High intrinsic loss power of multicore magnetic nanoparticles with blood-pooling property for hyperthermia

Kizuku Nishimoto,Yasushi Takemura,Ryoji Takeda,Satoshi Ota,Guannan Shi,Suko Bagus Trisnanto,Tsutomu Yamada

doi:10.1063/1.5079875

Kizuku Nishimoto, Yasushi Takemura + Show 5 more

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https://doi.org/10.1063/1.5079875

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Abstract

Magnetic hyperthermia is a promising application of magnetic nanoparticles (MNPs) in cancer therapy. It is important to consider and optimize the parameters that affect heat dissipation, such as particle diameters, structures, and surface coatings. In this study, we measured the magnetic properties of two superparamagnetic nanoparticles under DC and AC magnetic fields. Resovist is approved to be used as a magnetic resonance imaging contrast agent. CMEADM-033-02, with the blood-pooling property and biocompatibility, exhibits high magnetization. The blood-pooling property makes it easier for MNPs to accumulate in tumors and tissue. While preparing samples, we aligned the easy axis of the samples using a DC magnetic field to enhance heat dissipation. We discussed the magnetic property in terms of magnetic relaxation associated with anisotropy energy. We observed that the peak frequency of Néel relaxation was considerably shifted owing to effectively changed anisotropy by the alignment of the easy axis. However, the change in the peak frequency of Néel relaxation could not be directly confirmed. Furthermore, we calculated the intrinsic loss power (ILP) and specific loss power (SLP) for heat dissipation from the areas of AC magnetization curves and estimated the SLP at 1 MHz to compare with the high heating characteristic of ILP that has been reported in a conventional study. We achieved equivalent ILP for heat dissipation as that reported in the study by aligning the easy axis of the MNPs with the blood-pooling property under a therapeutic condition.

Highlights

One of expected applications of magnetic nanoparticles (MNPs) is magnetic fluid hyperthermia (MFH), which is based on the heat mechanism caused by the rotation of MNPs under an AC magnetic field.1–3 It has been investigated that heat dissipation is affected by core and hydrodynamic diameters,4 structures,5 coatings,6 dipolar interactions,7,8 and accumulation of MNPs.9,10 Optimizing these effects associated with heat dissipation is indispensable for MFH
We calculated the intrinsic loss power (ILP) and specific loss power (SLP) for heat dissipation from the areas of AC magnetization curves and estimated the SLP at 1 MHz to compare with the high heating characteristic of ILP that has been reported in a conventional study
This negatively charged MNP has been developed as a contrast agent for magnetic resonance imaging, and it exhibits longer pooling in blood vessels

Summary

Introduction

One of expected applications of magnetic nanoparticles (MNPs) is magnetic fluid hyperthermia (MFH), which is based on the heat mechanism caused by the rotation of MNPs under an AC magnetic field. It has been investigated that heat dissipation is affected by core and hydrodynamic diameters, structures (e.g., multicore, core-shell, chain), coatings, dipolar interactions, and accumulation of MNPs. Optimizing these effects associated with heat dissipation is indispensable for MFH. It has been investigated that heat dissipation is affected by core and hydrodynamic diameters, structures (e.g., multicore, core-shell, chain), coatings, dipolar interactions, and accumulation of MNPs.. It has been investigated that heat dissipation is affected by core and hydrodynamic diameters, structures (e.g., multicore, core-shell, chain), coatings, dipolar interactions, and accumulation of MNPs.9,10 Optimizing these effects associated with heat dissipation is indispensable for MFH. CMEADM-033-02 exhibits the blood-pooling property, which arises owing to surface coatings.11 This negatively charged MNP has been developed as a contrast agent for magnetic resonance imaging, and it exhibits longer pooling in blood vessels. We could obtain high specific loss power (SLP) under a therapeutic condition This value was comparable to the high value reported for the MNPs with the nanoflower structure.

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