Preparation of dual-modality yttrium-90 radiolabeled nanoparticles for therapeutic investigation.

Magnetic Fe₃O₄ nanoparticles with narrow size distribution were synthesized by simple and high yielded co-precipitation technique using ferrous salts with a molar ratio of Fe³⁺/Fe²⁺=2. After coating of the nanoparticles with Stöber silica (SiO₂@Fe₃O₄), nanoparticles were functionalized by amine groups. Then chelator molecules diethylenetriaminepentaacetic (DTPA) and tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) were coupled to the APTS-SiO₂@Fe₃O₄ to chelating Y-90 radiometal that makes these nanoparticles a suitable agent for therapeutic application as dual-modality PET/MRI imaging. The results show the coupling of DTPA takes place better than DOTA. Synthesis of magnetic nanoparticles (MNPs) was followed by structure identification using XRD, SEM, TGA and IR techniques. In order to trace MNPs biodistribution, the radiolabeled MNPs-DTPA were prepared using ⁹⁰Y (production of ⁹⁰Y/⁹⁰Sr generator) with a good labeling efficiency (about 92%, RTLS method). The biodistribution of the radiolabeled MNPs was checked in normal male rats up to 24 h compared to free Y³⁺. The data shows that the tracer accumulation is in reticuloendothelial tissue while the stability of the complex is highly retained. [ABSTRACT FROM AUTHOR]