Magnetic iron oxide nanoparticles (IONPs) have received significant interest for the use in biomedical applications. The assembly of IONPs into larger superstructures has been used to modify the properties and functionality of these particles. For example, the clustering of IONPs can lead to improvements in MRI contrast generation, changes in heat generation during magnetic fluid hyperthermia, and alterations to pharmacokinetics and biodistribution. Nevertheless, the IONP clustering leads to significant heterogeneity in the assembly. Here, we demonstrate a method for using DNA origami to precisely control the number and positions of IONPs. We also showed how this technique can be used to module the functionality of IONP clusters by showing how MRI contrast generation efficiency can be tuned by altering the number and spacing of IONPs. Finally, we show that these property changes can be dynamically regulated, demonstrating the possibility for this technology to be used in biosensing applications.

中文翻译：

---

使用DNA折纸的氧化铁纳米粒子的可编程组装。

磁性氧化铁纳米粒子（IONPs）在生物医学应用中已引起广泛关注。IONPs组装成更大的上部结构已被用来修改这些粒子的特性和功能。例如，IONP的聚类可以导致MRI造影剂产生的改善，磁流体热疗期间热量产生的变化以及药代动力学和生物分布的改变。然而，IONP聚类导致装配中明显的异质性。在这里，我们演示了一种使用DNA折纸来精确控制IONP的数量和位置的方法。我们还展示了如何通过更改IONP的数量和间距来调节MRI对比生成效率，从而展示了该技术如何用于组合IONP簇的功能。最后，