ABSTRACT
2Malignant tissue is characterized by several very specific traits, which offer the opportunity for the development of drugs with increased tumor specificity and tolerability. Here especially a changed redox homeostasis, altered blood supply, the occurrence of low oxygenated areas (hypoxia), decreased pH values, and specific enzyme expression need to be considered. Since several decades, metal compounds (especially Pt drugs) are key players in the daily therapy of cancer patients. The chemistry of diverse metal drugs has several characteristics, which allow the design of tumor-specific activated prodrugs. Of particular note is the activation by reduction principle, which is based on chemical changes induced by reduction of the central metal ion, representing a very 3elegant and powerful strategy for, e.g., Pt, Ru, Cu, and Co (pro)drugs. This chapter aims to give an overview of metal-based prodrugs and their nanoformulations, which have been designed to be activated by tumor-specific stimuli.
