Anti-tumor, -viral, and -bacterial activities of polyoxometalates for realizing an inorganic drug

Polyoxometalates (PMs) as discrete metal-oxide cluster anions comprise a versatile class of inorganic, anionic clusters that have a wide variety of structures, sizes, and a combination of metals, high solubility in water, and electrochemical activity. Recent investigation of anti-tumor, -viral, and -bacterial activities of PMs shows induced cell-apoptosis, inhibition of binding of virus to receptor, and the enhancement of P-lactam antibiotics as well as the inhibition of bacterial growth, respectively. PMs exemplified for each biological activity are discussed from the chemotherapeutic point of view for the establishment of a novel inorganic drug based on PMs.