Biological activity of laminin/polylaminin-coated poly-ℇ-caprolactone filaments on the regeneration and tissue replacement of the rat sciatic nerve

Abstract Unlike the central nervous system, peripheral nerves can regenerate after injury. However, depending on the size of the lesion, the endogenous regenerative potential is not enough to replace the nerve tissue lost. Many strategies have been employed to generate biomaterials capable of restoring nerve functions. Here, we set out to investigate whether adsorbing the extracellular matrix protein, laminin, to poli-ℇ-caprolactone (PCL) filaments would enhance functional nerve regeneration. Initial in vitro studies showed that explants of dorsal root ganglia (DRG) of P1 neonate mice exhibited stronger neuritogenesis on a substrate of laminin that had been previously polymerized (polyLM) than on ordinary laminin (LM). On the other hand, when silicone tubes filled with PCL filaments were used to bridge a 10 mm sciatic nerve gap in rats, only filaments coated with LM improved tissue replacement beyond that obtained with empty tubes. Motor function recovery correlated with tissue replacement as only LM-coated filaments consistently improved motor skills. Finally, analysis of lateral gastrocnemius muscle revealed that the LM group presented twice the amount of α-bungarotixin-labeled motor plates. In conclusion, while polyLM was more effective in stimulating growth of sensory fibers out of DRGs in vitro, LM adsorbed to PCL filaments exhibited the best regenerative properties to induce functional motor recovery after peripheral injury in vivo.