| Comparison Item | Stem Cells | Exosomes |
|---|---|---|
| Source | Living cells (fat/umbilical cord/bone marrow) | Nano-vesicles secreted by cells |
| Structure | Complete cells (with nucleus) | Nucleus-free nanoparticles (30–150 nm) |
| Function | Differentiate into various cell types | Transmit repair signals |
| Components | DNA, RNA, proteins, organelles | microRNA, growth factors, signaling proteins |
| Storage | Requires special conditions to maintain viability | -80°C for long-term preservation |
| Safety | Potential immune rejection and tumor risk | Non-proliferative, very low risk |