RESUMO
Chitosan (CS) of low molecular weight is prepared using γ-irradiation method in presence of H2O2 as oxidizing agent. The chemical treatment of folic acid (FA) with low molecular weight CS is carried out to prepare FACS complex based on the reaction between NH2 group of CS and γ-COOH group of FA. The structure and properties of FACS complex was characterized by FT-IR, 1H NMR, UV, SEM, TEM, DLS and XRD analyses. TEM and DLS results showed that FACS complex has nanostructure and the mean size of particles was unimodal with average diameters in the range of 165-252nm. Radiolabeling of FACS complex (99mTc-FACS) was done with Technetium-99m (99mTc). The optimum conditions of labeling were investigated. The labeling yield was 85% at pH=6 and 30min reaction time. The effect of time on the stability of 99mTc-FACS complex was studied and the results revealed that it is stable up to 6h after labeling. Biodistribution studies of 99mTc-FACS complex in Quail showed that it distributed to different organs mainly in blood, liver and kidney. The results revealed that the uptake of 99mTc-FACS in the sexual organs (ovary and ovarian) of female Quail was higher than that in the sexual organs (testes) of male Quail, so 99mTc-FACS could be used to differentiate between them. It also showed that FACS is consumed and more essential in female than that in male.
