Exosome-based nanomedicine for neurological disorders: mechanisms, engineering, and therapeutic potential

Exosomes are naturally occurring extracellular vesicles that have emerged as promising bio-inspired nanocarriers for the treatment of neurological disorders owing to their intrinsic biocompatibility, low immunogenicity, and ability to cross the blood-brain barrier. This review highlights recent advances in exosome biology, cargo-sorting mechanisms, and engineering strategies designed to enhance therapeutic delivery and targeting within the central nervous system. Particular emphasis is placed on the application of engineered exosomes in neurodegenerative diseases, stroke, spinal cord injury, neuropathic pain, and neuroinflammatory disorders. In addition, we discuss how exosomes compare with conventional delivery platforms and critically examine the major barriers limiting their clinical translation, including heterogeneity, scalability, reproducibility, purity, and regulatory standardization. By integrating mechanistic insights with translational perspectives, this review provides a framework for the rational design and future clinical implementation of exosome-based nanomedicines for neurological disorders. Relevant literature was identified through searches of PubMed, Scopus, Web of Science, and Google Scholar. Publications available from database inception through [Month Year] were screened using combinations of keywords including "exosomes," "extracellular vesicles," "neurological disorders," "brain-targeted delivery," "exosome engineering," "drug delivery," and "clinical trials." Additional relevant articles were identified through manual searches of reference lists from selected studies and recent reviews.