Department of Chemistry, University of California, Riverside, California 92521, United States.
Department of Mechanical Engineering, University of Minnesota, Minneapolis, Minnesota 55455, United States.
Nano Lett. 2024 Sep 18;24(37):11567-11572. doi: 10.1021/acs.nanolett.4c03081. Epub 2024 Sep 4.
Rewarming cryopreserved samples requires fast heating to avoid devitrification, a challenge previously attempted by magnetic nanoparticle-mediated hyperthermia. Here, we introduce FeO@SiO nanorods as the heating elements to manipulate the heating profile to ensure safe rewarming and address the issue of uneven heating due to inhomogeneous particle distribution. The magnetic anisotropy of the nanorods allows their prealignment in the cryoprotective agent (CPA) during cooling and promotes subsequent rapid rewarming in an alternating magnetic field with the same orientation to prevent devitrification. More importantly, applying an orthogonal static magnetic field at a later stage could decelerate heating, effectively mitigating local overheating and reducing CPA toxicity. Furthermore, this orientational configuration offers more substantial heating deceleration in areas of initially higher heating rates, therefore reducing temperature variations across the sample. The efficacy of this method in regulating heating rate and improving rewarming uniformity has been validated using both gel and porcine artery models.
复温冷冻保存的样本需要快速加热以避免玻璃化，这是之前通过磁性纳米颗粒介导的热疗来尝试解决的挑战。在这里，我们引入了 FeO@SiO 纳米棒作为加热元件，以控制加热曲线，确保安全复温，并解决由于颗粒分布不均匀导致的加热不均匀问题。纳米棒的磁各向异性允许它们在冷却过程中在保护剂（CPA）中预先对齐，并在相同方向的交变磁场中促进随后的快速复温，以防止玻璃化。更重要的是，在稍后阶段施加正交静态磁场可以减缓加热速度，有效地减轻局部过热并降低 CPA 毒性。此外，这种定向配置在初始加热速率较高的区域提供了更大的加热减速，从而降低了样品内的温度变化。使用凝胶和猪动脉模型验证了这种方法在调节加热速率和提高复温均匀性方面的效果。
