Current Pharmaceutical Design - Volume 10, Issue 24, 2004

Radioactive tracers have made an immense contribution to the understanding of human physiology and pathology. At the start of the 21st century nuclear imaging has emerged as the main metabolic imaging modality which is of growing importance in drug development and clinical pharmacology. Using techniques adapted from those undertaken in clinical radiopharmacy and nuclear medicine facilities drug molecule Read More

With the help of radiolabeled compounds, drug development can be made faster; especially with microdosing and radiopharmacokinetics, some elements of phase I and II trials necessary for conventional cancer drug development can be avoided. Imaging may proof the principle of actual targeting. However, radiopharmacokinetics is dependent on the radionuclide, the radionuclide linker with the drug and the size of the dr Read More

Nuclear medicine offers powerful noninvasive techniques for visualization of infectious and inflammatory disorders using whole body imaging enabling the determination of both localization and number of inflammatory foci. A wide variety of approaches depicting the different stages of the inflammatory response have been developed. Non-specific radiolabeled compounds, such as 67Ga-citrate and radiolabeled polyclonal h Read More

Peptide-based radiopharmaceuticals have been introduced into clinical work more than a decade ago. The first and most successful imaging agent to date is the somatostatin analog octreotide. It is used for somatostatin receptor scintigraphy and also receptor-mediated peptide-radiotherapy of neuroendocrine tumors. For in vivo use as radiopharmaceutical, the natural peptide is modified in order to enhance the metabolic stabili Read More

A major obstacle to successful cancer chemotherapy is drug resistance. Multidrug resistance (MDR) is often seen with chemotherapeutic agents such as anthracycline derivatives, vinca alkaloids and taxanes. Multiple aspects of cellular biochemistry have been implicated in the MDR process. Cellular mechanisms of resistance are due to the presence of efflux pumps, P-glycoprotein (P-gp) and multiple resistance-associated pro Read More

Liposomes, which are biodegradable and essentially non-toxic vehicles, can encapsulate both hydrophilic and hydrophobic materials, and are utilized as drug carriers in drug delivery systems. In addition, liposomes can be used to carry radioactive compounds as radiotracers can be linked to multiple locations in liposomes. One option is the hydrated compartment inside the liposome, another the lipid core into which especi Read More

Radiolabeled compounds are excellent investigative tools and widely used to carry out ADME studies during drug discovery and development stages. The most commonly used radioisotopes are 14C and 3H. 3H materials are generally easier to synthesize than 14C materials. Therefore, a variety of probes and substrates used in in vitro assays are labeled with 3H. Since synthesis of 14C material requires intensive resources Read More

Recent years have seen an increased effort in the development of peptide based radiopharmaceuticals for nuclear medicine applications in imaging and therapy. This field is of particular interest in the development of new cancer imaging and treatment strategies. Major developments in the molecular biology of cancer have brought forth the discovery of a number of receptor systems and other cell surface molecules tha Read More

Modern molecular targeting provides new opportunities for imaging, diagnosis and treatment of diseases. Small molecular weight peptides have the potential for enhancing targeting of compounds, and they may also have therapeutic effects by themselves. The limiting step for successful molecular targeting is the development of efficient peptide delivery systems. This review will focus on peptides developed by phage displ Read More