Preparation and biodistribution study of 67Ga-rosemary (Salvia rosmarinus Spenn.) extract nanoparticles and its SPECT imaging in healthy rainbow trout (Oncorhynchus mykiss)


1 Department of Seafood Science and Technology, Faculty of Fisheries and Environmental Sciences, Gorgan University of Agricultural Sciences and Natural Resource, Gorgan, Iran.

2 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.