The great advances in the studies on metal complexes for the treatment of different cancer forms, starting from the pioneering works on platinum derivatives, have fostered an increasingly growing interest in their properties and biomedical applications. Among the various metal-containing drugs investigated thus far, ruthenium(III) complexes have emerged for their selective cytotoxic activity in vitro and promising anticancer properties in vivo, also leading to a few candidates in advanced clinical trials. Aiming at addressing the solubility, stability and cellular uptake issues of low molecular weight Ru(III)-based compounds, some research groups have proposed the development of suitable drug delivery systems (e.g., taking advantage of nanoparticles, liposomes, etc.) able to enhance their activity compared to the naked drugs. This review highlights the unique role of Ru(III) complexes in the current panorama of anticancer agents, with particular emphasis on Ru-containing nanoformulations based on the incorporation of the Ru(III) complexes into suitable nanocarriers in order to enhance their bioavailability and pharmacokinetic properties. Preclinical evaluation of these nanoaggregates is discussed with a special focus on the investigation of their mechanism of action at a molecular level, highlighting their pharmacological potential in tumour disease models and value for biomedical applications.

Among the various advantages of aptamers over antibodies, remarkable is their ability to tolerate a large number of chemical modifications within their backbone or at the termini without losing significant activity. Indeed, aptamers can be easily equipped with a wide variety of reporter groups or coupled to different carriers, nanoparticles, or other biomolecules, thus producing valuable molecular recognition tools effective for diagnostic and therapeutic purposes. This review reports an updated overview on fluorescent DNA aptamers, designed to recognize significant cancer biomarkers both in soluble or membrane-bound form. In many examples, the aptamer secondary structure switches induced by target recognition are suitably translated in a detectable fluorescent signal using either fluorescently-labelled or label-free aptamers. The fluorescence emission changes, producing an enhancement (“signal-on”) or a quenching (“signal-off”) effect, directly reflect the extent of the binding, thereby allowing for quantitative determination of the target in bioanalytical assays. Furthermore, several aptamers conjugated to fluorescent probes proved to be effective for applications in tumour diagnosis and intraoperative surgery, producing tumour-type specific, non-invasive in vivo imaging tools for cancer pre- and post-treatment assessment.