INRIM, Advanced Materials Metrology and Life Sciences, Strada delle Cacce 91, I-10135 Torino, Italy.
Nanoscale. 2020 Mar 21;12(11):6360-6377. doi: 10.1039/c9nr09503a. Epub 2020 Mar 5.
The power released by magnetic nanoparticles submitted to an alternating driving field is temperature dependent owing to the variation of the fundamental magnetic properties. Therefore, the heating efficiency of magnetic nanoparticles for applications in precision nanomedicine (such as magnetic hyperthermia or heat-assisted drug delivery) can be significantly affected by the local instantaneous temperature of the host medium. A rate equation approach is used to determine the hysteretic properties and the power released by magnetite nanoparticles, and the heat transport equation is solved in a simple geometry with boundary conditions appropriate to both in-lab experiments and in vivo applications. Size plays a fundamental role in determining the heating efficiency of magnetic nanoparticles; above a critical size, nanoparticles remain inactive, although they can undergo secondary activation. The experimental conditions for optimal thermal efficiency are expressed by a thermal activity diagram for nanoparticles. In the light of the model's results, features, methods, advantages and dangers of magnetic-particle assisted precision nanomedicine ought to be reconsidered. In vivo antitumor applications should take into account the hazards arising from the heat generated by magnetic nanoparticles that diffuse into the neighboring healthy tissue.
由于基本磁性能的变化，在交变驱动场中施加的磁性纳米粒子所释放的能量取决于温度。因此，磁性纳米粒子在精密纳米医学中的应用（如磁热疗或热辅助药物输送）的加热效率会受到宿主介质局部瞬时温度的显著影响。我们采用滞后性能的速率方程方法来确定磁铁矿纳米粒子所释放的能量，并在简单的几何形状中求解热传输方程，边界条件适合实验室实验和体内应用。尺寸在确定磁性纳米粒子的加热效率方面起着至关重要的作用；在临界尺寸以上，纳米粒子虽然可以进行二次激活，但仍然处于非活动状态。通过纳米粒子的热活性图来表示最佳热效率的实验条件。根据模型的结果，应该重新考虑磁粒子辅助精密纳米医学的特点、方法、优势和危险。体内抗肿瘤应用应该考虑到扩散到邻近健康组织的磁性纳米粒子产生的热量所带来的危害。
