Yttrium-90 and Rhenium-188 Radiopharmaceuticals for Radionuclide Therapy

(d)
Caspase 3 assay
Assay was performed to assess the involvement of apoptosis marker protein
caspase 3 in the cell death process. Using a colorimetric assay kit, the activity of
caspase 3 was assayed in Hep G2 cultures exposed to the radiolabelled complex.
However, no appreciable difference could be observed between the sample and
the unexposed controls. As no protease inhibitor was used in the assay, it is
possible that degradation of caspase 3 in the sample may have occurred, which
needs to be investigated further.
6.3.1.2. In vivo assessment
In vivo assessment was performed in Wistar rats. A liver cancer model
was raised in the animals by chemical carcinogenesis using diethylnitrosamine.
After the induction period, the animals were taken for in vivo experiments.
Approximately 37 MBq (1 mCi) of 90 Y oxine in lipiodol (100 μL) was
administered into the liver via the intrahepatic artery. The in vivo distribution
patterns of the radiolabelled complex at 24 and 96 h are given in Fig. 6.19. The
in vivo patterns show significant disadvantages to potential application as a liver
cancer radiopharmaceutical. Even at 24 h, only ~50% of the injected activity
is retained in the liver, which reduces to