Search

The high importance of zirconium-89 (T1/2 = 78.41 h) is related to its applications in medical imaging. It can be produced at low-energy cyclotrons by the reaction 89Y(p,n)89Zr. There exist several publications on its production at low and intermediate energies but there is discrepancy with simulated data. In this study we considered the experimental parameters for four different types of yttrium foil targets reported in literature. The experimental parameters considered were the target geometry, beam profile, and angle of the target relative to the beam during irradiation. The Monte-Carlo code FLUKA was used to calculate production yields. The resulting values obtained by FLUKA from pencil beam or spread energy beam were compared to the theoretical yields obtained from the excitation function and the experimental ones. The FLUKA prediction for 89Z-yield reached ≈50 MBq/μA · h which agrees to a high extent with experimental and theoretical yields reported for the different targets.

THE ISOQUINOLINE derivative, 5-aminoisoquinoline (5-AIQ), is a potent inhibitor of poly (ADP-ribose) polymerase (PARP) activity; the DNA repairing protein frequently overexpressed in various carcinoma cells. The current study is dedicated for developing a highly specific radioiodinated PARP-1 binding tracer namlely, [131I] 5-aminoisoquinoline. The radioiodination of 5-aminoisoquinoline with 131I was carried out via electrophilic substitution reaction. In order to achieve the maximum radioiodination, the parameters including 5-aminoisoquinoline concentration, oxidizing agent, reaction time, temperature and type of solvent were optimized. the radiochemical purity was determined by high performance liquid chromatography (HPLC) using Reversed phase lichrosorb column 250×4.6 mm, C-18 5 μm. The maximum radiochemical yield was 80% with radiochemical purity reached 98%. The log P value for [131I] 5-aminoisoquinoline was found to be 2.08 ± 0.79. Data presented from Cell viability (MTT) cytotoxicity assay on Caco-2 cells showed matched IC50 values with the selected drug concentrations profile for either labeled or unlabeled 5-aminoisoquinoline. Likewise, the radioiodinated 5-aminoisoquinoline elucidated a higher cell uptake compared to free I-131.

For the production of radiogallium, the targets were prepared in two forms, namely, electroplated metal and pressed oxide. The target holder was selected from Cu-metal as a circular disk. The experimental yields of 66,67,68Ga produced from both irradiated natZnO and zinc metal targets are given and compared with the estimated yields as well as with the previously reported values. The ZnO target developed in this work appears to be more convenient and economical for local production of short-lived radiogallium, e.g. 66Ga and 68Ga.

Iodobenzamides are reported to possess some affinity for melanoma. This study describes the synthesis of a new benzamide analogue, N-(2-diethylamino-ethyl)-4-(4-chloro-nicotinamido)-5-[125I]iodo-2-methoxybenzamide ([125I]H4) designed to target melanoma. The synthesis was simply achieved in four steps. There were two PyCIU/DIPEA amide condensations and a transfer hydrogenation using an ammonium formate hydrogen donor. The radioiodination step was carried out with 125I via an electrophilic substitution reaction. The reaction conditions were optimized. The labeled compound was purified by HPLC. The maximum radiochemical yield was found to be 78% at a radiochemical purity of 98%. All compounds were characterized by MS and NMR techniques. The log P value for [125I]H4 was found as 3.96±0.5.

The broad-spectrum antibiotic agents have been demonstrated as promising diagnostic tools for early detection of infectious lesions. We set out ofloxacin (Oflo), a second-generation fluoroquinolone, for the radioiodination process. In particular, this was carried out with 125I via an electrophilic substitution reaction. The radiochemical yield was influenced by different factors; drug concentration, different oxidizing agents, e.g. chloramine-T, iodogen and n-bromosuccinimide, pH of medium, reaction time, temperature and different organic media. These parameters were studied to optimize the best conditions for labeling with ofloxacin. We found that radiolabeling in ethanol medium showed a 70% radiochemical yield of 125I-ofloxacin. The radioiodination was determined by means of TLC and HPLC. The cold labeled Oflo (127I-Oflo) was prepared and controlled by HPLC. The cold labeled Oflo was also confirmed by NMR and MS techniques. Furthermore, biodistribution studies for labeled 125I-Oflo were examined in two independent groups (3 mice in each one); control and E. Coli-injected (inflamed). The radiotracer showed a good localization in muscle of thigh for inflamed group as compared to control. In conclusion, ofloxacine might be a promising target as an anti-inflammatory imaging agent.