Preparation and Biological Evaluation of [67Ga]-Labeled-Superparamagnetic Iron Oxide Nanoparticles in Normal Rats

Gallium-67 labeled superparamagnetic iron oxide nanoparticles ([67Ga]-SPION) were prepared and evaluated for their altered biodistribution in normal rats. SPIONs with narrow size distribution were synthesized by co-precipitation technique using ferric and ferrous salts at molar ratio Fe3+/Fe2+=2:1 followed by structure identification using XRD, TGA, DSC, VSM, HRSEM, TEM and FT-IR techniques. In order to trace SPION bio-distribution, the radiolabeled iron oxide nanoparticles were prepared using 67Ga with a high labeling efficiency (over 96%, determined by RTLC method) and they also showed an excellent stability at room temperature for at least 4 days. The biodistribution of the radiolabeled SPION was checked in normal male rats up to 24 hours compared with the free Ga3+ cation biodistribution. The data strongly support the alteration of the tracer accumulation in reticuluendothelial system while the stability of the complex is highly retained. The result is promising for determining the position of the nanoparticles injected into a tissue when hyperthermia treatment/imaging is applied in biomedical fields.