Low-intensity pulsed ultrasound combination with iPSCs-NCSCs and GDF5 promotes sciatic nerve regeneration and functional recovery.

The treatment of lengthy peripheral nerve defect is challenging in the field of nerve regeneration. Our previous studies have shown that low-intensity pulsed ultrasound (LIPUS) could promote the proliferation, cell viability, and neural differentiation of induced pluripotent stem cells-derived neural crest stem cells (iPSCs-NCSCs) and improve the regeneration of damaged peripheral nerve. In this study, the mechanical signal transduction pathway of LIPUS promoting iPSCs-NCSCs proliferation and differentiation was further explored, and the effects of LIPUS combined with iPSCs-NCSCs, perfluorotributylamine (PFTBA), and growth differentiation factor 5 (GDF5) on the repair of peripheral nerve injury were evaluated. Results showed LIPUS may regulate the proliferation and differentiation of iPSCs-NCSCs through FAK-ERK1/2 signal pathway. PFTBA could supply sufficient oxygen to promote the viability of iPSCs-NCSCs under 5% hypoxia culture condition and provide a favorable microenvironment for nerve regeneration. The addition of GDF5 could promote the neural differentiation of iPSCs-NCSCs in vitro. LIPUS treatment of allogeneic decellularized nerve conduit containing iPSCs-NCSCs, PFTBA and GDF5 has very good effect on the repair of sciatic nerve injury. Taken together, these results provide functional evidence that LIPUS might be a useful tool to explore alternative approaches in the field of nerve regeneration.