3D extracellular matrix hydrogel loaded with exosomes promotes wound repair
Ling Huajun1, Cui Ruiwen2, Wang Qiyou3
1Second Department of Orthopedics and Traumatology, People’s Hospital of Gaoming District, Foshan 528500, Guangdong Province, China; 2Department of Organ Transplantation, Guangdong Province Chinese Medicine Hospital, Guangzhou 510120, Guangdong Province, China; 3Department of Orthopedics and Traumatology, Third Affiliated Hospital of Southern Medical University, Guangzhou 510630, Guangdong Province, China
Abstract: BACKGROUND: The application of extracellular matrix hydrogels can effectively deliver exosomes and bridge with the surrounding tissues of the skin, which is helpful for the repair of skin damage.
OBJECTIVE: To explore the effect of 3D gelatin extracellular matrix hydrogel loaded with bone marrow mesenchymal stem cells-derived exosomes on skin wounds.
METHODS: Exosomes of the supernatant of rat bone marrow mesenchymal cells were obtained by ultracentrifugation. (1) A methacrylic acid-modified gelatin hydrogel was prepared, and exosomes and photoinitiators were added to cross-link under ultraviolet light to form a 3D gelatin extracellular matrix hydrogel loaded with exosomes. (2) The fibroblasts were seeded on the exosome-loaded 3D gelatin extracellular matrix hydrogel and ordinary culture plates, respectively. After 12 hours of seeding, the cell migration was observed by scratch experiment. (3) A skin injury wound with a diameter of 1 cm and a depth of 0.2 cm was made on the back of 20 adult SD rats. The experimental group (n=10) was covered with 3D extracellular matrix hydrogel loaded with exosomes, and the control group (n=10) was covered with normal saline, and finally with sterile gauze. Two weeks after operation, the structural changes and collagen deposition of the wound were observed by hematoxylin-eosin staining and Masson staining.
RESULTS AND CONCLUSION: (1) The scratch experiment exhibited that the migration ability of fibroblasts on the exosome-loaded 3D gelatin extracellular matrix hydrogel was stronger than that of the ordinary culture plate. (2) Hematoxylin-eosin staining in the animal experiment displayed that skin tissue structure of the control group was broken to varying degrees, and the number of inflammatory cells increased. The skin tissue structure of the experimental group was relatively complete, the number of cells increased obviously, and the microvascular structure was clearly visible and the density increased. (3) Masson staining in animal experiment demonstrated that the skin tissue of the experimental group contained a large number of regularly arranged collagen fibers. There were only a few collagen fibers in the control group, and the structure was sparse. (4) It is concluded that 3D extracellular matrix-based hydrogel loaded with bone marrow mesenchymal stem cells-derived exosomes can be conducive to wound repair. It may be related to the promotion of fibroblast migration by exosomes.
Key words: skin injury, bone marrow mesenchymal stem cell, exosome, extracellular matrix, hydrogel, wound healing