Oxygen-supplementing mesoporous polydopamine nanosponges with WS₂ QDs-embedded for CT/MSOT/MR imaging and thermoradiotherapy of hypoxic cancer.

Abstract

Multifunctional nanoplatforms with flexible architectures and tumor microenvironment response are highly anticipated within the field of thermoradiotherapy. Herein, the multifunctional nanoplatforms for thermoradiotherapy have been successfully constructed by the embedding of tungsten disulfide quantum dots (WS₂ QDs) into mesoporous polydopamine nanosponges (MPDA NSs), followed by integration with manganese dioxide (MnO₂). MPDA-WS₂@MnO₂, the resultant nanoplatforms, exhibit radiosensitization enhanced behavior and a capacity for responsive oxygen self-supplementation. The ingenious mesoporous structure of MPDA NSs serves as reservoir for the assembly of WS₂ QDs to form MPDA-WS₂ nanoparticles (NPs), in which WS₂ QDs provide the radiation enhancement effect, whereas the MPDA NSs framework endows the MPDA-WS₂@MnO₂ with an excellent photothermal capability. Additionally, the integration of the MnO₂ component works to decompose the tumor-overexpressed H₂O₂ and alleviate tumor hypoxia subsequently, which has been demonstrated to enhance radiotherapy performance considerably. Meanwhile, the prepared MPDA-WS₂@MnO₂ nanoplatforms have been evaluated as trimodality contrast agents for computed tomography (CT), multispectral optoacoustic tomography (MSOT), and tumor microenvironment-responsive T₁-weighted magnetic resonance (MR) imaging that have the potential for real-time guidance and monitoring during cancer therapy. More importantly, when subjected to near infrared (NIR) laser irradiation and X-ray exposure, the tumor is found to be inhibited significantly through the process of combined thermoradiotherapy. The design concepts of embedding WS₂ QDs into MPDA NSs and oxygen self-supplementing hold great potential for multimodal imaging-guided thermoradiotherapy of hypoxic cancer.