Nerve gaps repaired with acellular nerve allografts recellularized with Schwann-like cells: Preclinical trial

Acellular nerve allografts (ANA) recellularized with mesenchymal stem cells (MSC) or Schwann cells (SC) are, at present, a therapeutic option for peripheral nerve injuries (PNI). This study aimed to evaluate the regenerative and functional capacity of a recellularized allograft (RA) compared with autograft nerve reconstruction in PNI.

Fourteen ovines were randomly included in two groups (n=7). A peroneal nerve gap 30 mm in length was excised, and nerve repair was performed by the transplantation of either an autograft or a recellularized allograft with SC-like cells. Evaluations included a histomorphological analysis of the ANA, MSC pre differentiated into SC-like cells, at one year follow-up functional limb recovery (support and gait), and nerve regeneration using neurophysiological tests and histomorphometric analysis. All evaluations were compared with the contralateral hindlimb as the control.

The nerve allograft was successfully decellularized and more than 70% of MSC were pre differentiated into SC-like cells. Functional assessment in both treated groups improved similarly over time (p <0.05). Neurophysiological results (latency, amplitude, and conduction velocity) also improved in both treated groups at twelve months. Histological results demonstrated a less organized arrangement of nerve fibers (p <0.05) with an active remyelination process (p <0.05) in both treated groups compared with controls at twelve months.

ANA recellularized with SC-like cells proved to be a successful treatment for nerve gaps. Motor recovery and nerve regeneration were satisfactorily achieved in both graft groups compared with their contralateral nontreated nerves. This approach could be useful for the clinical therapy of PNI.