Efficacy of Acellular-Lyophilized Human Umbilical Cord Powder Seeded with Human Umbilical Cord Mesenchymal Stem Cells in Peripheral Nerve Regeneration in Dogs Models

Abstract

Treatment of injuries to peripheral nerves after a segmental defect is one of the most challenging surgicalproblems. Therapies for peripheral nerves injury are largely ineffective. Therefore, the current study wasconducted to investigate effects either acellular human umbilical cord tissue powder on repair 1 cm criticalsize defect radial nerve guided by bovine urinary bladder matrix conduit alone or seeded with mesenchymalstem cells derived from human umbilical cord. For this purpose, sixteen healthy mongrel dogs were used.They were randomly divided into two equal groups (n=8), before proceeding with the surgical procedures,the dogs were generally anesthetized and aseptic conditions were established. Then, the surgery was carriedout with the aid of magnifying lens. All dogs subjected to radial nerve neurotmesis from the right limb. Inthe scaffold group, a 1cm of radial nerve was transected and resulted gap bridged with a portion of 14mmacellular bovine urinary bladder submucosa conduit which was then filled with 0.05mg acellular humanumbilical cord powder and then sutured to the two stumps using 6-0 nylon epineural by simple interruptedpattern. In combination group, the gap was bridged with acellular bovine urinary bladder submucosa conduitwhich was filled with 0.05mg acellular human umbilical cord powder then seeded with 50 µl (5x106)mesenchymal stem cells derived from human umbilical cord, then fixed onto two stumps using 6-0 nylonepineural by simple interrupted pattern. Each group was further divided into two equal subgroups (n=4)categorized according to the post operation periods, that were 8 and 16th weeks for neurohistopathologicalexaminations. The histopathological examination of regenerated nerve sections (two samples of 5 mm lengtheach) were collected from the middle (coaptation site) and distal segments were used to determine the degreeof the radial nerve regeneration. The histopathological findings relative convergence between the scaffoldand combination groups in their components such as the increased number of Schwann cells proliferation,parallel arrangement of nerve fibers and remarkable angiogenesis on 16th weeks. In conclusion; this studyshowed that the decellularized both scaffolds alone or seeded with mesenchymal stem cells derived fromhuman umbilical cord could support the radial nerve regeneration and allow the reinnervation of the targetorgan.