Alginate-Iron Speciation and Its Effect on In Vitro Cellular Iron Metabolism.
Alginate-Iron Speciation and Its Effect on In Vitro Cellular Iron Metabolism.
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藻酸盐铁物种及其对体外细胞铁代谢的影响。
DOI：
10.1371/journal.pone.0138240
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Tselepis C
中科院分区：
文献类型：
--
作者：
Horniblow RD;Dowle M;Iqbal TH;Latunde-Dada GO;Palmer RE;Pikramenou Z;Tselepis C
海藻酸盐是一类具有已知铁结合性能的生物聚合物，通常用于制备氧化铁纳米颗粒。此外，海藻酸盐还被认为会影响人体的铁吸收。然而，氧化铁纳米颗粒的合成使用非生理性的pH条件，而且纳米颗粒在体内的形成是否影响细胞内的铁代谢尚不清楚。因此，这项研究的目的是确定海藻酸盐和铁在与胃相似的pH条件下是如何相互作用的，以及这如何影响铁的代谢。利用生理条件下的一系列光谱技术证实了藻酸盐-铁的络合作用，并结合像差校正的扫描透射电子显微镜观察到了纳米颗粒。结果推断出铁结合的成核型模型，即海藻酸盐以铁-氢氧化物络合物的缩合为模板形成以氧化铁为中心的纳米颗粒。海藻酸盐和铁在细胞水平上的相互作用被发现使细胞铁的获取减少了37%(p<；0.05)，结合共聚焦显微镜，海藻酸盐通过细胞外铁螯合抑制细胞铁的运输，所产生的络合物没有被内化。这些结果推断，藻酸盐在螯合过量的铁方面是有用的，特别是在炎症性肠病和结直肠癌的背景下，过量的未被吸收的管状铁被认为是疾病的驱动因素。
Alginates are a class of biopolymers with known iron binding properties which are routinely used in the fabrication of iron-oxide nanoparticles. In addition, alginates have been implicated in influencing human iron absorption. However, the synthesis of iron oxide nanoparticles employs non-physiological pH conditions and whether nanoparticle formation in vivo is responsible for influencing cellular iron metabolism is unclear. Thus the aims of this study were to determine how alginate and iron interact at gastric-comparable pH conditions and how this influences iron metabolism. Employing a range of spectroscopic techniques under physiological conditions alginate-iron complexation was confirmed and, in conjunction with aberration corrected scanning transmission electron microscopy, nanoparticles were observed. The results infer a nucleation-type model of iron binding whereby alginate is templating the condensation of iron-hydroxide complexes to form iron oxide centred nanoparticles. The interaction of alginate and iron at a cellular level was found to decrease cellular iron acquisition by 37% (p < 0.05) and in combination with confocal microscopy the alginate inhibits cellular iron transport through extracellular iron chelation with the resulting complexes not internalised. These results infer alginate as being useful in the chelation of excess iron, especially in the context of inflammatory bowel disease and colorectal cancer where excess unabsorbed luminal iron is thought to be a driver of disease.