Cancer is the second worldwide cause of death after cardiovascular diseases. The treatments offered by conventional medicine, do not appear to be entirely effective for the eradication of the cancer and they can cause significant side effects. After the advent of nanotechnologies, their use in the medical field has highlighted the potential of nanomedicine, the application of nanomaterials for health and medicine. More specifically, smart nanoparticles have been increasingly studied thanks to their multifunctional properties that can provide rapid diagnosis, effective therapies and even their combination, labelled as theranostics. This is the context in which this Master Thesis is inserted. Among the available nanomaterials, zinc oxide nanoparticles (ZnO NPs) are widely used in biomedical applications thanks to their chemical and physical features, like semiconducting, piezoelectric and antibacterial properties.