The rehabilitation outcome and recovery, in people after stroke or with vascular severe brain injury(vSBI), are difficult to predict. Moreover, the clinical management of patients during hospitalization is problematic due to complex clinical conditions and complications, e.g. healthcare-associated infections(HAIs). Today we still lack early objective biomarkers that could predict the patient's trajectory at admission. Extracellular vesicles are nanoparticles naturally released by cells in physiological and pathological conditions. As important actors of cellular communication between different organs and body districts, EVs are currently under investigation as an informative tool able to reflect the clinical conditions of patients. Using an optimized Surface Plasmon Resonance imaging (SPRi) based biosensor, our main objective is to assess the predictive capacity of biomarkers associated to blood-derived extracellular vesicles for anticipating patients' recovery after stroke and vSBI. If successful, the project will 1) demonstrate the ability of the SPRi biosensor to reveal differences in the relative amount of specific cell-derived EV subpopulations and their molecular cargo during disease progression and rehabilitation-induced recovery, 2) verify the impact of HAI on patients' response, 3) perform a patient's stratification to personalize the rehabilitation protocol.