Polyoxometalate-biomolecule conjugates: a new approach to create hybrid drugs for cancer therapeutics.

Some polyoxometalate (POM) clusters have demonstrated attractive anticancer properties. Unfortunately, their cytotoxicity upon normal cell is one of fateful side effects obstructing their further clinic application as inorganic drugs. In this communication, we report a new approach to create hybrid drugs potentially for cancer therapeutics. At first, the POM cluster bioconjugates were created by attaching the bioactive ligands on an amine grafted POM via simple amidation reaction. The cytotoxicity study with breast cancer cells (MCF-7 and MDA-MB-231) and non-cancerous breast epithelial cell (MCF-10A) showed that rationally selected ligands with cancer-cell targeting ability on POM-biomolecule conjugates can impart enhanced anti-tumor activity and selectivity, thus representing a new concept to develop novel POM-biomolecule hybrid drugs with the potential synergistic effect: increased bioactivity and lower side effect.