The study of local magnetic nanoparticle hyperthermia characteristics

Исследование характеристик локальной магнитной гипертермии наночастиц
From 22.03.2018 till 31.12.2019
Grant holder: Oleg Polozhentsev
Members: Roman Matveev

Local magnetic nanoparticle hyperthermia is the one of the most promising methods for the treatment of malignant tumors, using magnetic nanoparticles (MNPs) as a result of its selective thermal effects on local tissues (malignant tumors) under the influence of alternating magnetic fields (AMF) and good compatibility with traditional methods of treatment in oncology. For the development of this technique it is necessary to synthesize MNPs with high heating efficiency (hyperthermic characteristics).
The goal of this project is to establish the fundamental laws linking the physicochemical characteristics of MNPs with the heating characteristics of local magnetic nanoparticle hyperthermia and to develop a method for determining the heating characteristics of MNPs. The objects of study are colloidal solutions of biocompatible superparamagnetic, ferromagnetic and ferrimagnetic nanoparticles with high heating characteristics under the action of an alternating magnetic field.
In the framework of the first year of the project, an analytical review of information sources on local magnetic hyperthermia, various types of magnetic nanosystems, heating mechanisms of MNPs, methods to determine heating characteristics, equipment for generating AMF and for measuring heating characteristics, and relationships of physicochemical characteristics MNP with their heating characteristics was carried out. It was determined that the main parameters affecting the improvement of heating characteristics are their chemical composition, crystal structure, size and shape of nanoparticles, magnetic characteristics, doping and/or substitution of elements, crystalline and magnetic anisotropy, compositions of nanosystems and magnetic exchange interactions of different phases, surface chemistry, etc. Based on the analysis of information sources, a database of various types of magnetic nanoparticles developed for the magnetic hyperthermia with description of their physico-chemical characteristics and heating characteristics was created.
A complex experimental and theoretical approach for determining the mechanisms (hysteresis losses, Néel and Brownian relaxations) and heating characteristics (SAR, ILP) for local magnetic hyperthermia based on the determination of the physicochemical characteristics of the magnetic nanosystems (TEM, XRD, DLS, XRF, VSM and Hyperthermia), as well as theoretical processing of experimental data to determine the heating characteristics of MNP. A protocol for measuring the heating characteristics of MNPs has been developed. For the convenience of obtaining results, an Excel program to calculate the heating characteristics from the input data of the measured heating temperature of a colloidal solution under the action of an AMF (frequency and amplitude), as well as additional data on the physicochemical characteristics of MNP was created.
Synthesis protocols for obtaining magnetic nanoparticles based on iron oxides with different magnetic core sizes, different magnetic characteristics (Ms, Mr, Hc), magnetic ordering (superparamagnetic, single-domain, multi-domain ferromagnetic and ferrimagnetic particles) doped with rare-earth elements, ferrite nanoparticles, coated with various surfactants, nanoparticles of different shapes, core@shell structures were developed.
Measurements of the physicochemical and heating characteristics of various groups of magnetic nanoparticles based on iron oxides of different sizes of the magnetic core, different chemical composition, different magnetic characteristics, and also nanoparticles of iron oxides doped with transition (Mn, Co, Ni, Cu, Zn) and rare-earth elements (Gd, Eu, Sm). The heating characteristics of the MNP were measured with the use of LocalHyperThermLabUnit TOR 04/16 setup for studying the characteristics of magnetic local hyperthermia.
A patent search for methods of treating malignant neoplasms using magnetic hyperthermia and magnetic nanoparticles used for these purposes. The conclusion is made about the possibility of patenting developed MNPs with high hyperthermic characteristics, possessing multimodal applications in oncology.
The results of the project can be found on the Internet site www.magnetic-hyperthermia.ru on the development of methods for local magnetic hyperthermia of nanoparticles in Russia and abroad.