Local delivery of controlled released nerve growth factor promotes sciatic nerve regeneration after crush injury.

Controlled released nerve growth factor (NGF)-microspheres are able to enhance peripheral nerve regeneration across short nerve gaps. However, such beneficial effect has never been investigated in crush injury model in vivo. The present study was designed to investigate such a possibility. The rats subjected to sciatic nerve crush injury were intraperitoneally administrated daily for 4 weeks with NGF or normal saline or locally injected controlled released NGF-microspheres only once. Sham operation group without injury was defined as normal group. Nerve regeneration was investigated by morphometric analysis. The recovery of nerve function was estimated by electrophysiological analysis, behavioral tests and morphometric observation of the denervated muscles. The results showed that both NGF and NGF-microspheres improved nerve regeneration and recovery of nerve function. In addition, NGF-microspheres achieved better results than NGF group. These findings show that this controlled released NGF-microspheres could enhance the beneficial effect of NGF on nerve regeneration and recovery of motor and sensory function after sciatic nerve crush injury in rats, indicating that the NGF-microspheres have the potential to be a neuroprotective agent for nerve crush injury repair applications.