The theranostic nanoagent Mo2C for multi-modal imaging-guided cancer synergistic phototherapy.

Multifunctional theranostic platforms, especially single component-based platforms, enable both cancer treatment and real-time imaging as well as enhance the efficiency of treatment. In this study, 50 nm Mo2C nanospheres were explored as a "one-for-all" theranostic agent. The light-harvesting of Mo2C covered the entire near infrared region, and NIR irradiation concurrently triggered hyperthermia and reactive oxygen species (ROS) production; thus, synergistic outcomes of photothermal and photodynamic therapy could be realized. Both in vitro and in vivo experiments have confirmed the superiority of the synergistic phototherapy in killing cancer cells and removing solid tumors; moreover, Mo2C proposed herein has been proven to be applicable as a photoacoustic imaging and CT imaging contrast agent for in vivo tumor depiction; furthermore, Mo2C demonstrates excellent biocompatibility, showing minimal hematotoxicity and tissue toxicity. A theoretical simulation performed by density functional theory revealed that the metallic character and the interband/intraband transition of Mo2C accounted for its broad photoabsorption. The antitumor mechanism of Mo2C was investigated on a solid tumor by B-mode ultrasonography (US) and magnetic resonance imaging (MRI), revealing a typical liquefactive necrosis process; hence, herein, the dual-imaging guided phototherapy was efficiently mediated by Mo2C.

SnxWO3 as a theranostic platform for realizing multi-imaging-guided photothermal/photodynamic combination therapy.

Precise oncotherapy requires effective cancer treatments that are guided by clinical imaging techniques. One of the most representative cases is multi-imaging-guided phototherapy. This study presents a novel multifunctional theranostic agent of SnxWO3 tungsten bronze, which is an excellent light absorber in the near infrared (NIR) range. Theoretical calculations based on density functional theory confirm that the insertion of donor Sn atoms into orthorhombic WO3 gives rise to the broadband visible-NIR absorption. Accordingly, both the photothermal effect and reactive oxygen species (ROS) production could be realized under NIR light irradiation by SnxWO3 tungsten bronze nanocrystals, thereby triggering the potent in vivo photothermal and photodynamic synergistic therapy. Meanwhile, modified SnxWO3 tungsten bronze has the functions of photoacoustic imaging (PAI), X-ray computed tomography (CT) imaging and near-infrared fluorescence (NIRF) imaging for tumor detection as well. Finally, for investigating the antitumor mechanism of in vivo solid tumors, clinical imaging modalities of B-mode ultrasonography (US) and magnetic resonance imaging (MRI) are employed to monitor the tumor evolution process after the photo-treatment, verifying a typically liquefactive necrosis process. These results indicate that the SnxWO3 tungsten bronze nanostructure is a promising theranostic agent for imaging-guided cancer therapy.

MoS2-Based multipurpose theranostic nanoplatform: realizing dual-imaging-guided combination phototherapy to eliminate solid tumor via a liquefaction necrosis process.

Theranostics that combines the disease diagnosis with treatment is of promising application in the foreground of personalized medicine to achieve a precise treatment with minimum side effects. In this work, we strategically designed a "four-in-one" theranostic nanoplatform for realizing the desired imaging-guided phototherapy, in which functions of fluorescent imaging, photoacoustic imaging tomography (PAT), photothermal therapy (PTT) and photodynamic therapy (PDT) were implemented by bioconjugated MoS2 nanosheets. The protagonist of MoS2 is a light-harvesting material in the near-infrared (NIR) region, which would produce localized hyperthermia at the tumor site to trigger the photothermal therapy effect for the tumor ablation as well as a PAT signal to depict the tumor concurrently upon NIR excitation. To our surprise, MoS2 has been found to be a photosensitizer for the cancer PDT treatment as well. Moreover, bovine serum albumin (BSA) decoration on MoS2 has been made to improve biocompatibility, which also allowed further conjugation with a fluorescent molecule of Cy5.5 to endow the overall nanoplatform with fluorescence imaging and monitoring features. On the basis of the above characters, great successes in cancer imaging and tumor photoablation were achieved in both in vitro and in vivo experiments. Innovatively, B-ultrasonography and MRI imaging were employed to monitor the elimination process of solid tumor after treatment, which clearly revealed a liquefaction necrosis process for rehabilitation. In short, MoS2 represents a nanoplatform of this work and manifested huge advantages in the cancer theranostics.