Peripheral nerve injuries can occur from trauma and are particularly problematic when the nerve continuity is disrupted. Nerve reattachment is traditionally done using microsurgical approaches. Additional needle trauma, leakage of neurotrophic factors and inflammatory invasion and scarring all adversely affect nerve regeneration and functional recovery. We have shown that photochemical bonding using a wrap of RB-coated human amnion over the repair site seals and isolates the internal nerve environment for optimal nerve regeneration (6-8). The procedure is shown in the video below in the case of a fully transected rabbit common peroneal nerve.
Figure 7. Amniotic membrane coated with RB, wrapped around the repair site and bonded to the nerve sheath by 532 nm light

In additional studies to address nerve deficit repair following major traumatic injury we have developed a novel neural conduit of crosslinked human amnion fashioned into a tube that can be photochemically bonded using RB to the nerve stumps to bridge the deficit. The procedure for bonding the conduit across the nerve deficit is shown in Figure 8.

Figure 8. Left – Schematic of model used for bridging neural deficit with crosslinked amnion conduit bonded photochemically to the nerve stumps. Right – Photograph of amnion conduit in situ following repair of deficit in rat sciatic nerve model.


In pre-clinical rat studies we have shown this conduit to produce equivalent functional recovery to the standard of care autologous nerve graft. If replicated in humans this would be highly significant as it could remove the requirement for a donor site graft with associated sensory loss and other complications.

Related Publications

6. Henry, F. P., N. A. Goyal, W. S. David, D. Wes, K. E. Bujold, M. A. Randolph, J. M. Winograd, I. E. Kochevar, and R. W. Redmond (2009) Improving electrophysiologic and histologic outcomes by photochemically sealing amnion to the peripheral nerve repair site. Surgery 145, 313-321.

7. Johnson, T. S., A. C. O'Neill, P. M. Motarjem, C. Amann, T. Nguyen, M. A. Randolph, J. M. Winograd, I. E. Kochevar, and R. W. Redmond (2007) Photochemical tissue bonding: a promising technique for peripheral nerve repair. J Surg Res 143, 224-229.

8. O'Neill, A. C., M. A. Randolph, K. E. Bujold, I. E. Kochevar, R. W. Redmond, and J. M. Winograd (2009) Photochemical sealing improves outcome following peripheral neurorrhaphy. J Surg Res 151, 33-39.

Research Projects

Mechanisms for light activated protein crosslinking
Closure of surgical wounds
Cornea: sealing incisions and transplantation
Peripheral nerve repair
Tendon repair
Blood vessel repair
Neocartilage generation