Interparticle interaction effect on magnetization dynamics of multicore iron oxide particles in alternating magnetic field

Magnetic multicore iron oxide particles are nowadays intensively studied for application in magnetic hyperthermia. These particles compose of superparamagnetic iron oxide cores densely packed due to magnetic interactions. The magnetic interaction leads to the increase of energy barrier of magnetization reversal and therefore the heating losses in alternating magnetic field can be enhanced. However, the magnetization dynamics of such systems in alternating magnetic field remains still unclear. Apparently, the main parameters influencing the interaction with magnetic field are the morphology of single cores and multicore particles as well as the intercore and interparticle magnetic interactions. In the current work, we investigate the effect of interparticle interactions between the multicore particles on the heating efficiency of magnetic dispersions in alternating magnetic field. Two types of multicore particles were prepared: naked multicore particles displaying dipole-dipole interactions and multicore particles with surface coating preventing the interaction of multicores. Both types of multicore particles were composed of 13 nm iron oxide cores and have the hydrodynamic size of about 85 nm. To study the absorption of AMF energy, multicore particles were dispersed in media with different viscosity (water and agarose). It was demonstrated that covered multicore particles display significantly higher heating efficiency in both media than naked particles, which is associated with the elimination of dipole-dipole interaction between multicores.ERDF, European Regional Development FundMinistry of Education, Youth and Sports of the Czech Republic Program NPU I [LO1504]; Operational Program Research and Development for Innovations - European Regional Development Fund (ERDF); national budget of the Czech Republic [CZ.1.05/2.1.00/19.0409

Magnetic nanomaterials for arterial embolization and hyperthermia of parenchymal organs tumors: A review

Magnetic hyperthermia (MH), proposed by R. K. Gilchrist in the middle of the last century as local hyperthermia, has nowadays become a recognized method for minimally invasive treatment of oncological diseases in combination with chemotherapy (ChT) and radiotherapy (RT). One type of MH is arterial embolization hyperthermia (AEH), intended for the presurgical treatment of primary inoperable and metastasized solid tumors of parenchymal organs. This method is based on hyperthermia after transcatheter arterial embolization of the tumor's vascular system with a mixture of magnetic particles and embolic agents. An important advantage of AEH lies in the double effect of embolotherapy, which blocks blood flow in the tumor, and MH, which eradicates cancer cells. Consequently, only the tumor undergoes thermal destruction. This review introduces the progress in the development of polymeric magnetic materials for application in AEH. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.8X20041; Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT: RP/CPC/2020/00

Size dependent heating efficiency of iron oxide single domain nanoparticles

The iron oxide nanoparticles have been synthesized by coprecipitation and solvothermal reduction methods. The particles obtained differ in size, the mean size of particles coprecipitated is of 13 nm and the particles, prepared by solvothermal reduction method have a size of 20 nm. Both kinds of nanoparticles demonstrate narrow particles sizes distribution. The particles which are prepared by coprecipitation method have narrow particles sizes distribution with mean size diameter of 13 nm and the particles, prepared by solvothermal reduction method have a size of 20 nm. The X-ray diffraction data analysis revealed that highly crystalline and single-phase magnetite nanoparticles are formed by solvothermal reduction technique, whereas coprecipitation leads to the formation of multi-phase composition of a magnetite (72%) and maghemite (28%). According to the size of nanoparticles obtained, they are in superparamagnetic state for iron oxides. The saturation magnetization of solvothermal prepared particles is higher than those for coprecipitated due to their higher crystallinity and phase purity. Nevertheless, the glycerol dispersion of particles coprecipitated shows higher SLP values than the dispersion of the particles, synthesized by solvothermal reduction method. The heating efficiency of nanoparticles based dispersions is explained by the particles size effect and properties of carrier medium. © 2015 The Authors

Magneto-responsive hyaluronan hydrogel for hyperthermia and bioprinting: Magnetic, rheological properties and biocompatibility

Magneto-responsive soft hydrogels are used for a number of biomedical applications, e.g., magnetic hyperthermia, drug delivery, tissue engineering, and neuromodulation. In this work, this type of hydrogel has been fabricated from hyaluronan (HA) filled with a binary system of Al2O3 nanoparticles and multicore magnetic particles (MCPs), which were obtained by clustering of superparamagnetic iron oxide FeOx NPs. It was established that the presence of diamagnetic Al2O3 has several positive effects: it enhances the hydrogel storage modulus and long-term stability in the cell cultivation medium; prevents the magnetic interaction among the MCPs. The HA hydrogel provides rapid heating of 0.3 °C per min under exposure to low amplitude radio frequency alternating magnetic field. Furthermore, the magneto-responsive hydrogel was successfully used to encapsulate cells and extrusion-based 3D printing with 87±6% cell viability, thus providing a bio-ink. The combination of high heating efficiency, softness, cytocompatibility, and 3D printability of magnetic HA hydrogel leads to a material suitable for biomedical applications.DKRVO, (RP/CPS/2022/003, RP/CPS/2022/005); Program Multilateral Scientific and Technological Cooperation in the Danube Region, (8X20041); Tomas Bata University in Zlin, TBU, (22–33307S, CZ.02.2.69/0.0/0.0/19_073/0016941, IGA/FT/2023/006); Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT; Grantová Agentura České Republiky, GA ČR, (RP/CPS/2022/001)Ministry of Education, Youth and Sports of the Czech Republic-DKRVO [RP/CPS/2022/003, RP/CPS/2022/005]; Program Multilateral Scientific and Technological Cooperation in the Danube Region [8X20041]; TBU [IGA/FT/2023/006]; Czech Science Foundation [22-33307S]; Ministry of Education, Youth and Sports of the Czech Republic [RP/CPS/2022/001

Alterations in PGC1[alfa] expression levels are involved in colorectal cancer risk: a qualitative systematic review

Background: Colorectal cancer (CRC) is a major global public health problem and the second leading cause of cancer-related death. Mitochondrial dysfunction has long been suspected to be involved in this type of tumorigenesis, as supported by an accumulating body of research evidence. However, little is known about how mitochondrial alterations contribute to tumorigenesis. Mitochondrial biogenesis is a fundamental cellular process required to maintain functional mitochondria and as an adaptive mechanism in response to changing energy requirements. Mitochondrial biogenesis is regulated by peroxisome proliferator-activated receptor gamma coactivator 1-? (PPARGC1A or PGC1?). In this paper, we report a systematic review to summarize current evidence on the role of PGC1? in the initiation and progression of CRC. The aim is to provide a basis for more comprehensive research. Methods: The literature search, data extraction and quality assessment were performed according to the document Guidance on the Conduct of Narrative Synthesis in Systematic Reviews and the PRISMA declaration. Results: The studies included in this review aimed to evaluate whether increased or decreased PGC1? expression affects the development of CRC. Each article proposes a possible molecular mechanism of action and we create two concept maps. Conclusion: Our systematic review indicates that altered expression of PGC1? modifies CRC risk. Most studies showed that overexpression of this gene increases CRC risk, while some studies indicated that lower than normal expression levels could increase CRC risk. Thus, various authors propose PGC1? as a good candidate molecular target for cancer therapy. Reducing expression of this gene could help to reduce risk or progression of CRC

The α-ketoglutarate dehydrogenase complex in cancer metabolic plasticity

Deregulated metabolism is a well-established hallmark of cancer. At the hub of various metabolic pathways deeply integrated within mitochondrial functions, the α-ketoglutarate dehydrogenase complex represents a major modulator of electron transport chain activity and tricarboxylic acid cycle (TCA) flux, and is a pivotal enzyme in the metabolic reprogramming following a cancer cell’s change in bioenergetic requirements. By contributing to the control of α-ketoglutarate levels, dynamics, and oxidation state, the α-ketoglutarate dehydrogenase is also essential in modulating the epigenetic landscape of cancer cells. In this review, we will discuss the manifold roles that this TCA enzyme and its substrate play in cancer