Magnetic hyperthermia performance of magnetite nanoparticle assemblies under different driving fields

Abstract

The heating performance of magnetic nanoparticles (MNPs) under an alternating magnetic field (AMF) is dependent on several factors. Optimizing these factors improves the heating efficiency for cancer therapy and meanwhile lowers the MNP treatment dosage. AMF is one of the most easily controllable variables to enhance the efficiency of heat generation. This paper investigated the optimal magnetic field strength and frequency for an assembly of magnetite nanoparticles. For hyperthermia treatment in clinical applications, monodispersed NPs are forming nanoclusters in target regions where a strong magnetically interactive environment is anticipated, which leads to a completely different situation than MNPs in ferrofluids. Herein, the energy barrier model is revisited and Néel relaxation time is tailored for high MNP packing densities. AMF strength and frequency are customized for different magnetite NPs to achieve the highest power generation and the best hyperthermia performance.

Systemic Administration of Polyelectrolyte Microcapsules: Where Do They Accumulate and When? In Vivo and Ex Vivo Study

“…Obviously, the components of these multifunctional delivery systems should be responsive to local media or external stimuli. Use of externally guided nanostructured carriers for drug delivery is a promising method in bio-nanotechnology, which can be used in areas such as diagnostics of tumors [ 1 , 2 ] for enhanced contrast at MRI visualization [ 3 , 4 ], targeted delivery of drugs to specific organs and tissues [ 5 , 6 , 7 ] and for magnetic hyperthermia of tumors [ 8 , 9 , 10 ]. This research has been undertaken to illustrate the promise of addressed delivery to particular sites in the body with the help of magnetic nanoparticles externally navigated with a magnetic field [ 11 ], which might also work as an accomplishing method with biological targeting performed by conjugation of nanoparticles with tumor-specific antibodies, followed by accumulation of nanoparticles in the targets [ 12 ].…”

Study of heating curves generated by magnetite nanoparticles aiming application in magnetic hyperthermia

“…The heat dissipation in small particles is caused by a delay in the relaxation of the magnetic moment through the rotation inside the particle (Néel mechanism), (Kurgan and Gas 2015), by the rotation of the particle itself (Brown rotation, viscous losses) or hysteresis loss (Wu and Wang 2017). Hysteresis losses are due to the movement of domain walls that are responsible for heat dissipation in larger particles (Wu and Wang 2017). These relaxation mechanisms are observed when the magnetic particles are exposed to an AC magnetic field with reversal of the magnetic field in a period shorter than the time of relaxation of the particles (Sharifi et al 2012) and can be modeled by the Néel-Brown theory (Mahopatra et al 2019).…”

“…High SAR-value nanoparticles are favorable as they allow the use of a lower dosage of nanofluid for the appropriate temperature range to induce tumor cell apoptosis (Wu and Wang, 2017).…”

Effect of internal chain-like structures on magnetic hyperthermia in non-liquid media

“…The main idea behind this approach is in embedding magnetic nanoparticles in the tumour area and heating the particles (and the tumour cells) by an alternating magnetic field. Numerous investigations show that in the temperature range 42-50°C the tumour cells die, whereas the healthy cells survive [3][4][5][6][7]. This is the key point of the therapeutic effect.…”