Institute of Biomedical Engineering, National Taiwan University, No1, Section 1, Jen-Ai Rd., Taipei 100, Taiwan. Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine Baltimore, MD 21231, United States of America.
Nanotechnology. 2018 Sep 14;29(37):375101. doi: 10.1088/1361-6528/aacda1. Epub 2018 Jun 19.
HepG2 cell death with magnetic hyperthermia (MHT) using hydroxyapatite nanoparticles (mHAPs) and alternating magnetic fields (AMF) was investigated in vitro. The mHAPs were synthesized as thermo-seeds by co-precipitation with the addition of Fe. The grain size of the HAPs and iron oxide magnetic were 39.1 and 19.5 nm and were calculated by the Scherrer formula. The HepG2 cells were cultured with mHAPs and exposed to an AMF for 30 min yielding maximum temperatures of 43 ± 0.5 °C. After heating, the cell viability was reduced by 50% relative to controls, lactate dehydrogenase (LDH) concentrations measured in media were three-fold greater than those measured in all control groups. Readouts of toxicity by live/dead staining were consistent with cell viability and LDH assay results. Measured reactive oxygen species (ROS) in cells exposed to MHT were two-fold greater than in control groups. Results of cDNA microarray and Western blotting revealed tantalizing evidence of ATM and GADD45 downregulation with possible MKK3/MKK6 and ATF-2 of p38 MAPK inhibition upon exposure to mHAPs and AMF combinations. These results suggest that the combination of mHAPs and AMF can increase intracellular concentrations of ROS to cause DNA damage, which leads to cell death that complement heat stress related biological effects.
体外研究了磁性热疗（MHT）联合羟磷灰石纳米粒子（mHAPs）和交变磁场（AMF）对 HepG2 细胞的杀伤作用。mHAPs 是通过共沉淀法合成的热种子，其中添加了 Fe。通过谢乐公式计算出 HAPs 和氧化铁磁性的晶粒尺寸分别为 39.1nm 和 19.5nm。将 HepG2 细胞与 mHAPs 共培养，并在 AMF 下暴露 30 分钟，达到 43±0.5°C 的最高温度。加热后，细胞活力相对于对照组降低了 50%，培养基中测量的乳酸脱氢酶（LDH）浓度比所有对照组都高出三倍。活/死染色的毒性读数与细胞活力和 LDH 测定结果一致。暴露于 MHT 的细胞中测量到的活性氧（ROS）是对照组的两倍。cDNA 微阵列和 Western blot 的结果表明，ATM 和 GADD45 的下调具有诱人的证据，并且可能在 mHAPs 和 AMF 联合作用下抑制了 MKK3/MKK6 和 p38 MAPK 的 ATF-2。这些结果表明，mHAPs 和 AMF 的联合作用可以增加细胞内 ROS 浓度，导致 DNA 损伤，从而导致细胞死亡，补充了与热应激相关的生物学效应。
