Search

The fast conversion of hydrogen peroxide (H2O2) into reactive oxygen species (ROS) at tumor sites is a promising anticancer strategy by manipulating nanomedicines with near‐infrared light in the second region (NIR‐II). However, this strategy is greatly compromised by the powerful antioxidant capacity of tumors and the limited ROS generation rate of nanomedicines. This dilemma mainly stems from the lack of an effective synthesis method to support high‐density copper‐based nanocatalysts on the surface of photothermal nanomaterials. Herein, a multifunctional nanoplatform (MCPQZ) with high–density cuprous (Cu2O) supported molybdenum disulfide (MoS2) nanoflowers (MC NFs) is developed for the efficient killing of tumors via a potent ROS storm by an innovative method. Under NIR‐II light irradiation, the ROS intensity and maximum reaction velocity (Vmax) produced by MC NFs are 21.6 and 33.8 times that of the non–irradiation group in vitro, which is much higher than most current nanomedicines. Moreover, the strong ROS storm in cancer cells is efficiently formed by MCPQZ (increased by 27.8 times compared to the control), thanks to the fact that MCPQZ effectively pre–weakens the multiple antioxidant systems of cancer cells. This work provides a novel insight to solve the bottleneck of ROS‐based cancer therapy. [ABSTRACT FROM AUTHOR]

Cancer immunotherapy effect can be greatly enhanced by other methods to induce immunogenic cell death (ICD), which has profoundly affected immunotherapy as a highly efficient paradigm. However, these treatments have significant limitations, either by causing damage of the immune system or limited to superficial tumors. Sonodynamic therapy (SDT) can induce ICD to promote immunotherapy without affecting the immune system because of its excellent spatiotemporal selectivity and low side effects. Nevertheless, SDT is still limited by low reactive oxygen species yield and the complex tumor microenvironment. Recently, some emerging SDT‐based nanomedicines have made numerous attractive and encouraging achievements in the field of cancer immunotherapy due to high immunotherapeutic efficiency. However, this cross‐cutting field of research is still far from being widely explored due to huge professional barriers. Herein, the characteristics of the tumor immune microenvironment and the mechanisms of ICD are firstly systematically summarized. Subsequently, the therapeutic mechanism of SDT is fully summarized, and the advantages and limitations of SDT are discussed. The representative advances of SDT‐based nanomedicines for cancer immunotherapy are further highlighted. Finally, the application prospects and challenges of SDT‐based immunotherapy in future clinical translation are discussed. [ABSTRACT FROM AUTHOR]

Gas‐mediated sonodynamic therapy (SDT) has the potential to become an effective strategy to improve the therapeutic outcome and survival rate of cancer patients. Herein, titanium sulfide nanosheets (TiSX NSs) are prepared as cascade bioreactors for sequential gas–sonodynamic cancer therapy. TiSX NSs themselves as hydrogen sulfide (H2S) donors can burst release H2S gas. Following H2S generation, TiSX NSs are gradually degraded to become S‐defective and partly oxidized into TiOX on their surface, which endows TiSX NSs with high sonodynamic properties under ultrasound (US) irradiation. In vitro and in vivo experiments show the excellent therapeutic effects of TiSX NSs. In detail, large amounts of H2S gas and reactive oxygen species (ROS) can simultaneously inhibit mitochondrial respiration and ATP synthesis, leading to cancer cell apoptosis. Of note, H2S gas also plays important roles in modulating and activating the immune system to effectively inhibit pulmonary metastasis. Finally, the metabolizable TiSX NSs are excreted out of the body without inducing any significant long‐term toxicity. Collectively, this work establishes a cascade bioreactor of TiSX NSs with satisfactory H2S release ability and excellent ROS generation properties under US irradiation for programmed gas–sonodynamic cancer therapy. [ABSTRACT FROM AUTHOR]