Bombesin functionalized ⁶⁴Cu-copper sulfide nanoparticles for targeted imaging of orthotopic prostate cancer

Aim: To synthesize and evaluate the imaging potential of Bom-PEG-[⁶⁴Cu]CuS nanoparticles (NPs) in orothotopic prostate tumor. Materials & methods: [⁶⁴Cu]CuS NPs were synthesized in aqueous solution by ⁶⁴CuCl₂ and Na₂S reaction. Then PEG linker with or without bombesin peptide were conjugated to the surface of [⁶⁴Cu]CuS NPs to produce Bom-PEG-[⁶⁴Cu]CuS and PEG-[⁶⁴Cu]CuS NPs. These two kinds of NPs were used for testing specific uptake in prostate cancer cells in vitro and imaging of orthotopic prostate tumor in vivo. Results: Bom-PEG-[⁶⁴Cu]CuS and PEG-[⁶⁴Cu]CuS NPs were successfully synthesized with core diameter of approximately 5 nm. Radioactive cellular uptake revealed that Bom-PEG-[⁶⁴Cu]CuS was able to specifically bind to prostate cancer cells, and the microPET-CT imaging indicated clear visualization of orthotopic prostate tumors. Conclusion: Radiolabeled Bom-PEG-[⁶⁴Cu]CuS NPs have potential as an ideal agent for orthotopic prostate tumor imaging by microPET-CT.