Phosphorescent Metal Halide Nanoclusters for Tunable Photodynamic Therapy

Abstract

Photodynamic therapy (PDT) is currently limited by the inability of photosensitizers (PSs) to enter cancer cells and generate sufficient reactive oxygen species. Utilizing phosphorescent triplet states of novel PSs to generate singlet oxygen offers exciting possibilities for PDT. Here, we report phosphorescent octahedral molybdenum (Mo)-based nanoclusters (NC) with tunable toxicity for PDT of cancer cells without use of rare or toxic elements. Upon irradiation with blue light, these molecules are excited to their singlet state and then undergo intersystem crossing to their triplet state. These NCs display surprising tunability between their cellular cytotoxicity and phototoxicity by modulating the apical halide ligand with a series of short chain fatty acids from trifluoroacetate to heptafluorobutyrate. The NCs are effective in PDT against breast, skin, pancreas, and colon cancer cells as well as their highly metastatic derivatives, demonstrating the robustness of these NCs in treating a wide variety of aggressive cancer cells. Furthermore, these NCs are internalized by cancer cells, remain in the lysosome, and can be modulated by the apical ligand to produce singlet oxygen. Thus, (Mo)-based nanoclusters are an excellent platform for optimizing PSs. Our results highlight the profound impact of molecular nanocluster chemistry in PDT applications.

Turning Silica into Enzymes by Hydrogenation: Simultaneously Achieving Oxygen Vacancy Engineering and Tumor Adaptive Accumulation for NIR‐II‐Potentiated Therapy

“…[ 4c,16 ] Overall, OVs‐engineered Mo‐based nanozymes not only have high photothermal conversion nature, [ 2a,17 ] but also can be used as photocatalysts to generate multiple ROS including singlet oxygen ( 1 O 2 ) and superoxide anion free radicals (·O 2 − ). [ 6c,18 ] Moreover, OVs can cause more low‐valence Mo ions, which are beneficial for realizing Fenton‐like reaction‐mediated CDT. [ 19 ] Therefore, the combination of Mo‐based nanozymes and OVs engineering will be an ingenious method to improve the catalytic anticancer outcome.…”