Mechanisms of Iron Uptake from Ferric Phosphate Nanoparticles in Human Intestinal Caco-2 Cells.
Mechanisms of Iron Uptake from Ferric Phosphate Nanoparticles in Human Intestinal Caco-2 Cells.
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DOI：
10.3390/nu9040359
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发表时间：
2017-04-04
期刊：
影响因子：
5.9
通讯作者：
Fairweather-Tait S
中科院分区：
文献类型：
--
作者：
Perfecto A;Elgy C;Valsami-Jones E;Sharp P;Hilty F;Fairweather-Tait S
减少缺铁性贫血的食品强化计划要求生物可利用的铁的形式不会对感官产生不利影响。啮齿动物研究表明，纳米磷酸铁(NP-FePO4)具有与硫酸亚铁相同的生物利用度，但对其吸收机理存在争议。我们进行了使用Caco-2细胞模型和模拟胃肠道(GI)消化的体外研究。培养上清铁浓度与pH成反比，当Np-FePO4在pH为1的条件下消化时，Caco-2细胞对铁的摄取量是在pH为2时的2-3倍。颗粒分布的D50为413 nm。用圆盘离心沉淀法，观察到模拟胃肠道消化后的NP-FePO_4有高度的团聚，仅有20%的颗粒≤为1000 nm。在Caco-2细胞中，二价金属转运体-1(DMT1)和内吞作用抑制剂表明NP-FePO4主要通过DMT1被吸收。小颗粒可被胞苷介导的内吞作用和微胞吞作用所吸收。在评估铁纳米颗粒用于食品强化的潜力时，应考虑这些发现。
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.