¹³¹I-labeled polyethylenimine-entrapped gold nanoparticles for targeted tumor SPECT/CT imaging and radionuclide therapy

Abstract

Purpose:

Polyethylenimine (PEI) has been widely used as a versatile template to develop multifunctional nanosystems for disease diagnosis and treatment. In this study, we manufactured iodine-131 (¹³¹I)-labeled PEI-entrapped gold nanoparticles (Au PENPs) as a novel nanoprobe for single-photon emission computed tomography/computed tomography (SPECT/CT) imaging and radionuclide therapy.

Materials and methods:

PEI was PEGylated and sequentially conjugated with Buthus martensii Karsch chlorotoxin (BmK CT, a tumor-specific ligand which can selectively bind to MMP2), 3-(4′-hydroxyphenyl)propionic acid-OSu (HPAO), and fluorescein isothiocyanate to form the multifunctional PEI template for entrapment of Au NPs. Then, the PEI surface was radiolabeled with ¹³¹I via HPAO to produce the novel nanoprobe (BmK CT-Au PENPs-¹³¹I).

Results:

The synthesized multifunctional Au PENPs before and after ¹³¹I radiolabeling were well-characterized as follows: structure, X-ray attenuation coefficient, colloid stability, cytocompatibility, and radiochemical stability in vitro. Furthermore, BmK CT-Au PENPs-¹³¹I were suitable for targeted SPECT/CT imaging and radionuclide therapy of tumor cells in vitro and in a xenograft tumor model in vivo.

Conclusion:

The developed multifunctional Au PENPs are a promising theranostic platform for targeted imaging and treatment of different MMP2-overexpressing tumors.

Keywords:

• polyethylenimine
• BmK CT
• gold nanoparticles
• SPECT/CT imaging
• radionuclide therapy

Acknowledgments

The present study was financially supported by the National Natural Science Foundation of China (81671712, 81801727, 21807059, and 81301245), and Shanghai Sailing Program (16YF1409300). The synthesis and characterization of the nanoparticles in this study were performed by J Zhu through the funding from and facilities at the Nanjing Tech University.  J Zhu is grateful for the support from the Natural Science Foundation of Jiangsu Province (BK20180711) and the Natural Science Foundation for Colleges and Universities in Jiangsu Province (17KJB350005).

Disclosure

The authors report no conflicts of interest in this work.