Bioavailability of Iron-nanoparticles with Ascorbic Acid in Anemic Mice

Recently, iron nanoparticles (Fe-NPs) have been used for cancer diagnosis and therapy for imaging contrast and drug delivery. However, there was no report on nutritional bioavailability of the Fe-NPs in the body. Ascorbic acid (AA) is known to help the absorption of iron in stomach by reducing Fe (III) to Fe (II). In this study, we investigated the bioavailability of Fe-NPs with AA in iron-deficiency-anemic mice in comparison with non-nano iron particles. Iron-deficient anemia was induced by feeding iron-deficient diet (4.5 mg Fe/kg) and ocular bleeding from retro-orbital venous plexus for 4 weeks. Normal control mice were given normal diet (45 mg Fe/kg). After induction of anemia in mice, Fe (40 mg/kg B.W.) + AA (5 g/kg B.W) and Fe-NPs (40 mg/kg B.W) + AA (5 g/kg B.W) were orally administered daily to the anemic mice. After sacrifice, liver and spleen tissues were observed by haematoxylin & eosin stain. Amount of trace iron in liver and upper small intestine was investigated using an inductively coupled plasma-atomic emission spectrometer. Red blood cell (RBC), hematocrit (Hct), hemoglobin (Hb), and total iron binding capacity were also measured. The concentrations of iron in Fe-NPs + AA group were significantly higher in liver and in upper small intestine than that in Fe + AA group. The values of RBC, Hct, and Hb in Fe-NPs + AA group were more rapidly increased to normal values compared with Fe + AA group with increasing time. These results suggest that Fe-NPs in the presence of AA may be more bioavailable than non-nano Fe in Fe-deficient anemic mice.