Development of molecular imaging probes for positron emission tomography

Positron emission tomography (PET) is the one molecular imaging modality that can be used in both pre-clinical and human studies. PET provides the most direct diagnoses in oncology with high sensitivity and quantitative analysis. The primary reason is that it can demonstrate dynamic metabolism in animal or human bodies during in vivo molecular imaging. However PET is not only confined to oncology. It can be used in other physiological or metabolic processes, as long as specific biomarkers are available. Therefore, the development of radiotracers is crucial for in vivo PET imaging. Synthetic chemistry provides a platform to synthesize cold standards (the counterpart of the non-radioactive material of PET radiotracers) and radio-labeling precursors. Once the compounds with high specificity and binding affinity are developed, chemical synthesis can make radiolabeling precursors for 11C, 18F or other positron emitting isotopes. In this thesis, two series of molecular probes are synthesized as PET imaging agents. One series of molecules are AP site specific binging agents and the other series of molecules are myelin specific probes. The former one is used for in vivo PET imaging of the AP site formation and can be used as imaging markers to evaluate DNA-targeted chemotherapeutic drugs. The latter type molecules are myelin-binding agents for in vivo imaging of myelination in the central nervous system (CNS). This thesis presents the application of synthetic chemistry in the development of 18F-labeled probes in two projects: development of [ 18F]-labeled PET tracers for imaging of DNA damage and repair in cancer chemotherapies & development of [18F]-labeled PET imaging probes for in vivo studies of myelin pathology.