Figure 5.

Representative $T_2^{*}$-weighted MR images of mouse 4T1 tumors before (A) and after (B) injection of SPIO@AuNS and after NIR laser irradiation (C). The darkening of the tumor after the injection of SPIO@AuNS indicates a decrease in $T_2^{*}$. (D) In vivo MRTI map of a tumor injected with SPIO@AuNS immediately after laser treatment. Twenty-four hours after injection, 4T1 tumors were irradiated with an 808-nm laser (180 s, 4 W/cm²). (E) Temperature elevation over time in tumors injected with SPIO@AuNS or with saline as a control (no nanoparticles). Only in tumors injected with SPIO@AuNS did the temperature rise above the 54 °C threshold (dotted line) for ensuring irreversible thermal ablation of tumors cells. The treatment volume from which the temperature values were obtained is boxed in panel D.