Biodegradable and Magnetic-Fluorescent Porous Silicon@Iron Oxide Nanocomposites for Fluorescence/Magnetic Resonance Bimodal Imaging of Tumor in Vivo.

Considering future clinical transactions, biodegradable and luminescent porous silicon nanoparticles instead of traditional heavy-metal quantum dots have an important significance on the construction of biodegradable and magnetic-fluorescent nanocomposites. Herein, to fabricate PSiNPs@Fe3O4 nanocomposites, superparamagnetic iron oxide nanoparticles were covalently incorporated into luminescent porous silicon nanoparticles by microwave-induced hydrosilylation. These resultant nanocomposites had near-infrared fluorescence (500 nm-800 nm) and superparamagnetism with high magnetic saturation value of 141 emu/g. The aqueous-dispersibility of PSiNPs@Fe3O4 nanocomposites could be significantly improved via simple ultrasonication in water. Furthermore, they also exhibited an excellent biodegradability and biocompatibility, whether in vitro or in vivo. Finally, their ability of fluorescence/magnetic resonance bimodal imaging had been successfully demonstrated for cancer cells in vitro or tumor tissues in vivo.