A novel rat model for studying bilateral cavernous nerve damage in vivo: exploring the potential of chitosan-blended membranes for nerve regeneration post-radical prostatectomy

BACKGROUND: The primary treatment for localized prostate cancer involves radical prostatectomy (RP) often resulting in iatrogenic damage to the periprostatic neurovascular bundles (NVB), leading to erectile dysfunction. The current study devised an experimental model involving bilateral cavernous nerve (CN) lesions in rats to replicate nerve damage close to the injury of the NVB in humans following radical prostatectomy. METHODS: Fifteen adult male Wistar rats were divided as follows: control rats without surgery (CTRL group); rats underwent bilateral resection of 2 mm of CN repaired with a glycerol-blended chitosan membranes (CS-MEM group); rats underwent a total resection of both CN and major pelvic ganglion (RES group). Two months after surgery, membranes with regenerated nerves were analyzed morphologically, and for gene and protein expression for the evaluation of nerve regeneration and vascularization. Rat penises were assessed for smooth muscle content, morphology, and tissue arrangement. Primary sensory neuron cultures and DRG explants were cultured on micro-grooved chitosan-blended membranes, to evaluate axonal orientation on different topographies. RESULTS: Regenerated nerve fibers and newly formed vessels colonized the whole CS-membrane. The regenerative process was also confirmed by gene and protein expression analyses. The target organ exhibited remodeling of smooth muscle tissue around sinusoidal spaces, indicating potential restoration of cavernous tissue. The quantitative analyses of α-actin smooth muscle (α-SMA) expression in CS-MEM groups displayed α-SMA protein signals comparable to controls. In-vitro experiments on micro-patterned membranes displayed oriented axonal growth, showing valuable insights into the ways in which topographical features can be considered for a more effective performance in vivo. CONCLUSIONS: Chitosan-blended membranes promote nerve fiber regeneration in an in-vivo model of nerve lesion that resembles the damage to the NVB occurring in men after radical prostatectomy. These results highlight the promising potential of this device in the clinical urological field, thus suggesting that the application of orientated micro-patterned membranes could further improve nerve regeneration.