Maximizing Specific Loss Power for Magnetic Hyperthermia by Hard–Soft Mixed Ferrites

Abstract

Maximized specific loss power and intrinsic loss power approaching theoretical limits for alternating-current (AC) magnetic-field heating of nanoparticles are reported. This is achieved by engineering the effective magnetic anisotropy barrier of nanoparticles via alloying of hard and soft ferrites. 22 nm Co Mn Fe O /SiO nanoparticles reach a specific loss power value of 3417 W g at a field of 33 kA m and 380 kHz. Biocompatible Zn Fe O /SiO nanoparticles achieve specific loss power of 500 W g and intrinsic loss power of 26.8 nHm kg at field parameters of 7 kA m and 380 kHz, below the clinical safety limit. Magnetic bone cement achieves heating adequate for bone tumor hyperthermia, incorporating an ultralow dosage of just 1 wt% of nanoparticles. In cellular hyperthermia experiments, these nanoparticles demonstrate high cell death rate at low field parameters. Zn Fe O /SiO nanoparticles show cell viabilities above 97% at concentrations up to 500 µg mL within 48 h, suggesting toxicity lower than that of magnetite.

The cell uptake properties and hyperthermia performance of Zn 0.5 Fe 2.5 O 4 /SiO 2 nanoparticles as magnetic hyperthermia agents

“…As mentioned above, these NPs were designed to induce tumour cells to die by the mechanical rotation. Meanwhile, there were also plenty of NPs designed to kill tumour cells by the local temperature rise [10,11,28]. Thus, we further investigate the relationship between the internalization and hyperthermia performance, then try to figure out which mechanism acts as the main role of Zn 0. without NPs and human osteosarcoma MG-63 cells with NPs but without AMF were used as negative and positive control groups, respectively.…”

Polyethylene glycol-coated porous magnetic nanoparticles for targeted delivery of chemotherapeutics under magnetic hyperthermia condition

“…, which is significantly higher than the clinical safety limit of 13 kAÁm À1 . However, the AMF strength required to melt the polymeric shell could be reduced in further studies by replacing the magnetite core with Zn.Fe.O or Co.Mn.Fe.O hard-soft mixed ferrites, which can present the SAR values of above 500 WÁg À1 at clinically relevant AMF strengths [40].…”

Transient Magnetothermal Neuronal Silencing Using the Chloride Channel Anoctamin 1 (TMEM16A)

“…Nanoparticles with higher heating efficiency are still being developed, lowering the AMF requirements ( Lee et al, 2011 ; Chen R. et al, 2013 ; Zhang et al, 2015 ; He et al, 2018 ). An upper limit of AMF power was determined by its effect on biological tissue, which depends on the product of AMF field strength and frequency ( Young et al, 1980 ), while the heating capacity of the magnetic nanoparticles is generally given by the product of the square of field strength and frequency ( Rosensweig, 2002 ).…”