Photodynamical therapy (PDT), as an emerging treatment modality, which takes advantage of reactive oxygen species (ROS) initiated by light illumination to ablate tumor, has suffered from the limited treatment depth,...

Exploiting two-dimensional nanomaterials as photo-based theranostic agent has witnessed great promise in highly effective ablation of deep-tissue buried tumors. However, it’s still limited by their poor absorption in the second...

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Photodynamic therapy (PDT) with organic photosensitizers generally goes through the oxygen‐dependent process, generating singlet oxygen and/or superoxide anion. However, the generation of reactive oxygen species is often suppressed as a result of hypoxia, one of the common features in tumors, therefore limiting the effectiveness of the tumor treatments. Consequently, it is urgent and significant to develop an oxygen‐independent hydroxyl radical photogenerator and unveil the mechanism. In this work, a hydroxyl radical (·OH) photogenerator originating from the electron transfer process is engineered. Detailed mechanism studies reveal that the optimized photosensitizer, WS2D, which contains a bithiophene unit, could both promote charge carrier generation and accelerate reaction efficiency, resulting in the efficient production of ·OH. In addition, WS2D nanoparticles are constructed to improve the polydispersity and stability in aqueous solution, which exhibit excellent biocompatibility and mitochondrial targeting. Bearing the above advantages, WS2D is employed in phototheranostics, which could release ·OH effectively and damage mitochondria precisely, achieving high PDT efficiency in vitro and in vivo. Overall, this work successfully provides valuable insights into the structural design of a hydroxyl radicals (·OH) photogenerator with great practical perspectives.

Defective black cobalt hydroxide-based nanoagents for efficient oxygen-evolving phototherapy.

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Chemodynamic therapy (CDT), as the emerging modality of cancer therapy based on Fenton or Fenton-like reactions, still suffers from low efficacy of hydroxyl radical generation, which requires full exposure of reaction sites of CDT nanoagents to intracellular H2O2. However, the amount of exposed reaction sites is severely restrained by the controlled size (<200 nm) and the limited specific surface area of nanoagents. Herein, we highlight the in-situ bloomed micrometer-scale CoMn-based layered double hydroxide (CoMn-LDH) ultrathin nanosheets, which are derived from CoMn boride-based CMB@ss-SF nanospheres in response to overexpressed glutathione (GSH) and dissolved oxygen in tumor microenvironment (TME), accomplishing intensive photothermal-enhanced CDT. The micrometer-scale CoMn-LDH ultrathin nanosheets would provide abundant reactive sites to accelerate heterogeneous Fenton-like reaction as well as GSH depletion, eliciting quick release of metal ions and further realizing intensive homogeneous Fenton-like reactions for ·OH generation. Moreover, the nanoagent can harvest 808 nm light into heat, which can be utilized to promote the CDT efficacy and realize photoacoustic imaging (PAI). Because of acidity and overexpressed GSH in TME, the nanoagent exhibited superior biodegradability. Benefiting from the synergistic advantages, CMB@ss-SF with negligible cytotoxicity completely eradicated the tumors in mouse. This work provides avenue for developing CDT nanoagents.

As an emerging cancer treatment, Ca2+-loaded nanoagents can disorder intracellular calcium homeostasis to induce cancer cell death. However, the developed Ca2+ nanocarriers are very limited in variety. Herein, we developed a metal oxide based nanoagent, Ca0.35CoO2@ss-SiO2-Ce6 (denoted as CCO@ss-SiO2-Ce6), which not only intensively released Ca2+ but also realized enhanced photothermal and photodynamic therapy. The excellent photothermal conversion efficacy (48.01% at 808 nm laser illumination, 1 W/cm2), high heat-enhanced release rate of Ca2+ (50.09% at pH 4.5), and catalase-mimic activity to generate oxygen as well as the facilitated production of the singlet oxygen all contributed to the enhanced synergistic cancer therapy efficacy. The in vitro and in vivo experiments displayed that CCO@ss-SiO2-Ce6 demonstrated superior biocompatibility and remarkable suppressive tumor growth. This work opens a pathway for fabricating synergistic therapeutic nanoplatforms.