Silica-coated superparamagnetic nanoparticles as contrast agent for magnetic resonance imaging: Synthesis and physicological charaterizations

Superparamagnetic iron oxide nanoparticles (SPIONs) have received a growing interest for various biomedical applications due to their interesting magnetic properties. Herein, we report a method for facile synthesis of colloidal silica-coated superparamagnetic iron oxide nanoparticles (Si-SPIONs). The polyvinyl alcohol (PVA)-SPIONs were successfully prepared and then coated with silica by the modified Stober method. The obtained Si-SPIONs are highly monodisperse with uniform morphology. Notably, comparing to uncoated SPIONs, silica coated ones show colloidal stability region at physiological pH which is applicable in biomedical applications and synthesis at the scale of grams was easily obta…