Optimized production, quality control and biological assessment of 68Ga-bleomycin as a possible PETimaging agent

Recently, several diagnostic radiopharmaceuticals includingbleomycin (blm) derivatives have been developed. due to the suitablephysical and chemical characteristics of 68ga as a radionuclide for petimaging, in this study, optimized production, quality control and preclinicalevaluation of 68ga-blm as a new pet imaging agent is reported for the firsttime. materials and methods: labeling of blm with 68ga was performed using68ge/68ga generator. experiments were carried out by changing blmconcentration, temperature and ph of the reaction to determine theoptimum parameters while the radiochemical purity was checked by radiothin layer chromatography at different times post labeling. stability of theradiolabeled complex was studied at room temperature and in human serumat 37 °c. biodistribution of the complex in balb/c mice was assessed afterintravenous injection and by counting the activity of each organ. also, imageswere acquired up to 120 min by dual-head spect system. results: the purityof this complex >96% (itlc). at the optimized conditions for preparation of68ga-blm (ph= 3.5-4, temperature = 90 ºc, reaction time = 15 minutes andligand concentration of 1 mg/ml) , the special activity of the labeled blmreached to around 17.5 gbq/mmol. biodistribution study showed significantaccumulation of radioactivity in lung and bladder that was differentpharmacokinetic compared to free 68ga cation. conclusion: results show that68ga-blm can be prepared in high radiochemical purity and high specialactivity only in 15 minutes and totally can be considered as a high potentialagent for pet imaging.