Radioisotope delivery

Fullerenes Radioisotope delivery to tumor cells, MRI contrast agents Antibacterial, neuroprotective, inhibition of HIV activity... 

Several clinical trials have evaluated (or continue to evaluate) monoclonal antibodies to which a radioactive tag has been conjugated. These are usually employed as potential anti-cancer agents. The rationale is selective delivery of the radioactivity directly to the tumour site. Most of the radioisotopes being evaluated are /i-emitters these include I and I (iodine), Re and Re (rhenium) and (yttrium). The medium-energy radioactivity these emit is capable of penetrating... 

Figure 2). In either case, the 8.28-hour half-life of Fe-52 (1 ) presents a problem with respect to the delivery of a significant quantity of the radioisotope to a potential user. Because of the shipping time involved, a factor of four to eight times more Fe-52 must be shipped in order to provide the user with a desired quantity. Therefore, a substantial amount of Fe-52 must be produced and recovered. 

Pure carbon spheres of Cf,(l the fullerenes—react avidly with free radicals with a higher antioxidant ability than the naturally occurring vitamin E (21). Endohedral fullerenes have been shown to be capable of encapsulating a variety of atoms such as radiotracers or noble gases, thereby making them efficient excipients in the delivery of radioisotopes to cancer cells or in magnetic resonance imaging (MRI) (22). 

Q.3.5 The PET (positron emission tomography) scanner uses a tagged radioisotope to measure glucose delivery to similar regions of the brain during brain tasks . Is this a better system for observing intellectual function than those described in Question 3.4 ... 

Drugs of the following categories are classified as Part B products Developed by other biotechnological processes Administered by means of new delivery systems New therapeutic indications Based on radioisotopes Derived from human blood or plasma New manufacturing processes New active substance... 

Crown thioethers have found a number of uses as ligands, related particularly to their affinity for late- and post-transition elements. Attention has focused on the coordination chemistry of silver, with relevance to photography, silver-selective electrodes, and ligands for chromogenic analysis and recovery of silver. Biomedical applications include the removal of toxic heavy metals such as Cd, Hg, Pb, and T1 and delivery of radioisotopes such as ""Tc, Re, and Re to specific sites in the body. Finally, some crown thioethers have been found to promote novel reactivity in their transition metal complexes, including activation of small molecules such as N2, CO and C2H4. 

Particular care is needed in designing aerosol deposition studies in children. Since children have a longer life expectancy than adults, the risk of a given radiation dose may be greater for them, and every effort must be made to minimize exposure (28). Minimal numbers of children should be used and doses of isotope should produce radiation levels that are only just enough above background levels to produce reliable data. In addition, only studies that are essential to improve and optimize aerosol delivery systems for children should use radioisotopes. For example, studies to assess different nebuhzer setups should use in vitro bench testing rather than in vivo assessments of deposition. 

Radiotherapy microspheres, sized 10 to 30 nm, are larger than capillaries and get trapped in first capillary bed when they come across. They are injected to the arteries that lead to tumor of interest. So, in all these conditions, radioactive microspheres deliver high-radiation dose to the targeted areas without damaging the normal surrounding tissues. It differs from drug delivery system, as radioactivity is not released from microspheres but acts within a radioisotope typical distance and the different kinds of radioactive microspheres are a emitters, p emitters, and y emitters. It offers new solutions for patients who need drugs delivered directly to tumors, diabetic ulcers, and other disease sites. 

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