The methodology of this study was meticulously designed to evaluate the therapeutic potential of stem cell-derived exosomes in promoting neurological regeneration. The protocols employed emphasized reproducibility and scientific rigor, particularly in the isolation, characterization, and application of exosomes derived from mesenchymal stem cells (MSCs), neural stem cells (NSCs), and induced pluripotent stem cells (iPSCs). Exosome isolation was conducted through differential ultracentrifugation, followed by size-exclusion chromatography, to obtain high-purity vesicle preparations. These techniques were selected for their effectiveness in separating exosomes from cellular debris and larger vesicles while preserving the integrity of the exosomal cargo.