Adipose-derived Stem Cell Transplantation Enhances Peripheral Nerve Regeneration in a Peroneal Nerve Injury Model in the Rat

Introduction: Despite advances in the treatment of peripheral nerve injury, patients still suffer from incomplete motor recovery. In vivo and in vitro studies demonstrated that adipose derived stem cells (AdSCs) promote peripheral nerve regeneration, but the effect on motor recovery remains unclear. Materials and Methods: According to sample size calculation and randomization 48 rats received either intramuscular, intraneural, combined or vehicle injection of AdSCs following common peroneal nerve contusion injury in narcosis. During the four-week follow-up period, the animals underwent weekly footprint and videometric joint-angle analysis. Finally, the animals underwent isometric force measurement of the tibialis anterior muscle for twitch force, tetanic force, fatigue and electromyography. Results: During the four weeks of follow-up all groups regained full recovery of their gait, marked by Inserra’s peroneal functional index analysing toespread and the joint angle analysis. In Isometric force measurement using twitch force, tetanic force and fatique, intramuscular transplantation was superior to intraneural or combined transplantation. Muscle trophy was highest in intraneural injection, measured by wet weight of the tibialis anterior muscle. Conclusion: Our preliminary data indicate a superior force regeneration with intramuscular AdSC transplantation compared to intraneural, combined or vehicle transplantation. Further exploratory data suggest that transplantation of extracellular vesicles presented with even higher force regeneration.