In Vivo PET/CT Imaging of Tumor Xenografts

Example 9

In vivo PET/CT imaging was conducted in NCr nude mice bearing bxpc3 (human pancreatic adenocarcinoma cell line) and 4T1 (a murine breast cancer cell line that overexpresses integrin α_vβ3 and CD13) tumor xenografts.

Mice were injected with bxpc3 cells (1 million cells in 150 μL PBS) into the subcutaneous flank of the right shoulder and 4T1 cells (1 million cells in 150 μL PBS) into the subcutaneous flank of the left shoulder. Either the CNGRC-(⁶⁸Ga)NOTA-RGDyK heterodimer (“CNGRC” disclosed as SEQ ID NO: 1), (⁶⁸Ga)NOTA(CNGRC) (“CNGRC” disclosed as SEQ ID NO: 1), or (⁶⁸Ga)NOTA(RGDyK) were injected into the bloodstream via tail vein injection. Blocking studies were conducted for the heterodimer studies by co-injecting 100 times of cyclo(CNGRC) (“CNGRC” disclosed as SEQ ID NO: 1) and cyclo(RGDyK). Small animal PET/CT was performed at 1 hour post injection of tracers (FIG. 14). The heterodimer CNGRC-(⁶⁸Ga)NOTA-RGDyK (“CNGRC” disclosed as SEQ ID NO: 1) showed improved enhanced in in vivo performance (such as longer blood retention, better tumor/non-tumor ratios).