Synthesis of novel nano-radiotracer for in-vivo bone imaging: 99mTc- citric acid based PEG dendrimer and its conjugation with alendronate

Abstract

Bone scan is the test that guide physician to diagnose diseases in the bone at the early stage, to prevent metastases to other organs. In this study, citric acid dendrimer conjugation with alendronate was synthesized. Obtained product was confirmed by FT-IR and TEM. Cytotoxicity assay at different concentrations showed no toxicity on normal cell line compared to control group. Radiolabeling process was optimized by Box-Behnken software which is a computational method to determine optimum of important radiolabeling parameters. Optimized parameter for reducing agent, dendrimer-G2-alendronate, and time for shaking was 1 mg, 12.3 mg, and 25 min respectively. For determination of in-vivo accumulation of 99mTc-dendrimer-G2-alendronate, SPECT imaging was done. Images showed high accumulation of radio-tracer in the skeletal compared to 99mTc-MDP which is the frequent bone scan agent. All in all, obtained results confirmed our hypothesis that the dendrimer-G2-alendronate can be noteworthy nano-radiopharmaceuticals to bone cancer imaging at early stage.

Keywords

• Citric acid dendrimer
• Alendronate
• Bone scan
• Radiolabeling
• SPECT
• MDP