Physicochemical and biological characterization of magnetic nanoparticles for biomedical applications

The overall goal of this project was the biological characterization by in vivo and in vitro testing of magnetic nanoparticles that can be used for various applications. The aim of this work was to understand which of the synthesized magnetic nanoparticles could be more suitable to be used as a carrier or platform for various applications in different scientific fields. Two different kinds of magnetic nanoparticles were developed: naked iron-oxide nanoparticles and silica or silica-based coated nanoparticles (core shell-type nanoparticles). Magnetic nanoparticles were prepared using a coprecipitation method. The structure, phase composition, physicochemical and surface properties, magnetic susceptibility, and release in vitro of MNPs were characterized by transmission electron microscopy, x-ray diffraction, scanning electron microscopy-energy dispersive x-ray spectroscopy, and a vibrating sample magnetometer. In vivo toxicity, in vitro toxicity, ROS production and genotoxicity were investigated. Therapeutic effects were evaluated by cell viability assays and flow cytometry assays. The tools developed in this thesis spanned a range of physical-chemical, biological and magnetic aspects and incorporate innovations on a nanometric range of scales. MNP-based technologies appear to hold a significant potential for a myriad of biomedical applications and the toxic potential of MNPs cannot be overlooked. For this reason we carried out different physicochemical and biological characterization of MNPs to identify a safe dose and formulation of MNPs. Understanding the relationship between the physicochemical properties of MNP constructs and their behavior will induce full translational potential of these nanoparticles. The magnetic nanoparticles prepared in this study have good biocompatibility and are suitable for further application in tumor hyperthermia.