Targeted delivery of platinum-based anticancer complexes.

The most widely used anticancer drugs are platinum-based. Their efficacy might be improved by carriers which can transport large numbers of Pt centres, shield the drug from premature activation, and/or deliver Pt specifically to cancer cells using vectors which recognise specific targets. We describe recent progress using functionalized carbon nanotubes (CNTs) and nanorods, hollow Prussian blue (HPB), magnetic iron oxide and gold nanoparticles, liposomes, nanogels and polymers, as well as active targeting by conjugation to biodegradable proteins and peptides (e.g. EGF, heparin, herceptin, somatostatin and TAT). Spatially targeted activation of Pt(IV) prodrugs using light is also a promising approach. Interestingly, use of these new delivery and targeting systems for platinum drugs can lead to species with unusual reactivity which can kill cancer cells by new mechanisms.