Xi'an Jiaotong University researchers have made important progress in high thermal efficiency and degradable magnetic nanoparticles tumor hyperthermia system

Magnetic (induction) hyperthermia is a technology that uses magnetic nanoparticles to produce heat under alternating magnetic fields to treat diseases This technology has a good application prospect in the field of tumor hyperthermia The thermal efficiency and degradation of magnetic nanoparticles are two very important aspects in magnetic induction thermotherapy At present, the particle size of magnetic nanoparticles with high magnetic thermal efficiency is large, which may accumulate in the body for a long time and cause potential safety hazards However, the particle size of magnetic nanoparticles that are easy to degrade in the body is too small, and the thermal efficiency is very low The magnetic thermotherapy equipment used is large in size, high in price, and the use power often exceeds the safety range Recently, Professor Wu Daocheng, Institute of biomedical imaging and application, School of life, Xi'an Jiaotong University, put forward new ideas to solve this problem They first designed a special equipment for animal magnetic hyperthermia, using Leeds coil water-cooling not only has a larger current carrying area than traditional copper tube water-cooling, but also can better control the coil surface temperature, and the equipment is small in size, low in price, and the use power is in the safe range of human body Then, doping cobalt into the iron oxide magnetic nanoparticles increases its magnetocrystalline anisotropy constant, thus increasing its thermal efficiency at small particle size, while maintaining its in vivo degradation The relationship between the thermal efficiency and the properties of the materials is simulated by the magnetothermal theory It is found that cubic nanoparticles are more close to the experimental results than spherical nanoparticles and have the highest thermal efficiency On this basis, the optimal heat production conditions of cobalt ferrite nanoparticles were obtained, and a cubic cobalt ferrite nanoparticles (cfnps) with high magnetocaloric efficiency and internal degradation was prepared The cfnps with a particle size of 10-13 nm and a surface modified caffeic acid layer of less than 1 nm were prepared to improve its water solubility It was found that cfnps with 11.8 nm particle size had the highest magnetic thermal efficiency (ILP 12.11 nhm2 / kg), which was much higher than that of the same type of magnetic nanoparticles reported Under the magnetic field with the amplitude of 33 Ka / M and the frequency of 115 kHz (H.F < 5 × 109 A / (M.S)), the tumor of nude mice was treated by magnetic hyperthermia It was found that cfnps could raise the temperature of tumor area to about 46 ℃ under the safe magnetic field and effectively inhibit the growth of tumor The particles can enter the blood and leave the tumor area slowly Once in the blood, 64% of nanoparticles can be discharged within 14 days, and its degradation performance is close to that of Feridex, which has reached the clinical application standard This study was published on the international authoritative journal biomaterials (DOI: 10.1016 / j.biomaterials 2019.119655) with the title of "ultra thin surface modified water-soluble cobalt ferrite nanoparticles with high magnetic thermal efficiency and rapid removal in vivo" The first author of this paper is Zhang Lingze, Ph.D student, School of life, Xi'an Jiaotong University The corresponding author is Professor Wu Daocheng, and Xi'an Jiaotong University is the only unit with the signature In recent years, Professor Wu Daocheng 's research group has made a series of research progress in nano drug carriers, magnetic materials and biosensors, and published a series of papers on Biomaterials This research is another important progress of the research group after the research of double drug loaded nano drug carrier system, high-efficiency through blood-brain barrier nano carrier, double drug infinite coordination polymer nano system and photothermal chemotherapy integrated nano system tumor synergistic chemotherapy.