Improving the Heating Efficiency of Iron Oxide Nanoparticles by Tuning Their Shape and Size
Improving the Heating Efficiency of Iron Oxide Nanoparticles by Tuning Their Shape and Size
复制标题
DOI：
10.1021/acs.jpcc.7b10528
复制
发表时间：
2018-02-01
影响因子：
3.7
通讯作者：
Srikanth, Hariharan
中科院分区：
文献类型：
--
作者：
Nemati, Zohreh;Alonso, Javier;Srikanth, Hariharan
磁性纳米粒子介导的热疗是一种非常有前途的癌症治疗方法。在该领域中，超顺磁性氧化铁纳米颗粒由于其固有的生物相容性而被普遍采用，但它们存在一些限制其加热效率（比吸收率，SAR）的局限性。因此，我们已经研究了如何调整这些氧化铁纳米颗粒的大小和形状可以有助于增强它们的热疗反应。单分散和结晶氧化铁纳米粒子已通过热分解以两种不同的形状（球形和立方体）在宽范围的尺寸，类似于10-100 nm的合成。我们已经彻底表征了它们的结构（X射线衍射和透射电子显微镜）和磁性（物理性能测量系统），然后我们使用量热和交流磁力测量（0-800 Oe，300 kHz）的组合分析了它们的加热效率。我们已经能够界定一系列最佳尺寸，以根据其形状最大限度地提高这些纳米颗粒的加热效率。我们发现，纳米球表现出最高的加热效率的尺寸约为30-50 nm，而纳米立方体显示在30-35 nm左右的加热效率急剧增加。SAR变化与纳米颗粒的磁各向异性有关，这取决于它们的大小、形状、排列和偶极相互作用。
Magnetic nanoparticle-mediated hyperthermia is a very promising therapy for cancer treatment. In this field, superparamagnetic iron oxide nanoparticles have been commonly employed because of their intrinsic biocompatibility, but they present some limitations that restrict their heating efficiency (specific absorption rate, SAR). Therefore, we have investigated how tuning the size and shape of these iron oxide nanoparticles can be useful to enhance their hyperthermia responses. Monodisperse and crystalline iron oxide nanoparticles have been synthesized by thermal decomposition in two different shapes (spheres and cubes) in a wide range of sizes, similar to 10-100 nm. We have thoroughly characterized them both structurally (X-ray diffraction and transmission electron microscopy) and magnetically (physical property measurement system), and then we have analyzed their heating efficiency using a combination of calorimetric and AC magnetometry measurements (0-800 Oe, 300 kHz). We have been able to delimit a range of optimum sizes to maximize the heating efficiency of these nanoparticles depending on their shape. We find that the nanospheres exhibit the highest heating efficiency for sizes around 30-50 nm, while the nanocubes show a sharp increase in the heating efficiency around 30-35 nm. The SAR variation has been related to the magnetic anisotropy of the nanoparticles that depends on their size, shape, arrangement, and dipolar interactions.