title: Extracellular matrix of human amnion manufactured into tubes as conduits for peripheral nerve regeneration.
abstract: The human amnion consists of the epithelial cell layer and underlying connective tissue. After removing the epithelial cells, the resulting acellular connective tissue matrix was manufactured into thin dry sheets called amnion matrix sheets. The sheets were further processed into tubes, amnion matrix tubes (AMTs), of varying diameters, with the walls of varying numbers of amnion matrix sheets with or without a gelatin coating. The AMTs were implanted into rat sciatic nerves. Regenerating nerves extended in bundles through tubes of 1-2 mm in diameter and further elongated into host distal nerves 1-3 weeks after implantation. Morphometrical analysis of the regenerated nerve cable at the middle of each amnion matrix tube 3 weeks after implantation was performed. The average numbers of myelinated axons were almost the same (ca. 80-112/10(4) microm(2)) in AMTs of 1-2 mm in diameter, as in the normal sciatic nerve (ca. 95/10(4) microm(2)). No myelinated fibers were found in AMTs composed of multiple thin tubes of 0.2 mm in diameter. The myelinated axons were thinner in implanted tubes than those in the normal sciatic nerve. The rate of occurrences of myelinated axons less than 4 microm in diameter was significantly higher in the AMTs, whereas axons in the normal sciatic nerve were diverse in distribution, with the highest population at 8-12 microm in diameter. Reinnervation to the gastrocnemius muscle was demonstrated electrophysiologically 9 months after implantation. It was concluded that the extracellular matrix sheet from the human amnion is an effective conduit material for peripheral nerve regeneration.
authors.affiliation: Department of Anatomy and Neurobiology, Kyoto University Graduate School of Medicine, Yoshida konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan. nuru@anat2.med.kyoto-u.ac.jp
authors.forename: Nurru
authors.initials: N
authors.lastname: Mligiliche
authors.forename: Katsuaki
authors.initials: K
authors.lastname: Endo
authors.forename: Keiko
authors.initials: K
authors.lastname: Okamoto
authors.forename: Etsuko
authors.initials: E
authors.lastname: Fujimoto
authors.forename: Chizuka
authors.initials: C
authors.lastname: Ide
mesh_terms: D000650:Amnion / Q000737:chemistry / Q000648:ultrastructure; D000818:Animals; D004594:Electrophysiology; D005109:Extracellular Matrix / Q000737:chemistry; D005260:Female; D005780:Gelatin; D006801:Humans; D018482:Muscle, Skeletal / Q000294:innervation; D009413:Nerve Fibers, Myelinated / Q000502:physiology; D009416:Nerve Regeneration; D019736:Prostheses and Implants; D051381:Rats; D017208:Rats, Wistar; D020127:Recovery of Function; D012584:Sciatic Nerve / Q000502:physiology* / Q000648:ultrastructure; D023822:Tissue Engineering
chemical_list: D005780:Gelatin