Extracellular vesicles: A new therapeutic drug for nerve injury repair

Extracellular vesicles are membranous structures actively released by cells. They efficiently mediate intercellular communication and play a role in reshaping the microenvironment. Their diverse bioactive cargo, including miRNAs, proteins, and lipids, along with their ability to cross the blood-brain barrier, holds broad therapeutic promise in the field of neuroregeneration. Current research focuses on exploring the mechanisms of action and clinical translational potential of extracellular vesicles from different sources, including exosomes derived from mesenchymal stem cells, neural stem cells, neurons, and vascular cells, in neural repair. Key issues restricting clinical translation include the lack of standardized isolation and characterization methods, insufficient dose determination and bioavailability assessment, and inadequate evidence for long-term safety. This review systematically summarizes the therapeutic research progress of extracellular vesicles from various sources in neurological disorders such as brain injury, spinal cord injury, and neurodegenerative diseases. It provides a comprehensive overview of the key molecular regulatory networks involving extracellular vesicles, including the regulation of neuroinflammation, axonal regeneration, mitochondrial function and metabolic homeostasis, as well as structural and functional support of the neurovascular unit. In addition, this review assesses the feasibility of extracellular vesicles as drug delivery vehicles. In summary, extracellular vesicles constitute a dynamic and multi-pathway regulatory network. A thorough elucidation of their mechanisms of action is expected to facilitate the development of novel therapeutic strategies in the field of neural repair and provide new perspectives and solutions for precision medicine.