Iron from nanostructured ferric phosphate: absorption and biodistribution in mice and bioavailability in iron deficient anemic women

Abstract

Food fortification with iron nanoparticles (NPs) could help prevent iron deficiency anemia, but the absorption pathway and biodistribution of iron-NPs and their bioavailability in humans is unclear. Dietary non-heme iron is physiologically absorbed via the divalent metal transporter-1 (DMT1) pathway. Using radio- iron isotope labelling in mice with a partial knockdown of intestine-specific DMT1, we assessed oral absorption and tissue biodistribution of nanostructured ferric phosphate (FePO4-NP; specific surface area [SSA] 98 m2g-1) compared to to ferrous sulfate (FeSO4), the reference compound. We show that absorption of iron from FePO4-NP appears to be largely DMT1 dependent and that its biodistribution after absorption is similar to that from FeSO4, without abnormal deposition of iron in the reticuloendothelial system. Furthermore, we demonstrate high bioavailability from iron NPs in iron deficient anemic women in a randomized, cross-over study using stable-isotope labelling: absorption and subsequent erythrocyte iron utilization from two 57Fe-labeled FePO4-NP with SSAs of 98 m2g−1 and 188 m2g−1 was 2.8-fold and 5.4-fold higher than from bulk FePO4 with an SSA of 25 m2g−1 (P < 0.001) when added to a rice and vegetable meal consumed by iron deficient anemic women. The FePO4-NP 188 m2g-1 achieved 72% relative bioavailability compared to FeSO4. These data suggest FePO4-NPs may be useful for nutritional applications.

Nanoscale coordination polymer Fe-DMY downregulating Poldip2-Nox4-H2O2 pathway and alleviating diabetic retinopathy

“…Unlike conventional iron supplements such as ferrous sulfate and ferrous gluconate, iron NPs do not alter the sensory properties of food [ 33 , 34 ]. Recently, iron NPs have even been recommended as direct dietary supplements for preventing iron deficiency, and their use has been suggested for food fortification purposes [ 35 ]. The doses of Fe-DMY NCPs used in our experiments are significantly lower than both the recommended daily intake of Fe as dietary supplements and the WHO-recommended daily Fe intake [ 36 ].…”

Iron from the gut: the role of divalent metal transporter 1

“…( 86 ) Furthermore, the FePO 4 nanoparticle bioavailability is not toxic to iron deficient women with anemia. ( 87 ) Indeed, oral intake of water-soluble iron alters the gut microbiota in patients with inflammatory backgrounds, such as obesity, inflammatory bowel disease, or colorectal cancer that may cause declined absorption. ( 12 ) To improve dietary iron supplementation, probiotics and prebiotics are explored to alter iron bioavailability, as impaired gut health-induced dysbiosis results in poor therapeutic effect.…”