Controlled Synthesis and Surface Modification of Magnetic Nanoparticles with High Performance for Cancer Theranostics Combining Targeted MR Imaging and Hyperthermia

Abstract

Magnetic nanoparticles (MNPs) are of great scientific interest for the researchers from a wide range of biomedicine applications, including clinical magnetic resonance imaging (MRI), cancer magnetic hyperthermia, triggered drug release, and catalysis. Especially, the high performance of these MNPs, such as controllable size and morphology, superior magnetism, high magnetically induced heating effects, favorable biocompatibility, accurate targeting ability, and long circulation, is crucial for their effective application in clinical diagnosis and therapy of disease. In a brief overview, the controlled chemical design and synthesis, the formation mechanism, as well as the surface functional strategy of MNPs are firstly presented. High-quality MNPs are typically prepared through a thermal decomposition of organometallic compounds in high-boiling organic solvent containing surfactants, in which the shape, size, composition, surface states, magnetic characteristics, biocompatibility, and some other important features are synthetically controlled. Understanding the interplay of these parameters is critical for the effective imaging and therapeutics, which include MRI relaxivity, heat emission, and attractive forces. We then discuss approaches to constructing versatile MNP probes as MRI contrast agents with high sensitivity, with which the sensitive and target-specific observation of biological imaging at the molecular and cellular levels is possible. Finally, we present an overview of recent breakthroughs in the development of MNP-based magnetic hyperthermia. The purpose of this section is to address different factors that affect the targeting, heating, and biodistribution to safely control the therapeutic efficacy of targeted magnetic hyperthermia (TMH).