Preparation and quality control of scandium-46 bleomycin as a possible therapeutic agent

Due to interesting therapeutic properties of 46Sc and antineoblastic antibiotic, bleomycin (BLM), 46Sc-bleomycin (46Sc-BLM) was developed as a possible therapeutic compound. In this work, Sc-46 chloride was obtained by thermal neutron flux (4 × 1013 n.cm-2.s-1) of natural metallic scandium sample followed by dissolution in acidic media as a substitute for 47Sc in radiolabeling studies which was further used for labeling of bleomycin (BLM) followed by stability studies as well as biodistribution in wild-type rats. Sc-46 was obtained in high radiochemical purity (ITLC, >99%, two systems) as well as acceptable specific activity. At optimized conditions a radiochemical purity of 98% was obtained for 46Sc-BLM shown by ITLC (Specific activity, 740 GBq/mmole). The accumulation of the radiolabeled compound in lungs, liver and spleen demonstrates a similar pattern to the other radiolabeled bleomycins. Sc-BLM is a possible therapeutic agent in human malignancies and the efficacy of the compound should be tested in various tumor-bearing models.