Electrospun PLGA composite hydrogel scaffold loaded with 3D extracellular vesicles for nasal septal cartilage defect repair

The nasal septum plays an important role in the growth and support of the human nose, and defects can cause nasal deformities. Extracellular vesicles (EVs) have demonstrated great potential in tissue repair. Stem cell EVs are widely used in the repair of articular cartilage defects, but their use for nasal septal cartilage defects has not been reported. Due to the low yield and loss of EVs during in situ injection, improved preparation methods and better carriers are needed for the effective sustained release of EVs in wounds. In this study, swelling and degradation experiments were initially conducted on the scaffold, along with mechanical performance testing, including observation of the scaffold morphology using scanning electron microscopy (SEM). Subsequently, in vitro cell experiments were conducted to evaluate the ability of 3D EVs to promote chondrocyte proliferation, migration, and extracellular matrix formation. Finally, the EV-laden gelatin methacrylic acid-polylactic acid-glycolic acid (Gel-PLGA) composite scaffold was implanted into the nasal septum defect site of rabbits in vivo to observe its repair effect on the defect. In vitro experiments demonstrated that the biological scaffold exhibited good biocompatibility and could effectively promote the proliferation and migration of chondrocytes. In vivo, the EV-laden composite biological scaffold was implanted into the nasal septum defect of rabbits, and the tissues were tested at 6 and 12 weeks after surgery. The results indicate that the composite scaffolds effectively facilitated the repair of defect sites. Taken together, 3D EVs facilitate tissue repair and healing, offering a novel approach to treating nasal septal defects.