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Mc Veigh M, Bellan LM. Microfluidic synthesis of radiotracers: recent developments and commercialization prospects. LAB ON A CHIP 2024; 24:1226-1243. [PMID: 38165824 DOI: 10.1039/d3lc00779k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2024]
Abstract
Positron emission tomography (PET) is a powerful diagnostic tool that holds incredible potential for clinicians to track a wide variety of biological processes using specialized radiotracers. Currently, however, a single radiotracer accounts for over 95% of procedures, largely due to the cost of radiotracer synthesis. Microfluidic platforms provide a solution to this problem by enabling a dose-on-demand pipeline in which a single benchtop platform would synthesize a wide array of radiotracers. In this review, we will explore the field of microfluidic production of radiotracers from early research to current development. Furthermore, the benefits and drawbacks of different microfluidic reactor designs will be analyzed. Lastly, we will discuss the various engineering considerations that must be addressed to create a fully developed, commercially effective platform that can usher the field from research and development to commercialization.
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Affiliation(s)
- Mark Mc Veigh
- Interdisciplinary Materials Science Program, Vanderbilt University, Nashville, TN, 37235, USA
| | - Leon M Bellan
- Department of Mechanical Engineering, Vanderbilt University, Nashville, TN, 37235, USA.
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37235, USA
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Elkawad H, Xu Y, Tian M, Jin C, Zhang H, Yu K, He Q. Recent advances in microfluidic devices for radiosynthesis of PET‐imaging probes. Chem Asian J 2022; 17:e202200579. [PMID: 35909081 DOI: 10.1002/asia.202200579] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 07/29/2022] [Indexed: 11/06/2022]
Affiliation(s)
- Husamelden Elkawad
- The second affiliated hospital of Zhejiang University Nuclear Medicine and PET center CHINA
| | - Yangyang Xu
- Zhejiang University b. College of Chemical & Biological Engineering CHINA
| | - Mei Tian
- The second affiliated hospital of Zhejiang University Nuclear Medicine & PET center CHINA
| | - Chenyang Jin
- Zhejiang University b. College of Chemical & Biological Engineering CHINA
| | - Hong Zhang
- The second affiliated hospital of Zhejiang University b. College of Chemical & Biological Engineering CHINA
| | - Kaiwu Yu
- Zhejiang University b. College of Chemical & Biological Engineering CHINA
| | - Qinggang He
- Zhejiang University Chemical Engineering 38 Zheda Rd. 310027 Hangzhou CHINA
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Jouberton E, Schmitt S, Maisonial-Besset A, Chautard E, Penault-Llorca F, Cachin F. Interest and Limits of [18F]ML-10 PET Imaging for Early Detection of Response to Conventional Chemotherapy. Front Oncol 2021; 11:789769. [PMID: 34988022 PMCID: PMC8722713 DOI: 10.3389/fonc.2021.789769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 11/29/2021] [Indexed: 11/25/2022] Open
Abstract
One of the current challenges in oncology is to develop imaging tools to early detect the response to conventional chemotherapy and adjust treatment strategies when necessary. Several studies evaluating PET imaging with 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) as a predictive tool of therapeutic response highlighted its insufficient specificity and sensitivity. The [18F]FDG uptake reflects only tumor metabolic activity and not treatment-induced cell death, which seems to be relevant for therapeutic evaluation. Therefore, to evaluate this parameter in vivo, several cell death radiotracers have been developed in the last years. However, few of them have reached the clinical trials. This systematic review focuses on the use of [18F]ML-10 (2-(5-[18F]fluoropentyl)-2-methylmalonic acid) as radiotracer of apoptosis and especially as a measure of tumor response to treatment. A comprehensive literature review concerning the preclinical and clinical investigations conducted with [18F]ML-10 was performed. The abilities and applications of this radiotracer as well as its clinical relevance and limitations were discussed. Most studies highlighted a good ability of the radiotracer to target apoptotic cells. However, the increase in apoptosis during treatment did not correlate with the radiotracer tumoral uptake, even using more advanced image analysis (voxel-based analysis). [18F]ML-10 PET imaging does not meet current clinical expectations for early detection of the therapeutic response to conventional chemotherapy. This review has pointed out the challenges of applying various apoptosis imaging strategies in clinical trials, the current methodologies available for image analysis and the future of molecular imaging to assess this therapeutic response.
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Affiliation(s)
- Elodie Jouberton
- Service de Médecine Nucléaire, Centre Jean PERRIN, Clermont-Ferrand, France
- Imagerie Moléculaire et Stratégies Théranostiques, UMR1240, Université Clermont Auvergne, INSERM, Clermont-Ferrand, France
- *Correspondence: Elodie Jouberton,
| | - Sébastien Schmitt
- Imagerie Moléculaire et Stratégies Théranostiques, UMR1240, Université Clermont Auvergne, INSERM, Clermont-Ferrand, France
| | - Aurélie Maisonial-Besset
- Imagerie Moléculaire et Stratégies Théranostiques, UMR1240, Université Clermont Auvergne, INSERM, Clermont-Ferrand, France
| | - Emmanuel Chautard
- Imagerie Moléculaire et Stratégies Théranostiques, UMR1240, Université Clermont Auvergne, INSERM, Clermont-Ferrand, France
- Service de Pathologie, Centre Jean PERRIN, Clermont-Ferrand, France
| | - Frédérique Penault-Llorca
- Imagerie Moléculaire et Stratégies Théranostiques, UMR1240, Université Clermont Auvergne, INSERM, Clermont-Ferrand, France
- Service de Pathologie, Centre Jean PERRIN, Clermont-Ferrand, France
| | - Florent Cachin
- Service de Médecine Nucléaire, Centre Jean PERRIN, Clermont-Ferrand, France
- Imagerie Moléculaire et Stratégies Théranostiques, UMR1240, Université Clermont Auvergne, INSERM, Clermont-Ferrand, France
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Knapp KA, Nickels ML, Manning HC. The Current Role of Microfluidics in Radiofluorination Chemistry. Mol Imaging Biol 2019; 22:463-475. [DOI: 10.1007/s11307-019-01414-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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5
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Vassileva V, Stribbling SM, Barnes C, Carroll L, Braga M, Abrahams J, Heinzmann K, Haegeman C, MacFarlane M, Simpson KL, Dive C, Honeychurch J, Illidge TM, Aboagye EO. Evaluation of apoptosis imaging biomarkers in a genetic model of cell death. EJNMMI Res 2019; 9:18. [PMID: 30783791 PMCID: PMC6381199 DOI: 10.1186/s13550-019-0487-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 02/01/2019] [Indexed: 01/10/2023] Open
Abstract
PURPOSE We have previously developed the caspase-based radiotracer, 18F-ICMT-11, for PET imaging to monitor treatment response. We further validated 18F-ICMT-11 specificity in a murine melanoma death-switch tumour model with conditional activation of caspase-3 induced by doxycycline. METHODS Caspase-3/7 activity and cellular uptake of 18F-ICMT-11, 18F-ML-10 and 18F-FDG were assessed in B16ova and B16ovaRevC3 cells after death-switch induction. Death-switch induction was confirmed in vivo in xenograft tumours, and 18F-ICMT-11 and 18F-ML-10 biodistribution was assessed by ex vivo gamma counting of select tissues. PET imaging was performed with 18F-ICMT-11, 18F-ML-10 and 18F-FDG. Caspase-3 activation was confirmed by immunohistochemistry. RESULTS Significantly increased caspase-3/7 activity was observed only in B16ovaRevC3 cells after death-switch induction, accompanied by significantly increased 18F-ICMT-11 (p < 0.001) and 18F-ML-10 (p < 0.05) and decreased 18F-FDG (p < 0.001) uptake compared with controls. B16ova and B16ovaRevC3 tumours had similar growth in vivo; however, B16ovaRevC3 growth was significantly reduced with death-switch induction (p < 0.01). Biodistribution studies showed significantly increased 18F-ICMT-11 tumour uptake following death-switch induction (p < 0.01), but not for 18F-ML-10. Tumour uptake of 18F-ICMT-11 was higher than that of 18F-ML-10 after death-switch induction. PET imaging studies showed that 18F-ICMT-11 can be used to detect apoptosis after death-switch induction, which was accompanied by significantly increased expression of cleaved caspase-3. 18F-FDG signal decreased in tumours after death-switch induction. CONCLUSIONS We demonstrate that 18F-ICMT-11 can be used to detect caspase-3 activation in a death-switch tumour model, independent of the confounding effects of cancer therapeutics, thus confirming its specificity and supporting the development of this radiotracer for clinical use to monitor tumour apoptosis and therapy response.
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Affiliation(s)
- Vessela Vassileva
- Cancer Imaging Centre, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN UK
| | - Stephen M. Stribbling
- Cancer Imaging Centre, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN UK
| | - Chris Barnes
- Cancer Imaging Centre, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN UK
| | - Laurence Carroll
- Cancer Imaging Centre, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN UK
| | - Marta Braga
- Cancer Imaging Centre, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN UK
| | - Joel Abrahams
- Cancer Imaging Centre, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN UK
| | - Kathrin Heinzmann
- Cancer Imaging Centre, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN UK
| | - Caroline Haegeman
- Cancer Imaging Centre, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN UK
| | - Marion MacFarlane
- MRC Toxicology Unit, Hodgkin Building, Lancaster Road, Leicester, LE1 9HN UK
| | - Kathryn L. Simpson
- Clinical and Experimental Pharmacology Group, Cancer Research UK Manchester Institute, The University of Manchester, Alderley Park, Manchester, SK10 4TG UK
| | - Caroline Dive
- Clinical and Experimental Pharmacology Group, Cancer Research UK Manchester Institute, The University of Manchester, Alderley Park, Manchester, SK10 4TG UK
| | - Jamie Honeychurch
- Targeted Therapy Group, Division of Cancer Sciences, Manchester Cancer Research Centre, Christie Hospital, Manchester Academic Health Sciences Centre, National Institute of Health Research Biomedical Research Centre, Manchester, UK
| | - Timothy M. Illidge
- Targeted Therapy Group, Division of Cancer Sciences, Manchester Cancer Research Centre, Christie Hospital, Manchester Academic Health Sciences Centre, National Institute of Health Research Biomedical Research Centre, Manchester, UK
| | - Eric O. Aboagye
- Cancer Imaging Centre, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN UK
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Molavipordanjani S, Tolmachev V, Hosseinimehr SJ. Basic and practical concepts of radiopharmaceutical purification methods. Drug Discov Today 2018; 24:315-324. [PMID: 30278224 DOI: 10.1016/j.drudis.2018.09.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 08/16/2018] [Accepted: 09/26/2018] [Indexed: 01/02/2023]
Abstract
The presence of radiochemical impurities in a radiopharmaceutical contributes to an unnecessary radiation burden for the patients or to an undesirable high radioactivity background, which reduces the imaging contrast or therapeutic efficacy. Therefore, if the radiolabeling process results in unsatisfactory radiochemical purity, a purification step is unavoidable. A successful purification process requires a profound knowledge about the radiopharmaceuticals of interest ranging from structural features to susceptibility to different conditions. Most radiopharmaceutical purification methods are based on solid-phase extraction (SPE), high-performance liquid chromatography (HPLC), size exclusion chromatography (SEC), ion-exchange chromatography (IEC), and liquid-liquid extraction (LLE). Here, we discuss the basic and applied concepts of these purifications methods as well as their advantages and limitations.
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Affiliation(s)
- Sajjad Molavipordanjani
- Department of Radiopharmacy, Faculty of Pharmacy, Pharmaceutical Sciences Research Center, Mazandaran University of Medical Sciences, Sari, Iran; Student Research Committee, Faculty of Pharmacy, Mazandaran University of Medical Sciences, Sari, Iran
| | - Vladimir Tolmachev
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Seyed Jalal Hosseinimehr
- Department of Radiopharmacy, Faculty of Pharmacy, Pharmaceutical Sciences Research Center, Mazandaran University of Medical Sciences, Sari, Iran.
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Lamichhane N, Dewkar GK, Sundaresan G, Wang L, Jose P, Otabashi M, Morelle JL, Farrell N, Zweit J. 18F-Labeled Carboplatin Derivative for PET Imaging of Platinum Drug Distribution. J Nucl Med 2017; 58:1997-2003. [PMID: 28729428 DOI: 10.2967/jnumed.117.191965] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 06/27/2017] [Indexed: 12/18/2022] Open
Abstract
Increasing evidence indicates that reduced intracellular drug accumulation is the parameter most consistently associated with platinum drug resistance, emphasizing the need to directly measure the intratumor drug concentration. In the era of precision medicine and with the advent of powerful imaging and proteomics technologies, there is an opportunity to better understand drug resistance by exploiting these techniques to provide new knowledge on drug-target interactions. Here, we contribute to this endeavor by reporting on the development of an 18F-labeled carboplatin derivative (18F-FCP) that has the potential to image drug uptake and retention, including intratumoral distribution, by PET. Methods: Fluorinated carboplatin (19F-FCP) was synthesized using 19F-labeled 2-(5-fluoro-pentyl)-2-methyl malonic acid (19F-FPMA) as the labeling agent to coordinate with the cisplatin-aqua complex. It was then used to treat cell lines and compared with cisplatin and carboplatin at different concentrations. Manual radiosynthesis and characterization of 18F-FCP were performed using 18F-FPMA for coordination with the cisplatin-aqua complex. Automated radiosynthesis of 18F-FCP was optimized on the basis of manual synthesis procedures. The stability of 18F-FCP was verified using high-performance liquid chromatography. 18F-FCP was evaluated using ex vivo biodistribution and in vivo PET imaging in non-tumor-bearing animals as well as in KB-3-1 and COLO-205 tumor xenograft-bearing nude mice. Results: In vitro cytotoxicity studies demonstrated that 19F-FCP has an antitumor activity profile similar to that of the parent drug carboplatin. In vivo plasma and urine stability analysis showed intact 18F-FCP at 24 h after injection. PET imaging and biodistribution studies showed fast clearance from blood and major accumulation in the kidneys, indicating substantial renal clearance of 18F-FCP. Using 18F-FCP PET, we could image and identify the intratumor drug profile. Conclusion: Our results demonstrated that 19F-FCP, like carboplatin, retains antitumor activity in various cell lines. 18F-FCP could be a useful imaging tool for measuring the intratumor drug distribution. This strategy of using a new therapeutic carboplatin derivative to quantify and track platinum drugs in tumors using PET has the potential to translate into a clinically useful imaging tool for individual patients.
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Affiliation(s)
- Narottam Lamichhane
- Center for Molecular Imaging, Department of Radiology, Virginia Commonwealth University, Richmond, Virginia
| | - Gajanan K Dewkar
- Center for Molecular Imaging, Department of Radiology, Virginia Commonwealth University, Richmond, Virginia
| | - Gobalakrishnan Sundaresan
- Center for Molecular Imaging, Department of Radiology, Virginia Commonwealth University, Richmond, Virginia
| | - Li Wang
- Center for Molecular Imaging, Department of Radiology, Virginia Commonwealth University, Richmond, Virginia
| | - Purnima Jose
- Center for Molecular Imaging, Department of Radiology, Virginia Commonwealth University, Richmond, Virginia
| | | | | | - Nicholas Farrell
- Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia
| | - Jamal Zweit
- Center for Molecular Imaging, Department of Radiology, Virginia Commonwealth University, Richmond, Virginia
- Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia
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Lamichhane N, Dewkar GK, Sundaresan G, Mahon RN, Zweit J. [ 18F]-Fluorinated Carboplatin and [ 111In]-Liposome for Image-Guided Drug Delivery. Int J Mol Sci 2017; 18:E1079. [PMID: 28524076 PMCID: PMC5454988 DOI: 10.3390/ijms18051079] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 05/02/2017] [Accepted: 05/08/2017] [Indexed: 11/16/2022] Open
Abstract
Radiolabeled liposomes have been employed as diagnostic tools to monitor in vivo distribution of liposomes in real-time, which helps in optimizing the therapeutic efficacy of the liposomal drug delivery. This work utilizes the platform of [111In]-Liposome as a drug delivery vehicle, encapsulating a novel 18F-labeled carboplatin drug derivative ([18F]-FCP) as a dual-molecular imaging tool as both a radiolabeled drug and radiolabeled carrier. The approach has the potential for clinical translation in individual patients using a dual modal approach of clinically-relevant radionuclides of 18F positron emission tomography (PET) and 111In single photon emission computed tomography (SPECT). [111In]-Liposome was synthesized and evaluated in vivo by biodistribution and SPECT imaging. The [18F]-FCP encapsulated [111In]-Liposome nano-construct was investigated, in vivo, using an optimized dual-tracer PET and SPECT imaging in a nude mouse. The biodistribution data and SPECT imaging showed spleen and liver uptake of [111In]-Liposome and the subsequent clearance of activity with time. Dual-modality imaging of [18F]-FCP encapsulated [111In]-Liposome showed significant uptake in liver and spleen in both PET and SPECT images. Qualitative analysis of SPECT images and quantitative analysis of PET images showed the same pattern of activity during the imaging period and demonstrated the feasibility of dual-tracer imaging of a single dual-labeled nano-construct.
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Affiliation(s)
- Narottam Lamichhane
- Center for Molecular Imaging, Department of Radiology, Virginia Commonwealth University, 1101 E. Marshall Street, Richmond, VA 23298-0031, USA.
| | - Gajanan K Dewkar
- Center for Molecular Imaging, Department of Radiology, Virginia Commonwealth University, 1101 E. Marshall Street, Richmond, VA 23298-0031, USA.
| | - Gobalakrishnan Sundaresan
- Center for Molecular Imaging, Department of Radiology, Virginia Commonwealth University, 1101 E. Marshall Street, Richmond, VA 23298-0031, USA.
| | - Rebecca N Mahon
- Center for Molecular Imaging, Department of Radiology, Virginia Commonwealth University, 1101 E. Marshall Street, Richmond, VA 23298-0031, USA.
| | - Jamal Zweit
- Center for Molecular Imaging, Department of Radiology, Virginia Commonwealth University, 1101 E. Marshall Street, Richmond, VA 23298-0031, USA.
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Liu S, Nie D, Jiang S, Tang G. Efficient automated synthesis of 2-(5-[ 18 F]fluoropentyl)-2-methylmalonic acid ([ 18 F]ML-10) on a commercial available [ 18 F]FDG synthesis module. Appl Radiat Isot 2017; 123:49-53. [DOI: 10.1016/j.apradiso.2017.02.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 02/11/2017] [Accepted: 02/17/2017] [Indexed: 11/26/2022]
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In Vivo Evaluation of Radiofluorinated Caspase-3/7 Inhibitors as Radiotracers for Apoptosis Imaging and Comparison with [18F]ML-10 in a Stroke Model in the Rat. Mol Imaging Biol 2015; 18:117-26. [DOI: 10.1007/s11307-015-0865-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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11
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Abstract
In view of the trend towards personalized treatment strategies for (cancer) patients, there is an increasing need to noninvasively determine individual patient characteristics. Such information enables physicians to administer to patients accurate therapy with appropriate timing. For the noninvasive visualization of disease-related features, imaging biomarkers are expected to play a crucial role. Next to the chemical development of imaging probes, this requires preclinical studies in animal tumour models. These studies provide proof-of-concept of imaging biomarkers and help determine the pharmacokinetics and target specificity of relevant imaging probes, features that provide the fundamentals for translation to the clinic. In this review we describe biological processes derived from the “hallmarks of cancer” that may serve as imaging biomarkers for diagnostic, prognostic and treatment response monitoring that are currently being studied in the preclinical setting. A number of these biomarkers are also being used for the initial preclinical assessment of new intervention strategies. Uniquely, noninvasive imaging approaches allow longitudinal assessment of changes in biological processes, providing information on the safety, pharmacokinetic profiles and target specificity of new drugs, and on the antitumour effectiveness of therapeutic interventions. Preclinical biomarker imaging can help guide translation to optimize clinical biomarker imaging and personalize (combination) therapies.
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Barth V, Need A. Identifying novel radiotracers for PET imaging of the brain: application of LC-MS/MS to tracer identification. ACS Chem Neurosci 2014; 5:1148-53. [PMID: 24828747 DOI: 10.1021/cn500072r] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Nuclear medicine imaging biomarker applications are limited by the radiotracers available. Radiotracers enable the measurement of target engagement, or occupancy in relation to plasma exposure. These tracers can also be used as pharmacodynamic biomarkers to demonstrate functional consequences of binding a target. More recently, radiotracers have also been used for patient tailoring in Alzheimer's disease seen with amyloid imaging. Radiotracers for the central nervous system (CNS) are challenging to identify, as they require a unique intersection of multiple properties. Recent advances in tangential technologies, along with the use of iterative learning for the purposes of deriving in silico models, have opened up additional opportunities to identify radiotracers. Mass spectral technologies and in silico modeling have made it possible to measure and predict in vivo characteristics of molecules to indicate potential tracer performance. By analyzing these data alongside other measures, it is possible to delineate guidelines to increase the likelihood of selecting compounds that can perform as radiotracers or serve as the best starting point to develop a radiotracer following additional structural modification. The application of mass spectrometry based technologies is an efficient way to evaluate compounds as tracers in vivo, but more importantly enables the testing of potential tracers that have either no label site or complex labeling chemistry which may deter assessment by traditional means; therefore, use of this technology allows for more rapid iterative learning. The ability to differentially distribute toward target rich tissues versus tissue with no/less target present is a unique defining feature of a tracer. By testing nonlabeled compounds in vivo and analyzing tissue levels by LC-MS/MS, rapid assessment of a compound's ability to differentially distribute in a manner consistent with target expression biology guides the focus of chemistry resources for both designing and labeling tracer candidates. LC-MS/MS has only recently been used for de novo tracer identification; however, this connection of mass spectral technology to imaging has initiated engagement from a wider community that brings diverse backgrounds into the tracer discovery arena.
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Affiliation(s)
- Vanessa Barth
- Eli Lilly and Co., Lilly Research Laboratories, Indianapolis, Indiana 46285, United States
| | - Anne Need
- Eli Lilly and Co., Lilly Research Laboratories, Indianapolis, Indiana 46285, United States
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13
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Affiliation(s)
- Joseph Sherma
- a Department of Chemistry , Lafayette College , Easton , Pennsylvania , USA
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14
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Bois F, Gallezot JD, Zheng MQ, Lin SF, Esterlis I, Cosgrove KP, Carson RE, Huang Y. Evaluation of [(18)F]-(-)-norchlorofluorohomoepibatidine ([(18)F]-(-)-NCFHEB) as a PET radioligand to image the nicotinic acetylcholine receptors in non-human primates. Nucl Med Biol 2014; 42:570-7. [PMID: 25858513 DOI: 10.1016/j.nucmedbio.2014.08.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 07/28/2014] [Accepted: 08/05/2014] [Indexed: 01/27/2023]
Abstract
INTRODUCTION The aims of the present study were to develop an optimized microfluidic method for the production of the selective nicotinic acetylcholine α4β2 receptor radiotracer [(18)F]-(-)-NCFHEB ([(18)F]-Flubatine) and to investigate its receptor binding profile and pharmacokinetic properties in rhesus monkeys in vivo. METHODS [(18)F]-(-)-NCFHEB was prepared in two steps, a nucleophilic fluorination followed by N-Boc deprotection. PET measurements were performed in rhesus monkeys including baseline and preblocking experiments with nicotine (0.24 mg/kg). Radiometabolites in plasma were measured using HPLC. RESULTS [(18)F]-(-)-NCFHEB was prepared in a total synthesis time of 140 min. The radiochemical purity in its final formulation was >98% and the mean specific radioactivity was 97.3 ± 16.1 GBq/μmol (n = 6) at end of synthesis (EOS). In the monkey brain, radioactivity concentration was high in the thalamus, moderate in the putamen, hippocampus, frontal cortex, and lower in the cerebellum. Nicotine blocked 98-100% of [(18)F]-(-)-NCFHEB specific binding, and the non-displaceable distribution volume (VND) was estimated at 5.9 ± 1.0 mL/cm(3) (n = 2), or 6.6 ± 1.1 mL/cm(3) after normalization by the plasma free fraction fP. Imaging data are amenable to kinetic modeling analysis using the multilinear analysis (MA1) method, and model-derived binding parameters display good test-retest reproducibility. In rhesus monkeys, [(18)F]-(-)-NCFHEB can yield robust regional binding potential (BPND) values (thalamus = 4.1 ± 1.5, frontal cortex = 1.2 ± 0.2, putamen = 0.96 ± 0.45, and cerebellum = 0.10 ± 0.29). CONCLUSION An efficient microfluidic synthetic method was developed for preparation of [(18)F]-(-)-NCFHEB. PET examination in rhesus monkeys showed that [(18)F]-(-)-NCFHEB entered the brain readily and its regional radioactivity uptake pattern was in accordance with the known distribution of α4β2 receptors. Estimated non-displaceable binding potential (BPND) values in brain regions were better than those of [(18)F]2-FA and comparable to [(18)F]AZAN. These results confirm previous findings and support further examination of [(18)F]-(-)-NCFHEB in humans.
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Affiliation(s)
- Frederic Bois
- PET Center, Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, CT, USA.
| | - Jean-Dominique Gallezot
- PET Center, Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, CT, USA
| | - Ming-Qiang Zheng
- PET Center, Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, CT, USA
| | - Shu-Fei Lin
- PET Center, Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, CT, USA
| | - Irina Esterlis
- PET Center, Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, CT, USA; Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Kelly P Cosgrove
- PET Center, Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, CT, USA; Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Richard E Carson
- PET Center, Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, CT, USA
| | - Yiyun Huang
- PET Center, Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, CT, USA
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Abstract
AbstractThe most important advances in planar chromatography published between November 1, 2011 and November 1, 2013 are reviewed in this paper. Included are an introduction to the current status of the field; student experiments, books, and reviews; theory and fundamental studies; apparatus and techniques for sample preparation and TLC separations (sample application and plate development with the mobile phase); detection and identification of separated zones (chemical and biological detection, TLC/mass spectrometry, and TLC coupled with other spectrometric methods); techniques and instruments for quantitative analysis; preparative layer chromatography; and thin layer radiochromatography. Numerous applications to a great number of compound types and sample matrices are presented in all sections of the review.
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