Improved Motor Neuron Preservation and Axonal Recovery Following Experimental Sciatic Nerve Repair With Heterologous Fibrin Biopolymer.

Peripheral nerve injuries severely impair motor function. Although neurorrhaphy is the gold-standard treatment, recovery is often incomplete. The heterologous fibrin biopolymer (HFB), a nonhuman-derived and biocompatible sealant, has shown regenerative potential in neural tissues, but its effects on the spinal cord microenvironment after peripheral nerve injury remain unclear. This study evaluated the chronic regenerative effects of HFB combined with neurorrhaphy after sciatic neurotmesis in rats. Forty adult male Wistar rats were divided into four groups: control, denervated, neurorrhaphy, and neurorrhaphy + HFB. After 120 days, the spinal cord, sciatic nerve, and soleus muscle were analyzed. Neurorrhaphy + HFB had more retrograded label neurons than neurorrhaphy, whereas 3D reconstruction suggests reduced neuronal dispersion compared with neurorrhaphy. HFB also positively modulated glial cells, while improving sciatic nerve integrity, with NF200, S100, and G ratio indicating improved axonal regeneration. Neuromuscular junctions in the HFB-treated group were more organized than those in the neurorrhaphy alone. Overall, findings suggest that HFB acts as a bioactive modulator, preserving central glial homeostasis and enhancing peripheral remyelination and reinnervation, representing a promising adjuvant to overcome the limitations of conventional suture.