Synthesis, radiolabeling and bioevaluation of 99mTc (CO) 3-folate azide complex for tumor detection

Folic acid is a common dietary vitamin. Various cancer lines exhibit folate receptors on their surface. Many studies have been carried out to radiolabel the folic acid for diagnostic and therapeutic study of tumor. The aim of the present work is to develop 99mTc(CO)3-folate azide complex for tumor scintigraphy. 1,2,3-Triazole-containing folate azide complex was synthesized by using click chemistry strategy. The product was characterized by matrix-assisted LASER desorption ionization (MALDI). The radiolabeling was carried out by using isolink kit for stable complexation of organometallic core with folate azide complex. The radiochemical purity of the product was observed by using paper chromatography (PC). The protein binding assay in human blood was also studied. Normal distribution and tumoral uptake study of the drug was carried out in Swiss Webster mice. MALDI data showed molecule ion peak of the folate azide complex at m/z 636.279,which confirmed the successful synthesis of the ligand. Radiochemical analysis showed 98.2 ± 1.6 % binding of radiometal with the ligand,which remained gt;96% up to 5h. Drug showed 70.1 ± 2.8 % binding with blood plasma proteins. Biodistribution results exhibited high uptake in targeted tumor and significantly low accumulation in non targeted organs. These data indicate that 99mTc(CO) 3-folate azide complex might prove a successful tumor scintigraphic agent in future clinical applications.