Carbon-covered magnetic nanomaterials and their application for the thermolysis of cancer cells

Yang Xu¹, Meena Mahmood¹, Ashley Fejleh¹, Zhongrui Li¹, Fumiya Watanabe¹, Steve Trigwell², Reginald B Little³, Vasyl P Kunets⁴, Enkeleda Dervishi¹, Alexandru R Biris⁵, Gregory J Salamo⁴, Alexandru S Biris¹

¹Nanotechnology Center and Applied Science Department, University of Arkansas at Little Rock, Little Rock, AR, USA; ²Applied Science and Technology, ASRC Aerospace, NASA Kennedy Space Center, FL, USA; ³Department of Chemistry, Elizabeth City State University, Elizabeth City, NC, USA; ⁴Physics Department, University of Arkansas, Fayetteville, AR, USA; ⁵National Institute for Research and Development of Isotopic and Molecular Technologies, Cluj Napoca, Romania

Abstract: Three types of graphitic shelled-magnetic core (Fe, Fe/Co, and Co) nanoparticles (named as C-Fe, C-Fe/Co, and C-Co NPs) were synthesized by radio frequency-catalytic chemical vapor deposition (RF-cCVD). X-ray diffraction and X-ray photoelectron spectroscopy analysis revealed that the cores inside the carbon shells of these NPs were preserved in their metallic states. Fluorescence microscopy images indicated effective penetrations of the NPs through the cellular membranes of cultured cancer HeLa cells, both inside the cytoplasm and the nucleus. Low RF radiation of 350 kHz induced localized heating of the magnetic NPs, which triggered cell death. Apoptosis inducement was found to be dependent on the RF irradiation time and NP concentration. It was showed that the Fe-C NPs had a much higher ability of killing the cancer cells (over 99%) compared with the other types of NPs (C-Co or C-Fe/Co), even at a very low concentration of 0.83 μg/mL. The localized heating of NPs inside the cancer cells comes from the hysteresis heating and resistive heating through eddy currents generated under the RF radiation. The RF thermal ablation properties of the magnetic NPs were correlated with the analysis provided by a superconducting quantum interference device (SQUID).

Keywords: graphitic shelled, magnetic nanoparticles, radio frequency, thermal ablation, HeLa cells