Development and preliminary biological evaluation of a theranostic system based on gadolinium-doped cadmium selenide quantum dots labeled with Lutetium-177

Karimian, Arezou; Haddadi, Asghar; Zolghadri, Samaneh; Feizi, Shazad; Yousefnia, Hassan

doi:10.24200/nst.2025.1850.2112

Development and preliminary biological evaluation of a theranostic system based on gadolinium-doped cadmium selenide quantum dots labeled with Lutetium-177

Articles in Press

Document Type : Research Paper

Authors

Arezou Karimian ¹

Asghar Haddadi ¹

samaneh zolghadri ²

Shazad Feizi ³

Hassan Yousefnia ⁴

¹ Department of Medical Radiation Engineering, SR.C., Islamic Azad University, Tehran, Iran.

² Radiation Application Research School, Nuclear Science and Technology Research Institute, Tehran - Iran

³ Radiation Application Research School, Nuclear Science and Technology Research Institute. Tehran-Iran

⁴ Radiation Application Research School, Nuclear Science and Technology Research Institute.Tehran-Iran

10.24200/nst.2025.1850.2112

Abstract

This study was conducted with the aim of developing an advanced theranostic system based on gadolinium-doped cadmium selenide nanoparticles, labeled with lutetium-177 ([¹⁷⁷Lu]Lu@Gd-CdSe). In the first stage, the nanoparticles were successfully synthesized and characterized, and the results revealed particles with an average size of approximately 3.5 nm and a cubic crystalline structure. Subsequently, 100 µL of these nanoparticles were radiolabeled with lutetium-177 under optimized conditions (temperature: 70°C, pH: 7, and duration: 60 minutes), achieving radiolabeling purity and yield greater than 99%. The results demonstrated that the radiolabeled compound exhibited significant stability in phosphate-buffered saline and in human serum. To evaluate the biodistribution, 7.4 MBq of the radiolabeled compound and free lutetium were injected into healthy mice via the tail vein. While the free lutetium showed notable accumulation in the bones and kidneys, the radiolabeled compound primarily accumulated in the liver, spleen, and lungs—mainly due to uptake by macrophages of the reticuloendothelial system. The very low bone accumulation of the radiolabeled compound indicates its high in vivo stability. These findings suggest that this novel system could be a promising candidate for targeted treatment of including hepatic tumors. This research represents a significant step forward in the advancement of nuclear medicine and integrated diagnostic-therapeutic (theranostic) approaches.

Keywords

Quantum Dots

Cadmium Selenide

Lutetium-177

Gadolinium

Radiolabeling

Biodistribution

Main Subjects