Introduction: Acridine is a well-known DNA intercalator and thereby gets easily inserted within
DNA. As uncontrolled rapid cell division is one of the primary characteristics of the tumors, it is expected that
acridine or its suitable derivatives will have preferential accumulation in the tumorous lesions. Therefore, an
attempt was made to radiolabel an acridine derivative with 68Ga and study the potential of the 68Ga-acridine
complex as a PET agent for tumor imaging.
Methods: 9-aminoacridine was coupled with p-NCS-benzyl-DOTA to render it suitable for labeling with 68Ga.
The purified acridine-DOTA conjugate was radiolabeled with 68Ga, eluted from a 68Ge/68Ga radionuclide generator.
Various radiolabeling parameters were optimized and the stability of the radiolabeled preparation was
studied. The biological behavior of the 68Ga-acridine complex was studied both in vitro and in vivo using Raji
cell line and fibrosarcoma tumor bearing Swiss mice, respectively.
Results: 68Ga-acridine complex was obtained with ~100% radiochemical purity under the optimized reaction
conditions involving incubation of 2mg/mL of ligand at 100°C for 30 minutes. The complex maintained a radiochemical
purity of >95% in normal saline and >65% in human blood serum at 3h post-incubation. In vitro cellular
study showed (3.2±0.1)% uptake of the radiotracer in the Raji cells. Biodistribution study revealed significant
tumor accumulation [(11.41±0.41)% injected activity in per gram] of the radiotracer within 1h postadministration
along with uptake in other non-target organs such as, blood, liver, GIT kidney etc.
Conclusion: The present study indicates the potential of 68Ga-acridine as a PET agent for imaging of tumorous
lesions. However, further detailed evaluation of the agent is warranted to explore its actual potential.