Potential of Intranasally Delivered Exosomes Derived from Mesenchymal Stem Cells as Treatment for Ischemic Stroke: Proton and Sodium MRI at 21.1 T

Motivation: Stroke treatments are hindered by inefficient delivery and patient tolerance. This study examines whether intranasal mesenchymal stem cell-derived extracellular vesicles (EV) can overcome limitations and improve outcomes. Goal(s): The study seeks to evaluate whether intranasal EV delivery improves recovery by investigating recovered sodium homeostasis and diffusional restrictions. Approach: Using a preclinical ischemic stroke model, EV were administered intranasally. High-resolution MRI, including spin-echo 1H EPI DWI, T2W FSE and 23Na CSI, were acquired over 21 d. Results: The EV-treated group displayed reduced damage and sodium imbalances, with the longitudinal consistency of ADC reflecting both reduced lesion volume and necrosis indicative of maintained cellular integrity. Impact: MRI-based evaluation of intranasal EV therapy provides a reliable approach to monitor recovery and sodium dynamics post-stroke, meeting a critical need for non-invasive, effective treatments and their assessment.