Iron oxide nanoparticles (IONPs) have become one of the
most promising
nanomaterials for biomedical applications because of their biocompatibility
and physicochemical properties. This study demonstrates the use of
protein engineering as a novel approach to design scaffolds for the
tunable synthesis of ultrasmall IONPs. Rationally designed proteins,
containing different number of metal-coordination sites, were evaluated
to control the size and the physicochemical and magnetic properties
of a set of protein-stabilized IONPs (Prot-IONPs). Prot-IONPs, synthesized
through an optimized coprecipitation approach, presented good T1 and
T2 relaxivity values, stability, and biocompatibility, showing potential
for magnetic resonance imaging (MRI) applications.