Abstract: Acellular nerve allografs can help preserve normal nerve structure and extracellular matrix composition. Tese allografs have low immunogenicity and are more readily available than autologous nerves for the repair of long-segment peripheral nerve defects. In this study, we repaired a 40-mm ulnar nerve defect in rhesus monkeys with tissue-engineered peripheral nerve, and compared the outcome with that of autograf. Te graf was prepared using a chemical extract from adult rhesus monkeys and seeded with allogeneic Schwann cells. Pathomorphology, electromyogram and immunohistochemistry fndings revealed the absence of palmar erosion or ulcers, and that the morphology and elasticity of the hypothenar eminence were normal 5 months postoperatively. Tere were no signifcant differences in the mean peak compound muscle action potential, the mean nerve conduction velocity, or the number of neuroflaments between the experimental and control groups. However, outcome was signifcantly better in the experimental group than in the blank group. Tese fndings suggest that chemically extracted allogeneic nerve seeded with autologous Schwann cells can repair 40-mm ulnar nerve defects in the rhesus monkey. Te outcomes are similar to those obtained with autologous nerve graf.

Key words: nerve regeneration, peripheral nerve injury, tissue engineering, rhesus monkey, ulnar nerve, chemical extraction, allogenic nerve, autologous nerve, transplantation, Schwann cells, neural regeneration