Exosome isolation from all stem cell types followed a consistent protocol. Upon reaching 80% confluence, cells were cultured in serum-free media for 48 hours to prevent contamination by serum-derived exosomes. Conditioned media were collected and subjected to differential centrifugation to remove cellular debris and larger vesicles. Centrifugation was first performed at 300 × g for 10 minutes, followed by 2,000 × g for 20 minutes to remove larger extracellular vesicles and apoptotic bodies. The supernatant was ultracentrifuged at 100,000 × g for 70 minutes using a Beckman Coulter Optima XPN ultracentrifuge with a 70Ti rotor. The exosome pellet was resuspended in phosphate-buffered saline (PBS) and passed through a 0.22 µm filter for purity.