Nanostructured materials functionalized with metal complexes: In search of alternatives for administering anticancer metallodrugs

Nanotechnology has shown great promise in unraveling several important issues of conventional anticancer chemotherapy. Expectations project that a new generation of effective cancer therapies will be developed with enormous potential to overcome the biological, biophysical and biomedical obstacles that the human body enacts against standard chemotherapeutic treatments. Generally, nanostructures protect the entombed drug molecules from degradation in blood, allowing their safe and unimpaired delivery to specific target sites in the body. Nanostructured macromolecular systems such as curcubit[n]urils, cyclodextrins, liposomes, lipid nanocapsules, proteins, polynuclear organometallic compounds, carbon nanotubes, polymeric nanoparticles and ceramic materials have shown great potential in facilitating the administration of potent anticancer metallodrugs. The uniqueness of these nanostructured materials lies in their suitability for functionalization with small molecule drugs. Recently, there has been a great deal of interest among oncologists and medicinal chemists in functionalizing nanostructured materials with anticancer metallodrugs to ensure better administration. In view of these facts, the state-of-art of nanostructured materials functionalized with metallodrugs as anticancer agents is described in this review. The functionalization of several classes of metal complexes including platinum and non-platinum compounds is also addressed. Special focus is given to the co-delivery of metallodrugs within nanostructures. Toxicity of nanomaterials is discussed and the associated concerns are also highlighted. Finally, the current challenges and the future perspectives of metallodrug functionalization have been commented upon. (C) 2016 Elsevier B.V. All rights reserved.