Fe-Cr-Nb-B Ferrofluid for Biomedical Applications

Abstract

A ferrofluid based on Fe67.2Cr12.5Nb0.3B20 magnetic particles with a low Curie temperature was prepared. The particles, most of which had dimensions under 60 nm, were dispersed in a calcium gluconate solution, leading to a stable ferrofluid. The obtained ferrofluid had a magnetization of 0.04 to 0.17 emu/cm3, depending on the particles’ concentration, and a viscosity that increased nonlinearly with the applied magnetic field. The ferrofluid appeared to be biocompatible, as it showed low cytotoxicity, even at high concentrations and for long intervals of co-incubation with human cells, demonstrating a good potential to be used for cancer therapies through magnetic hyperthermia as well as magneto-mechanical actuation.

Fe-Cr-Nb-B Magnetic Particles and Adipose-Derived Mesenchymal Cells Trigger Cancer Cell Apoptosis by Magneto-Mechanical Actuation

“…Ferrofluid preparation. An amount of 80 mg of Fe-Cr-Nb-B MPs obtained by milling in oleic acid, as described above, were washed 3 times with NaOH 5% to remove the oleic acid excess from the particle surface, followed by washing with deionized water until a pH of 7 was reached [19]. MPs were separated with a magnet, and the water was removed and replaced with 1 mL of calcium gluconate solution, 94 mg/mL.…”

“…They have non-zero coercivity at room temperature, large magnetic susceptibility, and a low Curie temperature [15]. The Fe-Cr-Nb-B MPs were used to prepare a ferrofluid (FF), which ensures good dispersion and prevents agglomeration [19] when the MPs are added to the cell culture medium. Calcium gluconate was used as a dispersion medium due to its biocompatibility [24].…”

“…Given these results, all subsequent experiments were performed using a concentration of 1 mg/mL MPs added to cell culture media. These particles were previously evaluated for biocompatibility, and they showed no cytotoxic effects on any of the cells that they were tested on, even when higher concentrations were used, such as 5 mg/mL [9,19].…”

Cancer Cell Destruction by Magneto-Mechanical Actuation of Nanowires Compared with Nano/Micromagnetic Particles

“…We prepared Fe67.2Cr12.5Nb0.3B20 magnetic particles by milling amorphous melt-spun ribbons in oleic acid, using a Retsch 200 high-energy ball mill. The MPs were dispersed in calcium gluconate to obtain a ferrofl uid that was added in cell culture media [6]. Fe64.5Co35.5 Nanowires (NW) with lengths, 4 microns were obtained by electrolytic deposition in alumina membranes with a pore diameter of 200 nm.…”

Biocompatible Ferrofluid‐Based Millirobot for Tumor Photothermal Therapy in Near‐Infrared‐II Window

“…[44,45] Ferrofluids have been the subject of recent research, with particular emphasis on their biocompatibility and potential for targeted therapeutic applications. [46][47][48] However, additional investigations are required to develop biocompatible oil-based ferrofluids and to address systematic issues such as motion control and cure efficiency in the context of targeted therapeutic interventions.…”