Peripheral nerve regeneration using autologous porcine skin-derived mesenchymal stem cells

Porcine skin-derived mesenchymal stem cells (pSMSCs) were evaluated on their biological MSC characterizations and differentiation into mesenchymal lineages, along with in vitro and in vivo neural inductions. Isolated pSMSCs showed plate-adherent growth, expression of various MSC-marker proteins and transcriptional factors, and differentiation potential into mesenchymal lineages. Neuron-like cell morphology and various neural markers were highly detected at 6 h and 24 h after in vitro neural induction of pSMSCs, but their neuron-like characteristics disappeared as induction time extended to 48 and 72 h. To evaluate the in vivo peripheral nerve regeneration potential of pSMSCs, a total of 5 × 10(6) autologous pSMSCs labelled with tracking dye, supplemented with fibrin glue scaffold and collagen tubulization, were transplanted into the peripheral nerve defected miniature pigs. At 2 and 4 weeks after cell transplantation, well-preserved transplanted cells and remarkable in vivo nerve regeneration, including histologically complete nerve bundles, were observed in the regenerated nerve tissues. Moreover, S-100 protein and p75 nerve growth factor receptor were more highly detected in regenerated nerve fibres compared to non-cell grafted control fibres. These results suggest that autologous pSMSCs transplanted with fibrin glue scaffold can induce prominent nerve regeneration in porcine peripheral nerve defect sites.