One of the major concerns that arises after the overt tumor regression in a patient is the cancer recurrence. The work of this Master thesis takes part in the European project XtraUS, aimed at developing targeted, non-immunogenic, stimuli-responsive nanoconstructs in combination with an extracorporeal bloodstream set-up to eliminate circulating tumor cells (CTCs), responsible for cancer relapse and metastasis spreading. As an initial analysis, the research relies on the effect of the external stimulation on nanoconstructs. For this purpose, an ultrasound stimulation is used together with ZnO nanoparticles, able to enhance the acoustic cavitation phenomenon by introducing a higher amount of gas bubbles in liquids.