Department of Seafood Science and Technology, Faculty of Fisheries and Environmental Sciences, Gorgan University of Agricultural Sciences and Natural Resource, Gorgan, Iran.
Nuclear Science and Technology Research Institute, Tehran, Iran.
The aim of this study was to evaluate the labeling of rosemary extract nanoparticles (RE-NPs) using 67Ga radioisotope, and their biodistribution in healthy rainbow trout (Oncorhynchus mykiss) tissues. RE-NPs were prepared by gamma irradiation (irradiated at a dose of 30 kGy of gamma-ray by 60Co (PX-30 IssIedovapel, Russia, dose rate of 0.02 Gy sec-1) and ultra-sonication methods at two concentrations of 0.5% and 1% and labeled by 67Ga radioisotope. Quality control studies were done using the RTLC method. The radiolabeling RE-NPs at 1% concentration showed 97% efficiency using a mixture of sodium acetate and acetic acid buffer at pH=6.5 after 30 min at room temperature. In the biodistribution study, 54 healthy fish were randomly distributed into two treatment groups (n=18 fish/treatment group) and one group served as healthy control. Fish received 3.7-7.4 MBq (300 µL) of radiolabeled RE-NPs at 1% concentration and free 67GaCl3, intraperitoneally. The 67Ga-RE-NPs single-photon emission computed tomography (SPECT) demonstrated the highest tracer accumulation in the kidney and the least uptake in the brain at 24 h after injection of 67Ga-RE-NPs. However, 48 h after injection of 67Ga-RE-NPs, the uptake was negligible in all organs as compared to free 67GaCl3. The obtained results revealed that administration of 67Ga-RE-NPs, as a natural tracer, by IP injection can be a good imaging method to visualize and understand the whole-body, especially the kidney and spleen tissues distribution and pharmacokinetics in healthy rainbow trout.