Experimental study of acellular nerve and adipose derived stem cells in repairing of nerve defects

Abstract

Objective To investigate the efficacy of allogenic acellular nerve scaffold and adipose derived stem cells (ADSCs) -differentiated Schwann-like in repairing the sciatic nerve defect of rats. Methods Thirty healthy F344 inbred rats were randomly divided into two groups (n=15 each). In these groups, a 10-mm sciatic nerve defect was bridged with different grafts: allogenic acellular nerve (from SD rat) scaffold in Group A, and allogenic acellular nerve scaffold seeded with Schwann-like cells differentiated from ADSCs in Group B. After 6 and 12 weeks, the both groups were compared for recovery rate of sciatic functional index (SFI%) and the neural electrophysiology (NEP) which included recovery rates of motor nerve conduction velocity (MNCV) of sciatic nerve, compound muscle action potential (CAMP) of gastrocnemius, regenerated myelinated fiber counts, nerve fiber diameter and myelin sheath thickness, as well as histological changes with myelin regeneration under light microscopy and transmission electron microscopy, so as to evaluate the experimental efficacy. Results At 6 and 12 weeks after operation, the Group B appeared advantageous over Group A in SFI% (at 6 weeks, 52.38±7.12 vs 46.32±5.13; at 12 weeks, 79.99±10.33 vs 72.73±8.06) , MNCV recovery rate (at 6 weeks, 51.12±8.15 vs 42.54±6.33; at12 weeks, 75.93±5.95 vs 69.34±9.13) , CAMP recovery rate (at 6 weeks, 45.38±4.12 vs 40.52±4.15; at 12 weeks, 75.98±10.99 vs 68.24±9.45) , regenerated myelinated nerve fiber count recovery rate (at 6 weeks, 44.29±7.52 vs 38.45±6.28; at 12 weeks, 77.06±11.54 vs 67.89±11.87) , nerve fiber diameter recovery rate (at 6 weeks, 43.58 ± 4.87 vs 40.11±4.32; at 12 weeks, 83.23 ±6.32 vs 76.37 ±9.38) , myelin sheath thickness recovery rate (at 6 weeks, 46.41±4.35 vs 41.33±4.58; at 12 weeks, 83.96±8.31 vs 77.62±7.98) (all P<0.05). Light microscopy revealed that the diameter and number of nerve fiber and the myelin sheath thickness were more favorable in Group B than in Group A. Transmission electron microscopy revealed that the nerve tissue was more densely arranged and with thicker myelin in Group B than as found for Group A. Conclusion Tissue-engineered nerve constructed from ADSCs-differentiated Schwann-like cells combined with allogenic acellular nerve can effectively repair nerve defects in rats. Key words: Adipose derived stem cells; Schwann cells; Nerve regeneration; Tissue engineering