Fe-Cr-Nb-B ferromagnetic particles with shape anisotropy for cancer cell destruction by magneto-mechanical actuation

Abstract

We introduce a new type of magnetic particles (MPs) prepared by wet milling of superferromagnetic Fe-Cr-Nb-B precursor glassy ribbons for cancer treatment by magneto-mechanical actuation in low magnetic fields (1 ÷ 20 Oe). The rectangular shapes of MPs and the superferromagnetism of the glassy alloys of which are made the MPs induce important magnetic shape anisotropies which, in association with a large saturation magnetization, generate an improved torque in a rotating magnetic field, producing important damages on the cellular viability of MG-63 human osteosarcoma (HOS) cells. The specific parameters such as MPs concentration, frequency and intensity of the applied magnetic field, or the time of exposure have a strong influence on the cancer cells viability. The specific behavior of the Fe-Cr-Nb-B MPs offers them destructive effect even in low magnetic fields such as 10 Oe, and this characteristic allows the use of coils systems which provide large experimental spaces. The novel MPs are used for the magneto-mechanical actuation alone or in association with hyperthermia, but also can be transported to the tumor sites by means of stem cells carriers.

Cancer treatment by magneto-mechanical effect of particles, a review

“…32 Similarly, a comparison between 10 and 30 min of treatment showed a better in vitro effect for 30 min, 33 although the best effect obtained was a 5% decrease in cell viability, which is rather low. Exposure times of less than 20 min were also tested, 49,52 and revealed a linear relationship between cell viability and exposure time. In conclusion, cell viability decreases with increased time of exposure to magnetic eld.…”

“…Although without statistical validation, we can observe some trends based on all the in vitro studies. As shown in Table 2 (column 6), apoptosis represents, in most cases, the latest stage of the above cited cellular perturbations, 21,22,25,27,30,32,[36][37][38][39][40][41][42][43]46,[50][51][52] however with variable rates of cancer cells mortality (or viability). Some of the studies show the induction of necrosis onlysuch as necrotic membrane disruption, cell membrane leakage or cell lysis.…”

Magnetic-field-assisted synthesis of anisotropic iron oxide particles: Effect of pH

“…Nanorods often have stronger magnetic properties and a larger length-scale of the locally induced magnetic field in comparison to nanospheres with a similar volume, providing an enhanced MRI contrast [ 11 , 19 , 23 ], higher specific adsorption rate in magnetic hyperthermia [ 13 ], and better separation efficiency in magnetic separation of immune cells [ 16 ]. Nanorods have been demonstrated to be effective in mechanically triggering tumoral cell death upon the application of low-frequency magnetic fields [ 24 – 25 ], which has not yet been observed in their spherical counterparts. In drug delivery, the elongated particles demonstrate a stronger binding to and an enhanced retention at the target sites [ 26 ] due to their larger contact area and multidentate interactions with the cell membranes.…”

Colloidal Stability of Aqueous Suspensions of Polymer-Coated Iron Oxide Nanorods: Implications for Biomedical Applications

“…On the other hand, the rod-like particle shape gives rise to several specific biomedical applications hardly possible with spherical particles. In particular, they have been successfully used for mechanical destruction of tumor cells under low-frequency applied magnetic fields [8][9][10] . As another example, hemozoin and βhaematin nanorods (naturally produced by the human body) are markers of malaria decease and have been successfully detected by magnetic field induced optical dichroism of blood samples contaminated by malaria parasites 11 .…”