Mechanisms of Iron Uptake from Ferric Phosphate Nanoparticles in Human Intestinal Caco-2 Cells

Nutrients

Christine Elgy¹  Eugenia Valsami-Jones²  Paul Sharp³  Susan Fairweather-Tait⁴  Florentine Hilty⁵  Antonio Perfecto⁶ 

[1] [e-mail]2School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK;[e-mail] (C.E.);[e-mail] (E.V.-J.)3Diabetes and Nutritional Sciences Division, King’s College London, London SE1 9NH, UK;[e-mail];[e-mail]4Institute of Food, Nutrition, and Health, ETH, Schmelzbergstrasse 9, 8092 Zürich, Switzerland;1Norwich Medical School, University of East Anglia, Norwich, Norfolk NR4 7UQ, UK;

关键词: nano iron;    NP-FePO4;    bioavailability;    Caco-2 cells;    simulated gastrointestinal digestion;    DMT1;    endocytosis;   

DOI  :  10.3390/nu9040359

来源: DOAJ

【 摘 要 】

Food fortification programs to reduce iron deficiency anemia require bioavailable forms of iron that do not cause adverse organoleptic effects. Rodent studies show that nano-sized ferric phosphate (NP-FePO4) is as bioavailable as ferrous sulfate, but there is controversy over the mechanism of absorption. We undertook in vitro studies to examine this using a Caco-2 cell model and simulated gastrointestinal (GI) digestion. Supernatant iron concentrations increased inversely with pH, and iron uptake into Caco-2 cells was 2–3 fold higher when NP-FePO4 was digested at pH 1 compared to pH 2. The size and distribution of NP-FePO4 particles during GI digestion was examined using transmission electron microscopy. The d50 of the particle distribution was 413 nm. Using disc centrifugal sedimentation, a high degree of agglomeration in NP-FePO4 following simulated GI digestion was observed, with only 20% of the particles ≤1000 nm. In Caco-2 cells, divalent metal transporter-1 (DMT1) and endocytosis inhibitors demonstrated that NP-FePO4 was mainly absorbed via DMT1. Small particles may be absorbed by clathrin-mediated endocytosis and micropinocytosis. These findings should be considered when assessing the potential of iron nanoparticles for food fortification.

【 授权许可】

Unknown