Insights into the synthesis optimization of Fe@SiO2 Core-Shell nanostructure as a highly efficient nano-heater for magnetic hyperthermia treatment

Magnetic hyperthermia in cancer therapy, mechanisms, and recent advances: A review

Hyperthermia therapy refers to the elevating of a region in the body for therapeutic purposes. Different techniques have been applied for hyperthermia therapy including laser, microwave, radiofrequency, ultrasonic, and magnetic nanoparticles and the latter have received great attention in recent years. Magnetic hyperthermia in cancer therapy aims to increase the temperature of the body tissue by locally delivering heat from the magnetic nanoparticles to cancer cells with the aid of an external alternating magnetic field to kill the cancerous cells or prevent their further growth. This review introduces magnetic hyperthermia with magnetic nanoparticles. It includes the mechanism of the operation and magnetism behind the magnetic hyperthermia phenomenon. Different synthesis methods and surface modification to enhance the biocompatibility, water solubility, and stability of the nanoparticles in physiological environments have been discussed. Recent research on versatile types of magnetic nanoparticles with their ability to increase the local temperature has been addressed.

Advances in the Optimization of Fe Nanoparticles: Unlocking Antifungal Properties for Biomedical Applications

In recent years, nanotechnology has achieved a remarkable status in shaping the future of biological applications, especially in combating fungal diseases. Owing to excellence in nanotechnology, iron nanoparticles (Fe NPs) have gained enormous attention in recent years. In this review, we have provided a comprehensive overview of Fe NPs covering key synthesis approaches and underlying working principles, the factors that influence their properties, essential characterization techniques, and the optimization of their antifungal potential. In addition, the diverse kinds of Fe NP delivery platforms that command highly effective release, with fewer toxic effects on patients, are of great significance in the medical field. The issues of biocompatibility, toxicity profiles, and applications of optimized Fe NPs in the field of biomedicine have also been described because these are the most significant factors determining their inclusion in clinical use. Besides this, the difficulties and regulations that exist in the transition from laboratory to experimental clinical studies (toxicity, specific standards, and safety concerns) of Fe NPs-based antifungal agents have been also summarized.

Engineering Gold Shelled Nanomagnets for Pre-Setting the Operating Temperature for Magnetic Hyperthermia

This study investigated the fabrication of spherical gold shelled maghemite nanoparticles for use in magnetic hyperthermia (MHT) assays. A maghemite core (14 ± 3 nm) was used to fabricate two samples with different gold thicknesses, which presented gold (g)/maghemite (m) content ratios of 0.0376 and 0.0752. The samples were tested in MHT assays (temperature versus time) with varying frequencies (100-650 kHz) and field amplitudes (9-25 mT). The asymptotic temperatures (T∞) of the aqueous suspensions (40 mg Fe/mL) were found to be in the range of 59-77 °C (naked maghemite), 44-58 °C (g/m=0.0376) and 33-51 °C (g/m=0.0752). The MHT data revealed that T∞ could be successful controlled using the gold thickness and cover the range for cell apoptosis, thereby providing a new strategy for the safe use of MHT in practice. The highest SAR (specific absorption rate) value was achieved (75 kW/kg) using the thinner gold shell layer (334 kHz, 17 mT) and was roughly twenty times bigger than the best SAR value that has been reported for similar structures. Moreover, the time that was required to achieve T∞ could be modeled by changing the thermal conductivity of the shell layer and/or the shape/size of the structure. The MHT assays were pioneeringly modeled using a derived equation that was analytically identical to the Box-Lucas method (which was reported as phenomenological).

Effects of axial pressure on the evolution of core-shell heterogeneous structures and magnetic properties of Fe-Si soft magnetic powder cores during hot-press sintering

Silicon dioxide (SiO2) has attracted much attention as an ideal coating material for iron (Fe)-based soft magnetic powder cores (SMPCs). However, maintaining the integrity and uniformity of Fe-based/SiO2 core-shell heterostructures is still a challenge. The evolution mechanism of core-shell heterostructures determines the performance of Fe-based SMPCs. Herein, the evolution of the core-shell structures and heterogeneous interfaces of Fe-Si@SiO2 SMPCs with axial pressure and the influence of the evolution on the SMPCs performance were investigated. The results show that in the axial pressure range of 10-15 kN, the core-shell heterostructures were gradually integrated, whereas the SiO2 insulation coatings underwent an amorphous-to-crystalline transformation. At axial pressure above 16 kN, the Fe-Si powder melted partially, and the core-shell heterostructure collapsed due to overheating, caused by the gradient temperature field during the hot-press sintering. When the core-shell heterostructure was intact, the Fe-Si@SiO2 SMPCs showed a permeability of over 38 with a wide and stable frequency range of 100-300 kHz, a saturation magnetisation of 231.7 emu g-1, resistivity of 0.8 mΩ cm and total loss of 704.7 kW m-3 at 10 mT and 100 kHz. When the core-shell heterostructure was destroyed, the resistivity dropped dramatically and the loss increased to 765.0 and 897.4 kW m-3. These results show the relationship between the core-shell heterostructure of Fe-Si@SiO2 SMPCs, axial pressure and magnetic properties, which would be vital in achieving high power density, high efficiency and miniaturisation in SMPCs.

An Overview of the Production of Magnetic Core-Shell Nanoparticles and Their Biomedical Applications

Several developments have recently emerged for core-shell magnetic nanomaterials, indicating that they are suitable materials for biomedical applications. Their usage in hyperthermia and drug delivery applications has escalated since the use of shell materials and has several beneficial effects for the treatment in question. The shell can protect the magnetic core from oxidation and provide biocompatibility for many materials. Yet, the synthesis of the core-shell materials is a multifaceted challenge as it involves several steps and parallel processes. Although reviews on magnetic core-shell nanoparticles exist, there is a lack of literature that compares the size and shape of magnetic core-shell nanomaterials synthesized via various methods. Therefore, this review outlines the primary synthetic routes for magnetic core-shell nanoparticles, along with the recent advances in magnetic core-shell nanomaterials. As core-shell nanoparticles have been proposed among others as therapeutic nanocarriers, their potential applications in hyperthermia drug delivery are discussed.