Objective To investigate the effect of bone marrow mesenchymal stem cells (BMSCs) embedded in fibrin glue around chemical extracted acellular nerve allograft (CEANA) on the peripheral nerve regeneration. Methods Twenty-oneadult male C57 mice (weighing 25-30 g) and 15 adult male Balb/c mice (weighing 25-30 g) were selected. The sciatic nerves were harvested from the Balb/c mice to prepare CEANA. The BMSCs were isolated from 3 C57 mice and were cultured; BMSCs embedded in fibrin glue were cultured for 3, 7, 14, and 21 days. Then the supernatant was obtained and co-cultured with PC12 cells for 2 days to observe the PC12 cell growth in vitro. The other 18 C57 mice were used to establ ish the left sciatic nerve defect models of 10 mm and divided into 3 groups: autogenous nerve graft with fibrin glue (group A, n=6), CEANA graft with BMSCs (5 × 106) embedded in fibrin glue (group B, n=6), and CEANA graft with fibrin glue (group C, n=6). The right sciatic nerves were exposed as the controls. At 2, 4, 6, and 8 weeks, the mouse static sciatic index (SSI) was measured. The histomorphometric assessment of triceps surae muscles and nerve grafts were evaluated by Masson staining, toluidine blue staining, and transmission electron microscope (TEM) observationat 8 weeks after operation. Results BMSCs were uniform distribution in fibrin glue, which were spherical in shape, and the cells began to grow apophysis at 3 days. PC12 cells differentiated into neuron-l ike cells after addition supernatant co-cultured after 2 days. Incisions healed well in each group. At 2, 4, 6, and 8 weeks, the SSI increased gradually in 3 groups. SSI in group A was higher than that in groups B and C at 4, 6, and 8 weeks after operation (P lt; 0.05). SSI in group B was sl ightly higher than that in group C, but had no significant difference (P gt; 0.05). At 8 weeks, the wet weight recovery rate of triceps surae muscles and fibers number of myel inated nerve were better in group B than in group C, but worse in group B than in group A, showing significant differences (P lt; 0.05). The triceps surae muscle fibers area and myel in sheath thickness had significant differences between group B and group C (P lt; 0.01), but there was no significant difference between group A and group B (P gt; 0.05). Conclusion BMSCs embedded in fibrin glue around CEANA can improve functional recovery of peripheral nerve injury.
Objective To construct chemically extracted acellular nerve allograft (CEANA) with Schwann cells (SCs) from different tissues and to compare the effect of repairing peripheral nerve defect. Methods Bone marrow mesenchymal stem cells (BMSCs) and adi pose-derived stem cells (ADSCs) were isolated and cultured from 3 4-week-old SD mice with weighing 80-120 g. BMSCs and ADSCs were induced to differentiated MSC (dMSC) and differentiated ADSC (dADSC) in vitro.dMSC and dADSC were identified by p75 protein and gl ial fibrillary acidic protein (GFAP). SCs were isolated and culturedfrom 10 3-day-old SD mice with weighing 6-8 g. CEANA were made from bilateral sciatic nerves of 20 adult Wistar mice with weighing 200-250 g. Forty adult SD mice were made the model of left sciatic nerve defect (15 mm) and divided into 5 groups (n=8 per group) according to CEANA with different sources of SCs: autografting (group A), acellular grafting with SCs (5 × 105) (group B), acellular grafting with dMSCs (5 × 105) (group C), acellular grafting with dADSCs (5 × 105) (group D), and acellular grafting alone (group E). Motor and sensory nerve recovery was assessed by Von Frey and tension of the triceps surae muscle testing 12 weeks after operation. Then wet weight recovery ratio of triceps surae muscles was measured and histomorphometric assessment of nerve grafts was evaluated. Results BMSCs and ADSCs did not express antigens CD34 and CD45, and expressed antigen CD90. BMSCs and ADSC were differentiated into similar morphous of SCs and confirmed by the detection of SCs-specific cellsurface markers. The mean 50% withdrawal threshold in groups A, B, C, D, and E was (13.8 ± 2.3), (15.4 ± 6.5), (16.9 ± 5.3), (16.3 ± 3.5), and (20.0 ± 5.3) g, showing significant difference between group A and group E (P lt; 0.01). The recovery of tension of the triceps surae muscle in groups A, B, C, D, and E was 87.0% ± 9.7%, 70.0% ± 6.6%, 69.0% ± 6.7%, 65.0% ± 9.8%, and 45.0%± 12.1%, showing significant differences between groups A, B, C, D, and group E (P lt; 0.05). No inflammatory reactionexisted around nerve graft. The histological observation indicated that the number of myel inated nerve fiber and the myel in sheath thickness in group E were significantly smaller than that in groups B, C, and D (P lt; 0.01). The fiber diameter of group B was significantly bigger than that of groups C and D (P lt; 0.05) Conclusion CEANA supplementing with dADSC has similar repair effect in peripheral nerve defect to supplementing with dMSC or SCs. dADSC, as an ideal seeding cell in nerve tissue engineering, can be benefit for treatment of peripheral nerve injuries.