Therapeutic agents radionuclides

Small antibody fragments can be converted into therapeutic agents by modification with suitable radionuclides, drugs (using cleavable linkers or liposomal preparations), enzymes catalyzing prodrug conversion, cytokines, pro-coagulant factors, photosensitizers, and other classes of... 

Fig. 6.3 Targeting moieties (ligands) can be converted into imaging or therapeutic agents by modification with suitable radionuclides, fluorophores, drugs, enzymes, cytokines or other bioactive molecules.

RADIOPHARMACEUTICALS A radiopharmaceutical is a preparation of adequately constant composition, radiochemical and radionuclidic purity and uniformity of physiological (pharmacological) action for use in medicine as a diagnostic aid or therapeutic agent... 

Because of the high radiotoxicity of the actinides and a widespread interest in the possible use of lanthanide radionuclides as diagnostic or therapeutic agents in clinical medicine, the ability of chelators to modify the biokinetics of f elements in the body has been widely studied. In the nuclear-energy industry, the interest has been predominantly in the development of chelators which could be used therapeutically in the case of an accident involving contamination with plutonium or americium to enhance the naturally slow rate of elimination of these elements from the body and thereby reduce the risk of long-term radiation injury. This aspect of chelation therapy has recently been reviewed in depth by Taylor (1991). Since the work on the effects of chelators on lanthanide interactions in vivo has been reviewed recently by Evans (1990), both aspects are discussed only briefly here. 

Sr, as the strontium ion (Sr2+), is used for pain palliation in patients with metastatic bone disease. The strontium ion is a calcium ion mimic, being taken up in metabolically active bone such as cancer. 89Sr is a therapeutic radionuclide with a half-life of 50.53 days, emitting a 1.49 MeV [3 particle on decay. Several recent reviews discuss the use of radionuclides and their complexes as pain palliation agents in metastatic bone disease.18,212-215... 

Development of therapeutic radiopharmaceuticals is one of the areas most widely explored by researchers. The many significant advances in this field have solved many of the technical problems involved in labelling biomolecules with a variety of radionuclides. These studies have the potential to provide a large array of target specific therapeutic radiopharmaceuticals [1.17]. However, to assist in the identification of an ideal agent, rehable laboratory methods for screening the potential candidates are essential. 

The present studies were aimed at the development of laboratory evaluation techniques for studying the efficacy of therapeutic radiopharmaceuticals. The primary goal was to develop radiotherapeutic agents using the peptide-BFCA conjugate DOTA-Tyr -octreotate (DOTATATE). The radioisotopes used for the therapeutic preparations were Lu and °Y. Lutetium-177 was identified as an ideal radionuclide for... 

In future, many antibody-derived molecules will be seen in many indications, in addition to single chain Fv fragments (scFv). Dimeric and tetrameric mini-antibodies, diabodies, single antibody domains, Fv fragments fused to toxins, cytokines, antibiotics or radionuclides, protein scaffolds with hypervariable antibody domains, and related molecules such as an-ticalines will emerge to complement the toolbox of affinity-based agents and enhance their therapeutic efficacy. 

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