Browsing by Author "Watts, P"

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    Microfluidics in Planar Microchannels: Synthesis of Chemical Compounds On-Chip.
    (Springer Link, 2014-10-14) Arima, V; Watts, P; Pascali, G
    Microreactors are a wide class of devices that are currently playing a prominent role in several research fields such as biology, medicine, food chemistry, environmental analysis, up to the production of compounds in organic chemistry. Several typologies of microreactors have been produced with tubular or planar shapes, of different materials and designs. In this chapter, an overview of planar microchannel-based microreactors and their application to organic chemistry is given. Initially, after recalling the main theoretical parameters of microfluidics, an introduction of the proposed technology and the main requirements to perform mixing, which is essential to perform chemical synthesis on-chip, is presented. Silicon and glass microreactors, the most common planar systems for organic chemistry, are described with the aim of pointing out the most important parameters to be taken into consideration in the planning of a specific microreactor to be used for mixing, purification or crystallization of chemicals at the microscale. Then, several applications of initially described microreactors to organic chemistry for research applications are given. In the next section, the use of planar microchannel microreactors in the field of radiochemistry is reported. The radiopharmaceutical application is not casual, being a sector in which the microreactor technology is very promising, due to the need of quickly producing small and fresh amounts of products in a controlled environment. Finally, for completeness, other approaches beyond planar microchannels are mentioned: mesoreactors towards industrial level synthesis and micro-vessels for radiochemistry. © Springer International Publishing Switzerland 2015
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    Microfluidics in radiopharmaceutical chemistry
    (Elsevier B.V., 2013-08-01) Pascali, G; Watts, P; Salvadori, PA
    The increased demand for molecular imaging tracers useful in assessing and monitoring diseases has stimulated research towards more efficient and flexible radiosynthetic routes, including newer technologies. The traditional vessel-based approach suffers from limitations concerning flexibility, reagent mass needed, hardware requirements, large number of connections and valves, repetitive cleaning procedures and overall big footprint to be shielded from radiation. For these reasons, several research groups have started to investigate the application of the fast growing field of microfluidic chemistry to radiosynthetic procedures. After the first report in 2004, many scientific papers have been published and demonstrated the potential for increased process yields, reduced reagent use, improved flexibility and general ease of setup. This review will address definitions occurring in microfluidics as well as analyze the different approaches under two macro-categories: microvessel and microchannel. In this perspective, several works will be collected, involving the use of positron emitting species (11C, 18F, 64Cu) and the fewer examples of gamma emitting radionuclides (99mTc, 125/131I). New directions in microfluidic research applied to PET radiochemistry, future developments and challenges are also discussed. © 2013 Elsevier Inc.
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    Purification of 2-[18F]fluoro-2-deoxy-d-glucose by on-chip solid-phase extraction
    (Elsevier B.V., 2013-03-08) Tarn, MD; Pascali, G; De Leonardis, F; Watts, P; Salvadori, PA; Pamme, N
    Microfluidic devices have shown great potential for the production of positron emission tomography (PET) radiotracers, but most devices have focused only on the synthesis step of the procedure, typically neglecting the other important steps such as [18F]fluoride pre-concentration and radiotracer purification that could equally benefit from miniaturisation. Here, we demonstrate the development of microfluidic modules for the purification of PET radiotracers, particularly 2-[18F]fluoro-2-deoxy-d-glucose ([18F]FDG), via the use of on-chip solid-phase extraction (SPE). In these initial tests, the SPE modules were able to yield [18F]FDG with up to 90% radiochemical purity, and methods are proposed for further increasing this value. © 2013 Elsevier B.V.
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    Radiochemistry on chip: towards dose-on-demand synthesis of PET radiopharmaceuticals
    (The Royal Society of Chemistry, 2013-03-25) Arima, V; Pascali, G; Lade, O; Kretschmer, HR; Bernsdorf, I; Hammond, V; Watts, P; De Leonardis, F; Tarn, MD; Pamme, N; Cvetkovic, BJ; Ditrrich, PS; Vasovic, N; Duane, R; Jaksic, A; Zacheo, A; Zizzari, A; Marra, L; Perrone, E; Salvadori, PA; Rinaldi, R
    AbstractWe have developed an integrated microfluidic platform for producing 2-[18F]-fluoro-2-deoxy-D-glucose (18F-FDG) in continuous flow from a single bolus of radioactive isotope solution, with constant product yields achieved throughout the operation that were comparable to those reported for commercially available vessel-based synthesisers (40–80%). The system would allow researchers to obtain radiopharmaceuticals in a dose-on-demand setting within a few minutes. The flexible architecture of the platform, based on a modular design, can potentially be applied to the synthesis of other radiotracers that require a two-step synthetic approach, and may be adaptable to more complex synthetic routes by implementing additional modules. It can therefore be employed for standard synthesis protocols as well as for research and development of new radiopharmaceuticals. © 2013 The Royal Society of Chemistry