Mesoscale Assemblies of Iron Oxide Nanocubes as Heat Mediators and Image Contrast Agents

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• 作者：Maria Elena Materia ; Pablo Guardia ; Ayyappan Sathya ; Manuel Pernia Leal ; Roberto Marotta ; Riccardo Di Corato ; Teresa Pellegrino
• 刊名：Langmuir
• 出版年：2015
• 出版时间：January 20, 2015
• 年：2015
• 卷：31
• 期：2
• 页码：808-816
• 全文大小：449K
• ISSN：1520-5827

文摘

Iron oxide nanocubes (IONCs) represent one of the most promising iron-based nanoparticles for both magnetic resonance image (MRI) and magnetically mediated hyperthermia (MMH). Here, we have set a protocol to control the aggregation of magnetically interacting IONCs within a polymeric matrix in a so-called magnetic nanobead (MNB) having mesoscale size (200 nm). By the comparison with individual coated nanocubes, we elucidate the effect of the aggregation on the specific adsorption rates (SAR) and on the T₁ and T₂ relaxation times. We found that while SAR values decrease as IONCs are aggregated into MNBs but still keeping significant SAR values (200 W/g at 300 kHz), relaxation times show very interesting properties with outstanding values of r₂/r₁ ratio for the MNBs with respect to single IONCs.