• MSC-exos repair skin barrier by modulating physical, immune, microbial, neural, and pigmentary components.
• Exosome efficacy is influenced by MSC source and preconditioning, with bioengineering enhancing therapeutic potential.
• Key translational challenges include standardization, scalable manufacturing, and regulatory pathways.
• MSC-exos offer a safer, cell-free alternative to whole-cell therapies with quantifiable dosing and lower risks.