Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162 CNRS/Université Paris Diderot, 10 rue Alice Domon et Léonie Duquet, F-75205, Paris Cedex 13, France.
Small. 2014 Aug 27;10(16):3325-37. doi: 10.1002/smll.201400281. Epub 2014 May 3.
Understanding the relation between the structure and the reactivity of nanomaterials in the organism is a crucial step towards efficient and safe biomedical applications. The multi-scale approach reported here, allows following the magnetic and structural transformations of multicore maghemite nanoflowers in a medium mimicking intracellular lysosomal environment. By confronting atomic-scale and macroscopic information on the biodegradation of these complex nanostuctures, we can unravel the mechanisms involved in the critical alterations of their hyperthermic power and their Magnetic Resonance imaging T1 and T2 contrast effect. This transformation of multicore nanoparticles with outstanding magnetic properties into poorly magnetic single core clusters highlights the harmful influence of cellular medium on the therapeutic and diagnosis effectiveness of iron oxide-based nanomaterials. As biodegradation occurs through surface reactivity mechanism, we demonstrate that the inert activity of gold nanoshells can be exploited to protect iron oxide nanostructures. Such inorganic nanoshields could be a relevant strategy to modulate the degradability and ultimately the long term fate of nanomaterials in the organism.
理解纳米材料在生物体中的结构和反应性之间的关系，是实现高效和安全的生物医学应用的关键步骤。这里报道的多尺度方法，使得能够在模拟细胞内溶酶体环境的介质中跟踪多核磁赤铁矿纳米花的磁性和结构转变。通过对比这些复杂纳米结构生物降解的原子尺度和宏观信息，我们可以揭示其高热功率和磁共振成像 T1 和 T2 对比效应关键变化的相关机制。具有优异磁性的多核纳米颗粒转化为磁性差的单核簇，突出了细胞介质对基于氧化铁的纳米材料治疗和诊断效果的有害影响。由于生物降解是通过表面反应机制发生的，我们证明了金纳米壳的惰性活性可以被利用来保护氧化铁纳米结构。这种无机纳米屏蔽可能是一种调节纳米材料在生物体中可降解性并最终影响其长期命运的有效策略。
