Radiochemical methods for labeling and isotope production

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This research program is focused on the development of new methods for the cyclotron production of radionuclides and developing reactions and tools to improve access to radionuclides for use in research, industry and health care. During the course of this research we will develop and show the application of solid phase labeling methods using F-18 fluoride and C-11 carbon for the labeling of molecules of biological interest. We will also use the neutron flux produced by a cyclotron during routine isotope production to create short-lived beta emitters via neutron activation that can be used for research and analysis. Application of Solid Phase Synthesis (SPS) Methods to Radiolabeling When introducing a radionuclide into a small molecule or protein for labeling as an imaging probe you are working against the clock. The isotope is always decaying so time spent performing the synthesis and purifying the product will negatively impact the yield of the tracer. Many of these reactions require some purification step to remove excess reagents and catalysts. This research program will develop SPS reagents and procedures to minimize reaction time and work to reduce the purification requirements. In radiochemistry the molecule to be labeled and reagents are in a large excess with respect to the radionuclide. This helps to ensure that most of the radionuclide reacts, it can also pose a challenge for separating the labeled product from the excess reagents. This portion of the program is focused on preparing "react and release" resins where the substrate to be labeled is immobilized on solid support and is only released on reaction with F-18. Cyclotron Neutron Activation The ability of cyclotrons to produce short lived PET radionuclides has been well established. What is significantly more difficult is the production of neutron rich beta emitters. Most often neutron activation requires access to a reactor-based neutron source. Unfortunately, space in research reactors is limited and can be costly, particularly with only a limited number of research reactors in Canada. There are, however, a growing number of medical cyclotrons available across the country. These cyclotrons typically are running on a regular, often daily, basis producing isotopes such as 18F for imaging. This research will leverage the neutron flux from routine cyclotron production runs for the irradiation of samples for mineral analysis. The application of this technique will allow access to radionuclides with very sort half-lives (T1/2 < 1 day) for research that shipping times would otherwise make inaccessible. Neutron activation will also be applied to the analysis of mineral samples. This will allow for now destructive, high throughput analysis of mineral, bullion and waste streams from the mining industry to identify metals such as gold, silver and the platinum group elements.