Hybrid Extracellular Vesicles With Combined Functional Properties From Mesenchymal Stem Cells and Astrocytes for Targeted Neurodegenerative Disease Applications

Extracellular vesicles (EVs) have been investigated as nanotherapeutics and drug delivery systems for a wide range of disease indications. However, translational application of EVs is challenging due to their physical heterogeneity and variation in functional potency. The current study generated a novel hybrid EV formulation by membrane fusion of mesenchymal stem/stromal cell‐derived EVs with astrocyte‐derived EVs and defined its physicochemical and functional properties. Both EV populations have translational potential for neurodegenerative disease applications—a disease area with limited treatment strategies due to its complex disease biology requiring multi‐faceted therapeutic approaches. However, individual EV sources lack the full set of therapeutic properties needed for comprehensive treatment. Stem cell‐derived EVs possess general neuroprotective and anti‐inflammatory effects but lack widespread blood–brain barrier penetration and specific neurodegenerative pathology targeting. Astrocytes are uniquely involved in key neuronal processes but are prone to adopting neuroinflammatory phenotypes in disease states. Using super resolution microscopy and quantitative proteomic analysis, we characterized, optimized, and validated a hybrid EV formulation for its brain cell targeting, neuroprotective function, and immunomodulatory capability. These results establish a platform for EV engineering through EV‐EV hybridization and demonstrate the potential of one formulation for neurodegenerative applications.