Department of Chemistry, Yonsei University, Seoul 120-749, Korea.
Nat Nanotechnol. 2011 Jun 26;6(7):418-22. doi: 10.1038/nnano.2011.95.
The conversion of electromagnetic energy into heat by nanoparticles has the potential to be a powerful, non-invasive technique for biotechnology applications such as drug release, disease treatment and remote control of single cell functions, but poor conversion efficiencies have hindered practical applications so far. In this Letter, we demonstrate a significant increase in the efficiency of magnetic thermal induction by nanoparticles. We take advantage of the exchange coupling between a magnetically hard core and magnetically soft shell to tune the magnetic properties of the nanoparticle and maximize the specific loss power, which is a gauge of the conversion efficiency. The optimized core-shell magnetic nanoparticles have specific loss power values that are an order of magnitude larger than conventional iron-oxide nanoparticles. We also perform an antitumour study in mice, and find that the therapeutic efficacy of these nanoparticles is superior to that of a common anticancer drug.
纳米粒子将电磁能转化为热能具有很大的潜力，可以应用于生物技术领域，如药物释放、疾病治疗和单细胞功能的远程控制，但迄今为止，低转换效率阻碍了其实际应用。在这封信件中，我们展示了通过纳米粒子提高磁热感应效率的显著效果。我们利用磁硬性内核与磁软性外壳之间的交换耦合来调整纳米粒子的磁性，并最大限度地提高比损耗功率，这是转换效率的一种衡量标准。优化后的核壳磁性纳米粒子的比损耗功率比传统的氧化铁纳米粒子高出一个数量级。我们还在小鼠中进行了抗肿瘤研究，发现这些纳米粒子的治疗效果优于常用的抗癌药物。
