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Magnetic heating effect of Fe 3 O 4 ferrofluids, surface-carboxylated and encapsulated by poly(styrene-acrylic acid) was studied. Magnetic Fe 3 O 4 NPs were synthesized by coprecipitation method and characterized by X-ray diffraction (XRD), Field Emission Electron Microscope (FESEM) and Vibrating Sample Magnetometer (VSM). Spectroscopic data (Infra red (IR) and Proton Nuclear Magnetic Resonance ( 1 H NMR) spectra) confirmed that Fe 3 O 4 NP surface was carboxylated and capable for protein binding ( e.g. , Hepatitis B surface antibody (HBsAb)). Magnetic measurement by Physical Properties Measurement System (PPMS) and magnetic heating experiments revealed that the saturation temperature of the ferrofluids could be advantageously applied in hyperthermic treatment, namely it could achieve as high as 48.6°–57 °C, with as low as 0.3–0.5 mg/ml of Fe 3 O 4 in the fluid, under magnetic field of 60 Oe and 236 kHz. Under those AC field parameters, the specific loss power (SLP) was measured as 0.84 kW/g and Sarcoma 180 cells were killed after 70–80 min-treatment in ex vivo heating experiment, meaning that the synthesized ferrofluid may be considered as promising in hyperthermic cancer treatments.

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.