Enhanced Cisplatin Chemotherapy by Iron Oxide Nanocarrier-Mediated Generation of Highly Toxic Reactive Oxygen Species.

Reactive oxygen species (ROS) plays a key role in therapeutic effects as well as side effects of platinum drugs. Cisplatin mediates activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX), which triggers oxygen (O2) to superoxide radical (O2•-) and its downstream H2O2. Through the Fenton's reaction, H2O2 could be catalyzed by Fe2+/Fe3+ to the toxic hydroxyl radicals (•OH), which cause oxidative damages to lipids, proteins, and DNA. By taking the full advantage of Fenton's chemistry, we herein demonstrated tumor site-specific conversion of ROS generation induced by released cisplatin and Fe2+/Fe3+ from iron-oxide nanocarriers with cisplatin(IV) prodrugs for enhanced anticancer activity but minimized systemic toxicity.