Construction of multifunctional organic–inorganic hybrid Bi2S3–PLGA capsules for highly efficient ultrasound-guided radiosensitization of brachytherapy

Abstract

The development of nanobiotechnology provides an efficient strategy to improve the therapeutic outcome of various therapeutic modalities against cancer. In this work, we successfully constructed a novel multifunctional theranostic platform based on Bi₂S₃-embeded poly(lactic-co-glycolic acid) composite capsules (Bi₂S₃–PLGA) to realize the highly efficient ultrasound-guided synergistic brachytherapy. The as-synthesized hydrophobic Bi₂S₃ nanodots were encapsulated into PLGA capsules to form Bi₂S₃–PLGA composite capsules by a simple but efficient water/oil/water (W/O/W) emulsion approach. The composite Bi₂S₃–PLGA capsules exhibit excellent contrast-enhanced ultrasound imaging performance in the prostate tumor-bearing nude mice model, which could accurately indicate the location of a radiation source. More importantly, this research has demonstrated for the first time both in vitro and in vivo that Bi₂S₃–PLGA capsules could function as an efficient radiosensitizer for synergistic brachytherapy. Thus, the elaborately designed novel Bi₂S₃–PLGA capsules based on nano-biotechnology provides an efficient protocol for enhancing the therapeutic efficiency of ultrasound imaging-guided brachytherapy against cancer.