Silica Coating of Ferromagnetic Iron Oxide Magnetic Nanoparticles Significantly Enhances Their Hyperthermia Performances for Efficiently Inducing Cancer Cells Death In Vitro

• Published in: Pharmaceutics Vol. 13; no. 12; p. 2026
• Main Authors: Iacoviță, Cristian, Fizeșan, Ionel, Nitica, Stefan, Florea, Adrian, Barbu-Tudoran, Lucian, Dudric, Roxana, Pop, Anca, Vedeanu, Nicoleta, Crisan, Ovidiu, Tetean, Romulus, Loghin, Felicia, Lucaciu, Constantin Mihai
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 27.11.2021; MDPI
• Subjects: alamar blue; Biocompatibility; cancer cells; Cancer therapies; Clinical trials; Cytotoxicity; Ethanol; Fever; Fourier transforms; Hyperthermia; iron oxide magnetic nanoparticles; magnetic hyperthermia; Microemulsions; Nanoparticles; neutral red; Polyethylene glycol; silica coating; Spectrum analysis; Transmission electron microscopy; United Kingdom > UK; United States > US; Germany; A35; neutral red; alamar blue; A549; BJ; cancer cells; silica coating; iron oxide magnetic nanoparticles; magnetic hyperthermia
• ISSN: 1999-4923; 1999-4923
• DOI: 10.3390/pharmaceutics13122026

Increasing the biocompatibility, cellular uptake, and magnetic heating performance of ferromagnetic iron-oxide magnetic nanoparticles (F-MNPs) is clearly required to efficiently induce apoptosis of cancer cells by magnetic hyperthermia (MH). Thus, F-MNPs were coated with silica layers of different thicknesses via a reverse microemulsion method, and their morphological, structural, and magnetic properties were evaluated by multiple techniques. The presence of a SiO layer significantly increased the colloidal stability of F-MNPs, which also enhanced their heating performance in water with almost 1000 W/g as compared to bare F-MNPs. The silica-coated F-MNPs exhibited biocompatibility of up to 250 μg/cm as assessed by Alamar Blues and Neutral Red assays on two cancer cell lines and one normal cell line. The cancer cells were found to internalize a higher quantity of silica-coated F-MNPs, in large endosomes, dispersed in the cytoplasm or inside lysosomes, and hence were more sensitive to in vitro MH treatment compared to the normal ones. Cellular death of more than 50% of the malignant cells was reached starting at a dose of 31.25 μg/cm and an amplitude of alternating magnetic field of 30 kA/m at 355 kHz.