Bifunctional Chelating Agents and Radioimmunoconjugates

Iodine-131 was among the first radioactive isotopes used for radioimmunoconjugate preparation (Order, 1982 Regoeczi, 1984). Since the earliest studies on the efficacy of radiotherapy, additional isotopes have been employed, such as iodine-125, bismuth-212, yttrium-90, yttrium-88, technetium-99m, copper-67, rhenium-188, rhenium-186, galium-66, galium-67, indium-111, indium-114m, indium-115, and boron-10. 

The following sections describe the major methods and BCAs used to create radio-immunoconj ugates. 

Amide Bond Formation with Opening of Carboxyiate Groups 

Although DTPA has been used extensively as a BCA to prepare radiopharmaceutical reagents, newer metal chelators such as those discussed below may show greater promise for use in in vivo applications. 

DFA or deferoxamine is N -[5-[[4-[[5-(acetylhydroxyamino)pentyl]amino]-l,4-dioxobutyl]-hydroxyamino]pentyl]-iV-(5-aminopentyl)-N-hydroxybutanediamide,anaturallyoccurringproduct 

Use of Thiolation Reagents for Direct Labeling to Sulfhydryl Groups 

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