Development of radiolabeled dextran coated iron oxide nanoparticles with 111In and its biodistributionstudies

Background: the main aim of this study is to radiolabel dextran coated ironoxide nanoparticles (nps) (with 80 nm hydrodynamic size) with theindium-111 and evaluation their biodistribution after intravenous injectionnormal mice. materials and method: the chelator diethylenetriaminepentaacetic acid (dtpa) dianhydride was conjugated to spion using a smallmodification of the well-known cyclic anhydride method at a ratio of 1:5(nps:dtpa) molar ratio. the reaction was purified with magnetic assortingcolumns (macs) using high gradient magnetic field following incubation. thenthe radiochemical purity of the radiolabeled nps were determined using rtlcmethod. the magnetic properties of nanoparticles were measured by a 1.5tesla clinical human mri. results: the nps showed high super paramagneticproperties whereas their r2/r1 was 17.6. the rtlc showed that the purity ofcompound was above 99% after purification and the compound has shown agood in-vitro stability until 6 hours in the presence of human serum. thebiodistribution of 111in-dtpa-nps in mice demonstrated high uptake in thereticuloendothelial system (res) and the blood clearance was so fast.conclusion: due to magnificent uptakes of this radiotracer in the liver andspleen, its stability and their fast clearance from other tissues, especially inblood, it is suggested that this radiotracer would be suitable for restheranostics purposes.