Figure 3. Magnetic property, magnetic resonance imaging (MRI) and cancer inhibition of the magnetosome-like GMNCs.

(a), Magnetization hysteresis loop of the as-prepared GMNCs at room temperature. Inset showed the magnified hysteresis loop in the coercive field from −1000 Oe to 1000 Oe. (b), T₂w image and pseudocolour T₂ map of our GMNCs. (c), plot of R₂ (1/T₂) over iron concentration (mM) of GMNCs, and the slope via linear fitting indicate the relaxivity (r₂). Inset is HeLa cellular T₂w image exposed to our GMNCs (left: MNCs group; right: control group). (d), Growth inhibition effect in murine S180 sarcoma model of the sample. The photos and weight ratios of tumor tissue from mice treated with normal saline (control group), GMNCs, Dox at low concentration, and GMNCs loading with Dox (without and with the guidance of external magnetic field), respectively.