as in NETs. Therefore, an investigation of the influence of different molar activities of 203/212Pb-PSC-TOC on cell uptake was investigated. (2) Methods: Optimized radiolabeling of 203/212Pb-PSC-TOC was performed with 50 µg of precursor in a NaAc/AcOH buffer at pH 5.3-5.5 within 15-45 min at 95° C. Cell uptake was studied in AR42 J, HEK293 sst2, and ZR75-1 cells. (3) Results: 203/212Pb-PSC-TOC was radiolabeled with high radiochemical purity >95% and high radiochemical yield >95%, with AM ranging from 0.2 to 61.6 MBq/nmol. The cell uptake of 203Pb-PSC-TOC (AM = 38 MBq/nmol) was highest in AR42 J (17.9%), moderate in HEK293 sstr (9.1%) and lowest in ZR75-1 (0.6%). Cell uptake increased with the level of AM. (4) Conclusions: A moderate AM of 15-40 MBq/nmol showed the highest cell uptake. No uptake limitation was found in the first 24-48 h. Further escalation experiments with even higher AM should be performed in the future. It was shown that AM plays an important role because of its direct dependence on the cellular uptake levels, possibly due to less receptor saturation with non-radioactive ligands at higher AM.
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Affiliation(s)
- Marc Pretze
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technical University Dresden, Fetscherstr. 74, 01307 Dresden, Germany; (E.M.); (R.R.); (K.W.); (K.T.); (F.B.); (J.K.)
| | - Enrico Michler
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technical University Dresden, Fetscherstr. 74, 01307 Dresden, Germany; (E.M.); (R.R.); (K.W.); (K.T.); (F.B.); (J.K.)
| | - Roswitha Runge
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technical University Dresden, Fetscherstr. 74, 01307 Dresden, Germany; (E.M.); (R.R.); (K.W.); (K.T.); (F.B.); (J.K.)
| | - Kerstin Wetzig
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technical University Dresden, Fetscherstr. 74, 01307 Dresden, Germany; (E.M.); (R.R.); (K.W.); (K.T.); (F.B.); (J.K.)
| | - Katja Tietze
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technical University Dresden, Fetscherstr. 74, 01307 Dresden, Germany; (E.M.); (R.R.); (K.W.); (K.T.); (F.B.); (J.K.)
| | - Florian Brandt
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technical University Dresden, Fetscherstr. 74, 01307 Dresden, Germany; (E.M.); (R.R.); (K.W.); (K.T.); (F.B.); (J.K.)
| | - Michael K. Schultz
- Department of Radiology, University of Iowa, Iowa City, IA 52240, USA;
- Viewpoint Molecular Targeting, Inc. (DBA Perspective Therapeutics), Coralville, IA 52241, USA
- Department of Chemistry, University of Iowa, Iowa City, IA 52241, USA
- Department of Radiation Oncology, University of Iowa, Iowa City, IA 52242, USA
| | - Jörg Kotzerke
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technical University Dresden, Fetscherstr. 74, 01307 Dresden, Germany; (E.M.); (R.R.); (K.W.); (K.T.); (F.B.); (J.K.)
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Wang L, Song L, Ma L, Zhang H, Wang Y, Ma Y, Dai X. A method for determining 212Bi by TDCR Cherenkov counting. J Radioanal Nucl Chem 2022. [DOI: 10.1007/s10967-022-08700-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Targeted Alpha Therapy: Progress in Radionuclide Production, Radiochemistry, and Applications. Pharmaceutics 2020; 13:pharmaceutics13010049. [PMID: 33396374 PMCID: PMC7824049 DOI: 10.3390/pharmaceutics13010049] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 12/15/2020] [Accepted: 12/23/2020] [Indexed: 12/17/2022] Open
Abstract
This review outlines the accomplishments and potential developments of targeted alpha (α) particle therapy (TAT). It discusses the therapeutic advantages of the short and highly ionizing path of α-particle emissions; the ability of TAT to complement and provide superior efficacy over existing forms of radiotherapy; the physical decay properties and radiochemistry of common α-emitters, including 225Ac, 213Bi, 224Ra, 212Pb, 227Th, 223Ra, 211At, and 149Tb; the production techniques and proper handling of α-emitters in a radiopharmacy; recent preclinical developments; ongoing and completed clinical trials; and an outlook on the future of TAT.
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Seo Y. Quantitative Imaging of Alpha-Emitting Therapeutic Radiopharmaceuticals. Nucl Med Mol Imaging 2019; 53:182-188. [PMID: 31231438 DOI: 10.1007/s13139-019-00589-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 02/02/2019] [Accepted: 02/07/2019] [Indexed: 11/24/2022] Open
Abstract
Targeted alpha therapy (TAT) is an active area of drug development as a highly specific and highly potent therapeutic modality that can be applied to many types of late-stage cancers. In order to properly evaluate its safety and efficacy, understanding biokinetics of alpha-emitting radiopharmaceuticals is essential. Quantitative imaging of alpha-emitting radiopharmaceuticals is often possible via imaging of gammas and positrons produced during complex decay chains of these radionuclides. Analysis of the complex decay chains for alpha-emitting radionuclides (Tb-149, At-211, Bi-212 (decayed from Pb-212), Bi-213, Ra-223, Ac-225, and Th-227) with relevance to imageable signals is attempted in this mini-review article. Gamma camera imaging, single-photon emission computed tomography, positron emission tomography, bremsstrahlung radiation imaging, Cerenkov luminescence imaging, and Compton cameras are briefly discussed as modalities for imaging alpha-emitting radiopharmaceuticals.
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Affiliation(s)
- Youngho Seo
- 1Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA USA
- 2Department of Radiation Oncology, University of California, San Francisco, CA USA
- 3Bakar Computational Health Sciences Institute, University of California, San Francisco, CA USA
- UC Berkeley - UCSF Bioengineering Graduate Program, Berkeley and San Francisco, CA USA
- 5Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA USA
- 6UCSF Physics Research Laboratory, 185 Berry Street, Suite 350, San Francisco, CA 94143-0946 USA
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Ciarrocchi E, Belcari N. Cerenkov luminescence imaging: physics principles and potential applications in biomedical sciences. EJNMMI Phys 2017; 4:14. [PMID: 28283990 PMCID: PMC5346099 DOI: 10.1186/s40658-017-0181-8] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 02/27/2017] [Indexed: 12/24/2022] Open
Abstract
Cerenkov luminescence imaging (CLI) is a novel imaging modality to study charged particles with optical methods by detecting the Cerenkov luminescence produced in tissue. This paper first describes the physical processes that govern the production and transport in tissue of Cerenkov luminescence. The detectors used for CLI and their most relevant specifications to optimize the acquisition of the Cerenkov signal are then presented, and CLI is compared with the other optical imaging modalities sharing the same data acquisition and processing methods. Finally, the scientific work related to CLI and the applications for which CLI has been proposed are reviewed. The paper ends with some considerations about further perspectives for this novel imaging modality.
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Affiliation(s)
- Esther Ciarrocchi
- Department of Physics "E. Fermi", University of Pisa, Pisa, Italy. .,INFN, section of Pisa, Pisa, Italy.
| | - Nicola Belcari
- Department of Physics "E. Fermi", University of Pisa, Pisa, Italy.,INFN, section of Pisa, Pisa, Italy
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