Self-Assembly and Antitumor Activity of a Polyoxovanadate-Based Coordination Nanocage

A new supramolecular nanocage, VMOP-31, based on polyoxovanadate as the molecular building block, has been designed and synthesized under solvothermal conditions. The structure of VMOP-31 was determined by single-crystal and powder X-ray diffraction, FTIR spectroscopy, UV/Vis spectrophotometry, and thermogravimetric analysis. The nanocage exhibits octahedral geometry and is constructed of six {V₅ O₉ Cl(COO)₄ } at the vertices and eight TATB (H₃ TATB=4,4',4''-(s-triazine-2,4,6-triyl)tribenzoic acid) ligands on the faces. Impressively, VMOP-31 exhibited high efficiency in the inhibition of cell growth of solid tumors, such as human liver cancer cells SMMC-7721, and superior results in the treatment of liver tumors in mice compared with classic cisplatin. Detailed studies revealed that the potential mechanism of cell death induced by VMOP-31 involves cell cycle arrests, DNA damage, and subsequent apoptosis. Moreover, VMOP-31 exhibited negligible side effects in the mice compared with cisplatin. To the best of our knowledge, VMOP-31 is the first supramolecular nanocage applied to hepatic tumors both in vitro and in vivo.