Photoacoustic Imaging-Guided Synergistic Photothermal/Radiotherapy Using Plasmonic Bi/Bi2O3-x Nanoparticles

The integration of photothermal agents and radiosensitizers has been widely implemented in synergistic antitumor treatment because it maintains the advantages of the single model; however, they result in unsatisfactory treatment effects due to their multi-component, unstable, and non-degradable nature. Herein, plasmonic Bi/Bi2O3-x is synthesized by in situ fabrication of Bi2O3-x on elemental Bi through a facile hydrothermal method. After encapsulation with DSPE-PEG2000-folate, the Bi/Bi2O3-x nanoparticles (NPs) effectively accumulate in tumor sites to serve as a multifunctional therapeutic agent that can damage tumor sections by absorbing near-infrared light and X-rays. As demonstrated in penetration depth experiments, the NPs exhibit excellent photoacoustic imaging capabilities for deep tissues. Both blood biochemistry tests and histological assays demonstrate the biosafety of Bi/Bi2O3-x NPs in vivo due to their acceptable toxicity and biological clearance properties. Consequently, the prepared NPs are a desirable candidate for effective second near-infrared photothermal/radiotherapy.

Automated summary

In this study, plasmonic Bi/Bi2O3-x nanoparticles with multifunctional therapeutic potential were synthesized. These nanoparticles can damage tumor sections by absorbing near-infrared light and X-rays, and demonstrate excellent photoacoustic imaging capabilities and good biocompatibility.