Development of ^(153)Sm-bleomycin as a possible therapeutic complex

Due to interesting therapeutic properties of ^(153)Sm and antineoplastic antibiotic,bleomycin(BLM), ^(153)Sm-bleomycin(^(153)Sm-BLM) was developed as a possible therapeutic compound using ^(153)SmCl_3 and BLM.The ^(153)SmCl_3 was obtained by thermal neutron flux(5×10^(13)n·cm^(-2)·s^(-1))of an enriched ^(152)Sm_2O_3 sample,dissolved in acidic media.Under optimized conditions(room temperature,45 min,0.1 mg bleomycin for 740-3700 MBq ^(153)SmCl_3) a radiochemical purity over 98%was obtained shown by HPLC(Specific activity = 55 TBq/mM).The ^(153)SmCl_3 and ^(153)Sm-BLM were administered into wild-type rats up to 96 h followed by biodistribution.The SPECT imaging of labeled compound in wild-type rats was performed and significant image pattern was observed for a radiolabeled bleomycin compound.The ^(153)Sm-BLM is a potential therapeutic compound and our experiments on this compound have shown satisfactory quality,and stability suitable for future therapeutic studies.

Preparation,quality control and biodistribution of [^(61)Cu]-doxorubicin for PET imaging

This work was conducted for radiolabeling of an anticancer antibiotic, i.e. doxorubicin with 61Cu for production of possible tracer used in PET oncology. 61Cu was prepared with natural zinc target and 22 MeV150 μA protons via natZn(p, xn)61Cu reaction with a yield of 123.2 MBq·μA-1·h-1. Optimization reactions were performed for pH, temperature and concentration. Biodistribution of the tracer was studied in normal and fibrosarcoma bearing mice. At the optimized conditions, ITLC showed that radiochemical purity was over 97% with a specific activity of 2.22× 103MBq ·mmol-1·L-1. This was kept unchanged even with presence of human serum as well as room temperature for 5 h. Biodistribution of the tracer in fibrosarcoma bearing mice demonstrated significant tumor uptake after 2 h. This tracer can be used in the detection of various tumors responding to doxorubicin chemotherapy using PET scan and/or determination of tumor therapy response to doxorubicin chemotherapy.

Radiosynthesis and biodistribution of [^(18)F]-tetracosactide using a semi-automated [^(18)F]SFB production module

In order to prepare a specific melanocortin type 2 receptor (MC2R) ligand, β1-24-corticotrophin was prepared in one-step reaction with [18F] SFB and β-1-24-corticotrophin pharmaceutical solution (1 mg/mL, pH=6.5). [18F]SFB was prepared in a semi-automated module in two steps with an overall radiochemical yield of 47% to EOB (not-decay corrected) in 90 min. The 18F-labeled intermediates and 18F-labeled peptide was checked by RTLC and HPLC. The results show that the radiochemical purity is >95% and the yield to EOB (not-decay corrected) is 29% for final 18F-labeled peptide at optimized conditions. Preliminary in vivo studies in normal mice were performed to determine biodistribution of the 18F-labeled peptide for 150 min. The results show that the major tracer uptake is consistent with the natural distribution of MC2R receptors in mammals. Testes/blood and testes/muscle ratios for 18F-labeled peptide at 150 min were 184 and 1.56, respectively, and adipocyte/blood and adipocyte/muscle ratios at 120 min were 221 and 142, respectively. The data support the specific receptor binding of the radiolabeled peptide as reported for MC2R receptor accumulation in adipocytes and testes and demonstrates the retention of biological activity of the peptide. This tracer can be used in detection of MC2R distribution in malignancies and sex organ diseases.