Radiochemistry Study

Radiochemistry is one branch of chemistry to study radiation from molecular perspective; explore isotopes transformation and radioactive reaction effects from molecular perspective, as well as physical and medical properties of radioisotopes. Research on radiochemistry using radioisotope to label chemical compounds as radiopharmaceuticals (radiotracers) for drug developments: radiopharmaceutical design and preparation, in vitro and in vivo biological studies, pharmacological study, preclinical and clinical studies. We focus on development of radiopharmaceuticals and their theranostic applications; devote specifically to 1) preparation of precursors, 2) radiolabelling techniques including radiosynthesis, purification, and analysis, 3) in vitro and in vivo radiopharmaceutical research, pharmacological investigation, 4) radiotracers for PET/SPECT imaging, preclinical or clinical trials, diagnostic and therapeutic applications, as well as potential personalized medicine.

Background: Yttrium-90 microspheres are widely used for the treatment of liver-dominant malignant tumour. They are infused via catheter into the hepatic artery branches supplying the tumour under fluoroscopic guidance based on pre-therapy angiography and Technetium-99m macroaggregated albumin planning. However, at present, these microspheres are suspended in radiolucent media such as dextrose 5% (D5) solution. In order to monitor the real-time implantation of the microspheres into the tumour, the 90Y microspheres could be suspended in omnipaque contrast for allowing visualization of the correct distribution of the microspheres into the tumour. The radiochemical purity of mixing 90Y-microspheres in various concentrations of omnipaque was investigated. The radiochemical purity and feasibility of mixing 99mTc-MAA with various concentrations of a standard contrast agent were also investigated. Results showed the radiochemical feasibility of mixing 90Y-microspheres with omnipaque is radiochemically acceptable for allowing real-time visualization of radioembolization under fluoroscopy.

Background: Lipophilic organic cation triphenylphosphonium (TPP) represents a novel mitochondrial targeting molecular probe. A series of its derivatives have been labelled with Cu-64 radioisotope for imaging mitochondrial rich glioma tumour.  We aim to develop 68Ga-radiolabeled TPP tracers for rhabdomyosarcoma tumour targeting; and to study the effects of targeting moiety, bifunctional chelator on biodistribution of the tracers. TPP ligands were radiolabelled with 68Ga at high efficiency and isolated in high purity. In vivo biodistribution studies showed uptake of 68Ga tracers to the rhabdomyosarcoma tumour using cell line RHB14-0120 was found with high tumour-to normal tissue ratio.