Fig. 4

In vivo biocompatibility studies of FeCO₃ NPs. A T2-weighted in vivo MR imaging of lung tumors 5 h, 24 h and 48 h post-injection (10 mg/kg of FeCO₃ NPs per mice were administered intravenously, MRI scans were performed on a 9.4 T MRI scanner). B Histopathological observation of major organs including heart, liver, spleen, kidney, and lung of mice 5 days post-injection of FeCO₃ NPs (10 mg/kg of FeCO₃ NPs per mice were administered intravenously, scale bars are 500 μm). C, D respectively show liver and kidney function analysis of in vivo mice 5-days post injection of PBS and FeCO₃ NPs (10 mg of Fe ion/kg of mice). n = 3 mice were used for all experiments. ns: ≥ 0.05; *P ≤ 0.05; **P ≤ 0.01; ***P ≤ 0.001