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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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2
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Haveman LYF, Vugts DJ, Windhorst AD. State of the art procedures towards reactive [ 18F]fluoride in PET tracer synthesis. EJNMMI Radiopharm Chem 2023; 8:28. [PMID: 37824021 PMCID: PMC10570257 DOI: 10.1186/s41181-023-00203-5] [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: 07/24/2023] [Accepted: 08/03/2023] [Indexed: 10/13/2023] Open
Abstract
BACKGROUND Positron emission tomography (PET) is a powerful, non-invasive preclinical and clinical nuclear imaging technique used in disease diagnosis and therapy assessment. Fluorine-18 is the predominant radionuclide used for PET tracer synthesis. An impressive variety of new 'late-stage' radiolabeling methodologies for the preparation of 18F-labeled tracers has appeared in order to improve the efficiency of the labeling reaction. MAIN BODY Despite these developments, one outstanding challenge into the early key steps of the process remains: the preparation of reactive [18F]fluoride from oxygen-18 enriched water ([18O]H2O). In the last decade, significant changes into the trapping, elution and drying stages have been introduced. This review provides an overview of the strategies and recent developments in the production of reactive [18F]fluoride and its use for radiolabeling. CONCLUSION Improved, modified or even completely new fluorine-18 work-up procedures have been developed in the last decade with widespread use in base-sensitive nucleophilic 18F-fluorination reactions. The many promising developments may lead to a few standardized drying methodologies for the routine production of a broad scale of PET tracers.
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Affiliation(s)
- Lizeth Y F Haveman
- Radiology and Nuclear Medicine, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, The Netherlands
- Chemistry and Pharmaceutical Sciences, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Amsterdam, The Netherlands
| | - Danielle J Vugts
- Radiology and Nuclear Medicine, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, The Netherlands
- Cancer Center Amsterdam (CCA), Amsterdam, The Netherlands
| | - Albert D Windhorst
- Radiology and Nuclear Medicine, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, The Netherlands.
- Neuroscience Amsterdam, Amsterdam, The Netherlands.
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3
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Tong Z, Shen C, Li Q, Yin H, Mao H. Combining sensors and actuators with electrowetting-on-dielectric (EWOD): advanced digital microfluidic systems for biomedical applications. Analyst 2023; 148:1399-1421. [PMID: 36752059 DOI: 10.1039/d2an01707e] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
The concept of digital microfluidics (DMF) enables highly flexible and precise droplet manipulation at a picoliter scale, making DMF a promising approach to realize integrated, miniaturized "lab-on-a-chip" (LOC) systems for research and clinical purposes. Owing to its simplicity and effectiveness, electrowetting-on-dielectric (EWOD) is one of the most commonly studied and applied effects to implement DMF. However, complex biomedical assays usually require more sophisticated sample handling and detection capabilities than basic EWOD manipulation. Alternatively, combined systems integrating EWOD actuators and other fluidic handling techniques are essential for bringing DMF into practical use. In this paper, we briefly review the main approaches for the integration/combination of EWOD with other microfluidic manipulation methods or additional external fields for specified biomedical applications. The form of integration ranges from independently operating sub-systems to fully coupled hybrid actuators. The corresponding biomedical applications of these works are also summarized to illustrate the significance of these innovative combination attempts.
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Affiliation(s)
- Zhaoduo Tong
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China. .,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chuanjie Shen
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China. .,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qiushi Li
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
| | - Hao Yin
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China. .,Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hongju Mao
- State Key Laboratory of Transducer Technology, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
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4
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Ahmadi F, Simchi M, Perry JM, Frenette S, Benali H, Soucy JP, Massarweh G, Shih SCC. Integrating machine learning and digital microfluidics for screening experimental conditions. LAB ON A CHIP 2022; 23:81-91. [PMID: 36416045 DOI: 10.1039/d2lc00764a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Digital microfluidics (DMF) has the signatures of an ideal liquid handling platform - as shown through almost two decades of automated biological and chemical assays. However, in the current state of DMF, we are still limited by the number of parallel biological or chemical assays that can be performed on DMF. Here, we report a new approach that leverages design-of-experiment and numerical methodologies to accelerate experimental optimization on DMF. The integration of the one-factor-at-a-time (OFAT) experimental technique with machine learning algorithms provides a set of recommended optimal conditions without the need to perform a large set of experiments. We applied our approach towards optimizing the radiochemistry synthesis yield given the large number of variables that affect the yield. We believe that this work is the first to combine such techniques which can be readily applied to any other assays that contain many parameters and levels on DMF.
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Affiliation(s)
- Fatemeh Ahmadi
- Department of Electrical and Computer Engineering, Concordia University, 1455 de Maisonneuve Blvd. West, Montréal, Québec, H3G 1M8, Canada.
- PERFORM Centre, Concordia University, 7200 Sherbrooke Street West, Montréal, Québec, H4B 1R6, Canada
- Centre for Applied Synthetic Biology, Concordia University, 7141 Sherbrooke Street West, Montréal, Québec, H4B 1R6, Canada
| | - Mohammad Simchi
- Department of Mechanical & Industrial Engineering, University of Toronto, 5 King's College Rd, Toronto, Ontario, M5S 3G8, Canada
| | - James M Perry
- PERFORM Centre, Concordia University, 7200 Sherbrooke Street West, Montréal, Québec, H4B 1R6, Canada
| | - Stephane Frenette
- PERFORM Centre, Concordia University, 7200 Sherbrooke Street West, Montréal, Québec, H4B 1R6, Canada
| | - Habib Benali
- Department of Electrical and Computer Engineering, Concordia University, 1455 de Maisonneuve Blvd. West, Montréal, Québec, H3G 1M8, Canada.
- PERFORM Centre, Concordia University, 7200 Sherbrooke Street West, Montréal, Québec, H4B 1R6, Canada
| | - Jean-Paul Soucy
- PERFORM Centre, Concordia University, 7200 Sherbrooke Street West, Montréal, Québec, H4B 1R6, Canada
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, 3801 University Street, Montréal, Québec, H3A 2B4, Canada
| | - Gassan Massarweh
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, 3801 University Street, Montréal, Québec, H3A 2B4, Canada
| | - Steve C C Shih
- Department of Electrical and Computer Engineering, Concordia University, 1455 de Maisonneuve Blvd. West, Montréal, Québec, H3G 1M8, Canada.
- PERFORM Centre, Concordia University, 7200 Sherbrooke Street West, Montréal, Québec, H4B 1R6, Canada
- Centre for Applied Synthetic Biology, Concordia University, 7141 Sherbrooke Street West, Montréal, Québec, H4B 1R6, Canada
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5
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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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6
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Wang J, van Dam RM. Economical Production of Radiopharmaceuticals for Preclinical Imaging Using Microdroplet Radiochemistry. Methods Mol Biol 2022; 2393:813-828. [PMID: 34837213 DOI: 10.1007/978-1-0716-1803-5_43] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The short-lived radiolabeled "tracers" needed for performing whole body imaging in animals or patients with positron-emission tomography (PET) are generally produced via automated "radiosynthesizers". Most current radiosynthesizers are designed for routine production of relatively large clinical batches and are very wasteful when only a small batch of a tracer is needed, such as is the case for preclinical in vivo PET imaging studies. To overcome the prohibitively high cost of producing small batches of PET tracers, we developed a droplet microreactor system that performs radiochemistry at the 1-10μL scale instead of the milliliter scale of conventional technologies. The overall yield for the droplet-based production of many PET tracers is comparable to conventional approaches, but 10-100× less reagents are consumed, the synthesis can be completed in much less time (<30 min), and only a small laboratory footprint and minimal radiation shielding are needed. By combining these advantages, droplet microreactors enable the economical production of small batches PET tracers on demand. Here, we describe the fabrication method of the droplet microreactor and the droplet-based synthesis of an example radiotracer ([18F]fallypride).
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Affiliation(s)
- Jia Wang
- Crump Institute for Molecular Imaging, University of California Los Angeles, Los Angeles, CA, USA
- Department of Molecular & Medical Pharmacology, University of California Los Angeles, Los Angeles, CA, USA
- Bioengineering Department, University of California Los Angeles, Los Angeles, CA, USA
| | - R Michael van Dam
- Crump Institute for Molecular Imaging, University of California Los Angeles, Los Angeles, CA, USA.
- Department of Molecular & Medical Pharmacology, University of California Los Angeles, Los Angeles, CA, USA.
- Bioengineering Department, University of California Los Angeles, Los Angeles, CA, USA.
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7
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Lisova K, Wang J, Hajagos TJ, Lu Y, Hsiao A, Elizarov A, van Dam RM. Economical droplet-based microfluidic production of [ 18F]FET and [ 18F]Florbetaben suitable for human use. Sci Rep 2021; 11:20636. [PMID: 34667246 PMCID: PMC8526601 DOI: 10.1038/s41598-021-99111-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 08/26/2021] [Indexed: 01/22/2023] Open
Abstract
Current equipment and methods for preparation of radiopharmaceuticals for positron emission tomography (PET) are expensive and best suited for large-scale multi-doses batches. Microfluidic radiosynthesizers have been shown to provide an economic approach to synthesize these compounds in smaller quantities, but can also be scaled to clinically-relevant levels. Batch microfluidic approaches, in particular, offer significant reduction in system size and reagent consumption. Here we show a simple and rapid technique to concentrate the radioisotope, prior to synthesis in a droplet-based radiosynthesizer, enabling production of clinically-relevant batches of [18F]FET and [18F]FBB. The synthesis was carried out with an automated synthesizer platform based on a disposable Teflon-silicon surface-tension trap chip. Up to 0.1 mL (4 GBq) of radioactivity was used per synthesis by drying cyclotron-produced aqueous [18F]fluoride in small increments directly inside the reaction site. Precursor solution (10 µL) was added to the dried [18F]fluoride, the reaction chip was heated for 5 min to perform radiofluorination, and then a deprotection step was performed with addition of acid solution and heating. The product was recovered in 80 µL volume and transferred to analytical HPLC for purification. Purified product was formulated via evaporation and resuspension or a micro-SPE formulation system. Quality control testing was performed on 3 sequential batches of each tracer. The method afforded production of up to 0.8 GBq of [18F]FET and [18F]FBB. Each production was completed within an hour. All batches passed quality control testing, confirming suitability for human use. In summary, we present a simple and efficient synthesis of clinically-relevant batches of [18F]FET and [18F]FBB using a microfluidic radiosynthesizer. This work demonstrates that the droplet-based micro-radiosynthesizer has a potential for batch-on-demand synthesis of 18F-labeled radiopharmaceuticals for human use.
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Affiliation(s)
- Ksenia Lisova
- Crump Institute for Molecular Imaging, University of California Los Angeles, Los Angeles, CA, USA
- Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, CA, USA
- Physics in Biology and Medicine Interdepartmental Graduate Program, University of California Los Angeles, Los Angeles, CA, USA
| | - Jia Wang
- Crump Institute for Molecular Imaging, University of California Los Angeles, Los Angeles, CA, USA
- Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, CA, USA
- Bioengineering Department, University of California Los Angeles, Los Angeles, CA, USA
| | | | - Yingqing Lu
- Crump Institute for Molecular Imaging, University of California Los Angeles, Los Angeles, CA, USA
- Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, CA, USA
- Physics in Biology and Medicine Interdepartmental Graduate Program, University of California Los Angeles, Los Angeles, CA, USA
| | | | | | - R Michael van Dam
- Crump Institute for Molecular Imaging, University of California Los Angeles, Los Angeles, CA, USA.
- Department of Molecular and Medical Pharmacology, University of California Los Angeles, Los Angeles, CA, USA.
- Physics in Biology and Medicine Interdepartmental Graduate Program, University of California Los Angeles, Los Angeles, CA, USA.
- Bioengineering Department, University of California Los Angeles, Los Angeles, CA, USA.
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8
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Kim TJ, Ha B, Bick AD, Kim M, Tang SK, Pratx G. Microfluidics-Coupled Radioluminescence Microscopy for In Vitro Radiotracer Kinetic Studies. Anal Chem 2021; 93:4425-4433. [PMID: 33647202 PMCID: PMC8006742 DOI: 10.1021/acs.analchem.0c04321] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Integrated bioassay systems that combine microfluidics and radiation detectors can deliver medical radiopharmaceuticals to live cells with precise timing, while minimizing radiation dose and sample volume. However, the spatial resolution of many radiation imaging systems is limited to bulk cell populations. Here, we demonstrate microfluidics-coupled radioluminescence microscopy (μF-RLM), a new integrated system that can image radiotracer uptake in live adherent cells growing inside microincubators with spatial resolution better than 30 μm. Our method enables on-chip radionuclide imaging by incorporating an inorganic scintillator plate (CdWO4) into a microfluidic chip. We apply this approach to investigate the factors that influence the dynamic uptake of [18F]fluorodeoxyglucose (FDG) by cancer cells. In the first experiment, we measured the effect of flow on FDG uptake of cells and found that a continuous flow of the radiotracer led to fourfold higher uptake than static incubation, suggesting that convective replenishment enhances molecular radiotracer transport into cells. In the second set of experiments, we applied pharmacokinetic modeling to show that lactic acidosis inhibits FDG uptake by cancer cells in vitro and that this decrease is primarily due to downregulation of FDG transport into the cells. The other two rate constants, which represent FDG export and FDG metabolism, were relatively unaffected by lactic acidosis. Lactic acidosis is common in solid tumors because of the dysregulated metabolism and inefficient vasculature. In conclusion, μF-RLM is a simple and practical approach for integrating high-resolution radionuclide imaging within standard microfluidics devices, thus potentially opening venues for investigating the efficacy of radiopharmaceuticals in in vitro cancer models.
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Affiliation(s)
- Tae Jin Kim
- Division of Medical Physics, Department of Radiation Oncology, Stanford University, 300 Pasteur Dr., Stanford, CA 94305, USA
| | - Byunghang Ha
- Department of Mechanical Engineering, Stanford University, 440 Escondido Mall, Stanford, CA 94305, USA
| | - Alison Dana Bick
- Department of Mechanical Engineering, Stanford University, 440 Escondido Mall, Stanford, CA 94305, USA
| | - Minkyu Kim
- Department of Mechanical Engineering, Stanford University, 440 Escondido Mall, Stanford, CA 94305, USA
| | - Sindy K.Y. Tang
- Department of Mechanical Engineering, Stanford University, 440 Escondido Mall, Stanford, CA 94305, USA
| | - Guillem Pratx
- Division of Medical Physics, Department of Radiation Oncology, Stanford University, 300 Pasteur Dr., Stanford, CA 94305, USA
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9
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van Dam RM, Chatziioannou AF. Cerenkov Luminescence Imaging in the Development and Production of Radiopharmaceuticals. FRONTIERS IN PHYSICS 2021; 9:632056. [PMID: 36213527 PMCID: PMC9544387 DOI: 10.3389/fphy.2021.632056] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Over the past several years there has been an explosion of interest in exploiting Cerenkov radiation to enable in vivo and intraoperative optical imaging of subjects injected with trace amounts of radiopharmaceuticals. At the same time, Cerenkov luminescence imaging (CLI) also has been serving as a critical tool in radiochemistry, especially for the development of novel microfluidic devices for producing radiopharmaceuticals. By enabling microfluidic processes to be monitored non-destructively in situ, CLI has made it possible to literally watch the activity distribution as the synthesis occurs, and to quantitatively measure activity propagation and losses at each step of synthesis, paving the way for significant strides forward in performance and robustness of those devices. In some cases, CLI has enabled detection and resolution of unexpected problems not observable via standard optical methods. CLI is also being used in analytical radiochemistry to increase the reliability of radio-thin layer chromatography (radio-TLC) assays. Rapid and high-resolution Cerenkov imaging of radio-TLC plates enables detection of issues in the spotting or separation process, improves chromatographic resolution (and/or allows reduced separation distance and time), and enables increased throughput by allowing multiple samples to be spotted side-by-side on a single TLC plate for parallel separation and readout. In combination with new multi-reaction microfluidic chips, this is creating a new possibility for high-throughput optimization in radiochemistry. In this mini review, we provide an overview of the role that CLI has played to date in the radiochemistry side of radiopharmaceuticals.
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Affiliation(s)
- R. Michael van Dam
- UCLA Crump Institute for Molecular Imaging, Los Angeles, CA, United States
- UCLA Department of Molecular and Medical Pharmacology, Los Angeles, CA, United States
| | - Arion F. Chatziioannou
- UCLA Crump Institute for Molecular Imaging, Los Angeles, CA, United States
- UCLA Department of Molecular and Medical Pharmacology, Los Angeles, CA, United States
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10
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Wang J, van Dam RM. High-Efficiency Production of Radiopharmaceuticals via Droplet Radiochemistry: A Review of Recent Progress. Mol Imaging 2020; 19:1536012120973099. [PMID: 33296272 PMCID: PMC7731702 DOI: 10.1177/1536012120973099] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 09/02/2020] [Accepted: 10/12/2020] [Indexed: 12/13/2022] Open
Abstract
New platforms are enabling radiochemistry to be carried out in tiny, microliter-scale volumes, and this capability has enormous benefits for the production of radiopharmaceuticals. These droplet-based technologies can achieve comparable or better yields compared to conventional methods, but with vastly reduced reagent consumption, shorter synthesis time, higher molar activity (even for low activity batches), faster purification, and ultra-compact system size. We review here the state of the art of this emerging direction, summarize the radiotracers and prosthetic groups that have been synthesized in droplet format, describe recent achievements in scaling up activity levels, and discuss advantages and limitations and the future outlook of these innovative devices.
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Affiliation(s)
- Jia Wang
- Crump Institute for Molecular Imaging and Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA, Los Angeles, CA, USA
| | - R. Michael van Dam
- Crump Institute for Molecular Imaging and Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA, Los Angeles, CA, USA
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11
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Wang J, Chao PH, Slavik R, van Dam RM. Multi-GBq production of the radiotracer [18F]fallypride in a droplet microreactor. RSC Adv 2020; 10:7828-7838. [PMID: 35492189 PMCID: PMC9049805 DOI: 10.1039/d0ra01212b] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 02/11/2020] [Indexed: 12/17/2022] Open
Abstract
Microfluidics offers numerous advantages for the synthesis of short-lived radiolabeled imaging tracers: performing 18F-radiosyntheses in microliter-scale droplets has exhibited high efficiency, speed, and molar activity as well as low reagent consumption. However, most reports have been at the preclinical scale. In this study we integrate a [18F]fluoride concentrator and a microdroplet synthesizer to explore the possibility of synthesizing patient doses and multi-patient batches of clinically-acceptable tracers. In the integrated system, [18F]fluoride (up to 41 GBq [1.1 Ci]) in [18O]H2O (1 mL) was first concentrated ∼80-fold and then efficiently transferred to the 8 μL reaction chip as a series of small (∼0.5 μL) droplets. Each droplet rapidly dried at the reaction site of the pre-heated chip, resulting in localized accumulation of large amounts of radioactivity in the form of dried [18F]TBAF complex. The PET tracer [18F]fallypride was synthesized from this concentrated activity in an overall synthesis time of ∼50 min (including radioisotope concentration and transfer, droplet radiosynthesis, purification, and formulation), in amounts up to 7.2 GBq [0.19 Ci], sufficient for multiple clinical PET scans. The resulting batches of [18F]fallypride passed all QC tests needed to ensure safety for clinical injection. This integrated technology enabled for the first time the impact of a wide range of activity levels on droplet radiosynthesis to be studied. Furthermore, this substantial increase in scale expands the applications of droplet radiosynthesis to the production of clinically-relevant amounts of radiopharmaceuticals, and potentially even centralized production of clinical tracers in radiopharmacies. The overall system could be applied to fundamental studies of droplet-based radiochemical reactions, or to the production of radiopharmaceuticals labeled with a variety of isotopes used for imaging and/or targeted radiotherapeutics. Using a micro-cartridge based radionuclide concentrator enables the production of multiple (10 s) of clinical doses of the PET tracer [18F]fallypride with a droplet micro-reactor platform (8 μL).![]()
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Affiliation(s)
- Jia Wang
- Department of Bioengineering
- Henry Samueli School of Engineering
- UCLA
- Los Angeles
- USA
| | - Philip H. Chao
- Department of Bioengineering
- Henry Samueli School of Engineering
- UCLA
- Los Angeles
- USA
| | - Roger Slavik
- Ahmanson Translational Imaging Division
- David Geffen School of Medicine
- University of California
- Los Angeles
- USA
| | - R. Michael van Dam
- Department of Bioengineering
- Henry Samueli School of Engineering
- UCLA
- Los Angeles
- USA
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12
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Frank C, Winter G, Rensei F, Samper V, Brooks AF, Hockley BG, Henderson BD, Rensch C, Scott PJH. Development and implementation of ISAR, a new synthesis platform for radiopharmaceutical production. EJNMMI Radiopharm Chem 2019; 4:24. [PMID: 31659546 PMCID: PMC6751239 DOI: 10.1186/s41181-019-0077-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 08/30/2019] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND PET radiopharmaceutical development and the implementation of a production method on a synthesis module is a complex and time-intensive task since new synthesis methods must be adapted to the confines of the synthesis platform in use. Commonly utilized single fluid bus architectures put multiple constraints on synthesis planning and execution, while conventional microfluidic solutions are limited by compatibility at the macro-to-micro interface. In this work we introduce the ISAR synthesis platform and custom-tailored fluid paths leveraging up to 70 individually addressable valves on a chip-based consumable. The ISAR synthesis platform replaces traditional stopcock valve manifolds with a fluidic chip that integrates all fluid paths (tubing) and valves into one consumable and enables channel routing without the single fluid bus constraint. ISAR can scale between the macro- (10 mL), meso- (0.5 mL) and micro- (≤0.05 mL) domain seamlessly, addressing the macro-to-micro interface challenge and enabling custom tailored fluid circuits for a given application. In this paper we demonstrate proof-of-concept by validating a single chip design to address the challenge of synthesizing multiple batches of [13N]NH3 for clinical use throughout the workday. RESULTS ISAR was installed at an academic PET Center and used to manufacture [13N]NH3 in > 96% radiochemical yield. Up to 9 batches were manufactured with a single consumable chip having parallel paths without the need to open the hot-cell. Quality control testing confirmed the ISAR-based [13N]NH3 met existing clinical release specifications, and utility was demonstrated by imaging a rodent with [13N]NH3 produced on ISAR. CONCLUSIONS ISAR represents a new paradigm in radiopharmaceutical production. Through a new system architecture, ISAR integrates the principles of microfluidics with the standard volumes and consumables established in PET Centers all over the world. Proof-of-concept has been demonstrated through validation of a chip design for the synthesis of [13N]NH3 suitable for clinical use.
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Affiliation(s)
| | - Georg Winter
- GE Healthcare, Oskar-Schlemmer-Str. 11, 80807 Munich, Germany
| | | | | | - Allen F. Brooks
- Department of Radiology, University of Michigan, 2276 Medical Science Bldg I, SPC 5610, Ann Arbor, MI 48109 USA
| | - Brian G. Hockley
- Department of Radiology, University of Michigan, 2276 Medical Science Bldg I, SPC 5610, Ann Arbor, MI 48109 USA
| | - Bradford D. Henderson
- Department of Radiology, University of Michigan, 2276 Medical Science Bldg I, SPC 5610, Ann Arbor, MI 48109 USA
| | | | - Peter J. H. Scott
- Department of Radiology, University of Michigan, 2276 Medical Science Bldg I, SPC 5610, Ann Arbor, MI 48109 USA
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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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14
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Wang J, Chao PH, van Dam RM. Ultra-compact, automated microdroplet radiosynthesizer. LAB ON A CHIP 2019; 19:2415-2424. [PMID: 31187109 PMCID: PMC7416997 DOI: 10.1039/c9lc00438f] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Application of microfluidics offers numerous advantages in the field of radiochemistry and could enable dramatic reductions in the cost of producing radiotracers for positron emission tomography (PET). Droplet-based microfluidics, in particular, requires only microgram quantities of expensive precursors and reagents (compared to milligram used in conventional radiochemistry systems), and occupies a more compact footprint (potentially eliminating the need for specialized shielding facilities, i.e. hot cells). However, the reported platforms for droplet radiosynthesis have several drawbacks, including high cost/complexity of microfluidic reactors, requirement for manual intervention (e.g. for adding reagents), or difficulty in precise control of droplet processes. We describe here a platform based on a particularly simple chip, where reactions take place atop a hydrophobic substrate patterned with a circular hydrophilic liquid trap. The overall supporting hardware (heater, rotating carousel of reagent dispensers, etc.) is very simple and the whole system could be packaged into a very compact format (about the size of a coffee cup). We demonstrate the consistent synthesis of [18F]fallypride with high yield, and show that protocols optimized using a high-throughput optimization platform we have developed can be readily translated to this device with no changes or re-optimization. We are currently exploring the use of this platform for routine production of a variety of 18F-labeled tracers for preclinical imaging and for production of tracers in clinically-relevant amounts by integrating the system with an upstream radionuclide concentrator.
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Affiliation(s)
- Jia Wang
- Crump Institute for Molecular Imaging and Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California at Los Angeles (UCLA), Los Angeles, CA, USA. and Department of Bioengineering, UCLA, Los Angeles, CA, USA
| | - Philip H Chao
- Crump Institute for Molecular Imaging and Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California at Los Angeles (UCLA), Los Angeles, CA, USA. and Department of Bioengineering, UCLA, Los Angeles, CA, USA
| | - R Michael van Dam
- Crump Institute for Molecular Imaging and Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California at Los Angeles (UCLA), Los Angeles, CA, USA. and Department of Bioengineering, UCLA, Los Angeles, CA, USA
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15
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Rios A, Wang J, Chao PH, van Dam RM. A novel multi-reaction microdroplet platform for rapid radiochemistry optimization. RSC Adv 2019; 9:20370-20374. [PMID: 35514735 PMCID: PMC9065505 DOI: 10.1039/c9ra03639c] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 06/17/2019] [Indexed: 12/20/2022] Open
Abstract
During the development of novel tracers for positron emission tomography (PET), the optimization of the synthesis is hindered by practical limitations on the number of experiments that can be performed per day. Here we present a microliter droplet chip that contains multiple sites (4 or 16) to perform reactions simultaneously under the same or different conditions to accelerate radiosynthesis optimization. Multi-reaction microdroplet chip enables rapid radiotracer optimization for positron emission tomography.![]()
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Affiliation(s)
- Alejandra Rios
- Crump Institute of Molecular Imaging, University of California Los Angeles (UCLA) Los Angeles CA USA .,Physics and Biology in Medicine Interdepartmental Graduate Program, UCLA USA
| | - Jia Wang
- Crump Institute of Molecular Imaging, University of California Los Angeles (UCLA) Los Angeles CA USA .,Department of Bioengineering, UCLA USA
| | - Philip H Chao
- Crump Institute of Molecular Imaging, University of California Los Angeles (UCLA) Los Angeles CA USA .,Department of Bioengineering, UCLA USA
| | - R Michael van Dam
- Crump Institute of Molecular Imaging, University of California Los Angeles (UCLA) Los Angeles CA USA .,Physics and Biology in Medicine Interdepartmental Graduate Program, UCLA USA.,Department of Bioengineering, UCLA USA.,Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, UCLA USA
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16
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Kim HK, Javed MR, Chen S, Zettlitz KA, Collins J, Wu AM, Kim CJ“CJ, Michael van Dam R, Keng PY. On-demand radiosynthesis of N-succinimidyl-4-[18F]fluorobenzoate ([18F]SFB) on an electrowetting-on-dielectric microfluidic chip for 18F-labeling of protein. RSC Adv 2019; 9:32175-32183. [PMID: 35530758 PMCID: PMC9072849 DOI: 10.1039/c9ra06158d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 09/17/2019] [Indexed: 12/16/2022] Open
Abstract
An all-electronic, droplet-based batch microfluidic device, operated using the electrowetting on dielectric (EWOD) mechanism was developed for on-demand synthesis of N-succinimidyl-4-[18F]fluorobenzoate ([18F]SFB), the most commonly used 18F-prosthetic group for biomolecule labeling. In order to facilitate the development of peptides, and proteins as new diagnostic and therapeutic agents, we have diversified the compact EWOD microfluidic platform to perform the three-step radiosynthesis of [18F]SFB starting from the no carrier added [18F]fluoride ion. In this report, we established an optimal microliter droplet reaction condition to obtain reliable yields and synthesized [18F]SFB with sufficient radioactivity for subsequent conjugation to the anti-PSCA cys-diabody (A2cDb) and for small animal imaging. The three-step, one-pot radiosynthesis of [18F]SFB radiochemistry was adapted to a batch microfluidic platform with a reaction droplet sandwiched between two parallel plates of an EWOD chip, and optimized. Specifically, the ratio of precursor to base, droplet volume, reagent concentration, reaction time, and evaporation time were found be to be critical parameters. [18F]SFB was successfully synthesized on the EWOD chip in 39 ± 7% (n = 4) radiochemical yield in a total synthesis time of ∼120 min ([18F]fluoride activation, [18F]fluorination, hydrolysis, and coupling reaction, HPLC purification, drying and reformulation). The reformulation and stabilization step for [18F]SFB was important to obtain a high protein labeling efficiency of 33.1 ± 12.5% (n = 3). A small-animal immunoPET pilot study demonstrated that the [18F]SFB-PSCA diabody conjugate showed specific uptake in the PSCA-positive human prostate cancer xenograft. The successful development of a compact footprint of the EWOD radiosynthesizer has the potential to empower biologists to produce PET probes of interest themselves in a standard laboratory. An all-electronic, droplet-based batch microfluidic device, operated using the electrowetting on dielectric (EWOD) mechanism was developed for on-demand synthesis of acommonly used 18F-prosthetic group for biomolecule labeling.![]()
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Affiliation(s)
- Hee-Kwon Kim
- Department of Molecular and Medical Pharmacology
- University of California, Los Angeles
- Los Angeles
- USA
- Crump Institute for Molecular Imaging
| | - Muhammad Rashed Javed
- Department of Molecular and Medical Pharmacology
- University of California, Los Angeles
- Los Angeles
- USA
- Crump Institute for Molecular Imaging
| | - Supin Chen
- Department of Materials Science and Engineering
- National Tsing Hua University
- Hsinchu
- Taiwan
| | - Kirstin A. Zettlitz
- Department of Molecular and Medical Pharmacology
- University of California, Los Angeles
- Los Angeles
- USA
- Crump Institute for Molecular Imaging
| | - Jeffrey Collins
- Department of Molecular and Medical Pharmacology
- University of California, Los Angeles
- Los Angeles
- USA
- Crump Institute for Molecular Imaging
| | - Anna M. Wu
- Department of Molecular and Medical Pharmacology
- University of California, Los Angeles
- Los Angeles
- USA
- Crump Institute for Molecular Imaging
| | - Chang-Jin “C. J.” Kim
- Bioengineering Department
- University of California, Los Angeles
- Los Angeles
- USA
- Mechanical and Aerospace Engineering Department
| | - R. Michael van Dam
- Department of Molecular and Medical Pharmacology
- University of California, Los Angeles
- Los Angeles
- USA
- Crump Institute for Molecular Imaging
| | - Pei Yuin Keng
- Department of Molecular and Medical Pharmacology
- University of California, Los Angeles
- Los Angeles
- USA
- Crump Institute for Molecular Imaging
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17
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Chao PH, Lazari M, Hanet S, Narayanam MK, Murphy JM, van Dam RM. Automated concentration of [ 18F]fluoride into microliter volumes. Appl Radiat Isot 2018; 141:138-148. [PMID: 30243135 PMCID: PMC6502507 DOI: 10.1016/j.apradiso.2018.06.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 06/07/2018] [Accepted: 06/20/2018] [Indexed: 11/23/2022]
Abstract
Concentration of [18F]fluoride has been mentioned in literature, however, reports have lacked details about system designs, operation, and performance. Here, we describe in detail a compact, fast, fully-automated concentration system based on a micro-sized strong anion exchange cartridge. The concentration of radionuclides enables scaled-up microfluidic synthesis. Our system can also be used to provide highly concentrated [18F]fluoride with minimal water content. We demonstrate how the concentrator can produce varying concentrations of [18F]fluoride for the macroscale synthesis of N-boc-5-[18F]fluoroindole without an azeotropic drying process, while enabling high starting radioactivity. By appropriate choice of solid-phase resin, flow conditions, and eluent solution, we believe this approach can be extended beyond [18F]fluoride to other radionuclides.
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Affiliation(s)
- Philip H Chao
- Department of Bioengineering, Henry Samueli School of Engineering, UCLA, Los Angeles, CA 90095, USA; Crump Institute for Molecular Imaging, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA; Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Mark Lazari
- Department of Bioengineering, Henry Samueli School of Engineering, UCLA, Los Angeles, CA 90095, USA; Crump Institute for Molecular Imaging, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA; Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Sebastian Hanet
- Crump Institute for Molecular Imaging, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA; Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Maruthi Kumar Narayanam
- Crump Institute for Molecular Imaging, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA; Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Jennifer M Murphy
- Crump Institute for Molecular Imaging, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA; Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - R Michael van Dam
- Department of Bioengineering, Henry Samueli School of Engineering, UCLA, Los Angeles, CA 90095, USA; Crump Institute for Molecular Imaging, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA; Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
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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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19
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Zhang X, Liu F, Knapp KA, Nickels ML, Manning HC, Bellan LM. A simple microfluidic platform for rapid and efficient production of the radiotracer [ 18F]fallypride. LAB ON A CHIP 2018; 18:1369-1377. [PMID: 29658049 DOI: 10.1039/c8lc00167g] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Herein, we report the development of a simple, high-throughput and efficient microfluidic system for synthesizing radioactive [18F]fallypride, a PET imaging radiotracer widely used in medical research. The microfluidic chip contains all essential modules required for the synthesis and purification of radioactive fallypride. The radiochemical yield of the tracer is sufficient for multiple animal injections for preclinical imaging studies. To produce the on-chip concentration and purification columns, we employ a simple "trapping" mechanism by inserting rows of square pillars with predefined gaps near the outlet of microchannel. Microspheres with appropriate functionality are suspended in solution and loaded into the microchannels to form columns for radioactivity concentration and product purification. Instead of relying on complicated flow control elements (e.g., micromechanical valves requiring complex external pneumatic actuation), external valves are utilized to control transfer of the reagents between different modules. The on-chip ion exchange column can efficiently capture [18F]fluoride with negligible loss (∼98% trapping efficiency), and subsequently release a burst of concentrated [18F]fluoride to the reaction cavity. A thin layer of PDMS with a small hole in the center facilitates rapid and reliable water evaporation (with the aid of azeotropic distillation and nitrogen flow) while reducing fluoride loss. During the solvent exchange and fluorination reaction, the entire chip is uniformly heated to the desired temperature using a hot plate. All aspects of the [18F]fallypride synthesis were monitored by high-performance liquid chromatography (HPLC) analysis, resulting in labelling efficiency in fluorination reaction ranging from 67-87% (n = 5). Moreover, after isolating unreacted [18F]fluoride, remaining fallypride precursor, and various by-products via an on-chip purification column, the eluted [18F]fallypride is radiochemically pure and of a sufficient quantity to allow for PET imaging (∼5 mCi). Finally, a positron emission tomography (PET) image of a rat brain injected with ∼300 μCi [18F]fallypride produced by our microfluidic chip is provided, demonstrating the utility of the product produced by the microfluidic reactor. With a short synthesis time (∼60 min) and a highly integrated on-chip modular configuration that allows for concentration, reaction, and product purification, our microfluidic chip offers numerous exciting advantages with the potential for applications in radiochemical research and clinical production. Moreover, due to its simplicity and potential for automation, we anticipate it may be easily integrated into a clinical environment.
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Affiliation(s)
- Xin Zhang
- Department of Mechanical Engineering, Vanderbilt University, Nashville, TN 37235, USA
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20
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Lisova K, Sergeev M, Evans-Axelsson S, Stuparu AD, Beykan S, Collins J, Jones J, Lassmann M, Herrmann K, Perrin D, Lee JT, Slavik R, van Dam RM. Microscale radiosynthesis, preclinical imaging and dosimetry study of [ 18F]AMBF 3-TATE: A potential PET tracer for clinical imaging of somatostatin receptors. Nucl Med Biol 2018; 61:36-44. [PMID: 29747035 DOI: 10.1016/j.nucmedbio.2018.04.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 03/28/2018] [Accepted: 04/01/2018] [Indexed: 02/08/2023]
Abstract
BACKGROUND Peptides labeled with positron-emitting isotopes are emerging as a versatile class of compounds for the development of highly specific, targeted imaging agents for diagnostic imaging via positron-emission tomography (PET) and for precision medicine via theranostic applications. Despite the success of peptides labeled with gallium-68 (for imaging) or lutetium-177 (for therapy) in the clinical management of patients with neuroendocrine tumors or prostate cancer, there are significant advantages of using fluorine-18 for imaging. Recent developments have greatly simplified such labeling: in particular, labeling of organotrifluoroborates via isotopic exchange can readily be performed in a single-step under aqueous conditions and without the need for HPLC purification. Though an automated synthesis has not yet been explored, microfluidic approaches have emerged for 18F-labeling with high speed, minimal reagents, and high molar activity compared to conventional approaches. As a proof-of-concept, we performed microfluidic labeling of an octreotate analog ([18F]AMBF3-TATE), a promising 18F-labeled analog that could compete with [68Ga]Ga-DOTATATE with the advantage of providing a greater number of patient doses per batch produced. METHODS Both [18F]AMBF3-TATE and [68Ga]Ga-DOTATATE were labeled, the former by microscale methods adapted from manual labeling, and were imaged in mice bearing human SSTR2-overexpressing, rat SSTR2 wildtype, and SSTR2-negative xenografts. Furthermore, a dosimetry analysis was performed for [18F]AMBF3-TATE. RESULTS The micro-synthesis exhibited highly-repeatable performance with radiochemical conversion of 50 ± 6% (n = 15), overall decay-corrected radiochemical yield of 16 ± 1% (n = 5) in ~40 min, radiochemical purity >99%, and high molar activity. Preclinical imaging with [18F]AMBF3-TATE in SSTR2 tumor models correlated well with [68Ga]Ga-DOTATATE. The favorable biodistribution, with the highest tracer accumulation in the bladder followed distantly by gastrointestinal tissues, resulted in 1.26 × 10-2 mSv/MBq maximal estimated effective dose in human, a value lower than that reported for current clinical 18F- and 68Ga-labeled compounds. CONCLUSIONS The combination of novel chemical approaches to 18F-labeling and microdroplet radiochemistry have the potential to serve as a platform for greatly simplified development and production of 18F-labeled peptide tracers. Favorable preclinical imaging and dosimetry of [18F]AMBF3-TATE, combined with a convenient synthesis, validate this assertion and suggest strong potential for clinical translation.
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Affiliation(s)
- Ksenia Lisova
- Physics in Biology and Medicine Interdepartmental Graduate Program, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Crump Institute for Molecular Imaging, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Maxim Sergeev
- Crump Institute for Molecular Imaging, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Susan Evans-Axelsson
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Ahmanson Translational Imaging Division, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Andreea D Stuparu
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Ahmanson Translational Imaging Division, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Seval Beykan
- Department of Nuclear Medicine, University of Würzburg, Würzburg, Germany
| | - Jeffrey Collins
- Crump Institute for Molecular Imaging, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Jason Jones
- Physics in Biology and Medicine Interdepartmental Graduate Program, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Crump Institute for Molecular Imaging, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Michael Lassmann
- Department of Nuclear Medicine, University of Würzburg, Würzburg, Germany
| | - Ken Herrmann
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Ahmanson Translational Imaging Division, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Jonsson Comprehensive Cancer Center (JCCC), UCLA, Los Angeles, CA, USA
| | - David Perrin
- Department of Chemistry, University of British Columbia, Vancouver, BC, Canada
| | - Jason T Lee
- Crump Institute for Molecular Imaging, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Jonsson Comprehensive Cancer Center (JCCC), UCLA, Los Angeles, CA, USA.
| | - Roger Slavik
- Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Ahmanson Translational Imaging Division, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Jonsson Comprehensive Cancer Center (JCCC), UCLA, Los Angeles, CA, USA.
| | - R Michael van Dam
- Physics in Biology and Medicine Interdepartmental Graduate Program, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Crump Institute for Molecular Imaging, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA; Jonsson Comprehensive Cancer Center (JCCC), UCLA, Los Angeles, CA, USA.
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Performing radiosynthesis in microvolumes to maximize molar activity of tracers for positron emission tomography. Commun Chem 2018; 1. [PMID: 34291178 DOI: 10.1038/s42004-018-0009-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Positron emission tomography (PET) is a molecular diagnostic imaging technology to quantitatively visualize biological processes in vivo. For many applications, including imaging of low tissue density targets (e.g. neuroreceptors), imaging in small animals, and evaluation of novel tracers, the injected PET tracer must be produced with high molar activity to ensure low occupancy of biological targets and avoid pharmacologic effects. Additionally, high molar activity is essential for tracers with lengthy syntheses or tracers transported to distant imaging sites. We show that radiosynthesis of PET tracers in microliter volumes instead of conventional milliliter volumes results in substantially increased molar activity, and we identify the most relevant variables affecting this parameter. Furthermore, using the PET tracer [18F]fallypride, we illustrate that molar activity can have a significant impact on biodistribution. With full automation, microdroplet platforms could provide a means for radiochemists to routinely, conveniently, and safely produce PET tracers with high molar activity.
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22
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Wang J, Chao PH, Hanet S, van Dam RM. Performing multi-step chemical reactions in microliter-sized droplets by leveraging a simple passive transport mechanism. LAB ON A CHIP 2017; 17:4342-4355. [PMID: 29164208 PMCID: PMC6530551 DOI: 10.1039/c7lc01009e] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Despite the increasing importance of positron emission tomography (PET) imaging in research and clinical management of disease, access to myriad new radioactive tracers is severely limited due to their short half-lives (which requires daily production) and the high cost and complexity of tracer production. The application of droplet microfluidics based on electrowetting-on-dielectric (EWOD) to the field of radiochemistry can significantly reduce the amount of radiation shielding necessary for safety and the amount of precursor and other reagents needed for the synthesis. Furthermore, significant improvements in the molar activity of the tracers have been observed. However, widespread use of this technology is currently hindered in part by the high cost of prototype chips and the operating complexity. To address these issues, we developed a novel microfluidic device based on patterned wettability for multi-step radiochemical reactions in microliter droplets and implemented automated systems for reagent loading and collection of the crude product after synthesis. In this paper, we describe a simple and inexpensive method for fabricating the chips, demonstrate the feasibility of prototype chips for performing multi-step radiochemical reactions to produce the PET tracers [18F]fallypride and [18F]FDG, and further show that synthesized [18F]fallypride can be used for in vivo mouse imaging.
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Affiliation(s)
- Jia Wang
- Crump Institute for Molecular Imaging and Department of Molecular & Medical Pharmacology, David Geffen School of Medicine, University of California at Los Angeles (UCLA), Los Angeles, CA, USA.
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23
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24
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Taggart MP, Tarn MD, Esfahani MMN, Schofield DM, Brown NJ, Archibald SJ, Deakin T, Pamme N, Thompson LF. Development of radiodetection systems towards miniaturised quality control of PET and SPECT radiopharmaceuticals. LAB ON A CHIP 2016; 16:1605-1616. [PMID: 27044712 DOI: 10.1039/c6lc00099a] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The ability to detect radiation in microfluidic devices is important for the on-chip analysis of radiopharmaceuticals, but previously reported systems have largely suffered from various limitations including cost, complexity of fabrication, and insufficient sensitivity and/or speed. Here, we present the use of sensitive, low cost, small-sized, commercially available silicon photomultipliers (SiPMs) for the detection of radioactivity inside microfluidic channels fabricated from a range of conventional microfluidic chip substrates. We demonstrate the effects of chip material and thickness on the detection of the positron-emitting isotope, [(18)F]fluoride, and find that, while the SiPMs are light sensors, they are able to detect radiation even through opaque chip materials via direct positron and gamma (γ) ray interaction. Finally, we employed the SiPM platform for analysis of the PET (positron emission tomography) radiotracers 2-[(18)F]fluoro-2-deoxy-d-glucose ([(18)F]FDG) and [(68)Ga]gallium-citrate, and highlight the ability to detect the γ ray emitting SPECT (single photon emission computed tomography) radiotracer, [(99m)Tc]pertechnetate.
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Affiliation(s)
- Matthew P Taggart
- Department of Physics and Astronomy, University of Sheffield, Hounsfield Road, Sheffield, S3 7RH, UK.
| | - Mark D Tarn
- Positron Emission Tomography Research Centre, University of Hull, Cottingham Road, Hull, HU6 7RX, UK and Department of Chemistry, University of Hull, Cottingham Road, Hull, HU6 7RX, UK.
| | | | - Daniel M Schofield
- LabLogic Systems Ltd., Paradigm House, 3 Melbourne Avenue, Broomhill, Sheffield, S10 2QJ, UK
| | - Nathaniel J Brown
- School of Engineering, University of Hull, Cottingham Road, Hull, HU6 7RX, UK
| | - Stephen J Archibald
- Positron Emission Tomography Research Centre, University of Hull, Cottingham Road, Hull, HU6 7RX, UK and Department of Chemistry, University of Hull, Cottingham Road, Hull, HU6 7RX, UK.
| | - Tom Deakin
- Department of Physics and Astronomy, University of Sheffield, Hounsfield Road, Sheffield, S3 7RH, UK. and LabLogic Systems Ltd., Paradigm House, 3 Melbourne Avenue, Broomhill, Sheffield, S10 2QJ, UK
| | - Nicole Pamme
- Department of Chemistry, University of Hull, Cottingham Road, Hull, HU6 7RX, UK.
| | - Lee F Thompson
- Department of Physics and Astronomy, University of Sheffield, Hounsfield Road, Sheffield, S3 7RH, UK.
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25
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Abstract
The emerging technology of digital microfluidics is opening up the possibility of performing radiochemistry at the microliter scale to produce tracers for positron emission tomography (PET) labeled with fluorine-18 or other isotopes. Working at this volume scale not only reduces reagent costs but also improves specific activity (SA) by reducing contamination by the stable isotope. This technology could provide a practical means to routinely prepare high-SA tracers for applications such as neuroimaging and could make it possible to routinely achieve high SA using synthesis strategies such as isotopic exchange. Reagent droplets are controlled electronically, providing high reliability, a compact control system, and flexibility for diverse syntheses with a single-chip design. The compact size may enable the development of a self-shielded synthesizer that does not require a hot cell. This article reviews the progress of this technology and its application to the synthesis of PET tracers.
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Affiliation(s)
- Pei Yuin Keng
- Crump Institute for Molecular Imaging and Department of Molecular & Medical Pharmacology University of California, Los Angeles
| | - R. Michael van Dam
- Crump Institute for Molecular Imaging and Department of Molecular & Medical Pharmacology University of California, Los Angeles
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Rackus DG, Dryden MDM, Lamanna J, Zaragoza A, Lam B, Kelley SO, Wheeler AR. A digital microfluidic device with integrated nanostructured microelectrodes for electrochemical immunoassays. LAB ON A CHIP 2015; 15:3776-84. [PMID: 26247922 DOI: 10.1039/c5lc00660k] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Nanostructured microelectrodes (NMEs) are three-dimensional electrodes that have superb sensitivity for electroanalysis. Here we report the integration of NMEs with the versatile fluid-handling system digital microfluidics (DMF), for eventual application to distributed diagnostics outside of the laboratory. In the new methods reported here, indium tin oxide DMF top plates were modified to include Au NMEs as well as counter and pseudoreference electrodes. The new system was observed to outperform planar sensing electrodes of the type that are typically integrated with DMF. A rubella virus (RV) IgG immunoassay was developed to evaluate the diagnostic potential for the new system, relying on magnetic microparticles coated with RV particles and analysis by differential pulse voltammetry. The limit of detection of the assay (0.07 IU mL(-1)) was >100× below the World Health Organization defined cut-off for rubella immunity. The sensitivity of the integrated device and its small size suggest future utility for distributed diagnostics.
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Affiliation(s)
- Darius G Rackus
- Department of Chemistry, University of Toronto, 80 St. George St., Toronto, ON M5S 3H6, Canada.
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Kaler KVIS, Prakash R. Droplet microfluidics for chip-based diagnostics. SENSORS (BASEL, SWITZERLAND) 2014; 14:23283-306. [PMID: 25490590 PMCID: PMC4299063 DOI: 10.3390/s141223283] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 11/04/2014] [Accepted: 11/27/2014] [Indexed: 12/29/2022]
Abstract
Droplet microfluidics (DMF) is a fluidic handling technology that enables precision control over dispensing and subsequent manipulation of droplets in the volume range of microliters to picoliters, on a micro-fabricated device. There are several different droplet actuation methods, all of which can generate external stimuli, to either actively or passively control the shape and positioning of fluidic droplets over patterned substrates. In this review article, we focus on the operation and utility of electro-actuation-based DMF devices, which utilize one or more micro-/nano-patterned substrates to facilitate electric field-based handling of chemical and/or biological samples. The underlying theory of DMF actuations, device fabrication methods and integration of optical and opto-electronic detectors is discussed in this review. Example applications of such electro-actuation-based DMF devices have also been included, illustrating the various actuation methods and their utility in conducting chip-based laboratory and clinical diagnostic assays.
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Affiliation(s)
- Karan V I S Kaler
- Department of Electrical and Computer Engineering, University of Calgary, 2500 University Drive NW, Calgary, AB-T2N 1N4, Canada.
| | - Ravi Prakash
- Department of Electrical and Computer Engineering, University of Calgary, 2500 University Drive NW, Calgary, AB-T2N 1N4, Canada.
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29
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Rensch C, Lindner S, Salvamoser R, Leidner S, Böld C, Samper V, Taylor D, Baller M, Riese S, Bartenstein P, Wängler C, Wängler B. A solvent resistant lab-on-chip platform for radiochemistry applications. LAB ON A CHIP 2014; 14:2556-2564. [PMID: 24879121 DOI: 10.1039/c4lc00076e] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The application of microfluidics to the synthesis of Positron Emission Tomography (PET) tracers has been explored for more than a decade. Microfluidic benefits such as superior temperature control have been successfully applied to PET tracer synthesis. However, the design of a compact microfluidic platform capable of executing a complete PET tracer synthesis workflow while maintaining prospects for commercialization remains a significant challenge. This study uses an integral system design approach to tackle commercialization challenges such as the material to process compatibility with a path towards cost effective lab-on-chip mass manufacturing from the start. It integrates all functional elements required for a simple PET tracer synthesis into one compact radiochemistry platform. For the lab-on-chip this includes the integration of on-chip valves, on-chip solid phase extraction (SPE), on-chip reactors and a reversible fluid interface while maintaining compatibility with all process chemicals, temperatures and chip mass manufacturing techniques. For the radiochemistry device it includes an automated chip-machine interface enabling one-move connection of all valve actuators and fluid connectors. A vial-based reagent supply as well as methods to transfer reagents efficiently from the vials to the chip has been integrated. After validation of all those functional elements, the microfluidic platform was exemplarily employed for the automated synthesis of a Gastrin-releasing peptide receptor (GRP-R) binding the PEGylated Bombesin BN(7-14)-derivative ([(18)F]PESIN) based PET tracer.
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Affiliation(s)
- Christian Rensch
- GE Global Research, Freisinger Landstrasse 50, 85748 Garching bei Munich, Germany.
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Cumming RC, Olberg DE, Sutcliffe JL. Rapid18F-radiolabeling of peptides from [18F]fluoride using a single microfluidics device. RSC Adv 2014. [DOI: 10.1039/c4ra10520f] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
To date the majority of18F-peptide radiolabeling approaches are multi-step, low yielding and time-consuming processes.
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Affiliation(s)
- Robin C. Cumming
- Department of Biomedical Engineering
- University of California Davis
- Davis, USA
| | - Dag Erlend Olberg
- Norsk Medisinsk Syklotronsenter AS
- Oslo University Hospital
- Oslo, Norway
| | - Julie L. Sutcliffe
- Department of Biomedical Engineering
- University of California Davis
- Davis, USA
- Department of Internal Medicine
- Division of Hematology/Oncology
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