Magnetic materials for smart therapy and diagnostics

large potential for a variety of applications. Gold-coated magnetic nanoparticles are a class of nanoparticles that have attracted much attention because of their advantageous characteristics, such as their inertness, non-toxicity, super magneticity, ease of detection in the human body, a magnetic core that is protected against oxidation, their facilitated bio-conjugating ability, catalytic surface, and their potential for a variety of biological applications. Gold-coated nanoparticles have great biocompatibility with the human body with the ability to interact with biomolecules such as polypeptides, DNA, and polysaccharides. Herein we report a synthetic procedure for the preparation of water-soluble Fe3O4, Fe3O4@Au core-shell and dumbbell nanoparticles, simple protocol for their synthesis, purification by exclusion chromatography and method for functionalization of gold surface with a number of sulfur-containing ligands (L-cystein, 3-mercaptopropionic acid, 11-mercaptoundecanoic acid, lipoic acid, HS-PEG-COOH, 2-aminoethanethiol, and others). Finally, magnetic nanoparticles were functionalized by immobilization of enzymes, PSMA targeted ligands, fluorescent dyes. These magnetic nanoparticles were characterized by transmission electron microscopy (TEM), FTIR, DLS and UV-Vis spectroscopy. We describe a distinct effect of non-heating superlow-frequency magnetic fields on the kinetics of chemical reactions catalyzed by the enzymes immobilized on core-shell nanoparticles.The observation is unprecedented and suggests the significance of magneto-mechanochemical effects induced by realignment of MNP magnetic moments in an AC magnetic field rather than traditional heating. Such low frequency and amplitude fields are safe and are not expected to cause any damage to biological tissues. The authors knowledge financial support from Ministry of Education and Science of the Russian Federation (14.607.21.0132, RFMEFI60715X0132)

Theranostic materials for MRI and targeted delivery based on functionalized magnetite nanoparticles

In the last decades, the synthesis of magnetic nanoparticles, in particular magnetite nanoparticles (MNPs), has received increased attention due to their wide range of applications in biomedicine and technology. MNPs can be effectively used for diagnostics and treatment of various diseases. Size, shape, charge and surface chemistry of NPs are fundamental characteristics that determine substantially their properties. Moreover, these characteristics have a big role in the processes of pharmacokinetics and pharmacodynamics. Magnetite nanoparticles are nontoxic, biocompatible and degradable material. Considering current demographic trends in the world and the nature of the dynamics of morbidity, we can expect that even if the average level of cancer incidence will occur more than 15 million new cases of malignant neoplasms in the population each year. It is obviously that the increase of cancer incidence will be occur substantially due to prostate cancer in men, tumors of the colon and rectum in men and women. Thus the problem of creating universal drug (theranostic materials) for early diagnosis and treatment of malignancy becomes more and more actual. The opportunity of application of magnetite nanoparticles in MRI and drug delivery is highly dependent on their sizes and magnetic characteristics. In this work we attempted to create materials based on MNPs for prostate cancer therapy and diagnostics. We carried out synthesis of magnetite nanoparticles with different morphology (cubes, rod-like, star-like and flower-like) and with average size from 10 to 50 nm. Obtained nanoparticles were synthesized by thermal decomposition of iron-containing precursors in high-boiling organic solvents, as well as the aging method in aqueous medium. All nanoparticles were characterized by different physicochemical methods such as: transmission electron microscopy, X-ray diffraction, thermogravimetric analysis, ICP - MS. Also magnetic measurements of samples were carried out. For transfer of MNPs from the organic into the aqueous medium and to prevent aggregation MNPs were functionalized and coated with biocompatible copolymers based on polyethyleneglycol and pluronic. Please click Additional Files below to see the full abstract

In Silico Studies on Pharmacokinetics and Neuroprotective Potential of ²⁵Mg²⁺: Releasing Nanocationites - Background and Perspectives

Sharp blood circulation disorders are known for their capability to promote such abundant and hardly treatable pathologies as myocardium infarction and the ischemic brain stroke (“insult”). Noteworthy, the stroke — related brain tissue metabolic damages involve an essential ATP deplete clash along with a suppression of brain specific nucleotide — associated kinases and ATP synthase, both Mg2+ — dependent complex enzyme “machineries”. This itself makes the latter’s a legitimate target for some advanced pharmaceuticals as long as the drug — induced overstimulation of corresponding enzymatic activity is the case. Thus, magnetic isotope effects (MIE) of the nuclear spin possessing paramagnetic 25Mg2+ ions might modulate the brain creatine kinase, alfa-glycerophosphate kinase and pyruvate kinase catalytic activities in a way of a remarkable ATP hyperproduction required to compensate the hypoxia caused acute metabolic breakdown. To realize the Magnesium-25 pharmacological potential, a low-toxic amphiphilic cationite nanoparticles were introduced lately. Particularly, the Magnesium — releasing porphyrin-fullerene nanoadduct (cyclohexyl-C60-porphyrin, PMC16) has been proposed to meet expectations dealing with a targeted delivery of 25Mg2+ towards the brain ischemia surrounding areas. In order to optimize a multi-step [25Mg2+]4PMC16 preclinical trial scenario, the In Silico algorithms are to be developed and analyzed. In this study, these algorithms are in a focus with a special emphasize on a novel combination of slightly modified Gompertzian equation systems and a non-Markov population dynamics concept. This In Silico approach takes into account some literature-available patterns of brain hypoxia pathogenesis, the resulted simulation model could be considered as a promising tool for further research on experimental nanopharmacology of the ischemic stroke