^99mTc radiolabeling of polyethylenimine capped carbon dots for tumor targeting: synthesis, characterization and biodistribution

Abstract

Purpose

Due to the favorable physicochemical properties and the biocompatibility, carbon dots (CDs) have gained a great attention as a tumor targeting agent. This study investigates polyethylenimine capped CDs (PEI capped CDs) as a prospective nanocarrier of technetium-99m (^99mTc) for tumor targeting. Technetium-labeled CDs could be introduced as a promising candidate for single photon emission tomography (SPECT) imaging.

Materials and methods

Polyethylenimine capped CDs were prepared by hydrothermal method using hyperbranched PEI and citric acid. For a purpose of comparison, citrate capped CDs were also prepared by microwave irradiation. Both types of CDs were characterized and radiolabeled with ^99mTc using sodium borohydride (NaBH₄) as a reducing agent. Biodistribution and tumor targeting efficiency of the produced radiolabeled CDs have been studied in Earlich ascites tumor mice model.

Results

Citrate capped CDs and PEI capped CDs have been synthesized successfully and characterized. High radiochemical yield of ^99mTc-citrate capped CDs ^99mTc-PEI capped CDs was obtained (97 ± 0.7 and 90 ± 0.2, respectively). Biodistribution studies of ^99mTc-labeled PEI capped CDs have shown a potential tumor uptake (10 ± 0.5% Radioactivity/gram tumor) with high target to non-target ratio (T/NT) around 7 at 1-h post injection. ^99mTc-citrate capped CDs have achieved a lower tumor uptake level (3.8 ± 0.3% Radioactivity/gram tumor 1 h post injection).

Conclusion

This study introduces PEI capped CDs as a promising nanocarrier of ^99mTc for efficient tumor targeting. Technetium-labeled PEI capped CDs could be utilized as a potential SPECT tumor imaging agent.

Keywords:

• Carbon dots
• Polyethylenimine
• Technetium-99m
• Tumor

Disclosure statement

The authors declare that they have no conflict of interest. They read and approved the manuscript before submission.

Additional information

Notes on contributors

Noha A. Bayoumi

Noha Anwer Bayoumi, PhD in pharmaceutical chemistry, is a researcher at the Department of Radiolabeled Compounds, Hot Lab Center, Egyptian Atomic Energy Authority, Cairo, Egypt.

Ahmed N. Emam

Ahmed N. Emam, PhD in Laser applications in chemistry and photobiology, is a Researcher at the Department of Refractories, Ceramics and Building Materials, National Research Center, Cairo, Egypt; Nanomedicine and Tissue Engineering Lab, Medical Center of Excellence National Research Center, Cairo, Egypt; Faculty of Postgraduate studies for Nanotechnology, Cairo University, Zayed City, Giza, Egypt.