# Magnetic Nanoparticles as Mediators for Magnetic Hyperthermia Therapy Applications: A Status Review
## 1 Introduction
This finding was based on the observation that the growth of cancer cells can be stopped at a temperature above 42 \({}^{\circ}\)C, while healthy cells survive at higher temperatures. Thermal energy is generated by magnetic particles adhering to diseased tissue exposed to an AMF. The basis of this method is the irradiation of cancerous tissue with implanted magnetic material in the form of magnetic particles or MNPs in an AMF. The amount of thermal energy released depends on the type of magnetic material and the parameters of the magnetic field. MH is a therapy in which tissue temperature can be increased by exposing MNPs to an alternating magnetic field (AMF). The final heating temperature achieved depends on the Curie temperature (\(T_{\text{C}}\)) of the MNPs [99]. This method must overcome two problems: the temperature increase must be strictly limited only in the target region so that all other regions are not affected, and the temperature must be controlled inside and outside the target region. Self-regulation MH is a phenomenon in which the \(T_{\text{C}}\) changes with the changing chemical composition of the MNPs. Magnetic materials lose their magnetic properties above \(T_{\text{C}}\), so magnetic heating is stopped. This type of therapy results in the death of cancer cells with minimal damage to surrounding healthy tissue [100; 101; 102]. The most important feature of magnetic hyperthermia is the fact that it is thermal energy generated in a well-defined space associated with the distribution of magnetic particles that we can design. In magnetic hyperthermia, in which magnetic nanoparticles are involved, four different mechanisms are mainly active, depending on the morphology of the magnetic particles and the frequencies of the alternating magnetic field: eddy losses, hysteresis losses, relaxation losses, and resonance losses, but these are small due to the relatively low frequencies. The main characteristic of magnetic particles in an alternating magnetic field is their heating and the conversion of magnetic energy into thermal energy, which heats their surroundings. In particular, the absorption rate of magnetic energy, which is then reflected in the heating of samples, is represented by the parameter \"specific absorption rate\" (SAR). This describes the heating ability of the corresponding material--MNPs--or the SAR that we consider to be the average absorbed power, not the unit mass of the material at the time it is exposed to a fluctuating magnetic field [103; 104; 105]. Despite all the biomedical applications of superparamagnetic nanoparticles, this short review mainly focuses on the superparamagnetic Fe\({}_{2}\)O\({}_{3}\), Mg\({}_{1+x}\)Fe\({}_{2-2x}\)Ti\({}_{3}\)O\({}_{4}\), Ni\({}_{1-x}\)Cu\({}_{x}\), and Cr\({}_{x}\)Ni\({}_{1-x}\) MNPs synthesized by various synthesis methods and their applications in MH. With this brief review, we have aimed to show the relationship between the synthesis routes, surface chemistry, magnetic properties, and \(T_{\rm C}\), which is near or in the therapeutic range of superparamagnetic nanoparticles. We wanted to explain their influence on the heating efficiency when they are only under the influence of an external alternating magnetic field.