Theoretical Study on Specific Loss Power and Heating Temperature in CoFe2O4 Nanoparticles as Possible Candidate for Alternative Cancer Therapy by Superparamagnetic Hyperthemia

Abstract

In this paper, we present a theoretical study on the maximum specific loss power in the admissible biological limit (PsM)l for CoFe2O4 ferrimagnetic nanoparticles, as a possible candidate in alternative and non-invasive cancer therapy by superparamagnetic hyperthermia. The heating time of the nanoparticles (Δto) at the optimum temperature of approx. 43 °C for the efficient destruction of tumor cells in a short period of time, was also studied. We found the maximum specific loss power PsM (as a result of superparamegnetic relaxation in CoFe2O4 nanoparticles) for very small diameters of the nanoparticles (Do), situated in the range of 5.88–6.67 nm, and with the limit frequencies (fl) in the very wide range of values of 83–1000 kHz, respectively. Additionally, the optimal heating temperature (To) of 43 °C was obtained for a very wide range of values of the magnetic field H, of 5–60 kA/m, and the corresponding optimal heating times (Δto) were found in very short time intervals in the range of ~0.3–44 s, depending on the volume packing fraction (ε) of the nanoparticles. The obtained results, as well as the very wide range of values for the amplitude H and the frequency f of the external alternating magnetic field for which superparamagnetic hyperthermia can be obtained, which are great practical benefits in the case of hyperthermia, demonstrate that CoFe2O4 nanoparticles can be successfully used in the therapy of cancer by superaparamagnetic hyperthermia. In addition, the very small size of magnetic nanoparticles (only a few nm) will lead to two major benefits in cancer therapy via superparamagnetic hyperthermia, namely: (i) the possibility of intracellular therapy which is much more effective due to the ability to destroy tumor cells from within and (ii) the reduced cell toxicity.

Study on Maximum Specific Loss Power in Fe3O4 Nanoparticles Decorated with Biocompatible Gamma-Cyclodextrins for Cancer Therapy with Superparamagnetic Hyperthermia

“…The results obtained depending on the frequency show a shift of the maximum specific loss power towards smaller values of the nanoparticles diameter, respectively from 18.1 nm to 16.2 nm, when the frequency of the magnetic field increases in the range 100-500 kHz (Figure 9a), simultaneously with the almost linear increase of the maximum specific loss power (Figure 9b). A similar variation in the diameter of nanoparticles DM was observed both in the case of F3O4 nanoparticles [37] and in the case of CoFe2O4 nanoparticles [52]. However, in the case of Fe3O4 nanoparticles coated with γ-CDs it is found that there is a difference between the diameter values corresponding to the maximum specific loss power compared with the case of Fe3O4 nanoparticles, a difference that increases as the frequency decreases at 100 kHz.…”

“…This difference obtained in the case of bionanoparticles of Fe3O4-γ-CDs is due to the presence of the organic layer of CDs at the surface of the nanoparticles, which contributes through its thickness to the hydrodynamic diameter and implicitly to the Brown relaxation mechanisms. As a result, the maximum specific loss power shifts to A similar variation in the diameter of nanoparticles D M was observed both in the case of F 3 O 4 nanoparticles [37] and in the case of CoFe 2 O 4 nanoparticles [52]. However, in the case of Fe 3 O 4 nanoparticles coated with γ-CDs it is found that there is a difference between the diameter values corresponding to the maximum specific loss power compared with the case of Fe 3 O 4 nanoparticles, a difference that increases as the frequency decreases at 100 kHz.…”

“…In conclusion, in order to obtain the maximum efficiency in superparamagnetic hyperthermia with Fe3O4-γ-CDs bionanoparticles, the optimal conditions established above must be achieved: the magnetic field must be in the range 5-25 kA/m, the frequency in the range 200-500 kHz or even up to 1000 kHz, under the condition given by Equation (10), and the diameter of the bionanoparticles should be in the range 16.2-17.1 nm or even up to 15.5 nm. Thus, the values obtained for the maximum specific loss powers in the range of 5-25 kA/m are sufficient for the rapid heating, necessary in magnetic hyperthermia for the irreversible destruction of tumor cells by apoptosis [54,55], of magnetic nanoparticles [52] to temperatures of 42.5-43 °C.…”

Magnetite Nanoparticles in Magnetic Hyperthermia and Cancer Therapies: Challenges and Perspectives

“…With precise delivery of microwave radiation to the desired place, localization of hyperthermia to the pathological site is possible. Among the magnetic nanoparticles, due to the magnetic properties and efficiency in energy dissipation (in this case, the conversion of magnetic energy into thermal energy), the most promising seems to be magnetite-based (Fe 3 O 4 ) [ 105 ]. There are also other significant features of Fe 3 O 4 nanoparticles that can be used in treatment.…”

Fe3O4-PAA–(HP-γ-CDs) Biocompatible Ferrimagnetic Nanoparticles for Increasing the Efficacy in Superparamagnetic Hyperthermia

“…Nevertheless, Fe 3 O 4 NPs are usually coated with different hydrophilic layers to ensure a lack of interactions between the nanoparticles (van der Waals and magnetic dipole-dipole, which lead to agglomerates) and the colloidal stability [ 7 ]. Fe 3 O 4 ferrimagnetic nanoparticles smaller than 30–50 nm have been found to be targeted for magnetic hyperthermia and superparamagnetic hyperthermia [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ], but many other studies have been carried out to find other suitable ferrimagnetic nanoparticles or those more suitable than magnetite, both in terms of thermal efficiency and cell toxicity [ 24 , 25 , 26 , 27 , 28 , 29 , 30 ]. Research in this field has also focused on ferromagnetic nanoparticles [ 31 , 32 ], with special attention given to Fe nanoparticles, which in terms of efficiency of loss power and heating would be most suitable due to their high magnetization and initial susceptibility [ 33 ] compared to ferrimagnetic nanoparticles [ 34 ].…”