Fig. 17.

a Schematic illustration and TEM images of the synthesis of ^99mTc-Hf-TCPP-PEG. b in vivo SPECT images of 4T1 tumor-bearing mice after intravenous injection with ^99mTc-Hf-TCPP-PEG NCPs. c Quantification of SPECT signals in the liver, kidney, tumor, and muscle of 4T1 tumor bearing mice for mice at different time points after intravenous injection with ^99mTc-Hf-TCPP-PEG NCPs. Reproduced with permission [139]. Copyright 2018, American Chemical Society