3D-printed PCL scaffold coated with chitosan–hyaluronic acid hydrogel loaded with NGF-overexpressing UiPSC-derived neural crest cells restores erectile function via cavernous nerve regeneration

This study investigated whether erectile function could be restored by promoting cavernous nerve (CN) regeneration via perineural administration of nerve-growth-factor (NGF)-overexpressing neural-crest-cells (NCCs) within a 3D-printed cytocompatible scaffold in a CN-injured rat model. We generated induced-pluripotent-stem-cells (iPSCs) from urine-derived stem-cells (USCs), overexpressed NGF, and differentiated them into NCCs. Additionally, a polycaprolactone (PCL) scaffold was fabricated via extrusion 3D-printing and coated with a thermosensitive chitosan/hyaluronic acid (HA)/β-glycerophosphate hydrogel. The NGF-NCCs were loaded onto the scaffold, with in vitro assays validating high cell loading, survival, and differentiation potential. Sixty 12-week-old male Sprague-Dawley rats were assigned to five groups: sham (S); CN injury (I); and injury groups receiving PCL coated with chitosan–HA-hydrogel alone (H), NGF–UiPSC–NCCs alone (N), or PCL coated with chitosan–HA-hydrogel loaded with NGF–UiPSC–NCCs (NH) around the injured CNs. Four weeks post-surgery, Groups H, N, and NH showed significantly improved erectile responses during electrostimulation compared to Group I, with Group NH exhibiting the most pronounced recovery. Regarding CN regeneration, Groups H, N, and NH demonstrated increased axonal density and upregulated expression of neuronal regeneration and remyelination markers. Furthermore, these groups showed decreased cavernosal apoptosis and preserved endothelial content and smooth muscle/collagen ratio. Across all metrics, Group NH demonstrated the superior therapeutic effect, followed by Groups N and H. Our results indicate that perineural application of NGF–UiPSC–NCCs loaded 3D-printed PCL coated with chitosan–HA-hydrogels can restore erectile function by enhancing CN regeneration, subsequent recovery of neurotransmission, and suppression of structural alterations in the corpus cavernosum.