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EN
A novel bisphosphonate derivative (1-aminoethane-1,1-diyl)diphosphonic acid (AEDP) has been prepared and successfully labeled with 99mTc at high labeling yields. The in vivo biodistribution of 99mTc-AEDP has been investigated and compared with two reference compounds Tc-99m methylene diphosphonate (99mTc-MDP) and Tc-99m (1-hydroxyethylidene) diphosphonate (99mTc-HEDP). The biodistribution studies have demonstrated a high uptake of the radiotracer 99mTc-AEDP in the bone and a rapid clearance from the blood (such as the two technetium-labeled bone imaging agents in current use: 99mTc-MDP and 99mTc-HEDP). Additionally, the scintigraphic images of 99mTc-AEDP in normal rats have revealed high selective skeletal uptake.
EN
Due to interesting therapeutic properties of 177Lu and antineoblastic antibiotic, bleomycin (BLM), 177Lu-bleomycin (177Lu-BLM) was developed as a possible therapeutic compound. Lu-177 of 2.6-3 GBq/mg specific activity was obtained by irradiation of a natural Lu2O3 sample with a thermal neutron flux of 4 × 1013 nźcm-2źs-1. The product was converted into chloride form which was further used for labeling of BLM. In optimized conditions a radiochemical purity of 98% was obtained for 177Lu-BLM shown by instant thin-layer chromatography (ITLC) (specific activity, 740 GBq/mmole). Biodistribution studies of Lu-177 chloride and 177Lu-BLM were performed in wild-type rats. The accumulation of the radiolabeled compound in lungs, liver and spleen demonstrates a pattern similar to the other radiolabeled bleomycins. Lu-BLM is a possible therapeutic agent in human malignancies and the efficacy of the compound should be tested in various tumor-bearing models.
EN
In order to develop a possible Ga-labeled glucagon (GCG) compound for imaging studies, biosynthetic glucagon (GCG) was labeled with [67Ga]-gallium chloride after conjugation with freshly prepared diethylenetriaminepentaacetic acid dianhydride (ccDTPA). After solid phase purification of the radiolabeled hormone, high performance liquid chromatography (HPLC) and instant thin-layer chromatography (ITLC) showed a radiochemical purity around 95 per cent in optimized conditions (specific activity = 296–370 GBq/mM; labeling efficiency 85 per cent). Preliminary in vivo studies (IDźg–1 per cent) in male wild-type rats showed heart:muscle, liver:muscle, lung:muscle and stomach:muscle ratios to be 5.53, 2.9, 7.56, 3.69, 3.2 (in 5 min), respectively while after 2 h liver:blood, lung:blood and spleen:blood ratios were 14.21, 16.86 and 7.8, respectively. The data suggests 5 min post injection, the tracer is accumulated in GCGR rich tissues which is in agreement with biodistribution studies and reported GCG receptors (GCGRs). The results of the present study can possibly offer a candidate for non-invasive imaging of glucagon receptor related diseased and malignancies such as glucagonoma.
EN
Human recombinant insulin was successively labeled with [67Ga]-gallium chloride after conjugation with freshly prepared cyclic DTPA-dianhydride (ccDTPA). The best results of the conjugation were obtained by the addition of 0.5 ml of an insulin pharmaceutical solution (5 mg/ml, in phosphate buffer, pH = 8) to a glass tube precoated with DTPA-dianhydride (0.01 mg) at 25°C with continuous mild stirring for 30 min. Radiothin-layer chromatography (RTLC), instant thin-layer chromatography (ITLC) and high-performance liquid chromatography (HPLC) showed overall radiochemical purity higher than 96% in optimized conditions (specific activity = 300 500 MBq/mg, labeling efficiency 77%). Preliminary in vivo studies with normal rats were performed to determine the biodistribution of the radiotracer up to 110 h. They showed a high liver uptake of the tracer which is consistent with other reported radiolabeled insulins.
EN
Due to the anticancer properties of bleomycin (BLM) complexes, production of [103Pd]bleomycin ([103Pd]BLM) was targeted. Palladium-103 (T1/2 = 16.96 d) was produced via the 103Rh(p,n)103Pd nuclear reaction using a natural rhodium target. Proton energy was 18 MeV with 200 mA irradiation for 15 h (final activity 25.9 GBq of 103Pd2+, RCP > 95%, radionuclidic purity > 99%). 103Pd was separated from the irradiated target by anion exchange using a Dowex 1´8 (Cl-)/100-200 mesh resin in the form of Pd(NH3)2Cl2 in order to react with bleomycin to yield [103Pd]BLM. Chemical purity of the final product was in accordance to the accepted limits. [103Pd]BLM was prepared with a radiochemical yield of more than 98% at 80°C in 30 min. The labeling reaction was optimized for time, temperature and ligand concentration. Radiochemical purity of more than 99% was obtained using RTLC with specific activity of about 370 MBq/mmol. The stability of the tracer was checked in the final product and presence of human serum at up to 3 h. The complex was stable in human serum at 37°C up to 2 h of incubation. Biodistribution studies using a SPECT system performed in normal rats in the first 2-3 h.
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