Villanueva Danny, G Gubieda Alicia, Gandarias Lucía, Abad Díaz de Cerio Ana, Orue Iñaki, Ángel García José, de Cos David, Alonso Javier, Fdez-Gubieda M Luisa
Departamento de Electricidad y Electrónica, Universidad del País Vasco (UPV/EHU), 48940 Leioa, Spain.
Departamento de Inmunología, Microbiología y Parasitología, Universidad del País Vasco (UPV/EHU), 48940 Leioa, Spain.
ACS Appl Mater Interfaces. 2024 Dec 11;16(49):67216-67224. doi: 10.1021/acsami.4c13152. Epub 2024 Nov 26.
Magnetotactic bacteria have been proposed as ideal biological nanorobots due to the presence of an intracellular chain of magnetic nanoparticles (MNPs), which allows them to be guided and controlled by external magnetic fields and provides them with theragnostic capabilities intrinsic to magnetic nanoparticles, such as magnetic hyperthermia for cancer treatment. Here, we study three different bacterial species, (MSR-1), (AMB-1), and (MV-1), which synthesize magnetite nanoparticles with different morphologies and chain arrangements. We analyzed the impact of these parameters on the effective magnetic anisotropy, , and the heating capacity or Specific Absorption Rate, SAR, under alternating magnetic fields. SAR values have been obtained from the area of experimental AC hysteresis loops, while has been determined from simulations of AC hysteresis loops using a dynamic Stoner-Wohlfarth model. The results demonstrate a clear relationship between the effective magnetic anisotropy and the heating efficiency of bacteria. As the value increases, the saturated SAR values are higher; however, the threshold magnetic field required to observe a SAR response simultaneously increases. This factor is crucial to choose a bacterial species as the optimal hyperthermia agent.
由于磁趋细菌细胞内存在磁性纳米颗粒（MNP）链，它们被认为是理想的生物纳米机器人。这种磁性纳米颗粒链使磁趋细菌能够被外部磁场引导和控制，并赋予它们磁性纳米颗粒固有的诊疗能力，如用于癌症治疗的磁热疗。在此，我们研究了三种不同的细菌物种，即（MSR - 1）、（AMB - 1）和（MV - 1），它们合成具有不同形态和链排列的磁铁矿纳米颗粒。我们分析了这些参数对有效磁各向异性以及在交变磁场下的加热能力或比吸收率（SAR）的影响。SAR值通过实验交流磁滞回线的面积获得，而则使用动态斯托纳 - 沃尔法模型通过交流磁滞回线模拟确定。结果表明有效磁各向异性与细菌的加热效率之间存在明显关系。随着值的增加，饱和SAR值更高；然而，同时观察到SAR响应所需的阈值磁场也会增加。这个因素对于选择一种细菌物种作为最佳热疗剂至关重要。
