Abstract
The clinical translation of magnetic hyperthermia (MH) needs magnetic nanoparticles (MNPs) with enhanced heating properties and good biocompatibility. Many studies were devoted lately to the increase in the heating power of iron oxide MNPs by doping the magnetite structure with divalent cations. A series of MNPs with variable Zn/Fe molar ratios (between 1/10 and 1/1) were synthesized by using a high-temperature polyol method, and their physical properties were studied with different techniques (Transmission Electron Microscopy, X-ray diffraction, Fourier Transform Infrared Spectroscopy). At low Zn doping (Zn/Fe ratio 1/10), a significant increase in the saturation magnetization (90 e.m.u./g as compared to 83 e.m.u./g for their undoped counterparts) was obtained. The MNPs’ hyperthermia properties were assessed in alternating magnetic fields up to 65 kA/m at a frequency of 355 kHz, revealing specific absorption rates of up to 820 W/g. The Zn ferrite MNPs showed good biocompatibility against two cell lines (A549 cancer cell line and BJ normal cell line) with a drop of only 40% in the viability at the highest dose used (500 μg/cm2). Cellular uptake experiments revealed that the MNPs enter the cells in a dose-dependent manner with an almost 50% higher capacity of cancer cells to accommodate the MNPs. In vitro hyperthermia data performed on both cell lines indicate that the cancer cells are more sensitive to MH treatment with a 90% drop in viability after 30 min of MH treatment at 30 kA/m for a dose of 250 μg/cm2. Overall, our data indicate that Zn doping of iron oxide MNPs could be a reliable method to increase their hyperthermia efficiency in cancer cells.
Highlights
We have recently shown that the polyol method performed at elevated temperature (300 ◦ C) and high pressure enables the formation of polyhedral Fe3 O4 particles with enhanced magnetic and hyperthermia properties [47]
The Zn ferrites (ZnF) particles were imaged by Transmission Electron Microscopy (TEM), while their size distribution histograms were determined from 200 particles per sample on TEM images and fitted by a log-normal function
A series of magnetic nanoparticles with different zinc doping levels were successfully synthesized by the polyol method
Summary
Have been centered on the development of Fe3 O4 particles, exhibiting different sizes, shapes, and morphologies being either in a superparamagnetic (SP) or ferromagnetic (F) state at room temperature (RT), with the final aim of improving the therapeutic efficiency [8–12]. As proven by both in vitro and in vivo studies, the mobility of SP-Fe3 O4 particles, responsible for Brownian relaxation, is inhibited when they are internalized into tumor cells, causing a decrease of the heating efficiency because the SP-Fe3 O4 particles can only undergo Néel relaxation. In the case of F-Fe3 O4 particles, the intracellular clustering leads to a decrease in their heating efficiency as well [13]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
