title: Nerve growth factor enhances peripheral nerve regeneration in non-human primates.
abstract: Fibronectin mat implants impregnated with NGF have been successfully used in rat nerve regeneration model. The aim of this study was to assess their action in a primate model. Mats were implanted into a 5 mm gap in a peripheral nerve in Macaca fascicularis monkeys, either alone (Fn) or in the presence of nerve growth factor (Fn + NGF). Four months postoperatively, the regenerated nerve was analysed by light microscopy, and target skin reinnervation was assessed by quantification of cutaneous nerve terminals immunostained with protein gene product (PGP) antibodies. The diameter of the regenerated nerve was similar in Fn + NGF grafts and nerve autografts, but significantly larger for plain Fn grafts with evidence of more connective tissue surrounding the axons. Myelinated fibres counts showed similarities in normal control nerve, nerve autograft and Fn + NGF graft groups. However, in nerve grafted with plain Fn mats the regenerating fibres were lower in number and showed a wider variability in diameter and myelination, resulting in a significantly smaller G-ratio (axonal diameter/myelinated fibre diameter). The amount of cutaneous reinnervation was lowest in Fn graft group, while comparable amounts of skin reinnervation were observed in the Fn + NGF and autograft groups. These results suggest that Fn-mats are a suitable conduit to promote peripheral nerve regeneration also in primate, and supplying NGF locally at the lesion site can further enhance nerve regrowth.
authors.affiliation: Plastic Surgery, Tissue Repair Unit, Royal Free and University College Medical School, London, UK.
authors.forename: Z
authors.initials: Z
authors.lastname: Ahmed
authors.forename: R A
authors.initials: RA
authors.lastname: Brown
authors.forename: C
authors.initials: C
authors.lastname: Ljungberg
authors.forename: M
authors.initials: M
authors.lastname: Wiberg
authors.forename: G
authors.initials: G
authors.lastname: Terenghi
mesh_terms: D000818:Animals; D001369:Axons / Q000502:physiology; D005353:Fibronectins / Q000008:administration & dosage; D007150:Immunohistochemistry; D008252:Macaca fascicularis; D008297:Male; D009413:Nerve Fibers, Myelinated / Q000502:physiology; D020932:Nerve Growth Factor / Q000494:pharmacology* / Q000502:physiology; D009416:Nerve Regeneration / Q000187:drug effects* / Q000502:physiology; D010525:Peripheral Nerves / Q000637:transplantation; D011506:Proteins / Q000032:analysis; D012867:Skin / Q000294:innervation
chemical_list: D005353:Fibronectins; D011506:Proteins; D020932:Nerve Growth Factor