(1) The acellular nerve allografts prepared in this study were completely decellularized, with an intact structure remaining. The laminin and basilar membrane, which could promote axonal growth, were also retained.Research Highlights
(2) Scanning electron microscope showed that the prepared acellular nerve allografts had a good affinity to the in vitro cultured bone marrow mesenchymal stem cells, which were evenly distributed in the grafts.Research Highlights
(3) Under the induction of acellular nerve allografts and the in vivo regeneration microenvironment, bone marrow mesenchymal stem cells with multiple differentiation potential could differentiate into Schwann cells, and promote the axons at the proximal end of 15 mm sciatic nerve defects to grow towards the distal end, thus improving the motor functional recovery of rat hind limbs.
In this study, we constructed tissue-engineered nerves with acellular nerve allografts in Sprague-Dawley rats, which were prepared using chemical detergents-enzymatic digestion and mechanical methods, in combination with bone marrow mesenchymal stem cells of Wistar rats cultured in vitro, to repair 15 mm sciatic bone defects in Wistar rats. At postoperative 12 weeks, electrophysiological detection results showed that the conduction velocity of regenerated nerve after repair with tissue-engineered nerves was similar to that after autologous nerve grafting, and was higher than that after repair with acellular nerve allografts. Immunohistochemical staining revealed that motor endplates with acetylcholinesterase-positive nerve fibers were orderly arranged in the middle and superior parts of the gastrocnemius muscle; regenerated nerve tracts and sprouted branches were connected with motor endplates, as shown by acetylcholinesterase histochemistry combined with silver staining. The wet weight ratio of the tibialis anterior muscle at the affected contralateral hind limb was similar to the sciatic nerve after repair with autologous nerve grafts, and higher than that after repair with acellular nerve allografts. The hind limb motor function at the affected side was significantly improved, indicating that acellular nerve allografts combined with bone marrow mesenchymal stem cell bridging could promote functional recovery of rats with sciatic nerve defects.