Nanoscale Coordination Polymers for Synergistic NO and Chemodynamic Therapy of Liver Cancer

Nitric oxide (NO) induces a multitude of antitumor activities, encompassing the induction of apoptosis, sensitization to chemo-, radio-, or immune-therapy, and inhibition of metastasis, drug resistance, angiogenesis, and hypoxia, thus attracting much attention in the area of cancer intervention. To improve the precise targeting and treatment efficacy of NO, a glutathione (GSH)-sensitive NO donor (1,5-bis[(l-proline-1-yl)diazen-1-ium-1,2-diol-O2-yl]-2,4-dinitrobenzene, BPDB) coordinates with iron ions to form the nanoscale coordination polymer (NCP) via a simple precipitation and then partial ion exchange process. The obtained Fe(II)-BNCP shows desirable solubility, biocompatibility, and circulation stability. Quick NO release triggered by high concentrations of GSH in tumor cells improves the specificity of NO release in situ, thus avoiding side effects in other tissues. Meanwhile, under high concentrations of H2O2 in tumors, Fe2+ ions in BPDB-based NCP, named Fe(II)-BNCP, exert Fenton activity to generat...