Materia Maria Elena, Guardia Pablo, Sathya Ayyappan, Leal Manuel Pernia, Marotta Roberto, Di Corato Riccardo, Pellegrino Teresa
Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy.
Langmuir. 2015 Jan 20;31(2):808-16. doi: 10.1021/la503930s. Epub 2015 Jan 8.
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.
氧化铁纳米立方体（IONCs）是用于磁共振成像（MRI）和磁介导热疗（MMH）最具前景的铁基纳米颗粒之一。在此，我们制定了一种方案，以控制在具有中尺度尺寸（200纳米）的所谓磁性纳米珠（MNB）的聚合物基质内磁性相互作用的IONCs的聚集。通过与单个包覆纳米立方体进行比较，我们阐明了聚集对比吸收率（SAR）以及T1和T2弛豫时间的影响。我们发现，虽然随着IONCs聚集成MNBs，SAR值会降低，但仍保持显著的SAR值（在300千赫兹时为200瓦/克），弛豫时间表现出非常有趣的特性，相对于单个IONCs，MNBs的r2/r1比值具有出色的值。
