Biodegradation of Iron Oxide Nanocubes: High-Resolution In Situ Monitoring
Biodegradation of Iron Oxide Nanocubes: High-Resolution In Situ Monitoring
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DOI：
10.1021/nn305719y
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发表时间：
2013-05-01
期刊：
影响因子：
17.1
通讯作者：
Gazeaut, Florence
中科院分区：
文献类型：
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作者：
Lartigue, Lenaic;Alloyeau, Damien;Gazeaut, Florence
纳米材料在生物环境中的长期命运是一个关键问题，它决定了环境效应和对人类健康的潜在风险。预测这些风险需要了解纳米颗粒的转变、持久性和降解性，但到目前为止，一些问题不知何故被忽视了。无机纳米结构在设计上是安全的，正被设想用于治疗，但其在生物系统中加工的基本原理、物理性质的变化和原位降解性尚未得到彻底评估。在这里，我们报告了纵向可视化的氧化铁纳米立方体转变所造成的细胞内环境。用像差校正的高分辨电子显微镜在原子尺度上监测了具有两种不同表面涂层(两亲性聚合物壳分子和聚乙二醇配体分子)的单个纳米立方体的结构退化。我们的结果表明，聚合物涂层控制表面反应性，而螯合剂的可用性和对晶体表面的访问控制降解率。这项关于单个纳米立方体降解的原位研究与静脉注射后14天观察到的小鼠细胞内变化进行了比较，揭示了纳米颗粒聚集、降解室内的细胞内分选以及铁转移和回收到铁蛋白储存蛋白中的作用。我们的方法缩小了模拟生物环境的原位纳米级观察与体内纳米粒子命运的真实跟踪之间的差距。
The long-term fate of nanomaterials in biological environment represents a critical matter, which determines environmental effects and potential risks for human health. Predicting these risks requires understanding of nanoparticle transformations, persistence, and degradation, some issues somehow ignored so far. Safe by design, inorganic nanostructures are being envisioned for therapy, yet fundamental principles of their processing in biological systems, change in physical properties, and in situ degradability have not been thoroughly assessed. Here we report the longitudinal visualization of iron oxide nanocube transformations inflicted by the intracellular-like environment. Structural degradation of individual nanocubes with two different surface coatings (amphiphilic polymer shell and polyethylene glycol ligand molecules) was monitored at the atomic scale with aberration-corrected high-resolution transmission electron microscopy. Our results suggest that the polymer coating controls surface reactivity and that availability and access of chelating agents to the crystal surface govern the degradation rate. This in situ study of single nanocube degradation was compared to intracellular transformations observed in mice over 14 days after intravenous injection, revealing the role of nanoparticle clustering, intracellular sorting within degradation compartments, and iron transfer and recycling into ferritin storage proteins. Our approach reduces the gap between in situ nanoscale observations in mimicking biological environments and in vivo real tracking of nanoparticle fate.