Radiopharmaceuticals: On-Going Research for Better Diagnosis, Therapy, Environmental, and Pharmaceutical Applications

Radiopharmaceutical material is a pharmaceutical product or drug that may exert spontaneous degradation of unstable nuclei with nuclear particles or photons emission. Radiopharmaceuticals may be used in research, diagnosis, therapy, and environmental purposes. Moreover, radiopharmaceuticals act as radioactive tracers among patients via gamma-ray emissions. Therefore, the uses of radiopharmaceuticals as diagnostic agents may be given to patients to examine any biochemical, molecular biology, physiological, or anatomical abnormalities. Therapeutic radiopharmaceutical may be administered internally for therapeutic purposes via selective effect on certain abnormal cells or organs. The best known example for therapeutic radiopharmaceuticala is iodide131 for thyroid ablation in among patients with hyperthyroid. A third class of radiopharmaceutical is drug labeling which mainly used in research by using small amount of radioactive substances not for diagnostic purposes, but to investigate the metabolism, bio-distribution, pharmakodynamic, and pharmakokinetic of certain drugs in a nonradioactive form. This chapter focuses mainly on basic fundamentals of radiopharmaceutical chemistry, preparation, environmental, pharmaceutical, diagnostic, therapeutic, and research applications.

Novel Bifunctional [16]aneS4-Derived Chelators for Soft Radiometals

The field of targeted radionuclide therapy is rapidly growing, highlighting the need for wider radionuclide availability. Soft Lewis acid ions, such as radioisotopes of platinum, rhodium and palladium, are particularly underdeveloped. This is due in part to a lack of compatible bifunctional chelators. These allow for the practical bioconjugation to targeting vectors, in turn enabling radiolabeling. The [16]andS4 macrocycle has been reported to chelate a number of relevant soft metal ions. In this work, we present a procedure for synthesizing [16]andS4 in 45% yield (five steps, 12% overall yield), together with a selection of strategies for preparing bifunctional derivatives. An ester-linked N-hydroxysuccimide ester (NHS, seven steps, 4% overall yield), an ether-linked isothiocyanate (NCS, eight steps, 5% overall yield) and an azide derivative were prepared. In addition, a new route to a carbon-carbon linked carboxylic acid functionalized derivative is presented. Finally, a general method for conjugating the NHS and NCS derivatives to a polar peptide (octreotide) is presented, by dissolution in water:acetonitrile (1:1), buffered to pH 9.4 using borate. The reported compounds will be readily applicable in radiopharmaceutical chemistry, by facilitating the labeling of a range of molecules, including peptides, with relevant soft radiometal ions.

Radiolabeled Peptides for Cancer Imaging and Therapy: From Bench-to-Bedside

Radiolabeled peptides can deliver radiation selectively to tumors via targeting peptide receptors that are overexpressed on the surface of cancer cells. The radiation is used either for detection (imaging) or for destruction (therapy) of these tumors. The Division of Radiopharmaceutical Chemistry at the University Hospital Basel has conducted pioneering work on the development of peptide-based radiopharmaceuticals. Our research covers the entire spectrum of such developments, from bench-to-bedside, and it is illustrated in this article by selective cases.

invitation to submit a Frontiers article to Dalton Transactions - Inorganic radiopharmaceutical chemistry of oxine

8-Hydroxyquinoline (8-HQ, oxine) is a small, monoprotic, bicyclic aromatic compound and its relative donor group orientation imparts impressive bidentate metal chelating abilities that have been exploited in a vast array...