BACKGROUND：Tissue engineered acellular nerves are good autologous nerve substitutes. Acellular peripheral nerves prepared using a conventional chemical extraction method cause a great deal of damage to nerve structur...BACKGROUND：Tissue engineered acellular nerves are good autologous nerve substitutes. Acellular peripheral nerves prepared using a conventional chemical extraction method cause a great deal of damage to nerve structures, and the allograff affects the nerve regeneration following transplantation.OBJECTIVE：To prepare peripheral nerve grafts through an acellular tissue engineering method, and observe their histology, ultrastructure, protein components and histocompatibility.DESIGN, TIME AND SETTING：A randomized, controlled, in vivo nerve tissue engineering experiment was performed at the Department of Biochemistry and Molecular Biology, Shenyang Medical College, China, from September 2006 to June 2007.MATERIALS：Triton X-100, Pepstatin A, Aprotinin and Leupeptin were purchased from Sigma, USA; Tris （hydroxymethyl） aminomethane was purchased from Gibco, USA.METHODS：The bilateral sciatic nerves of Wistar rats were harvested, treated with 0.05 mol/L Tris-HCI buffer, followed by proteinase inhibitor and Triton X-100 to prepare acellular peripheral nerves. The nerves were implanted in the quadriceps femoris muscle of healthy Wistar rats.MAIN OUTCOME MEASURES：Tissue structure and ultrastructure of acellular peripheral nerves were observed by optical microscopy and scanning electron microscopy. Growth associated proteins were analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Nerve allograft and the surrounding muscles were observed by hematoxylin-eosin staining.RESULTS：Acellular treatment eliminated Schwann cells, epineurium or perineurium cells, myelin sheaths and axons of nerve fibers in normal peripheral nerves, while the spatial structure, comprising basement membrane tubes of Schwann cells and the extracellular matrix of perineurium and nerve fascicles was maintained. Protein bands at the region of 30 kD were no longer visible, had slightly decreased at 43 kD and remained unchanged at 65 kD. Following implantation for 7 days, epineurium cells were absorbed. However, increased fibroblasts, decreased newly-generated capillaries and maturation of granulation tissue were observed.CONCLUSION：The acellular nerve allograft prepared through the use of a hypotonic, acellular method displays good histocompatibility, eliminates immune substances and retains growth associated proteins that induce the growth of the neural axis. In addition, this method provides an ideal scaffold to construct artificial nerves.展开更多
文摘BACKGROUND：Tissue engineered acellular nerves are good autologous nerve substitutes. Acellular peripheral nerves prepared using a conventional chemical extraction method cause a great deal of damage to nerve structures, and the allograff affects the nerve regeneration following transplantation.OBJECTIVE：To prepare peripheral nerve grafts through an acellular tissue engineering method, and observe their histology, ultrastructure, protein components and histocompatibility.DESIGN, TIME AND SETTING：A randomized, controlled, in vivo nerve tissue engineering experiment was performed at the Department of Biochemistry and Molecular Biology, Shenyang Medical College, China, from September 2006 to June 2007.MATERIALS：Triton X-100, Pepstatin A, Aprotinin and Leupeptin were purchased from Sigma, USA; Tris （hydroxymethyl） aminomethane was purchased from Gibco, USA.METHODS：The bilateral sciatic nerves of Wistar rats were harvested, treated with 0.05 mol/L Tris-HCI buffer, followed by proteinase inhibitor and Triton X-100 to prepare acellular peripheral nerves. The nerves were implanted in the quadriceps femoris muscle of healthy Wistar rats.MAIN OUTCOME MEASURES：Tissue structure and ultrastructure of acellular peripheral nerves were observed by optical microscopy and scanning electron microscopy. Growth associated proteins were analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Nerve allograft and the surrounding muscles were observed by hematoxylin-eosin staining.RESULTS：Acellular treatment eliminated Schwann cells, epineurium or perineurium cells, myelin sheaths and axons of nerve fibers in normal peripheral nerves, while the spatial structure, comprising basement membrane tubes of Schwann cells and the extracellular matrix of perineurium and nerve fascicles was maintained. Protein bands at the region of 30 kD were no longer visible, had slightly decreased at 43 kD and remained unchanged at 65 kD. Following implantation for 7 days, epineurium cells were absorbed. However, increased fibroblasts, decreased newly-generated capillaries and maturation of granulation tissue were observed.CONCLUSION：The acellular nerve allograft prepared through the use of a hypotonic, acellular method displays good histocompatibility, eliminates immune substances and retains growth associated proteins that induce the growth of the neural axis. In addition, this method provides an ideal scaffold to construct artificial nerves.
