Multifunction bismuth gadolinium oxide nanoparticles as radiosensitizer in radiation therapy and imaging.

Abstract

Multifunction bismuth-based nanoparticles with the ability of diagnostic and therapeutic functions have drawn extensive attention as theranostic agent in radiation therapy and imaging due to high atomic number, low toxicity, and low cost. Herein, we tried to introduce multifunction bismuth gadolinium oxide nanoparticles (BiGdO3) as a new theranostic agent for radiation therapy, computed tomography (CT) and magnetic resonance imaging (MRI). After synthesized of BiGdO3 nanoparticles and surface modifications of them with PEG, biocompatibility of the nanoparticle was evaluated by the CCK-8 assay. We investigated dose amplification property of the nanoparticles by gel dosimetry, in vitro, and in vivo assays. According to clonogenic assay radiation sensitizer enhancement ratio (SER) was achieved as 1.75 and 1.66 (100 µg/mL-NPs), for MCF-7 and 4T1 cell lines at low energy x-ray, respectively. Radiation dose enhancement effect of the nanoparticles was proved for high concentration (500 µg/ml) by gel dosimetry. For further investigation, in vivo cancer radiotherapy was carried out by using female BALB/c mice with 4T1 breast tumors. In vivo result emphasized radiosensitizing effect of BiGdO3-PEG nanoparticles. Whereas both bismuth and gadolinium provide contrast CT and gadolinium afford for a contrast MRI T1, so we evaluated contrast enhancement of BiGdO3-PEG nanoparticles as a dual-modal imaging agent in MR and CT imaging. Collectively, our experimental results clearly display property of BiGdO3-PEG nanoparticles as a multimodal imaging and radiosensitising agents. The results show that the nanoparticles deserve further study as a new theranostic agent.