Iron is the crucial element for living organisms and its deficiency is described as the most common nutritional disorder all over the world. Nowadays, more effective and safe iron supplementation strategies for both humans and animals become one of the most important challenges in the therapy of nutritional deficiencies. Our previous in vivo studies confirmed safety and biodegradability of in-house manufactured zinc oxide-based nanoparticles and their rapid distribution to majority of organs and tissues in the body. In vitro examinations performed on Caco-2 cell line, a model of epithelial cells of the gastrointestinal tract, revealed a low toxicity of studied nanomaterials. In the current study, we investigated biodegradable zinc oxide nanoparticles doped with Fe(III) as a perspective supplementation strategy for iron deficiency. Biodegradable ZnO:Fe nanoparticles were intra-gastrically administered to adult mice and following 24 h, animals were sacrificed with collection of internal organs for further analyses. The iron concentration measured with atomic absorption spectrometry and histological staining (Perl's method) showed a rapid distribution of iron-doped nanoparticles to tissues specifically related with iron homeostasis. Accumulation of iron was also visible within hepatocytes and around blood vessels within the spleen, which might indicate the transfer of Fe-doped nanoparticles from the bloodstream into the tissue. Reassuming, preliminary results obtained in the current study suggest that biodegradable ZnO nanoparticles doped with Fe might be a good carriers of exogenous iron in the living body. Therefore, subsequent investigations focus on determination an exact mechanisms related with an iron deposition in the tissue and influence of nanoparticle carriers on iron metabolism are required.

中文翻译：

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掺杂铁的可生物降解氧化锌纳米颗粒作为铁向生物体输送的潜在形式的初步研究。


铁是生物体的关键元素，其缺乏被描述为全世界最常见的营养失调。如今，对人类和动物更有效、更安全的铁补充剂策略成为营养缺乏治疗中最重要的挑战之一。我们之前的体内研究证实了内部制造的氧化锌纳米颗粒的安全性和生物降解性，以及它们能够快速分布到体内的大多数器官和组织。对 Caco-2 细胞系（胃肠道上皮细胞模型）进行的体外检查表明，所研究的纳米材料毒性较低。在当前的研究中，我们研究了掺杂 Fe(III) 的可生物降解的氧化锌纳米颗粒作为缺铁的一种前瞻性补充策略。将可生物降解的 ZnO:Fe 纳米颗粒灌胃给成年小鼠，24 小时后处死动物，收集内脏器官用于进一步分析。用原子吸收光谱法和组织学染色（Perl 法）测量的铁浓度显示，铁掺杂纳米粒子快速分布到与铁稳态特别相关的组织中。肝细胞内和脾内血管周围也可见铁的积累，这可能表明铁掺杂纳米颗粒从血流转移到组织中。回顾一下，当前研究中获得的初步结果表明，掺杂Fe的可生物降解的ZnO纳米粒子可能是活体内外源性铁的良好载体。 因此，后续研究的重点是确定与组织中铁沉积相关的确切机制以及纳米颗粒载体对铁代谢的影响。