Abstract: Objective To prepare HAMA/PEGDA/GelMA hydrogel materials loaded with adipose-derived mesenchymal stem cell exosomes （hADMSC-Exo） and explore their effect on the repair of full-thickness skin defects. Methods  hADMSC-Exo were extracted and identified by electron microscopy， particle size， and Western Blot. Composite hydrogel materials were constructed by photo-crosslinking. Their microstructure was detected by electron microscopy， and the exosome release characteristics were observed by extraction method. The extract of composite hydrogels was co-cultured with human umbilical vein endothelial cells（ hUVECs） to observe exosome uptake and cell migration. A mouse full-thickness skin defect model was established. On the 12th day after surgery， HE and Masson histological staining were used to evaluate the role in wound repair. Results  The composite hydrogel materials were successfully prepared. hADMSC-Exo could be slowly released and taken up by hUVECs， and significantly promoted cell migration （P<0.05）. Animal experiment results showed that on the 12th day， compared with the negative control group， the HAMA/PEGDA/GelMA+Exo group had a higher wound closure rate， better collagen deposition. Conclusion HAMA/PEGDA/GelMA composite hydrogels loaded with hADMSCExo can significantly accelerate the healing of full-thickness skin defects. The mechanism may be related to regulating the inflammatory response， promoting angiogenesis and collagen deposition， which provides experimental basis and a new strategy for the development of new wound coverage dressings.

Key words: &emsp, Hydrogel, &emsp, Adipose-derived mesenchymal stem cells, &emsp, Exosomes, &emsp, Wound repair