Darwish Mohamed S A, Kim Hohyeon, Lee Hwangjae, Ryu Chiseon, Lee Jae Young, Yoon Jungwon
School of Integrated Technology, Gwangju Institute of Science and Technology, Gwangju 61005, Korea.
Petrochemicals Department, Egyptian Petroleum Research Institute, 1 Ahmed El-Zomor Street, El Zohour Region, Nasr City, Cairo 11727, Egypt.
Nanomaterials (Basel). 2019 Aug 16;9(8):1176. doi: 10.3390/nano9081176.
Magnetic nanoparticles (MNPs) that exhibit high specific loss power (SLP) at lower metal content are highly desirable for hyperthermia applications. The conventional co-precipitation process has been widely employed for the synthesis of magnetic nanoparticles. However, their hyperthermia performance is often insufficient, which is considered as the main challenge to the development of practicable cancer treatments. In particular, ferrite MNPs have unique properties, such as a strong magnetocrystalline anisotropy, high coercivity, and moderate saturation magnetization, however their hyperthermia performance needs to be further improved. In this study, cobalt ferrite (CoFeO) and zinc cobalt ferrite nanoparticles (ZnCoFeO) were prepared to achieve high SLP values by modifying the conventional co-precipitation method. Our modified method, which allows for precursor material compositions (molar ratio of Fe:Fe:Co/Zn of 3:2:1), is a simple, environmentally friendly, and low temperature process carried out in air at a maximum temperature of 60 °C, without the need for oxidizing or coating agents. The particles produced were characterized using multiple techniques, such as X-ray diffraction (XRD), dynamic light scattering (DLS), transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV-Vis spectroscopy), and a vibrating sample magnetometer (VSM). SLP values of the prepared nanoparticles were carefully evaluated as a function of time, magnetic field strength (30, 40, and 50 kA m), and the viscosity of the medium (water and glycerol), and compared to commercial magnetic nanoparticle materials under the same conditions. The cytotoxicity of the prepared nanoparticles by in vitro culture with NIH-3T3 fibroblasts exhibited good cytocompatibility up to 0.5 mg/mL. The safety limit of magnetic field parameters for SLP was tested. It did not exceed the 5 × 10 Am s threshold. A saturation temperature of 45 °C could be achieved. These nanoparticles, with minimal metal content, can ideally be used for in vivo hyperthermia applications, such as cancer treatments.
在较低金属含量下表现出高比损耗功率（SLP）的磁性纳米颗粒（MNPs）在热疗应用中极具吸引力。传统的共沉淀法已被广泛用于合成磁性纳米颗粒。然而，它们的热疗性能往往不足，这被认为是开发可行的癌症治疗方法的主要挑战。特别是，铁氧体MNPs具有独特的性质，如强磁晶各向异性、高矫顽力和适度的饱和磁化强度，但其热疗性能仍需进一步提高。在本研究中，通过改进传统的共沉淀法制备了钴铁氧体（CoFeO）和锌钴铁氧体纳米颗粒（ZnCoFeO），以实现高SLP值。我们改进的方法允许前驱体材料组成（Fe:Fe:Co/Zn的摩尔比为3:2:1），是一种简单、环保且低温的过程，在空气中于最高60°C的温度下进行，无需氧化剂或涂层剂。使用多种技术对所制备的颗粒进行了表征，如X射线衍射（XRD）、动态光散射（DLS）、透射电子显微镜（TEM）、紫外可见光谱（UV-Vis光谱）和振动样品磁强计（VSM）。仔细评估了所制备纳米颗粒的SLP值随时间、磁场强度（30、40和50 kA/m）以及介质（水和甘油）粘度的变化，并与相同条件下的商业磁性纳米颗粒材料进行了比较。通过与NIH-3T3成纤维细胞进行体外培养，所制备纳米颗粒的细胞毒性在浓度高达0.5 mg/mL时表现出良好的细胞相容性。测试了SLP的磁场参数安全极限。它未超过5×10 A/m·s的阈值。可实现45°C的饱和温度。这些金属含量极低的纳米颗粒非常适合用于体内热疗应用，如癌症治疗。
