Development of a radiolabeled beta-human chorionic gonadotropin

Area of Science:

• Nuclear Medicine
• Radiopharmaceutical Chemistry
• Endocrinology

Background:

• Beta-Human chorionic gonadotropin (beta-hCG) plays a crucial role in early pregnancy and is a target in certain cancers.
• Developing targeted radiotracers for beta-hCG is essential for diagnostic imaging and therapeutic applications.

Purpose of the Study:

• To develop and characterize a Gallium-67 labeled beta-hCG radiotracer.
• To evaluate the in vivo biodistribution and targeting potential of the radiolabeled beta-hCG.

Main Methods:

• Beta-hCG was conjugated with diethylenetriaminepentaacetic acid dianhydride (ccDTPA) and radiolabeled with Gallium-67 ([ (67)Ga ]-gallium chloride).
• Radiochemical purity was assessed using high-performance liquid chromatography (HPLC).
• In vivo biodistribution studies were performed in male wild-type rats.

Main Results:

• High radiochemical purity (>95%) and labeling efficiency (80%) were achieved for [ (67)Ga ]-beta-hCG.
• Significant gonadal uptake of the tracer was observed in rats after 240 minutes.
• High target-to-blood (up to 15.2) and target-to-muscle (up to 40) ratios were achieved at 24 hours post-injection.

Conclusions:

• The developed [ (67)Ga ]-beta-hCG conjugate is a promising radiotracer with high radiochemical purity.
• The observed gonadal uptake aligns with known beta-hCG receptor distribution, suggesting potential for imaging applications.