Stem Cell-Derived Extracellular Vesicles Restore Sodium & Energetic Homeostasis in Ischemic Stroke as Quantified by Longitudinal MRI/S at 21.1 T

Motivation: A leading cause of death and disability, stroke is treated foremost by restoring blood flow, but follow-up therapies that focus on ischemic tissue recovery are critical as is the evaluation of therapeutic efficacy. Goal(s): This work administers extracellular vesicles (EV) derived from human mesenchymal cells (hMSC) to salvage tissue while monitoring recovery and metabolic changes longitudinally using ultra-high field MRI/S. Approach: T2-W MRI,23Na-CSI, and 1H-MRS were used to quantify lesion reduction, sodium homeostasis and energetic remodeling. Results: Upon EV treatment, sodium (and to a lesser extent proton) lesions were reduced by day 3, while lactate, creatine and NAA were stabilized compared to control. Impact: Combined sodium MRI and proton MRS provide a more sensitive and early quantitative metric to evaluate the efficacy of stem cell-derived therapy following ischemia and longitudinal metabolic, ionic and functional recovery. Such methods can evaluate other treatments against different pathologies.