Bone mesenchymal stem cell-derived exosome-loaded injectable hydrogel for minimally invasive treatment of spinal cord injury

Aim: Bone mesenchymal stem cell-derived exosomes (Exos) have been shown to exert therapeutic effects in spinal cord injury (SCI). In this study, we aimed to apply bioengineering approaches to promote Exo retention and their sustained release for SCI repair. Materials & methods: 3D gelatin methacrylate hydrogel (GelMA) was used as a transplanted Exo delivery system (GelMA-Exos). The viability, proliferation, and differentiation of neural stem cells cultured on hydrogel were assessed. Further, GelMA-Exos was injected into the damaged lesions to assess its repair potential. Results: GelMA hydrogel enhanced the retention of Exos, which promoted the neuronal differentiation and extension in vitro. Furthermore, GelMA-Exos promoted neurogenesis and attenuated glial scars in the damaged lesions. Conclusion: The injectable Exo-loaded 3D hydrogel induced neurological functional recovery post SCI.