Controllable Assembly of Mo36VI-Based Polyoxometalate Porous Frameworks with Silver Ions and Lung Cancer Cell-Specific Cytotoxicity

The controllable construction of pure inorganic polyoxometalate (POM)zite materials with well-defined secondary building units (SBUs) is of great challenge. In this work, three distinct POM porous framework compounds 1-3 based on [(Mo36O112)-O-VI(H2O)(16)](8-)({Mo-36}) SBUs with various active growth points and transition-metal Ag linkers, both as countercations and structure directors, were self-assembled from simple salts to ordered porous frameworks (compound 1 is a 3D framework with channels of 20.1 angstrom in diameter, while compound 2 and compound 3 are 2D frameworks with channels of 29.1 and 26.8 angstrom in diameter, respectively, and the channels of compound 3 are formed by the fourfold spiral winding of {Mo-36} SBUs) by controlling the reaction conditions, providing valuable experience for synthetic chemists to obtain more interesting and functional materials. The {Mo-36}-based POM porous framework compounds 1-3 exhibit cell type-specific, dose-dependent, and pH-sensitive anticancer behavior, with the lowest IC50 in A549 lung cancer cells. Further, the monomer precursors AgNO3 and Mo-36 SBU, however, are less cytotoxic to A549 cells than compound Ag-{Mo-36}, suggesting a synergistic action of hybrid materials. Mechanistic insights into the anticancer activity of compounds 1-3 show that they induce mitochondria-mediated apoptosis and necrosis in A549 cells. Thus, {Mo-36}-based POM porous framework materials with silver ions could serve as promising anticancer agents for lung cancer therapy.

Automated summary

The controllable construction of pure inorganic polyoxometalate (POM) zite materials with well-defined secondary building units (SBUs) is challenging. In this work, three distinct POM porous framework compounds 1-3 based on specific SBUs and transition-metal Ag linkers were self-assembled, providing valuable experience for synthetic chemists to obtain more interesting materials. Compound 1-3 exhibit cell type-specific, dose-dependent, and pH-sensitive anticancer behavior, making them promising anticancer agents for lung cancer therapy.