Efficacy of sliced nerves of different thickness in a biodegradable nerve conduit to promote Schwann cell migration and axonal growth: An experimental study in the rat model

Abstract

Background Using the rat sciatic nerve model, sliced nerves of different thickness was combined to a biodegradable nerve conduit and the amount of nerve fragment necessary to promote nerve regeneration was investigated. Materials and Methods Harvested sciatic nerve (n = 6) was processed in sliced nerve of the different width; 2, 1, 0.5 mm, respectively. Western blot analysis was carried out to determine protein expression of Erk1/2. Subsequently, a total of 246 rats were used to create a 10 mm gap in the sciatic nerve. A polyglycolic acid‐based nerve conduit was used to bridge the gap, with one sliced (width; 2, 1, 0.5 mm) or two (width; 1 mm × 2) incorporated within the conduit (n = 6 at each point in each group). At 2, 4, 8, and 20 weeks after surgery, samples were resected and subjected to immune‐histological, transmission electron microscopic, and motor functional evaluation for nerve regeneration. Results Western blot analysis demonstrated Erk1/2 expressions were significantly increased in the groups of 2‐mm and 1‐mm width and attenuated in the 0.5‐mm width group (p < .05). The immune‐histological study showed the migration of Schwann cells and axon elongation were significantly extended in the groups of 2‐mm, 1‐mm, and 1 mm × 2 width at 4 weeks (p < .01), in which nerve conduction velocity was marked at 20 weeks (p < .01) after implantation. Conclusion When nerve tissue was inserted in the biodegradable nerve conduit as a sliced nerve, the method of inserting two sheets with a slice width of 1 mm most strongly accelerated motor function.