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Alberto S, Ordonez AA, Arjun C, Aulakh GK, Beziere N, Dadachova E, Ebenhan T, Granados U, Korde A, Jalilian A, Lestari W, Mukherjee A, Petrik M, Sakr T, Cuevas CLS, Welling MM, Zeevaart JR, Jain SK, Wilson DM. The Development and Validation of Radiopharmaceuticals Targeting Bacterial Infection. J Nucl Med 2023; 64:1676-1682. [PMID: 37770110 PMCID: PMC10626374 DOI: 10.2967/jnumed.123.265906] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 08/18/2023] [Indexed: 10/03/2023] Open
Abstract
The International Atomic Energy Agency organized a technical meeting at its headquarters in Vienna, Austria, in 2022 that included 17 experts representing 12 countries, whose research spanned the development and use of radiolabeled agents for imaging infection. The meeting focused largely on bacterial pathogens. The group discussed and evaluated the advantages and disadvantages of several radiopharmaceuticals, as well as the science driving various imaging approaches. The main objective was to understand why few infection-targeted radiotracers are used in clinical practice despite the urgent need to better characterize bacterial infections. This article summarizes the resulting consensus, at least among the included scientists and countries, on the current status of radiopharmaceutical development for infection imaging. Also included are opinions and recommendations regarding current research standards in this area. This and future International Atomic Energy Agency-sponsored collaborations will advance the goal of providing the medical community with innovative, practical tools for the specific image-based diagnosis of infection.
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Affiliation(s)
- Signore Alberto
- Nuclear Medicine Unit, Department of Medical-Surgical Sciences and Translational Medicine, Faculty of Medicine and Psychology, University of Rome "Sapienza," Rome, Italy
| | - Alvaro A Ordonez
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Chanda Arjun
- Radiopharmaceutical Program, Board of Radiation and Isotope Technology, Mumbai, India
| | - Gurpreet Kaur Aulakh
- Department of Small Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Nicolas Beziere
- Werner Siemens Imaging Center, Department of Preclinical Imaging and Radiopharmacy, Eberhard Karls University of Tübingen, Tübingen, Germany
| | - Ekaterina Dadachova
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Thomas Ebenhan
- Nuclear Medicine, University of Pretoria, and Radiochemistry, Applied Radiation, South African Nuclear Energy Corporation, Pelindaba, South Africa
| | - Ulises Granados
- Department of Nuclear Medicine, Hospital Internacional de Colombia-Fundación Cardiovascular de Colombia, Piedecuesta, Colombia
| | - Aruna Korde
- Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Vienna, Austria
| | - Amirreza Jalilian
- Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Vienna, Austria
| | - Wening Lestari
- National Nuclear Energy Agency, South Tangerang, Indonesia
| | - Archana Mukherjee
- Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai, India
| | - Milos Petrik
- Institute of Molecular and Translational Medicine and Czech Advanced Technology and Research Institute, Faculty of Medicine and Dentistry, Palacky University Olomouc, Olomouc, Czech Republic
| | - Tamer Sakr
- Radioactive Isotopes and Generator Department, Hot Labs Center, Egyptian Atomic Energy Authority, Cairo, Egypt
| | | | - Mick M Welling
- Interventional Molecular Imaging Laboratory, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands; and
| | - Jan Rijn Zeevaart
- Nuclear Medicine, University of Pretoria, and Radiochemistry, Applied Radiation, South African Nuclear Energy Corporation, Pelindaba, South Africa
| | - Sanjay K Jain
- Center for Infection and Inflammation Imaging Research, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - David M Wilson
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California
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2
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Sorlin A, López-Álvarez M, Rabbitt SJ, Alanizi AA, Shuere R, Bobba KN, Blecha J, Sakhamuri S, Evans MJ, Bayles KW, Flavell RR, Rosenberg OS, Sriram R, Desmet T, Nidetzky B, Engel J, Ohliger MA, Fraser JS, Wilson DM. Chemoenzymatic Syntheses of Fluorine-18-Labeled Disaccharides from [ 18F] FDG Yield Potent Sensors of Living Bacteria In Vivo. J Am Chem Soc 2023; 145:17632-17642. [PMID: 37535945 PMCID: PMC10436271 DOI: 10.1021/jacs.3c03338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Indexed: 08/05/2023]
Abstract
Chemoenzymatic techniques have been applied extensively to pharmaceutical development, most effectively when routine synthetic methods fail. The regioselective and stereoselective construction of structurally complex glycans is an elegant application of this approach that is seldom applied to positron emission tomography (PET) tracers. We sought a method to dimerize 2-deoxy-[18F]-fluoro-d-glucose ([18F]FDG), the most common tracer used in clinical imaging, to form [18F]-labeled disaccharides for detecting microorganisms in vivo based on their bacteria-specific glycan incorporation. When [18F]FDG was reacted with β-d-glucose-1-phosphate in the presence of maltose phosphorylase, the α-1,4- and α-1,3-linked products 2-deoxy-[18F]-fluoro-maltose ([18F]FDM) and 2-deoxy-2-[18F]-fluoro-sakebiose ([18F]FSK) were obtained. This method was further extended with the use of trehalose (α,α-1,1), laminaribiose (β-1,3), and cellobiose (β-1,4) phosphorylases to synthesize 2-deoxy-2-[18F]fluoro-trehalose ([18F]FDT), 2-deoxy-2-[18F]fluoro-laminaribiose ([18F]FDL), and 2-deoxy-2-[18F]fluoro-cellobiose ([18F]FDC). We subsequently tested [18F]FDM and [18F]FSK in vitro, showing accumulation by several clinically relevant pathogens including Staphylococcus aureus and Acinetobacter baumannii, and demonstrated their specific uptake in vivo. Both [18F]FDM and [18F]FSK were stable in human serum with high accumulation in preclinical infection models. The synthetic ease and high sensitivity of [18F]FDM and [18F]FSK to S. aureus including methicillin-resistant (MRSA) strains strongly justify clinical translation of these tracers to infected patients. Furthermore, this work suggests that chemoenzymatic radiosyntheses of complex [18F]FDG-derived oligomers will afford a wide array of PET radiotracers for infectious and oncologic applications.
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Affiliation(s)
- Alexandre
M. Sorlin
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Marina López-Álvarez
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Sarah J. Rabbitt
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Aryn A. Alanizi
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Rebecca Shuere
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Kondapa Naidu Bobba
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Joseph Blecha
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Sasank Sakhamuri
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Michael J. Evans
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Kenneth W. Bayles
- Department
of Pathology and Microbiology, University
of Nebraska Medical Center, Omaha, Nebraska 68198, United States
| | - Robert R. Flavell
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
| | - Oren S. Rosenberg
- Department
of Medicine University of California, San
Francisco, San Francisco, California 94158, United States
| | - Renuka Sriram
- Department
of Biotechnology, Ghent University, Gent B-9000, Belgium
| | - Tom Desmet
- Department
of Biotechnology, Ghent University, Gent B-9000, Belgium
| | - Bernd Nidetzky
- Institute
of Biotechnology and Biochemical Engineering, Graz University of Technology, Graz 8010, Austria
| | - Joanne Engel
- Department
of Biotechnology, Ghent University, Gent B-9000, Belgium
| | - Michael A. Ohliger
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
- Department
of Radiology Zuckerberg San Francisco General
Hospital, San Francisco, California 94110, United States
| | - James S. Fraser
- Department
of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, California 94158, United States
| | - David M. Wilson
- Department
of Radiology and Biomedical Imaging, University
of California, San Francisco, San Francisco, California 94158, United States
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Sorlin AM, López-Álvarez M, Rabbitt SJ, Alanizi AA, Shuere R, Bobba KN, Blecha J, Sakhamuri S, Evans MJ, Bayles KW, Flavell RR, Rosenberg OS, Sriram R, Desmet T, Nidetzky B, Engel J, Ohliger MA, Fraser JS, Wilson DM. Chemoenzymatic syntheses of fluorine-18-labeled disaccharides from [ 18 F]FDG yield potent sensors of living bacteria in vivo. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.20.541529. [PMID: 37293043 PMCID: PMC10245702 DOI: 10.1101/2023.05.20.541529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Chemoenzymatic techniques have been applied extensively to pharmaceutical development, most effectively when routine synthetic methods fail. The regioselective and stereoselective construction of structurally complex glycans is an elegant application of this approach, that is seldom applied to positron emission tomography (PET) tracers. We sought a method to dimerize 2-deoxy-[ 18 F]-fluoro-D-glucose ([ 18 F]FDG), the most common tracer used in clinical imaging, to form [ 18 F]-labeled disaccharides for detecting microorganisms in vivo based on their bacteria-specific glycan incorporation. When [ 18 F]FDG was reacted with β-D-glucose-1-phosphate in the presence of maltose phosphorylase, both the α-1,4 and α-1,3-linked products 2-deoxy-[ 18 F]-fluoro-maltose ([ 18 F]FDM) and 2-deoxy-2-[ 18 F]-fluoro-sakebiose ([ 18 F]FSK) were obtained. This method was further extended with the use of trehalose (α,α-1,1), laminaribiose (β-1,3), and cellobiose (β-1,4) phosphorylases to synthesize 2-deoxy-2-[ 18 F]fluoro-trehalose ([ 18 F]FDT), 2-deoxy-2-[ 18 F]fluoro-laminaribiose ([ 18 F]FDL), and 2-deoxy-2-[ 18 F]fluoro-cellobiose ([ 18 F]FDC). We subsequently tested [ 18 F]FDM and [ 18 F]FSK in vitro, showing accumulation by several clinically relevant pathogens including Staphylococcus aureus and Acinetobacter baumannii, and demonstrated their specific uptake in vivo. The lead sakebiose-derived tracer [ 18 F]FSK was stable in human serum and showed high uptake in preclinical models of myositis and vertebral discitis-osteomyelitis. Both the synthetic ease, and high sensitivity of [ 18 F]FSK to S. aureus including methicillin-resistant (MRSA) strains strongly justify clinical translation of this tracer to infected patients. Furthermore, this work suggests that chemoenzymatic radiosyntheses of complex [ 18 F]FDG-derived oligomers will afford a wide array of PET radiotracers for infectious and oncologic applications.
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Hevey R. The Role of Fluorine in Glycomimetic Drug Design. Chemistry 2020; 27:2240-2253. [DOI: 10.1002/chem.202003135] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Indexed: 11/10/2022]
Affiliation(s)
- Rachel Hevey
- Department of Pharmaceutical Sciences University of Basel, Pharmazentrum Klingelbergstrasse 50 4056 Basel Switzerland
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Gabr MT, Haywood T, Gowrishankar G, Srinivasan A, Gambhir SS. New synthesis of 6″-[ 18 F]fluoromaltotriose for positron emission tomography imaging of bacterial infection. J Labelled Comp Radiopharm 2020; 63:466-475. [PMID: 32602175 DOI: 10.1002/jlcr.3868] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 05/27/2020] [Accepted: 06/26/2020] [Indexed: 01/22/2023]
Abstract
6″-[18 F]fluoromaltotriose is a positron emission tomography tracer that can differentiate between bacterial infection and inflammation in vivo. Bacteria-specific uptake of 6″-[18 F]fluoromaltotriose is attributed to the targeting of maltodextrin transporter in bacteria that is absent in mammalian cells. Herein, we report a new synthesis of 6″-[18 F]fluoromaltotriose as a key step for its clinical translation. In comparison with the previously reported synthesis, the new synthesis features unambiguous assignment of the fluorine-18 position on the maltotriose unit. The new method utilizes direct fluorination of 2″,3″,4″-tri-O-acetyl-6″-O-trifyl-α-D-glucopyranosyl-(1-4)-O-2',3',6'-tri-O-acetyl-α-D-glucopyranosyl-(1-4)-1,2,3,6-tetra-O-acetyl-D-glucopyranose followed by basic hydrolysis. Radiolabeling of the new maltotriose triflate precursor proceeds using a single HPLC purification step, which results in shorter reaction time in comparison with the previously reported synthesis. Successful synthesis of 6″-[18 F]fluoromaltotriose has been achieved in 3.5 ± 0.3% radiochemical yield (decay corrected, n = 7) and radiochemical purity above 95%. The efficient radiosynthesis of 6″-[18 F]fluoromaltotriose would be critical in advancing this positron emission tomography tracer into clinical trials for imaging bacterial infections.
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Affiliation(s)
- Moustafa T Gabr
- Bio-X Program and Molecular Imaging Program at Stanford (MIPS), Stanford University, Stanford, California, USA
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Tom Haywood
- Bio-X Program and Molecular Imaging Program at Stanford (MIPS), Stanford University, Stanford, California, USA
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Gayatri Gowrishankar
- Bio-X Program and Molecular Imaging Program at Stanford (MIPS), Stanford University, Stanford, California, USA
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Ananth Srinivasan
- Bio-X Program and Molecular Imaging Program at Stanford (MIPS), Stanford University, Stanford, California, USA
- Department of Radiology, Stanford University, Stanford, California, USA
| | - Sanjiv S Gambhir
- Bio-X Program and Molecular Imaging Program at Stanford (MIPS), Stanford University, Stanford, California, USA
- Department of Radiology, Stanford University, Stanford, California, USA
- Department of Materials Science and Engineering, Bio-X Program, Stanford University, Stanford, California, USA
- Department of Bioengineering, Bio-X Program, Stanford University, Stanford, California, USA
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Goldenberg JM, Berthusen AJ, Cárdenas-Rodríguez J, Pagel MD. Differentiation of Myositis-Induced Models of Bacterial Infection and Inflammation with T 2-Weighted, CEST, and DCE-MRI. ACTA ACUST UNITED AC 2020; 5:283-291. [PMID: 31572789 PMCID: PMC6752290 DOI: 10.18383/j.tom.2019.00009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
We used T2 relaxation, chemical exchange saturation transfer (CEST), and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) to assess whether bacterial infection can be differentiated from inflammation in a myositis-induced mouse model. We measured the T2 relaxation time constants, %CEST at 5 saturation frequencies, and area under the curve (AUC) from DCE-MRI after maltose injection from infected, inflamed, and normal muscle tissue models. We applied principal component analysis (PCA) to reduce dimensionality of entire CEST spectra and DCE signal evolutions, which were analyzed using standard classification methods. We extracted features from dimensional reduction as predictors for machine learning classifier algorithms. Normal, inflamed, and infected tissues were evaluated with H&E and gram-staining histological studies, and bacterial-burden studies. The T2 relaxation time constants and AUC of DCE-MRI after injection of maltose differentiated infected, inflamed, and normal tissues. %CEST amplitudes at −1.6 and −3.5 ppm differentiated infected tissues from other tissues, but these did not differentiate inflamed tissue from normal tissue. %CEST amplitudes at 3.5, 3.0, and 2.5 ppm, AUC of DCE-MRI for shorter time periods, and relative Ktrans and kep values from DCE-MRI could not differentiate tissues. PCA and machine learning of CEST-MRI and DCE-MRI did not improve tissue classifications relative to traditional analysis methods. Similarly, PCA and machine learning did not further improve tissue classifications relative to T2 MRI. Therefore, future MRI studies of infection models should focus on T2-weighted MRI and analysis of T2 relaxation times.
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Affiliation(s)
- Joshua M Goldenberg
- Department of Pharmaceutical Sciences, University of Arizona, Tucson, AZ.,Department of Genitourinary Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX
| | | | | | - Mark D Pagel
- Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, TX
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Kalita M, Parker MFL, Luu JM, Stewart MN, Blecha JE, VanBrocklin HF, Evans M, Flavell RR, Rosenberg OS, Ohliger MA, Wilson DM. Arabinofuranose-derived positron-emission tomography radiotracers for detection of pathogenic microorganisms. J Labelled Comp Radiopharm 2020; 63:231-239. [PMID: 32222086 PMCID: PMC7364301 DOI: 10.1002/jlcr.3835] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/06/2020] [Accepted: 02/26/2020] [Indexed: 12/16/2022]
Abstract
PURPOSE Detection of bacteria-specific metabolism via positron emission tomography (PET) is an emerging strategy to image human pathogens, with dramatic implications for clinical practice. In silico and in vitro screening tools have recently been applied to this problem, with several monosaccharides including l-arabinose showing rapid accumulation in Escherichia coli and other organisms. Our goal for this study was to evaluate several synthetically viable arabinofuranose-derived 18 F analogs for their incorporation into pathogenic bacteria. PROCEDURES We synthesized four radiolabeled arabinofuranose-derived sugars: 2-deoxy-2-[18 F]fluoro-arabinofuranoses (d-2-18 F-AF and l-2-18 F-AF) and 5-deoxy-5-[18 F]fluoro-arabinofuranoses (d-5-18 F-AF and l-5-18 F-AF). The arabinofuranoses were synthesized from 18 F- via triflated, peracetylated precursors analogous to the most common radiosynthesis of 2-deoxy-2-[18 F]fluoro-d-glucose ([18 F]FDG). These radiotracers were screened for their uptake into E. coli and Staphylococcus aureus. Subsequently, the sensitivity of d-2-18 F-AF and l-2-18 F-AF to key human pathogens was investigated in vitro. RESULTS All 18 F radiotracer targets were synthesized in high radiochemical purity. In the screening study, d-2-18 F-AF and l-2-18 F-AF showed greater accumulation in E. coli than in S. aureus. When evaluated in a panel of pathologic microorganisms, both d-2-18 F-AF and l-2-18 F-AF demonstrated sensitivity to most gram-positive and gram-negative bacteria. CONCLUSIONS Arabinofuranose-derived 18 F PET radiotracers can be synthesized with high radiochemical purity. Our study showed absence of bacterial accumulation for 5-substitued analogs, a finding that may have mechanistic implications for related tracers. Both d-2-18 F-AF and l-2-18 F-AF showed sensitivity to most gram-negative and gram-positive organisms. Future in vivo studies will evaluate the diagnostic accuracy of these radiotracers in animal models of infection.
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Affiliation(s)
- Mausam Kalita
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Matthew F. L. Parker
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Justin M. Luu
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Megan N. Stewart
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Joseph E. Blecha
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Henry F. VanBrocklin
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Michael Evans
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Robert R. Flavell
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Oren S. Rosenberg
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Michael A. Ohliger
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA 94158, USA
- Department of Radiology, Zuckerberg San Francisco General Hospital, San Francisco, CA 94110, USA
| | - David M. Wilson
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, San Francisco, CA 94158, USA
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Northrup JD, Mach RH, Sellmyer MA. Radiochemical Approaches to Imaging Bacterial Infections: Intracellular versus Extracellular Targets. Int J Mol Sci 2019; 20:E5808. [PMID: 31752318 PMCID: PMC6888724 DOI: 10.3390/ijms20225808] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 11/04/2019] [Accepted: 11/12/2019] [Indexed: 02/03/2023] Open
Abstract
The discovery of penicillin began the age of antibiotics, which was a turning point in human healthcare. However, to this day, microbial infections are still a concern throughout the world, and the rise of multidrug-resistant organisms is an increasing challenge. To combat this threat, diagnostic imaging tools could be used to verify the causative organism and curb inappropriate use of antimicrobial drugs. Nuclear imaging offers the sensitivity needed to detect small numbers of bacteria in situ. Among nuclear imaging tools, radiolabeled antibiotics traditionally have lacked the sensitivity or specificity necessary to diagnose bacterial infections accurately. One reason for the lack of success is that the antibiotics were often chelated to a radiometal. This was done without addressing the ramifications of how the radiolabeling would impact probe entry to the bacterial cell, or the mechanism of binding to an intracellular target. In this review, we approach bacterial infection imaging through the lens of bacterial specific molecular targets, their intracellular or extracellular location, and discuss radiochemistry strategies to guide future probe development.
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Affiliation(s)
- Justin D. Northrup
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA; (J.D.N.); (R.H.M.)
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA
- Institute for Translational Medicine and Therapeutics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Robert H. Mach
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA; (J.D.N.); (R.H.M.)
| | - Mark A. Sellmyer
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA; (J.D.N.); (R.H.M.)
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA
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Hevey R. Bioisosteres of Carbohydrate Functional Groups in Glycomimetic Design. Biomimetics (Basel) 2019; 4:E53. [PMID: 31357673 PMCID: PMC6784292 DOI: 10.3390/biomimetics4030053] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 07/25/2019] [Accepted: 07/26/2019] [Indexed: 02/07/2023] Open
Abstract
The aberrant presentation of carbohydrates has been linked to a number of diseases, such as cancer metastasis and immune dysregulation. These altered glycan structures represent a target for novel therapies by modulating their associated interactions with neighboring cells and molecules. Although these interactions are highly specific, native carbohydrates are characterized by very low affinities and inherently poor pharmacokinetic properties. Glycomimetic compounds, which mimic the structure and function of native glycans, have been successful in producing molecules with improved pharmacokinetic (PK) and pharmacodynamic (PD) features. Several strategies have been developed for glycomimetic design such as ligand pre-organization or reducing polar surface area. A related approach to developing glycomimetics relies on the bioisosteric replacement of carbohydrate functional groups. These changes can offer improvements to both binding affinity (e.g., reduced desolvation costs, enhanced metal chelation) and pharmacokinetic parameters (e.g., improved oral bioavailability). Several examples of bioisosteric modifications to carbohydrates have been reported; this review aims to consolidate them and presents different possibilities for enhancing core interactions in glycomimetics.
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Affiliation(s)
- Rachel Hevey
- Molecular Pharmacy, Department Pharmaceutical Sciences, University of Basel, Klingelbergstr. 50, 4056 Basel, Switzerland.
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10
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Selection of abstracts from the scientific sessions of the Society of Nuclear Medicine and Molecular Imaging, Philadelphia PA June 23–26, 2018. J Nucl Cardiol 2018. [DOI: 10.1007/s12350-018-1405-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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