Nanosized magnetofluorescent Fe3O4–curcumin conjugate for multimodal monitoring and drug targeting

Magnetic drug targeting, the targeting of a drug conjugated with a magnetic material under the action of external magnetic field constitutes an important drug delivery system. This paper describes the strategy to design a multifunctional, nanosized magnetofluorescent water-dispersible Fe3O4–curcumin conjugate and its multiple ability to label, target and treat the tumor cells. The conjugate possesses magnetic nano Fe3O4 core, chitosan (CS) or oleic acid (OL) as outer shell and entrapped curcumin (Cur), serving dual function of naturally autofluorescent dye as well as anti-tumor model drug, delivered to the cells with the help of macrophage (Cur possesses anti-oxidant, anti-inflammatory and anti-tumor ability). Fe3O4–Cur conjugate exhibited a high loading cellular uptake which was clearly visualized dually by Fluorescence Microscope, Laser scanning confocal microscope (LSCM) as well as magnetization measurement (Physical properties measurement systems, PPMS). Preliminary magnetic resonance imaging (MRI) study also showed a clear contrast enhancement by using Fe3O4–Cur conjugate.