Nano-functionalization of metal complexes for molecular imaging and anticancer therapy

• We examine combinations of nanoparticles and coordination complexes for anticancer applications.
• We conduct a survey of the nanomaterials, biomolecules and bioconjugation strategies used.
• Different systems and therapy options using coordination chemistry-based drugs are covered.
• We report actively and passively targeted systems for multimodal imaging and diagnosis.
• Achievements, challenges and opportunities are briefly discussed.

Recently, there has been a growing interest in functionalizing metal complexes with biomolecules and nanomaterials for molecular imaging and anticancer therapy applications. In this review, we present the different strategies being used for inducing interaction and attachment of metal complexes to different types of biomolecules and nanomaterials. We explain and justify these new research efforts by considering the limitations of existing metal-based contrast agents and drugs as well as current challenges in therapy, diagnosis and visualization of biological processes at the molecular or cellular level. Representative examples in which nano-functionalisation of metal complexes enabled targeted delivery of small metal-based imaging probes, anti-cancer drugs and radiopharmaceuticals are used to illustrate the wide range of opportunities and challenges of this emerging approach.