Protective effect of tissue-engineered artificial nerve on peripheral target organ and spinal cord neurons after rat sciatic nerve defect / 中华创伤杂志

Objective To explore the protective effect of olfactory ensheathing cell(OEC)Schwann cell(SC)-extracellular matrix(ECM)-poly(DL-lactide-co-glycolide acid)(PLGA)bridging complex on peripheral target organ and spinal cord neurons after rat sciatic nerve defect.Methods A 15 mm right sciatic nerve defect model was established in SD rats and repaired with OEC-SC-ECM-PLGA bridging complex that contained OEC,SC,ECM and self-made PLGA conduit.At the same time,the study set OEC-ECM-PLGA group,SC-ECM-PLGA group,ECM-PLGA group,PLGA group and nerve autograft control group.At 1,3,6 and 9 weeks after surgery,the gastrocnemius muscle water weight test and motor end-plate test were performed.At the 9th week after surgery,CM-DiI and horseradish peroxidase(HRP)retrograde tracing were performed.Results The gastrocnemius muscle water weight and number of motor end-plate were decreased in all groups after surgery but gradually increased after three weeks except for ECM-PLGA group and PLGA group.At the 9th week,OEC-SC-ECM-PLGA group showed no statistical differences with nerve autograft group in aspects of gastrocnemius muscle water weight,number of motor end-plate and length of motor end-plate major axis(P ＞ 0.05).At the 9th week,CM-DiI and HRP retrograde tracing found that the number of positive neurons in spinal cord in OEC-SC-ECM-PLGA group showed no statistical differences compared with nerve autograft group(P ＞0.05).Conclusions OEC-SC-ECM-PLGA bridging complex can partially protect peripheral target organ and spinal cord neurons after rat sciatic nerve defect.

Role of stromal cell-derived factor-1α in inducing recruitment of bone marrow-derived cells to cutaneous wound area / 中华创伤杂志

Objective To explore the effect of stromal cell-derived factor-1 α (SDF-1 α) on inducing recruitment of bone marrow-derived cells (BMDCs) to wound area. Methods BMDCs were isolated from bone marrow, cultured with routine method and identified by CXCR4 antibody. Cells cultured with CXCR4 antibody (100 ng,/mL) for 6 hours were labeled with CM-DiI and injected into the tail vein of full-thickness incisional wound model (set as anti-CXCR4 group). BMDCs labeled with CM-DiI without antibody treatment were injected to the rats in BMDCs group, and rats were injected with DMEM/F12 serum-free medium in the control group. The quantity of labeled BMDCs at the wound site and the percentage of wound closure were measured. Results (1) All BMDCs expressed CXCR4. (2) The percentages of wound closure at days 7 and 14 in BMDCs group (7 d: 41.3% ±4.6%; 14 d:92.3% ±2. 1%) were significantly higher than those of control group (7 d: 29.3% ±2. 3%; 14 d: 77.3% ±2.5%) and anti-CXCR4 group (7 d: 30.7% ±4.6% ;14 d: 85.7% ±1.5%) (P＜0.05). The percentage of wound closure of anti-CXCR4 group was significantly higher than that of control group at day 14(P ＜ 0.05). (3) The number of CM-DiI labeled BMDCs at wound site at days 7 and 14 in BMDCs group [7 d: (535 ±84) cells/hpf; 14 d: (769 ±124) cells/hpf) were greater than those of anti-CXCR4 group [7 d: (335 ±97) cells/hpf; 14 d: (521 ± 127) cells/hpf] (P＜0.05). Conclusions BMDCs participate in the cutaneous wound healing. SDF-1α plays an important role in recruiting BMDCs to wound area.