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

2021 ◽  
Vol 11 (12) ◽  
pp. 5505
Author(s):  
Costica Caizer

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.

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3294
Author(s):  
Costica Caizer

The efficacy in superparamagnetic hyperthermia (SPMHT) and its effectiveness in destroying tumors without affecting healthy tissues depend very much on the nanoparticles used. Considering the results previously obtained in SPMHT using magnetite and cobalt ferrite nanoparticles, in this paper we extend our study on CoxFe3−xO4 nanoparticles for x = 0–1 in order to be used in SPMHT due to the multiple benefits in alternative cancer therapy. Due to the possibility of tuning the basic observables/parameters in SPMHT in a wide range of values by changing the concentration of Co2+ ions in the range 0–1, the issue explored by us is a very good strategy for increasing the efficiency and effectiveness of magnetic hyperthermia of tumors and reducing the toxicity levels. In this paper we studied by computational simulation the influence of Co2+ ion concentration in a very wide range of values (x = 0–1) on the specific loss power (Ps) in SPMHT and the nanoparticle diameter (DM) which leads to the maximum specific loss power (PsM). We also determined the maximum specific loss power for the allowable biological limit (PsM)l which doesn’t affect healthy tissues, and how it influences the change in the concentration of Co2+ ions. Based on the results obtained, we established the values for concentrations (x), nanoparticle diameter (DM), amplitude (H) and frequency (f) of the magnetic field for which SPMHT with CoxFe3−xO4 nanoparticles can be applied under optimal conditions within the allowable biological range. The obtained results allow the obtaining a maximum efficacy in alternative and non-invasive tumor therapy for the practical implementation of SPMHT with CoxFe3−xO4 nanoparticles.


Nanomaterials ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 40
Author(s):  
Costica Caizer

The cancer therapy with the lowest possible toxicity is today an issue that raises major difficulties in treating malignant tumors because chemo- and radiotherapy currently used in this field have a high degree of toxicity and in many cases are ineffective. Therefore, alternative solutions are rapidly being sought in cancer therapy, in order to increase efficacy and a reduce or even eliminate toxicity to the body. One of the alternative methods that researchers believe may be the method of the future in cancer therapy is superparamagnetic hyperthermia (SPMHT), because it can be effective in completely destroying tumors while maintaining low toxicity or even without toxicity on the healthy tissues. Superparamagnetic hyperthermia uses the natural thermal effect in the destruction of cancer cells, obtained as a result of the phenomenon of superparamagnetic relaxation of the magnetic nanoparticles (SPMNPs) introduced into the tumor; SPMNPs can heat the cancer cells to 42–43 °C under the action of an external alternating magnetic field with frequency in the range of hundreds of kHz. However, the effectiveness of this alternative method depends very much on finding the optimal conditions in which this method must be applied during the treatment of cancer. In addition to the type of magnetic nanoparticles and the biocompatibility with the biological tissue or nanoparticles biofunctionalization that must be appropriate for the intended purpose a key parameter is the size of the nanoparticles. Also, establishing the appropriate parameters for the external alternating magnetic field (AMF), respectively the amplitude and frequency of the magnetic field are very important in the efficiency and effectiveness of the magnetic hyperthermia method. This paper presents a 3D computational study on specific loss power (Ps) and heating temperature (ΔT) which allows establishing the optimal conditions that lead to efficient heating of Fe3O4 nanoparticles, which were found to be the most suitable for use in superparamagnetic hyperthermia (SPMHT), as a non-invasive and alternative technique to chemo- and radiotherapy. The size (diameter) of the nanoparticles (D), the amplitude of the magnetic field (H) and the frequency (f) of AMF were established in order to obtain maximum efficiency in SPMHT and rapid heating of magnetic nanoparticles at the required temperature of 42–43 °C for irreversible destruction of tumors, without affecting healthy tissues. Also, an analysis on the amplitude of the AMF is presented, and how its amplitude influences the power loss and, implicitly, the heating temperature, observables necessary in SPMHT for the efficient destruction of tumor cells. Following our 3D study, we found for Fe3O4 nanoparticles the optimal diameter of ~16 nm, the optimal range for the amplitude of the magnetic field of 10–25 kA/m and the optimal frequency within the biologically permissible limit in the range of 200–500 kHz. Under the optimal conditions determined for the nanoparticle diameter of 16.3 nm, the magnetic field of 15 kA/m and the frequency of 334 kHz, the magnetite nanoparticles can be quickly heated to obtain the maximum hyperthermic effect on the tumor cells: in only 4.1–4.3 s the temperature reaches 42–43 °C, required in magnetic hyperthermia, with major benefits in practical application in vitro and in vivo, and later in clinical trials.


Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2151
Author(s):  
Gabriele Barrera ◽  
Marco Coisson ◽  
Federica Celegato ◽  
Luca Martino ◽  
Priyanka Tiwari ◽  
...  

An important research effort on the design of the magnetic particles is increasingly required to optimize the heat generation in biomedical applications, such as magnetic hyperthermia and heat-assisted drug release, considering the severe restrictions for the human body’s exposure to an alternating magnetic field. Magnetic nanoparticles, considered in a broad sense as passive sensors, show the ability to detect an alternating magnetic field and to transduce it into a localized increase of temperature. In this context, the high biocompatibility, easy synthesis procedure and easily tunable magnetic properties of ferrite powders make them ideal candidates. In particular, the tailoring of their chemical composition and cation distribution allows the control of their magnetic properties, tuning them towards the strict demands of these heat-assisted biomedical applications. In this work, Co0.76Zn0.24Fe2O4, Li0.375Zn0.25Fe2.375O4 and ZnFe2O4 mixed-structure ferrite powders were synthesized in a ‘dry gel’ form by a sol-gel auto-combustion method. Their microstructural properties and cation distribution were obtained by X-ray diffraction characterization. Static and dynamic magnetic measurements were performed revealing the connection between the cation distribution and magnetic behavior. Particular attention was focused on the effect of Co2+ and Li+ ions on the magnetic properties at a magnetic field amplitude and the frequency values according to the practical demands of heat-assisted biomedical applications. In this context, the specific loss power (SLP) values were evaluated by ac-hysteresis losses and thermometric measurements at selected values of the dynamic magnetic fields.


2021 ◽  
Vol 22 (18) ◽  
pp. 10071
Author(s):  
Costica Caizer ◽  
Isabela Simona Caizer

Different chemical agents are used for the biocompatibility and/or functionality of the nanoparticles used in magnetic hyperthermia to reduce or even eliminate cellular toxicity and to limit the interaction between them (van der Waals and magnetic dipolar interactions), with highly beneficial effects on the efficiency of magnetic hyperthermia in cancer therapy. In this paper we propose an innovative strategy for the biocompatibility of these nanoparticles using gamma-cyclodextrins (γ-CDs) to decorate the surface of magnetite (Fe3O4) nanoparticles. The influence of the biocompatible organic layer of cyclodextrins, from the surface of Fe3O4 ferrimagnetic nanoparticles, on the maximum specific loss power in superparamagnetic hyperthermia, is presented and analyzed in detail in this paper. Furthermore, our study shows the optimum conditions in which the magnetic nanoparticles covered with gamma-cyclodextrin (Fe3O4–γ-CDs) can be utilized in superparamagnetic hyperthermia for an alternative cancer therapy with higher efficiency in destroying tumoral cells and eliminating cellular toxicity.


1970 ◽  
Vol 30 ◽  
pp. 41-50
Author(s):  
Hosne Ara Jasmine

A theoretical study of the hydromagnetic instability due to slow hydromagnetic waves has been carried out after simplifying the complexity of governing equations. A series of stability conditions have been derived for wide range of magnetic field profiles. It has been shown that regardless of the magnetic field profile, any unstable disturbances propagate against the basic rotation. GANIT J. Bangladesh Math. Soc. (ISSN 1606-3694) 30 (2010) 41-50  DOI: http://dx.doi.org/10.3329/ganit.v30i0.8502


Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 485 ◽  
Author(s):  
Karol Szałowski ◽  
Pamela Kowalewska

We calculated the magnetocaloric properties of the molecular nanomagnet Cu5-NIPA, consisting of five spins S = 1 / 2 arranged in two corner-sharing triangles (hourglass-like structure without magnetic frustration). The thermodynamics of the system in question was described using the quantum Heisenberg model solved within the field ensemble (canonical ensemble) using exact numerical diagonalization. The dependence of the magnetic entropy and magnetic specific heat on the temperature and the external magnetic field was investigated. The isothermal entropy change for a wide range of initial and final magnetic fields was discussed. Due to plateau-like behavior of the isothermal entropy change as a function of the temperature, a high degree of tunability of magnetocaloric effect with the initial and final magnetic field was demonstrated.


2015 ◽  
Vol 230 ◽  
pp. 101-107
Author(s):  
Alexander I. Tovstolytkin ◽  
S.O. Solopan ◽  
V.M. Kalita ◽  
S.M. Ryabchenko ◽  
Anatolii G. Belous

Structural and magnetic characteristics of (La,Sr)MnO3 nanoparticles synthesized by different methods have been studied in the work. The specific loss power which is released on the exposure of an ensemble of synthesized particles to alternating magnetic field was calculated and measured experimentally. The contributions to the specific loss power resulted from different heating mechanisms have been discussed. The directions to enhance the heating efficiency of various kinds of magnetic nanoparticles are outlined


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