The strategy of linking signal-responsive prodrugs to a carrier material is a promising approach to improve the selectivity of chemotherapy drugs. Besides the improved water solubility, it enables controlled drug release profiles via temporal-, or local activation. Prodrugs or caged drugs are chemically modified therapeutics that are inactive until their activation via stimulusinduced removal of the cage group. In cancer therapy models, a variety of stimuli have been used as triggers for controlled drug activation via chemical de-caging, including pH , glutathione (GSH) , reactive oxygen species (ROS) , hypoxia or enzymes , amongst others .