Increased axonal regeneration through a biodegradable amnionic tube nerve conduit: Effect of local delivery and incorporation of nerve growth factor/hyaluronic acid media

The authors emphasize the possible pharmacological enhancement of axonal re generation using a specific growth factor/extracellular media incorporated in a biodegradable nonneural nerve conduit material, They investigated the early effects on nerve regeneration of continuous local delivery of nerve g rowth factor (NGF) and the local incorporation of hyaluronic acid (HA) insi de a newly manufactured nerve conduit material from fresh human amnionic me mbrane, Human amnionic membrane contains important biochemical factors that play a major neurotrophic role in the nerve regeneration process. The proc ess of manufacturing a nerve conduit from fresh human amnionic membrane is described. This nerve conduit system was used in rabbits to bridge a 25-mm nerve gap over 3 months. NGF was released locally, over 28 days, at the dis tal end of the tube via a system of slow release, and HA was incorporated i nside the lumen of the tube at the time of surgery. NGF/HA treatment promot ed axonal regeneration across the amnionic tube nerve conduit (8,962 +/- 38 3 myelinated axons) 45% better than the nontreated amnionic tube group (6,1 80 +/- 353 myelinated axons). The authors demonstrate that NGF/HA media enh ances additional axonal regeneration in the amnionic tube nerve conduit. Th is result is secondary to the effect of the amnion promoting bio-chemical f actors, in combination with the NGF/HA effect on facilitating early events in the nerve regeneration process.