Development of decellularised allogeneic nerve grafts

Peripheral nerve injuries affect a large proportion of the population and are often associated with prolonged disability. Current surgical interventions, including autografts and nerve guidance conduits (NGCs), are associated with a number of limitations. Decellularised nerve grafts offer considerable potential for peripheral nerve repair, by providing a non-immunogenic extracellular matrix (ECM) scaffold with biological, biochemical and biomechanical characteristics similar to native nerve. The aim of this study was to develop a decellularised peripheral nerve allograft with a native ECM histioarchitecture and biochemical composition, able to support viable cell populations. A previously established protocol for the decellularisation of porcine peripheral nerves, utilising a combination of hypotonic buffers, low concentration sodium dodecyl sulphate (SDS) and nuclease enzymes, was further developed to maintain the efficacy of decellularisation whilst minimising structural changes to the ECM. The improved protocol was shown to achieve sufficient cell and DNA removal, and decellularised porcine peripheral nerves were shown to be biocompatible and retain a native ECM histioarchitecture and composition. The protocol was then translated for the decellularisation of human femoral nerves. Following further development, the protocol was shown to achieve sufficient cell and DNA removal, and decellularised human femoral nerves were also found to be biocompatible and retain a native ECM histioarchitecture and composition. Human femoral nerves were then cultured in vitro with primary rat dorsal root ganglion (DRG) explants to assess long term biocompatibility and neurite outgrowth. The results presented suggest that decellularised human femoral nerve is a suitable substrate to support cellular infiltration and axon regeneration. Decellularised human femoral nerve was shown to support the long-term cell viability, migration, and neurite outgrowth of DRG explants, for up to 28 days in vitro. In this study, a novel decellularised human femoral nerve graft was developed with clinical potential for use in peripheral nerve repair. Although the results presented in this study are promising, further studies are required prior to clinical translation. A sterilisation process must be developed and evaluated for the decellularised nerve graft, and the biomechanical properties of decellularised and sterilised human femoral nerves must be investigated. The in vivo biocompatibility and efficacy of a decellularised and sterilised human femoral nerve graft for peripheral nerve repair must also be evaluated.