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Tosato M, Gandini A, Happel S, Bas M, Donzella A, Zenoni A, Salvini A, Andrighetto A, Di Marco V, Asti M. Chromatographic separation of silver-111 from neutron-irradiated palladium target: toward direct labeling of radiotracers. EJNMMI Radiopharm Chem 2023; 8:43. [PMID: 38123869 PMCID: PMC10733254 DOI: 10.1186/s41181-023-00232-0] [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: 10/27/2023] [Accepted: 12/15/2023] [Indexed: 12/23/2023] Open
Abstract
BACKGROUND Silver-111 is a promising β--emitting radioisotope with ideal characteristics for targeted radionuclide therapy and associated single photon emission tomography imaging. Its decay properties closely resemble the clinically established lutetium-177, making it an attractive candidate for therapeutic applications. In addition, the clinical value of silver-111 is further enhanced by the existence of the positron-emitting counterpart silver-103, thus imparting a truly theranostic potential to this element. A so-fitting matching pair could potentially overcome the current limitations associated with the forced use of chemically different isotopes as imaging surrogates of lutetium-177, leading to more accurate and efficient diagnosis and treatment. However, the use of silver-111-based radiopharmaceuticals in vivo has faced obstacles due to the challenges related to its production and radiochemical separation from the target material. To address these issues, this study aims to implement a chromatographic separation methodology for the purification of reactor-produced silver-111. The ultimate goal is to achieve a ready-to-use formulation for the direct radiolabeling of tumour-seeking biomolecules. RESULTS A two-step sequence chromatographic process was validated for cold Ag-Pd separation and then translated to the radioactive counterpart. Silver-111 was produced via the 110Pd(n,γ)111Pd nuclear reaction on a natural palladium target and the subsequent β--decay of palladium-111. Silver-111 was chemically separated from the metallic target via the implemented chromatographic process by using commercially available LN and TK200 resins. The effectiveness of the separations was assessed by inductively coupled plasma optical emission spectroscopy and γ-spectrometry, respectively, and the Ag+ retrieval was afforded in pure water. Recovery of silver-111 was > 90% with a radionuclidic purity > 99% and a separation factor of around 4.21·10-4. CONCLUSIONS The developed separation method was suitable to obtain silver-111 with high molar activity in a ready-to-use water-based formulation that can be directly employed for the labeling of radiotracers. By successfully establishing a robust and efficient production and purification method for silver-111, this research paves the way for its wider application in targeted radionuclide therapy and precision imaging.
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Affiliation(s)
- Marianna Tosato
- Radiopharmaceutical Chemistry Section, Nuclear Medicine Unit, AUSL di Reggio Emilia: Azienda Unità Sanitaria Locale - IRCCS Tecnologie Avanzate e Modelli Assistenziali in Oncologia di Reggio Emilia, Via Amendola 2, 42122, Reggio Emilia, Italy
- Department of Chemical Sciences, University of Padova, 35131, Padua, Italy
| | - Andrea Gandini
- Laboratory of Applied Nuclear Energy, 27100, Pavia, Italy
| | | | - Marine Bas
- TrisKem International SAS, 35170, Brittany, France
| | - Antonietta Donzella
- Department of Mechanical and Industrial Engineering, University of Brescia, 25123, Brescia, Italy
- Italian Institute of Nuclear Physics, Pavia Section, 27100, Pavia, Italy
| | - Aldo Zenoni
- Department of Mechanical and Industrial Engineering, University of Brescia, 25123, Brescia, Italy
- Italian Institute of Nuclear Physics, Pavia Section, 27100, Pavia, Italy
| | - Andrea Salvini
- Laboratory of Applied Nuclear Energy, 27100, Pavia, Italy
| | - Alberto Andrighetto
- Italian Institute of Nuclear Physics, Legnaro National Laboratories, 35020, Legnaro, (Padova), Italy
| | - Valerio Di Marco
- Department of Chemical Sciences, University of Padova, 35131, Padua, Italy
| | - Mattia Asti
- Radiopharmaceutical Chemistry Section, Nuclear Medicine Unit, AUSL di Reggio Emilia: Azienda Unità Sanitaria Locale - IRCCS Tecnologie Avanzate e Modelli Assistenziali in Oncologia di Reggio Emilia, Via Amendola 2, 42122, Reggio Emilia, Italy.
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Tosato M, Franchi S, Dalla Tiezza M, Orian L, Gyr T, Alker A, Zanoni G, Pastore P, Andrighetto A, Köster U, Jensen M, Mäcke H, Asti M, Di Marco V. Tuning the Framework of Thioether-Functionalized Polyazamacrocycles: Searching for a Chelator for Theranostic Silver Radioisotopes. Inorg Chem 2023; 62:20777-20790. [PMID: 37768780 DOI: 10.1021/acs.inorgchem.3c02456] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2023]
Abstract
Silver-111 is an attractive unconventional candidate for targeted cancer therapy as well as for single photon emission computed tomography and can be complemented by silver-103 for positron emission tomography noninvasive diagnostic procedures. However, the shortage of chelating agents capable of forming stable complexes tethered to tumor-seeking vectors has hindered their in vivo application so far. In this study, a comparative investigation of a series of sulfur-containing structural homologues, namely, 1,4,7-tris[2-(methylsulfanyl)ethyl)]-1,4,7-triazacyclononane (NO3S), 1,5,9-tris[2-(methylsulfanyl)ethyl]-1,5,9-triazacyclododecane (TACD3S), 1,4,7,10-tetrakis[2-(methylsulfanyl)ethyl]-1,4,7,10-tetraazacyclotridecane (TRI4S), and 1,4,8,11-tetrakis[2-(methylsulfanyl)ethyl]-1,4,8,11-tetraazacyclotetradecane (TE4S) was conducted to appraise the influence of different polyazamacrocyclic backbones on Ag+ complexation. The performances of these macrocycles were also compared with those of the previously reported Ag+/[111Ag]Ag+-chelator 1,4,7,10-tetrakis[2-(methylsulfanyl)ethyl]-1,4,7,10-tetraazacyclododecane (DO4S). Nuclear magnetic resonance data supported by density functional theory calculations and X-ray crystallographic results gave insights into the coordination environment of these complexes, suggesting that all of the donor atoms are generally involved in the metal coordination. However, the modifications of the macrocycle topology alter the dynamic binding of the pendant arms or the conformation of the ring around the metal center. Combined pH/pAg-potentiometric and spectroscopic experiments revealed that the 12-member N4 backbone of DO4S forms the most stable Ag+ complex while both the enlargement and the shrinkage of the macrocyclic frame dwindle the stability of the complexes. Radiolabeling experiments, conducted with reactor-produced [111Ag]Ag+, evidenced that the thermodynamic stability trend is reflected in the ligand's ability to incorporate the radioactive ion at high molar activity, even in the presence of a competing cation (Pd2+), as well as in the integrity of the corresponding complexes in human serum. As a consequence, DO4S proved to be the most favorable candidate for future in vivo applications.
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Affiliation(s)
- Marianna Tosato
- Department of Chemical Sciences, University of Padova, 35131 Padova, Italy
- Radiopharmaceutical Chemistry Section, Nuclear Medicine Unit, AUSL-IRCCS Reggio Emilia, 42122 Reggio Emilia, Italy
| | - Sara Franchi
- Department of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | - Marco Dalla Tiezza
- Department of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | - Laura Orian
- Department of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | - Thomas Gyr
- Division of Radiopharmaceutical Chemistry, Clinic of Radiology and Nuclear Medicine, University Hospital Basel, 4058 Basel, Switzerland
| | - André Alker
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel F. Hoffmann-La Roche, 4058 Basel, Switzerland
| | - Giordano Zanoni
- Department of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | - Paolo Pastore
- Department of Chemical Sciences, University of Padova, 35131 Padova, Italy
| | - Alberto Andrighetto
- Italian Institute of Nuclear Physics, Legnaro National Laboratories, 35020 Legnaro, Padova, Italy
| | - Ulli Köster
- Institut Laue-Langevin, 38042 Grenoble, France
| | - Mikael Jensen
- The Hevesy Laboratory, Department Health Technology, Technical University of Denmark, 4000 Roskilde, Denmark
| | - Helmut Mäcke
- Department of Nuclear Medicine, University Hospital Freiburg, D-79106 Freiburg, Germany
| | - Mattia Asti
- Radiopharmaceutical Chemistry Section, Nuclear Medicine Unit, AUSL-IRCCS Reggio Emilia, 42122 Reggio Emilia, Italy
| | - Valerio Di Marco
- Department of Chemical Sciences, University of Padova, 35131 Padova, Italy
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3
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Tosato M, Asti M. Lights and Shadows on the Sourcing of Silver Radioisotopes for Targeted Imaging and Therapy of Cancer: Production Routes and Separation Methods. Pharmaceuticals (Basel) 2023; 16:929. [PMID: 37513841 PMCID: PMC10383325 DOI: 10.3390/ph16070929] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 06/21/2023] [Accepted: 06/22/2023] [Indexed: 07/30/2023] Open
Abstract
The interest in silver radioisotopes of medical appeal (silver-103, silver-104m,g and silver-111) has been recently awakened by the versatile nature of their nuclear decays, which combine emissions potentially suitable for non-invasive imaging with emissions suited for cancer treatment. However, to trigger their in vivo application, the production of silver radioisotopes in adequate amounts, and with high radionuclidic purity and molar activity, is a key prerequisite. This review examines the different production routes of silver-111, silver-103 and silver-104m,g providing a comprehensive critical overview of the separation and purification strategies developed so far. Aspects of quality (radiochemical, chemical and radionuclidic purity) are also emphasized and compared with the aim of pushing towards the future implementation of this theranostic triplet in preclinical and clinical contexts.
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Affiliation(s)
- Marianna Tosato
- Radiopharmaceutical Chemistry Section, Nuclear Medicine Unit, AUSL-IRCCS di Reggio Emilia, 42122 Reggio Emilia, Italy
| | - Mattia Asti
- Radiopharmaceutical Chemistry Section, Nuclear Medicine Unit, AUSL-IRCCS di Reggio Emilia, 42122 Reggio Emilia, Italy
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4
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Tosato M, Asti M, Di Marco V, Jensen ML, Schell J, Dang TT, Köster U, Jensen M, Hemmingsen L. Towards in vivo applications of 111Ag perturbed angular correlation of γ-rays (PAC) spectroscopy. Appl Radiat Isot 2022; 190:110508. [DOI: 10.1016/j.apradiso.2022.110508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 10/04/2022] [Accepted: 10/05/2022] [Indexed: 11/27/2022]
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Blackadar C, Choi KYG, Embree MF, Hennkens HM, Rodríguez-Rodríguez C, Hancock REW, Saatchi K, Häfeli UO. SPECT/CT Imaging of 111Ag for the Preclinical Evaluation of Silver-Based Antimicrobial Nanomedicines. ACS APPLIED MATERIALS & INTERFACES 2022; 14:26382-26393. [PMID: 35653648 DOI: 10.1021/acsami.2c03609] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
With the growing interest in developing silver-based antimicrobials, there is a need to better understand the behavior of silver within biological systems. To address this, we showed that single-photon emission computed tomography (SPECT) is a suitable method to noninvasively image 111Ag-labeled compounds in mice. Formed by neutron irradiation of palladium foil, 111Ag can be rapidly isolated with a high degree of purity and stably incorporated into antimicrobial silver nanoparticles. The imaging showed that nanoparticles are retained in the lungs for up to 48 h following intratracheal instillation, with limited uptake into the systemic circulation or organs of the reticuloendothelial system. Furthermore, in a mouse model of pulmonary Pseudomonas aeruginosa infection, the nanoparticles reduced the bacterial burden by 11.6-fold without inducing the production of pro-inflammatory mediators. Overall, SPECT imaging with 111Ag is a useful tool for noninvasively visualizing the biodistribution of silver-containing compounds in rodents. This knowledge of how silver nanoparticles distribute in vivo can be used to predict their therapeutic efficacy.
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Affiliation(s)
- Colin Blackadar
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, BC V6T1Z3, Canada
| | - Ka-Yee Grace Choi
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, Faculty of Science, University of British Columbia, Vancouver, BC V6T1Z4, Canada
| | - Mary F Embree
- University of Missouri Research Reactor Center (MURR), 13513 Research Park Drive, Columbia, Missouri 65211, United States
| | - Heather M Hennkens
- University of Missouri Research Reactor Center (MURR), 13513 Research Park Drive, Columbia, Missouri 65211, United States
- Department of Chemistry, University of Missouri, 125 Chemistry Building, Columbia, Missouri 65211, United States
| | - Cristina Rodríguez-Rodríguez
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, BC V6T1Z3, Canada
- Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T1Z1, Canada
| | - Robert E W Hancock
- Centre for Microbial Diseases and Immunity Research, Department of Microbiology and Immunology, Faculty of Science, University of British Columbia, Vancouver, BC V6T1Z4, Canada
| | - Katayoun Saatchi
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, BC V6T1Z3, Canada
| | - Urs O Häfeli
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, BC V6T1Z3, Canada
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, Copenhagen 2100, Denmark
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Ohya T, Nagatsu K, Hanyu M, Minegishi K, Zhang MR. Separation of radiosilver from a cyclotron-irradiated palladium target. RADIOCHIM ACTA 2020. [DOI: 10.1515/ract-2019-3211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
We studied the simple separation of radiosilvers from proton- or deuteron-irradiated natural palladium (natPd) targets, and successfully separated radiorhodium, radiosilver and radiopalladium using an anion-exchange resin. The yields of radiosilvers were 105Ag: 1.0 ± 0.32 MBq/μAh; 106mAg: 2.0 ± 0.64 MBq/μAh; 110mAg: 0.019 ± 0.0063 MBq/μAh (n = 4) at the end of bombardment with a total recovery rate of 98 % under the following irradiation conditions (deuteron beam energy: 20 MeV; beam current: 10 μA; irradiation time: 2.25 ± 0.50 h). We also evaluated the recycling of the palladium target.
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Affiliation(s)
- Tomoyuki Ohya
- Department of Radiopharmaceuticals Development, National Institutes for Quantum and Radiological Science and Technology (NIRS-QST) , 4-9-1 Anagawa, Inage-ku , Chiba 263-8555 , Japan
| | - Kotaro Nagatsu
- National Institutes for Quantum and Radiological Science and Technology (NIRS-QST) , 4-9-1 Anagawa, Inage-ku , Chiba 263-8555 , Japan
| | - Masayuki Hanyu
- National Institutes for Quantum and Radiological Science and Technology (NIRS-QST) , 4-9-1 Anagawa, Inage-ku , Chiba 263-8555 , Japan
| | - Katsuyuki Minegishi
- National Institutes for Quantum and Radiological Science and Technology (NIRS-QST) , 4-9-1 Anagawa, Inage-ku , Chiba 263-8555 , Japan
| | - Ming-Rong Zhang
- National Institutes for Quantum and Radiological Science and Technology (NIRS-QST) , 4-9-1 Anagawa, Inage-ku , Chiba 263-8555 , Japan
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7
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Tosato M, Asti M, Dalla Tiezza M, Orian L, Häussinger D, Vogel R, Köster U, Jensen M, Andrighetto A, Pastore P, Marco VD. Highly Stable Silver(I) Complexes with Cyclen-Based Ligands Bearing Sulfide Arms: A Step Toward Silver-111 Labeled Radiopharmaceuticals. Inorg Chem 2020; 59:10907-10919. [PMID: 32658468 PMCID: PMC8009516 DOI: 10.1021/acs.inorgchem.0c01405] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
With a half-life of 7.45 days, silver-111 (βmax 1.04 MeV, Eγ 245.4 keV [Iγ 1.24%], Eγ 342.1 keV [Iγ 6.7%]) is a promising candidate for targeted cancer therapy with β- emitters as well as for associated SPECT imaging. For its clinical use, the development of suitable ligands that form sufficiently stable Ag+-complexes in vivo is required. In this work, the following sulfur-containing derivatives of tetraazacyclododecane (cyclen) have been considered as potential chelators for silver-111: 1,4,7,10-tetrakis(2-(methylsulfanyl)ethyl)-1,4,7,10-tetraazacyclododecane (DO4S), (2S,5S,8S,11S)-2,5,8,11-tetramethyl-1,4,7,10-tetrakis(2-(methylsulfanyl)ethyl)-1,4,7,10-tetraazacyclododecane (DO4S4Me), 1,4,7-tris(2-(methylsulfanyl)ethyl)-1,4,7,10-tetraazacyclododecane (DO3S), 1,4,7-tris(2-(methylsulfanyl)ethyl)-10-acetamido-1,4,7,10-tetraazacyclododecane (DO3SAm), and 1,7-bis(2-(methylsulfanyl)ethyl)-4,10,diacetic acid-1,4,7,10-tetraazacyclododecane (DO2A2S). Natural Ag+ was used in pH/Ag-potentiometric and UV-vis spectrophotometric studies to determine the metal speciation existing in aqueous NaNO3 0.15 M at 25 °C and the equilibrium constants of the complexes, whereas NMR and DFT calculations gave structural insights. Overall results indicated that sulfide pendant arms coordinate Ag+ allowing the formation of very stable complexes, both at acidic and physiological pH. Furthermore, radiolabeling, stability in saline phosphate buffer, and metal-competition experiments using the two ligands forming the strongest complexes, DO4S and DO4S4Me, were carried out with [111Ag]Ag+ and promising results were obtained.
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Affiliation(s)
- Marianna Tosato
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy
| | - Mattia Asti
- Radiopharmaceutical Chemistry Section, Nuclear Medicine Unit, AUSL-IRCCS di Reggio Emilia, Viale Risorgimento 80, 42122 Reggio Emilia, Italy
| | - Marco Dalla Tiezza
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy
| | - Laura Orian
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy
| | - Daniel Häussinger
- Department of Chemistry, University of Basel, St. Johannsring 19, 4056, Basel, Switzerland
| | - Raphael Vogel
- Department of Chemistry, University of Basel, St. Johannsring 19, 4056, Basel, Switzerland
| | - Ulli Köster
- Institut Laue-Langevin, 71 avenue des Martyrs CS 20156, 38042 Grenoble Cedex 9, France
| | - Mikael Jensen
- The Hevesy Laboratory, Department Health Technology, Technical University of Denmark (DTU), Frederiksborgvej 399, 4000, Roskilde, Denmark
| | - Alberto Andrighetto
- Italian Institute of Nuclear Physics, Legnaro National Laboratories, Viale dell'Università 2, 35020 Legnaro (Padova), Italy
| | - Paolo Pastore
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy
| | - Valerio Di Marco
- Department of Chemical Sciences, University of Padova, via Marzolo 1, 35131 Padova, Italy
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9
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Mass Spectrometry Reveals Complexing Properties of Modified PNP-Lariat Ether Containing Benzyl Derivative of (S)-Prolinamine. MOLECULES (BASEL, SWITZERLAND) 2019; 25:molecules25010136. [PMID: 31905750 PMCID: PMC6983243 DOI: 10.3390/molecules25010136] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 12/23/2019] [Accepted: 12/27/2019] [Indexed: 11/16/2022]
Abstract
In the investigation presented here the synthesis of new lariat ether derivative obtained from the modification of tetrapyrrolidinyl-PNP-crown ether macrocycle is described. The polyheterotopic molecular coreceptor consisted of the replacement of chlorine atoms with an optically active (S)-(1-benzylpyrrolidin-2-yl) methanamine. The structure was confirmed by using elemental analysis, mass spectrometry, and NMR spectroscopy. This work covers results concerning the complexing properties of the new ligand towards Ag+, Cu2+, Co2+, Ni2+, and Zn2+ ions. The formation of non-covalent complexes of 1:1 stoichiometry with the Cu2+, Co2+, Ni2+, and Zn2+ ions have been confirmed by mass spectrometry. Due to the previous work and application possibilities, a large emphasis was put on the investigation of the complexation ability of lariat ether with silver (I) cation to determine stability constants by direct potentiometric method. In this case, the formation of four different forms of complexes AgL, Ag2L, Ag3L, and Ag4L has been proved. The observed unusual binding through the nitrogen atoms from the exocyclic substituents may provide the structural unit to build a new coordination polymers.
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Andrighetto A, Tosato M, Ballan M, Corradetti S, Borgna F, Di Marco V, Marzaro G, Realdon N. The ISOLPHARM project: ISOL-based production of radionuclides for medical applications. J Radioanal Nucl Chem 2019. [DOI: 10.1007/s10967-019-06698-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Li Z, Wiratpruk N, Barnard PJ. Stepwise Synthesis of Tetra-imidazolium Macrocycles and Their N-Heterocyclic Carbene Metal Complexes. Front Chem 2019; 7:270. [PMID: 31069216 PMCID: PMC6491846 DOI: 10.3389/fchem.2019.00270] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 04/02/2019] [Indexed: 11/13/2022] Open
Abstract
A modular stepwise synthetic method has been developed for the preperation of tetra-imidazolium macrocycles. Initially a series of three bis(imidazolylmethyl)benzene precursors were alkylated with 1,2-dibromoethane to produce the corresponding bis-bromoethylimidazolium bromide salts. In the second step the bis-bromoethylimidazolium bromide salts were reacted with selected bis(imidazolylmethyl)benzene molecules to produce a series of two symmetrical and three asymmetrical tetra-imidazolium macrocycles. These tetra-imidazolium salts act receptors for anions and 1H-NMR titration studies were used to determine the association constants between two of the macrocycles and the halide anions chloride, bromide and iodide. The tetra-imidazolium salts are precursors for N-heterocyclic carbene (NHC) ligands and the corresponding silver(I), gold(I), and palladium(II) NHC complexes have been prepared. Varied structures were obtained, which depend on the chosen macrocyclic ligand and metal ion and in the case of the coinage metals Ag(I) and Au(I), mono, di, and hexanuclear complexes were formed.
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Affiliation(s)
| | | | - Peter J. Barnard
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, Australia
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Pandolfi F, Mattiello L, Zane D, Feroci M. Electrochemical behaviour of 9-methylcaffeinium iodide and in situ electrochemical synthesis of hymeniacidin. Electrochim Acta 2018. [DOI: 10.1016/j.electacta.2018.05.073] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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13
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A novel in vitro metric predicts in vivo efficacy of inhaled silver-based antimicrobials in a murine Pseudomonas aeruginosa pneumonia model. Sci Rep 2018; 8:6376. [PMID: 29686296 PMCID: PMC5913254 DOI: 10.1038/s41598-018-24200-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 03/19/2018] [Indexed: 11/08/2022] Open
Abstract
To address the escalating problem of antimicrobial resistance and the dwindling antimicrobial pipeline, we have developed a library of novel aerosolizable silver-based antimicrobials, particularly for the treatment of pulmonary infections. To rapidly screen this library and identify promising candidates, we have devised a novel in vitro metric, named the “drug efficacy metric” (DEM), which integrates both the antibacterial activity and the on-target, host cell cytotoxicity. DEMs calculated using an on-target human bronchial epithelial cell-line correlates well (R2 > 0.99) with in vivo efficacy, as measured by median survival hours in a Pseudomonas aeruginosa pneumonia mouse model following aerosolized antimicrobial treatment. In contrast, DEMs derived using off-target primary human dermal fibroblasts correlate poorly (R2 = 0.0595), which confirms our hypothesis. SCC1 and SCC22 have been identified as promising drug candidates through these studies, and SCC22 demonstrates a dose-dependent survival advantage compared to sham treatment. Finally, silver-bearing biodegradable nanoparticles were predicted to exhibit excellent in vivo efficacy based on its in vitro DEM value, which was confirmed in our mouse pneumonia model. Thus, the DEM successfully predicted the efficacy of various silver-based antimicrobials, and may serve as an excellent tool for the rapid screening of potential antimicrobial candidates without the need for extensive animal experimentation.
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Mastren T, Radchenko V, Engle JW, Weidner JW, Owens A, Wyant LE, Copping R, Brugh M, Nortier FM, Birnbaum ER, John KD, Fassbender ME. Chromatographic separation of the theranostic radionuclide 111Ag from a proton irradiated thorium matrix. Anal Chim Acta 2017; 998:75-82. [PMID: 29153089 DOI: 10.1016/j.aca.2017.10.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 09/26/2017] [Accepted: 10/19/2017] [Indexed: 11/24/2022]
Abstract
Column chromatographic methods have been developed to separate no-carrier-added 111Ag from proton irradiated thorium targets and associated fission products as an ancillary process to an existing 225Ac separation design. Herein we report the separation of 111Ag both prior and subsequent to 225Ac recovery using CL resin, a solvent impregnated resin (SIR) that carries an organic solution of alkyl phosphine sulfides (R3P = S) and alkyl phosphine oxides (R3P = O). The recovery yield of 111Ag was 93 ± 9% with a radiochemical purity of 99.9% (prior) and 87 ± 9% with a radiochemical purity of 99.9% (subsequent to) 225Ac recovery. Both processes were successfully performed with insignificant impacts on 225Ac yields or quality. Measured equilibrium distribution coefficients for silver and ruthenium (a residual contaminant) on CL resin in hydrochloric and nitric acid media are reported, to the best of our knowledge, for the first time. Additionally, measured cross sections for the production of 111Ag and 110mAg for the 232Th(p,f)110m,111Ag reactions are reported within.
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Affiliation(s)
- Tara Mastren
- Chemistry Division, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545, USA
| | - Valery Radchenko
- Chemistry Division, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545, USA
| | - Jonathan W Engle
- Chemistry Division, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545, USA
| | - John W Weidner
- Chemistry Division, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545, USA
| | - Allison Owens
- Nuclear Security and Isotope Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Lance E Wyant
- Nuclear Security and Isotope Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Roy Copping
- Nuclear Security and Isotope Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Mark Brugh
- Chemistry Division, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545, USA
| | - F Meiring Nortier
- Chemistry Division, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545, USA
| | - Eva R Birnbaum
- Chemistry Division, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545, USA
| | - Kevin D John
- Chemistry Division, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545, USA
| | - Michael E Fassbender
- Chemistry Division, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545, USA.
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15
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Wooten AL, Aweda TA, Lewis BC, Gross RB, Lapi SE. Biodistribution and PET Imaging of pharmacokinetics of manganese in mice using Manganese-52. PLoS One 2017; 12:e0174351. [PMID: 28306727 PMCID: PMC5357058 DOI: 10.1371/journal.pone.0174351] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 03/07/2017] [Indexed: 11/28/2022] Open
Abstract
Manganese is essential to life, and humans typically absorb sufficient quantities of this element from a normal healthy diet; however, chronic, elevated ingestion or inhalation of manganese can be neurotoxic, potentially leading to manganism. Although imaging of large amounts of accumulated Mn(II) is possible by MRI, quantitative measurement of the biodistribution of manganese, particularly at the trace level, can be challenging. In this study, we produced the positron-emitting radionuclide 52Mn (t1/2 = 5.6 d) by proton bombardment (Ep<15 MeV) of chromium metal, followed by solid-phase isolation by cation-exchange chromatography. An aqueous solution of [52Mn]MnCl2 was nebulized into a closed chamber with openings through which mice inhaled the aerosol, and a separate cohort of mice received intravenous (IV) injections of [52Mn]MnCl2. Ex vivo biodistribution was performed at 1 h and 1 d post-injection/inhalation (p.i.). In both trials, we observed uptake in lungs and thyroid at 1 d p.i. Manganese is known to cross the blood-brain barrier, as confirmed in our studies following IV injection (0.86%ID/g, 1 d p.i.) and following inhalation of aerosol, (0.31%ID/g, 1 d p.i.). Uptake in salivary gland and pancreas were observed at 1 d p.i. (0.5 and 0.8%ID/g), but to a much greater degree from IV injection (6.8 and 10%ID/g). In a separate study, mice received IV injection of an imaging dose of [52Mn]MnCl2, followed by in vivo imaging by positron emission tomography (PET) and ex vivo biodistribution. The results from this study supported many of the results from the biodistribution-only studies. In this work, we have confirmed results in the literature and contributed new results for the biodistribution of inhaled radiomanganese for several organs. Our results could serve as supporting information for environmental and occupational regulations, for designing PET studies utilizing 52Mn, and/or for predicting the biodistribution of manganese-based MR contrast agents.
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Affiliation(s)
- A. Lake Wooten
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Biomedical Engineering, Washington University, St. Louis, United States of America
| | - Tolulope A. Aweda
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Benjamin C. Lewis
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Physics, Washington University, St. Louis, United States of America
| | - Rebecca B. Gross
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Suzanne E. Lapi
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Biomedical Engineering, Washington University, St. Louis, United States of America
- Department of Radiology, University of Alabama at Birmingham, Birmingham, United States of America
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16
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Aweda TA, Zhang S, Mupanomunda C, Burkemper J, Heo GS, Bandara N, Lin M, Cutler CS, Cannon CL, Youngs W, Wooley KL, Lapi SE. Investigating the pharmacokinetics and biological distribution of silver-loaded polyphosphoester-based nanoparticles using (111) Ag as a radiotracer. J Labelled Comp Radiopharm 2015; 58:234-41. [PMID: 25952472 PMCID: PMC4457551 DOI: 10.1002/jlcr.3289] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 03/24/2015] [Indexed: 11/09/2022]
Abstract
Purified (111) Ag was used as a radiotracer to investigate silver loading and release, pharmacokinetics, and biodistribution of polyphosphoester-based degradable shell crosslinked knedel-like (SCK) nanoparticles as a comparison to the previously reported small molecule, N-heterocyclic silver carbene complex analog (SCC1) for the delivery of therapeutic silver ions in mouse models. Biodistribution studies were conducted by aerosol administration of (111) Ag acetate, [(111) Ag]SCC1, and [(111) Ag]SCK doses directly into the lungs of C57BL/6 mice. Nebulization of the (111) Ag antimicrobials resulted in an average uptake of 1.07 ± 0.12% of the total aerosolized dose given per mouse. The average dose taken into the lungs of mice was estimated to be 2.6 ± 0.3% of the dose inhaled per mouse for [(111) Ag]SCC1 and twice as much dose was observed for the [(111) Ag]SCKs (5.0 ± 0.3% and 5.9 ± 0.8% for [(111) Ag]aSCK and [(111) Ag]zSCK, respectively) at 1 h post administration (p.a.). [(111) Ag]SCKs also exhibited higher dose retention in the lungs; 62-68% for [(111) Ag]SCKs and 43% for [(111) Ag]SCC1 of the initial 1 h dose were observed in the lungs at 24 h p.a.. This study demonstrates the utility of (111) Ag as a useful tool for monitoring the pharmacokinetics of silver-loaded antimicrobials in vivo.
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Affiliation(s)
- Tolulope A. Aweda
- Mallinckrodt Institute of Radiology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Shiyi Zhang
- Department of Chemistry, Texas A&M University, College Station, TX 77843-3255
| | - Chiedza Mupanomunda
- Mallinckrodt Institute of Radiology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Jennifer Burkemper
- Mallinckrodt Institute of Radiology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Gyu Seong Heo
- Department of Chemistry, Texas A&M University, College Station, TX 77843-3255
| | - Nilantha Bandara
- Mallinckrodt Institute of Radiology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Mai Lin
- Mallinckrodt Institute of Radiology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
| | - Cathy S. Cutler
- University of Missouri, Research Reactor Center, 1513 Research Park Drive, Columbia, MO 65211
| | - Carolyn L. Cannon
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, 407 Reynolds Medical Building, College Station, TX 77843-1114
| | - Wiley Youngs
- Department of Chemistry, University of Akron, Akron, OH 44325-3601
| | - Karen L. Wooley
- Department of Chemistry, Texas A&M University, College Station, TX 77843-3255
| | - Suzanne E. Lapi
- Mallinckrodt Institute of Radiology, Washington University School of Medicine in St. Louis, St. Louis, MO 63110
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