Nanomedicine currently stands at the forefront of modern medicine, offering innovative strategies to address the limitations of conventional antitumoral therapies. In this context, Zinc Oxide (ZnO) has garnered significant attention due to its semiconductor properties and its potential for cancer cell selective cytotoxicity. However, the clinical translation of ZnO is still limited due to its inherent instability in biological fluids. This leads to the unregulated leakage of zinc ions and premature ROS production, which pose a significant risk of off-target toxicity to healthy tissues. The primary objective of this thesis is to mitigate this off-target toxicity and overcome the limitations of the system in biological environments.