Hypoxic‐preconditioned mesenchymal stem cell‐derived small extracellular vesicles promote the recovery of spinal cord injury by affecting the phenotype of astrocytes through the <scp>miR</scp>‐21/<scp>JAK2</scp>/<scp>STAT3</scp> pathwayZhelun Yang, Chunmei Chen|CNS Neuroscience & Therapeutics|2023Cited by 51