Multifunctional Fe3O4-TiO2 nanocomposites for magnetic resonance imaging and potential photodynamic therapy.

Multifunctional Fe3O4–TiO2 nanocomposites with Janus structure for magnetic resonance imaging (MRI) and potential photodynamic therapy (PDT) were synthesized, in which Fe3O4 was used as a MRI contrast agent and TiO2 as an inorganic photosensitizer for PDT. Their morphology, structure, and MRI and PDT performance were characterized, respectively. Moreover, the location of Fe3O4–TiO2 nanocomposites in MCF-7 cells was also investigated by the staining of Prussian blue and alizarin red, respectively. The results showed that the as-prepared Fe3O4–TiO2 nanocomposites had good T2-weighted MRI performance, and the MCF-7 cells incubated with nanocomposites could be killed under the irradiation of UV light. Compared with traditional organic photosensitizers, TiO2 inorganic photosensitizers could have more stable PDT performance due to their nanoscale size and anti-photodegradable stability. Therefore, the as-prepared Fe3O4–TiO2 nanocomposites could have potential applications as a new kind of multifunctional agent for both MRI and PDT.