  Nanomaterials, in addition to their small size, possess unique
physicochemical properties that differ from the bulk materials, making them
ideal for a host of novel applications. Magnetic nanoparticle (MNP) is one
important class of nanomaterials that have been widely studied for their
potential applications in nanomedicine. Due to the fact that MNPs can be
detected and manipulated by remote magnetic fields, it opens a wide opportunity
for them to be used in vivo. Nowadays, MNPs have been used for diverse
applications including magnetic biosensing (diagnostics), magnetic imaging,
magnetic separation, drug and gene delivery, and hyperthermia therapy, etc.
This review aims to provide a comprehensive assessment of the state-of-the-art
biological and biomedical applications of MNPs. In addition, the development of
high magnetic moment MNPs with proper surface functionalization has progressed
exponentially over the past decade. Herein, we also reviewed the recent
advances in the synthesis and surface coating strategies of MNPs. This review
is not only to provide in-depth insights into the different synthesis,
biofunctionalization, biosensing, imaging, and therapy methods but also to give
an overview of limitations and possibilities of each technology.
