Tabacchi Gloria, Armenia Ilaria, Bernardini Giovanni, Masciocchi Norberto, Guagliardi Antonietta, Fois Ettore
Dipartimento di Scienza e Alta Tecnologia (DSAT), University of Insubria, and INSTM, Via Valleggio 11, I-22100 Como, Italy.
Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, Zaragoza 50009, Spain.
ACS Appl Nano Mater. 2023 May 17;6(14):12914-12921. doi: 10.1021/acsanm.3c01643. eCollection 2023 Jul 28.
Magnetic iron oxide nanoparticles (IONPs) have gained momentum in the field of biomedical applications. They can be remotely heated via alternating magnetic fields, and such heat can be transferred from the IONPs to the local environment. However, the microscopic mechanism of heat transfer is still debated. By X-ray total scattering experiments and first-principles simulations, we show how such heat transfer can occur. After establishing structural and microstructural properties of the maghemite phase of the IONPs, we built a maghemite model functionalized with aminoalkoxysilane, a molecule used to anchor (bio)molecules to oxide surfaces. By a linear response theory approach, we reveal that a resonance mechanism is responsible for the heat transfer from the IONPs to the surroundings. Heat transfer occurs not only via covalent linkages with the IONP but also through the solvent hydrogen-bond network. This result may pave the way to exploit the directional control of the heat flow from the IONPs to the anchored molecules-i.e., antibiotics, therapeutics, and enzymes-for their activation or release in a broader range of medical and industrial applications.
磁性氧化铁纳米颗粒（IONPs）在生物医学应用领域已获得发展势头。它们可通过交变磁场进行远程加热，且这种热量能从IONPs传递至局部环境。然而，热传递的微观机制仍存在争议。通过X射线全散射实验和第一性原理模拟，我们展示了这种热传递是如何发生的。在确定IONPs磁赤铁矿相的结构和微观结构特性后，我们构建了一个用氨基烷氧基硅烷功能化的磁赤铁矿模型，氨基烷氧基硅烷是一种用于将（生物）分子锚定到氧化物表面的分子。通过线性响应理论方法，我们揭示了一种共振机制是IONPs与周围环境之间热传递的原因。热传递不仅通过与IONP的共价键发生，还通过溶剂氢键网络进行。这一结果可能为在更广泛的医学和工业应用中利用从IONPs到锚定分子（即抗生素、治疗剂和酶）的热流方向控制来实现它们的激活或释放铺平道路。
