Preparation, characterization and biodistribution in quails of ^99mTc-folic acid/chitosan nanostructure

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.