comparison of radiolabeled bisphosphonates in bone metastasis

Bisphosphonates have a very high affinity for bone minerals because they bind to hydroxyapatite crystals. based on this fact, it was hypothesized to evaluate bone uptake for 99mtc/188re radiolabeled bisphosphonates to determine the order of uptake in the bone as agents for imaging or treatment of skeletal disorders. radiolabeling of bisphosphonate samples were performed by adding 185 mbq of 99mtc/188re in saline, and sncl2, 2h2o and ascorbic acid as reducing agents. radioactive thin layer chromatography (rtlc) was used to determine the radiochemical purity. the stability of radiocomplexes was investigated in saline and human serum. bone uptake was evaluated through biodistribution experiments in normal mice. a radiochemical purity of > 90% was obtained for evaluated radiotracers. bone accumulation and rapid renal excretion were observed in the biological assessment of all evaluated bisphosphonates at 2 hours post injection. although bone uptake was desirable for investigated bisphosphonates, it appears that third-generation bisphosphonates can be used as novel bone imaging or therapeutic agents.