ABSTRACT
The 153Sm-[tris[1, 10-phenanthroline] Samarium[III]]complex [153Sm-PL3] was prepared in view of development of targeting therapeutic compounds for malignancies, and interesting in-vitro anti-tumor activities of lanthanide phenanthroline complexes,. Sm-153 chloride was obtained by thermal neutron flux [4 × 1013 n.cm- 2.s-1] of enriched 152Sm2O3 sample, dissolved in acidic media. The labeling was performed in ethanol in 24h, controlled by ITLC [1.0mM DTPA, pH.5, as mobile phase]. The partition coefficient for the labeled compound was also determined. Results: A radiochemical yield of more than 95% was obtained. Radiochemical purity of 96% was obtained using ITLC with specific activity of about 27.75 GBq/mg. The radio-labeled complex was stable in aqueous solution at least 24 hours and no significant amount of free 153Sm was released from the complex. The partition coefficient for the labeled compound was determined [log P. 3.4]. The complex was stable in final formulation for 66h. The biological evaluation of the compound is under investigation. The radiolabeled compound used in this study was a very inexpensive and useful agent for the use as a therapeutic compound
ABSTRACT
Chlorotoxin is a 36-amino acid peptide found in the venom of the Leiurus quinquestriatus which blocks small-conductance chloride channels. Chlorotoxin binds preferentially to glioma cells that allow development of new methods for the treatment and diagnosis of several types of cancer. Thus chlorotoxin derivative was labeled with [131]I for further investigation. A chlorotoxin derivative was synthesized on a solid phase using a standard Fmoc strategy. Labeling with iodine-131 was performed through chloramine-T method and radiochemical analysis involved sephadex G-25 and HPLC methods. The stability of radiopeptide was checked in the presence of PBS and human serum at 37 °C up to 24 h. The biodistribution was studied in mice. The chemical purity of synthesized peptide as assessed by analytical RP-HPLC was 95%. Labeling of peptide resulted in a radiochemical yield of 80% with radiochemical purity of > 95% with specific activity of 0.740 GBq/ micro mol. Result of in vitro studies demonstrated acceptable stability of compound in human serum and PBS solution. Biodistribution data showed moderate blood clearance, with concentration of radioactivity in the kidneys, liver, intestine and stomach. Results indicates that the labeled Chlorotoxin derivative might be useful in determining tumor extent and also, tumor therapy of gliomas or possibily other cancers